1e3b3d0f5SGreg Kroah-Hartman // SPDX-License-Identifier: GPL-2.0+ 2157b9394SAndrei Pistirica /* 3157b9394SAndrei Pistirica * PIC32 Integrated Serial Driver. 4157b9394SAndrei Pistirica * 5157b9394SAndrei Pistirica * Copyright (C) 2015 Microchip Technology, Inc. 6157b9394SAndrei Pistirica * 7157b9394SAndrei Pistirica * Authors: 8157b9394SAndrei Pistirica * Sorin-Andrei Pistirica <andrei.pistirica@microchip.com> 9157b9394SAndrei Pistirica */ 10157b9394SAndrei Pistirica 11157b9394SAndrei Pistirica #include <linux/kernel.h> 12157b9394SAndrei Pistirica #include <linux/platform_device.h> 13157b9394SAndrei Pistirica #include <linux/of.h> 14157b9394SAndrei Pistirica #include <linux/of_irq.h> 15157b9394SAndrei Pistirica #include <linux/of_gpio.h> 16157b9394SAndrei Pistirica #include <linux/init.h> 17157b9394SAndrei Pistirica #include <linux/module.h> 18157b9394SAndrei Pistirica #include <linux/slab.h> 19157b9394SAndrei Pistirica #include <linux/console.h> 20157b9394SAndrei Pistirica #include <linux/clk.h> 21157b9394SAndrei Pistirica #include <linux/tty.h> 22157b9394SAndrei Pistirica #include <linux/tty_flip.h> 23157b9394SAndrei Pistirica #include <linux/serial_core.h> 24157b9394SAndrei Pistirica #include <linux/delay.h> 25157b9394SAndrei Pistirica 26157b9394SAndrei Pistirica #include <asm/mach-pic32/pic32.h> 27157b9394SAndrei Pistirica 28157b9394SAndrei Pistirica /* UART name and device definitions */ 29157b9394SAndrei Pistirica #define PIC32_DEV_NAME "pic32-uart" 30157b9394SAndrei Pistirica #define PIC32_MAX_UARTS 6 31157b9394SAndrei Pistirica #define PIC32_SDEV_NAME "ttyPIC" 32157b9394SAndrei Pistirica 3329574d0dSJiri Slaby #define PIC32_UART_DFLT_BRATE 9600 3429574d0dSJiri Slaby #define PIC32_UART_TX_FIFO_DEPTH 8 3529574d0dSJiri Slaby #define PIC32_UART_RX_FIFO_DEPTH 8 3629574d0dSJiri Slaby 3729574d0dSJiri Slaby #define PIC32_UART_MODE 0x00 3829574d0dSJiri Slaby #define PIC32_UART_STA 0x10 3929574d0dSJiri Slaby #define PIC32_UART_TX 0x20 4029574d0dSJiri Slaby #define PIC32_UART_RX 0x30 4129574d0dSJiri Slaby #define PIC32_UART_BRG 0x40 4229574d0dSJiri Slaby 4329574d0dSJiri Slaby /* struct pic32_sport - pic32 serial port descriptor 4429574d0dSJiri Slaby * @port: uart port descriptor 4529574d0dSJiri Slaby * @idx: port index 4629574d0dSJiri Slaby * @irq_fault: virtual fault interrupt number 4729574d0dSJiri Slaby * @irq_fault_name: irq fault name 4829574d0dSJiri Slaby * @irq_rx: virtual rx interrupt number 4929574d0dSJiri Slaby * @irq_rx_name: irq rx name 5029574d0dSJiri Slaby * @irq_tx: virtual tx interrupt number 5129574d0dSJiri Slaby * @irq_tx_name: irq tx name 52e9c9d3bbSAndy Shevchenko * @cts_gpiod: clear to send GPIO 5329574d0dSJiri Slaby * @dev: device descriptor 5429574d0dSJiri Slaby **/ 5529574d0dSJiri Slaby struct pic32_sport { 5629574d0dSJiri Slaby struct uart_port port; 5729574d0dSJiri Slaby int idx; 5829574d0dSJiri Slaby 5929574d0dSJiri Slaby int irq_fault; 6029574d0dSJiri Slaby const char *irq_fault_name; 6129574d0dSJiri Slaby int irq_rx; 6229574d0dSJiri Slaby const char *irq_rx_name; 6329574d0dSJiri Slaby int irq_tx; 6429574d0dSJiri Slaby const char *irq_tx_name; 65e8616bd0SJiri Slaby bool enable_tx_irq; 6629574d0dSJiri Slaby 67e9c9d3bbSAndy Shevchenko struct gpio_desc *cts_gpiod; 6829574d0dSJiri Slaby 6929574d0dSJiri Slaby struct clk *clk; 7029574d0dSJiri Slaby 7129574d0dSJiri Slaby struct device *dev; 7229574d0dSJiri Slaby }; 7341231472SJiri Slaby 7441231472SJiri Slaby static inline struct pic32_sport *to_pic32_sport(struct uart_port *port) 7541231472SJiri Slaby { 7641231472SJiri Slaby return container_of(port, struct pic32_sport, port); 7741231472SJiri Slaby } 7829574d0dSJiri Slaby 7929574d0dSJiri Slaby static inline void pic32_uart_writel(struct pic32_sport *sport, 8029574d0dSJiri Slaby u32 reg, u32 val) 8129574d0dSJiri Slaby { 82343f23cfSJiri Slaby __raw_writel(val, sport->port.membase + reg); 8329574d0dSJiri Slaby } 8429574d0dSJiri Slaby 8529574d0dSJiri Slaby static inline u32 pic32_uart_readl(struct pic32_sport *sport, u32 reg) 8629574d0dSJiri Slaby { 87343f23cfSJiri Slaby return __raw_readl(sport->port.membase + reg); 8829574d0dSJiri Slaby } 8929574d0dSJiri Slaby 9029574d0dSJiri Slaby /* pic32 uart mode register bits */ 9129574d0dSJiri Slaby #define PIC32_UART_MODE_ON BIT(15) 9229574d0dSJiri Slaby #define PIC32_UART_MODE_FRZ BIT(14) 9329574d0dSJiri Slaby #define PIC32_UART_MODE_SIDL BIT(13) 9429574d0dSJiri Slaby #define PIC32_UART_MODE_IREN BIT(12) 9529574d0dSJiri Slaby #define PIC32_UART_MODE_RTSMD BIT(11) 9629574d0dSJiri Slaby #define PIC32_UART_MODE_RESV1 BIT(10) 9729574d0dSJiri Slaby #define PIC32_UART_MODE_UEN1 BIT(9) 9829574d0dSJiri Slaby #define PIC32_UART_MODE_UEN0 BIT(8) 9929574d0dSJiri Slaby #define PIC32_UART_MODE_WAKE BIT(7) 10029574d0dSJiri Slaby #define PIC32_UART_MODE_LPBK BIT(6) 10129574d0dSJiri Slaby #define PIC32_UART_MODE_ABAUD BIT(5) 10229574d0dSJiri Slaby #define PIC32_UART_MODE_RXINV BIT(4) 10329574d0dSJiri Slaby #define PIC32_UART_MODE_BRGH BIT(3) 10429574d0dSJiri Slaby #define PIC32_UART_MODE_PDSEL1 BIT(2) 10529574d0dSJiri Slaby #define PIC32_UART_MODE_PDSEL0 BIT(1) 10629574d0dSJiri Slaby #define PIC32_UART_MODE_STSEL BIT(0) 10729574d0dSJiri Slaby 10829574d0dSJiri Slaby /* pic32 uart status register bits */ 10929574d0dSJiri Slaby #define PIC32_UART_STA_UTXISEL1 BIT(15) 11029574d0dSJiri Slaby #define PIC32_UART_STA_UTXISEL0 BIT(14) 11129574d0dSJiri Slaby #define PIC32_UART_STA_UTXINV BIT(13) 11229574d0dSJiri Slaby #define PIC32_UART_STA_URXEN BIT(12) 11329574d0dSJiri Slaby #define PIC32_UART_STA_UTXBRK BIT(11) 11429574d0dSJiri Slaby #define PIC32_UART_STA_UTXEN BIT(10) 11529574d0dSJiri Slaby #define PIC32_UART_STA_UTXBF BIT(9) 11629574d0dSJiri Slaby #define PIC32_UART_STA_TRMT BIT(8) 11729574d0dSJiri Slaby #define PIC32_UART_STA_URXISEL1 BIT(7) 11829574d0dSJiri Slaby #define PIC32_UART_STA_URXISEL0 BIT(6) 11929574d0dSJiri Slaby #define PIC32_UART_STA_ADDEN BIT(5) 12029574d0dSJiri Slaby #define PIC32_UART_STA_RIDLE BIT(4) 12129574d0dSJiri Slaby #define PIC32_UART_STA_PERR BIT(3) 12229574d0dSJiri Slaby #define PIC32_UART_STA_FERR BIT(2) 12329574d0dSJiri Slaby #define PIC32_UART_STA_OERR BIT(1) 12429574d0dSJiri Slaby #define PIC32_UART_STA_URXDA BIT(0) 12529574d0dSJiri Slaby 126157b9394SAndrei Pistirica /* pic32_sport pointer for console use */ 127157b9394SAndrei Pistirica static struct pic32_sport *pic32_sports[PIC32_MAX_UARTS]; 128157b9394SAndrei Pistirica 129157b9394SAndrei Pistirica static inline void pic32_wait_deplete_txbuf(struct pic32_sport *sport) 130157b9394SAndrei Pistirica { 131157b9394SAndrei Pistirica /* wait for tx empty, otherwise chars will be lost or corrupted */ 132157b9394SAndrei Pistirica while (!(pic32_uart_readl(sport, PIC32_UART_STA) & PIC32_UART_STA_TRMT)) 133157b9394SAndrei Pistirica udelay(1); 134157b9394SAndrei Pistirica } 135157b9394SAndrei Pistirica 136157b9394SAndrei Pistirica /* serial core request to check if uart tx buffer is empty */ 137157b9394SAndrei Pistirica static unsigned int pic32_uart_tx_empty(struct uart_port *port) 138157b9394SAndrei Pistirica { 139157b9394SAndrei Pistirica struct pic32_sport *sport = to_pic32_sport(port); 140157b9394SAndrei Pistirica u32 val = pic32_uart_readl(sport, PIC32_UART_STA); 141157b9394SAndrei Pistirica 142157b9394SAndrei Pistirica return (val & PIC32_UART_STA_TRMT) ? 1 : 0; 143157b9394SAndrei Pistirica } 144157b9394SAndrei Pistirica 145157b9394SAndrei Pistirica /* serial core request to set UART outputs */ 146157b9394SAndrei Pistirica static void pic32_uart_set_mctrl(struct uart_port *port, unsigned int mctrl) 147157b9394SAndrei Pistirica { 148157b9394SAndrei Pistirica struct pic32_sport *sport = to_pic32_sport(port); 149157b9394SAndrei Pistirica 150157b9394SAndrei Pistirica /* set loopback mode */ 151157b9394SAndrei Pistirica if (mctrl & TIOCM_LOOP) 152157b9394SAndrei Pistirica pic32_uart_writel(sport, PIC32_SET(PIC32_UART_MODE), 153157b9394SAndrei Pistirica PIC32_UART_MODE_LPBK); 154157b9394SAndrei Pistirica else 155157b9394SAndrei Pistirica pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_MODE), 156157b9394SAndrei Pistirica PIC32_UART_MODE_LPBK); 157157b9394SAndrei Pistirica } 158157b9394SAndrei Pistirica 159157b9394SAndrei Pistirica /* serial core request to return the state of misc UART input pins */ 160157b9394SAndrei Pistirica static unsigned int pic32_uart_get_mctrl(struct uart_port *port) 161157b9394SAndrei Pistirica { 162157b9394SAndrei Pistirica struct pic32_sport *sport = to_pic32_sport(port); 163157b9394SAndrei Pistirica unsigned int mctrl = 0; 164157b9394SAndrei Pistirica 165e9c9d3bbSAndy Shevchenko /* get the state of CTS input pin for this port */ 166e9c9d3bbSAndy Shevchenko if (!sport->cts_gpiod) 167157b9394SAndrei Pistirica mctrl |= TIOCM_CTS; 168e9c9d3bbSAndy Shevchenko else if (gpiod_get_value(sport->cts_gpiod)) 169157b9394SAndrei Pistirica mctrl |= TIOCM_CTS; 170157b9394SAndrei Pistirica 171157b9394SAndrei Pistirica /* DSR and CD are not supported in PIC32, so return 1 172157b9394SAndrei Pistirica * RI is not supported in PIC32, so return 0 173157b9394SAndrei Pistirica */ 174157b9394SAndrei Pistirica mctrl |= TIOCM_CD; 175157b9394SAndrei Pistirica mctrl |= TIOCM_DSR; 176157b9394SAndrei Pistirica 177157b9394SAndrei Pistirica return mctrl; 178157b9394SAndrei Pistirica } 179157b9394SAndrei Pistirica 180157b9394SAndrei Pistirica /* stop tx and start tx are not called in pairs, therefore a flag indicates 181157b9394SAndrei Pistirica * the status of irq to control the irq-depth. 182157b9394SAndrei Pistirica */ 183157b9394SAndrei Pistirica static inline void pic32_uart_irqtxen(struct pic32_sport *sport, u8 en) 184157b9394SAndrei Pistirica { 185e8616bd0SJiri Slaby if (en && !sport->enable_tx_irq) { 186157b9394SAndrei Pistirica enable_irq(sport->irq_tx); 187e8616bd0SJiri Slaby sport->enable_tx_irq = true; 188e8616bd0SJiri Slaby } else if (!en && sport->enable_tx_irq) { 189157b9394SAndrei Pistirica /* use disable_irq_nosync() and not disable_irq() to avoid self 190157b9394SAndrei Pistirica * imposed deadlock by not waiting for irq handler to end, 191157b9394SAndrei Pistirica * since this callback is called from interrupt context. 192157b9394SAndrei Pistirica */ 193157b9394SAndrei Pistirica disable_irq_nosync(sport->irq_tx); 194e8616bd0SJiri Slaby sport->enable_tx_irq = false; 195157b9394SAndrei Pistirica } 196157b9394SAndrei Pistirica } 197157b9394SAndrei Pistirica 198157b9394SAndrei Pistirica /* serial core request to disable tx ASAP (used for flow control) */ 199157b9394SAndrei Pistirica static void pic32_uart_stop_tx(struct uart_port *port) 200157b9394SAndrei Pistirica { 201157b9394SAndrei Pistirica struct pic32_sport *sport = to_pic32_sport(port); 202157b9394SAndrei Pistirica 203157b9394SAndrei Pistirica if (!(pic32_uart_readl(sport, PIC32_UART_MODE) & PIC32_UART_MODE_ON)) 204157b9394SAndrei Pistirica return; 205157b9394SAndrei Pistirica 206157b9394SAndrei Pistirica if (!(pic32_uart_readl(sport, PIC32_UART_STA) & PIC32_UART_STA_UTXEN)) 207157b9394SAndrei Pistirica return; 208157b9394SAndrei Pistirica 209157b9394SAndrei Pistirica /* wait for tx empty */ 210157b9394SAndrei Pistirica pic32_wait_deplete_txbuf(sport); 211157b9394SAndrei Pistirica 212157b9394SAndrei Pistirica pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_STA), 213157b9394SAndrei Pistirica PIC32_UART_STA_UTXEN); 214157b9394SAndrei Pistirica pic32_uart_irqtxen(sport, 0); 215157b9394SAndrei Pistirica } 216157b9394SAndrei Pistirica 217157b9394SAndrei Pistirica /* serial core request to (re)enable tx */ 218157b9394SAndrei Pistirica static void pic32_uart_start_tx(struct uart_port *port) 219157b9394SAndrei Pistirica { 220157b9394SAndrei Pistirica struct pic32_sport *sport = to_pic32_sport(port); 221157b9394SAndrei Pistirica 222157b9394SAndrei Pistirica pic32_uart_irqtxen(sport, 1); 223157b9394SAndrei Pistirica pic32_uart_writel(sport, PIC32_SET(PIC32_UART_STA), 224157b9394SAndrei Pistirica PIC32_UART_STA_UTXEN); 225157b9394SAndrei Pistirica } 226157b9394SAndrei Pistirica 227157b9394SAndrei Pistirica /* serial core request to stop rx, called before port shutdown */ 228157b9394SAndrei Pistirica static void pic32_uart_stop_rx(struct uart_port *port) 229157b9394SAndrei Pistirica { 230157b9394SAndrei Pistirica struct pic32_sport *sport = to_pic32_sport(port); 231157b9394SAndrei Pistirica 232157b9394SAndrei Pistirica /* disable rx interrupts */ 233157b9394SAndrei Pistirica disable_irq(sport->irq_rx); 234157b9394SAndrei Pistirica 235157b9394SAndrei Pistirica /* receiver Enable bit OFF */ 236157b9394SAndrei Pistirica pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_STA), 237157b9394SAndrei Pistirica PIC32_UART_STA_URXEN); 238157b9394SAndrei Pistirica } 239157b9394SAndrei Pistirica 240157b9394SAndrei Pistirica /* serial core request to start/stop emitting break char */ 241157b9394SAndrei Pistirica static void pic32_uart_break_ctl(struct uart_port *port, int ctl) 242157b9394SAndrei Pistirica { 243157b9394SAndrei Pistirica struct pic32_sport *sport = to_pic32_sport(port); 244157b9394SAndrei Pistirica unsigned long flags; 245157b9394SAndrei Pistirica 2468975ed8cSThomas Gleixner uart_port_lock_irqsave(port, &flags); 247157b9394SAndrei Pistirica 248157b9394SAndrei Pistirica if (ctl) 249157b9394SAndrei Pistirica pic32_uart_writel(sport, PIC32_SET(PIC32_UART_STA), 250157b9394SAndrei Pistirica PIC32_UART_STA_UTXBRK); 251157b9394SAndrei Pistirica else 252157b9394SAndrei Pistirica pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_STA), 253157b9394SAndrei Pistirica PIC32_UART_STA_UTXBRK); 254157b9394SAndrei Pistirica 2558975ed8cSThomas Gleixner uart_port_unlock_irqrestore(port, flags); 256157b9394SAndrei Pistirica } 257157b9394SAndrei Pistirica 258157b9394SAndrei Pistirica /* get port type in string format */ 259157b9394SAndrei Pistirica static const char *pic32_uart_type(struct uart_port *port) 260157b9394SAndrei Pistirica { 261157b9394SAndrei Pistirica return (port->type == PORT_PIC32) ? PIC32_DEV_NAME : NULL; 262157b9394SAndrei Pistirica } 263157b9394SAndrei Pistirica 264157b9394SAndrei Pistirica /* read all chars in rx fifo and send them to core */ 265157b9394SAndrei Pistirica static void pic32_uart_do_rx(struct uart_port *port) 266157b9394SAndrei Pistirica { 267157b9394SAndrei Pistirica struct pic32_sport *sport = to_pic32_sport(port); 268157b9394SAndrei Pistirica struct tty_port *tty; 269157b9394SAndrei Pistirica unsigned int max_count; 270157b9394SAndrei Pistirica 271157b9394SAndrei Pistirica /* limit number of char read in interrupt, should not be 272157b9394SAndrei Pistirica * higher than fifo size anyway since we're much faster than 273157b9394SAndrei Pistirica * serial port 274157b9394SAndrei Pistirica */ 275157b9394SAndrei Pistirica max_count = PIC32_UART_RX_FIFO_DEPTH; 276157b9394SAndrei Pistirica 2778975ed8cSThomas Gleixner uart_port_lock(port); 278157b9394SAndrei Pistirica 279157b9394SAndrei Pistirica tty = &port->state->port; 280157b9394SAndrei Pistirica 281157b9394SAndrei Pistirica do { 282157b9394SAndrei Pistirica u32 sta_reg, c; 283157b9394SAndrei Pistirica char flag; 284157b9394SAndrei Pistirica 285157b9394SAndrei Pistirica /* get overrun/fifo empty information from status register */ 286157b9394SAndrei Pistirica sta_reg = pic32_uart_readl(sport, PIC32_UART_STA); 287157b9394SAndrei Pistirica if (unlikely(sta_reg & PIC32_UART_STA_OERR)) { 288157b9394SAndrei Pistirica 289157b9394SAndrei Pistirica /* fifo reset is required to clear interrupt */ 290157b9394SAndrei Pistirica pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_STA), 291157b9394SAndrei Pistirica PIC32_UART_STA_OERR); 292157b9394SAndrei Pistirica 293157b9394SAndrei Pistirica port->icount.overrun++; 294157b9394SAndrei Pistirica tty_insert_flip_char(tty, 0, TTY_OVERRUN); 295157b9394SAndrei Pistirica } 296157b9394SAndrei Pistirica 297157b9394SAndrei Pistirica /* Can at least one more character can be read? */ 298157b9394SAndrei Pistirica if (!(sta_reg & PIC32_UART_STA_URXDA)) 299157b9394SAndrei Pistirica break; 300157b9394SAndrei Pistirica 301157b9394SAndrei Pistirica /* read the character and increment the rx counter */ 302157b9394SAndrei Pistirica c = pic32_uart_readl(sport, PIC32_UART_RX); 303157b9394SAndrei Pistirica 304157b9394SAndrei Pistirica port->icount.rx++; 305157b9394SAndrei Pistirica flag = TTY_NORMAL; 306157b9394SAndrei Pistirica c &= 0xff; 307157b9394SAndrei Pistirica 308157b9394SAndrei Pistirica if (unlikely((sta_reg & PIC32_UART_STA_PERR) || 309157b9394SAndrei Pistirica (sta_reg & PIC32_UART_STA_FERR))) { 310157b9394SAndrei Pistirica 311157b9394SAndrei Pistirica /* do stats first */ 312157b9394SAndrei Pistirica if (sta_reg & PIC32_UART_STA_PERR) 313157b9394SAndrei Pistirica port->icount.parity++; 314157b9394SAndrei Pistirica if (sta_reg & PIC32_UART_STA_FERR) 315157b9394SAndrei Pistirica port->icount.frame++; 316157b9394SAndrei Pistirica 317157b9394SAndrei Pistirica /* update flag wrt read_status_mask */ 318157b9394SAndrei Pistirica sta_reg &= port->read_status_mask; 319157b9394SAndrei Pistirica 320157b9394SAndrei Pistirica if (sta_reg & PIC32_UART_STA_FERR) 321157b9394SAndrei Pistirica flag = TTY_FRAME; 322157b9394SAndrei Pistirica if (sta_reg & PIC32_UART_STA_PERR) 323157b9394SAndrei Pistirica flag = TTY_PARITY; 324157b9394SAndrei Pistirica } 325157b9394SAndrei Pistirica 326157b9394SAndrei Pistirica if (uart_handle_sysrq_char(port, c)) 327157b9394SAndrei Pistirica continue; 328157b9394SAndrei Pistirica 329157b9394SAndrei Pistirica if ((sta_reg & port->ignore_status_mask) == 0) 330157b9394SAndrei Pistirica tty_insert_flip_char(tty, c, flag); 331157b9394SAndrei Pistirica 332157b9394SAndrei Pistirica } while (--max_count); 333157b9394SAndrei Pistirica 3348975ed8cSThomas Gleixner uart_port_unlock(port); 335157b9394SAndrei Pistirica 336157b9394SAndrei Pistirica tty_flip_buffer_push(tty); 337157b9394SAndrei Pistirica } 338157b9394SAndrei Pistirica 339157b9394SAndrei Pistirica /* fill tx fifo with chars to send, stop when fifo is about to be full 340157b9394SAndrei Pistirica * or when all chars have been sent. 341157b9394SAndrei Pistirica */ 342157b9394SAndrei Pistirica static void pic32_uart_do_tx(struct uart_port *port) 343157b9394SAndrei Pistirica { 344157b9394SAndrei Pistirica struct pic32_sport *sport = to_pic32_sport(port); 345157b9394SAndrei Pistirica struct circ_buf *xmit = &port->state->xmit; 346157b9394SAndrei Pistirica unsigned int max_count = PIC32_UART_TX_FIFO_DEPTH; 347157b9394SAndrei Pistirica 348157b9394SAndrei Pistirica if (port->x_char) { 349157b9394SAndrei Pistirica pic32_uart_writel(sport, PIC32_UART_TX, port->x_char); 350157b9394SAndrei Pistirica port->icount.tx++; 351157b9394SAndrei Pistirica port->x_char = 0; 352157b9394SAndrei Pistirica return; 353157b9394SAndrei Pistirica } 354157b9394SAndrei Pistirica 355157b9394SAndrei Pistirica if (uart_tx_stopped(port)) { 356157b9394SAndrei Pistirica pic32_uart_stop_tx(port); 357157b9394SAndrei Pistirica return; 358157b9394SAndrei Pistirica } 359157b9394SAndrei Pistirica 360157b9394SAndrei Pistirica if (uart_circ_empty(xmit)) 361157b9394SAndrei Pistirica goto txq_empty; 362157b9394SAndrei Pistirica 363157b9394SAndrei Pistirica /* keep stuffing chars into uart tx buffer 364157b9394SAndrei Pistirica * 1) until uart fifo is full 365157b9394SAndrei Pistirica * or 366157b9394SAndrei Pistirica * 2) until the circ buffer is empty 367157b9394SAndrei Pistirica * (all chars have been sent) 368157b9394SAndrei Pistirica * or 369157b9394SAndrei Pistirica * 3) until the max count is reached 370157b9394SAndrei Pistirica * (prevents lingering here for too long in certain cases) 371157b9394SAndrei Pistirica */ 372157b9394SAndrei Pistirica while (!(PIC32_UART_STA_UTXBF & 373157b9394SAndrei Pistirica pic32_uart_readl(sport, PIC32_UART_STA))) { 374157b9394SAndrei Pistirica unsigned int c = xmit->buf[xmit->tail]; 375157b9394SAndrei Pistirica 376157b9394SAndrei Pistirica pic32_uart_writel(sport, PIC32_UART_TX, c); 377157b9394SAndrei Pistirica 37898fdebeeSIlpo Järvinen uart_xmit_advance(port, 1); 379157b9394SAndrei Pistirica if (uart_circ_empty(xmit)) 380157b9394SAndrei Pistirica break; 381157b9394SAndrei Pistirica if (--max_count == 0) 382157b9394SAndrei Pistirica break; 383157b9394SAndrei Pistirica } 384157b9394SAndrei Pistirica 385157b9394SAndrei Pistirica if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) 386157b9394SAndrei Pistirica uart_write_wakeup(port); 387157b9394SAndrei Pistirica 388157b9394SAndrei Pistirica if (uart_circ_empty(xmit)) 389157b9394SAndrei Pistirica goto txq_empty; 390157b9394SAndrei Pistirica 391157b9394SAndrei Pistirica return; 392157b9394SAndrei Pistirica 393157b9394SAndrei Pistirica txq_empty: 394157b9394SAndrei Pistirica pic32_uart_irqtxen(sport, 0); 395157b9394SAndrei Pistirica } 396157b9394SAndrei Pistirica 397157b9394SAndrei Pistirica /* RX interrupt handler */ 398157b9394SAndrei Pistirica static irqreturn_t pic32_uart_rx_interrupt(int irq, void *dev_id) 399157b9394SAndrei Pistirica { 400157b9394SAndrei Pistirica struct uart_port *port = dev_id; 401157b9394SAndrei Pistirica 402157b9394SAndrei Pistirica pic32_uart_do_rx(port); 403157b9394SAndrei Pistirica 404157b9394SAndrei Pistirica return IRQ_HANDLED; 405157b9394SAndrei Pistirica } 406157b9394SAndrei Pistirica 407157b9394SAndrei Pistirica /* TX interrupt handler */ 408157b9394SAndrei Pistirica static irqreturn_t pic32_uart_tx_interrupt(int irq, void *dev_id) 409157b9394SAndrei Pistirica { 410157b9394SAndrei Pistirica struct uart_port *port = dev_id; 411157b9394SAndrei Pistirica unsigned long flags; 412157b9394SAndrei Pistirica 4138975ed8cSThomas Gleixner uart_port_lock_irqsave(port, &flags); 414157b9394SAndrei Pistirica pic32_uart_do_tx(port); 4158975ed8cSThomas Gleixner uart_port_unlock_irqrestore(port, flags); 416157b9394SAndrei Pistirica 417157b9394SAndrei Pistirica return IRQ_HANDLED; 418157b9394SAndrei Pistirica } 419157b9394SAndrei Pistirica 420157b9394SAndrei Pistirica /* FAULT interrupt handler */ 421157b9394SAndrei Pistirica static irqreturn_t pic32_uart_fault_interrupt(int irq, void *dev_id) 422157b9394SAndrei Pistirica { 423157b9394SAndrei Pistirica /* do nothing: pic32_uart_do_rx() handles faults. */ 424157b9394SAndrei Pistirica return IRQ_HANDLED; 425157b9394SAndrei Pistirica } 426157b9394SAndrei Pistirica 427157b9394SAndrei Pistirica /* enable rx & tx operation on uart */ 428157b9394SAndrei Pistirica static void pic32_uart_en_and_unmask(struct uart_port *port) 429157b9394SAndrei Pistirica { 430157b9394SAndrei Pistirica struct pic32_sport *sport = to_pic32_sport(port); 431157b9394SAndrei Pistirica 432157b9394SAndrei Pistirica pic32_uart_writel(sport, PIC32_SET(PIC32_UART_STA), 433157b9394SAndrei Pistirica PIC32_UART_STA_UTXEN | PIC32_UART_STA_URXEN); 434157b9394SAndrei Pistirica pic32_uart_writel(sport, PIC32_SET(PIC32_UART_MODE), 435157b9394SAndrei Pistirica PIC32_UART_MODE_ON); 436157b9394SAndrei Pistirica } 437157b9394SAndrei Pistirica 438157b9394SAndrei Pistirica /* disable rx & tx operation on uart */ 439157b9394SAndrei Pistirica static void pic32_uart_dsbl_and_mask(struct uart_port *port) 440157b9394SAndrei Pistirica { 441157b9394SAndrei Pistirica struct pic32_sport *sport = to_pic32_sport(port); 442157b9394SAndrei Pistirica 443157b9394SAndrei Pistirica /* wait for tx empty, otherwise chars will be lost or corrupted */ 444157b9394SAndrei Pistirica pic32_wait_deplete_txbuf(sport); 445157b9394SAndrei Pistirica 446157b9394SAndrei Pistirica pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_STA), 447157b9394SAndrei Pistirica PIC32_UART_STA_UTXEN | PIC32_UART_STA_URXEN); 448157b9394SAndrei Pistirica pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_MODE), 449157b9394SAndrei Pistirica PIC32_UART_MODE_ON); 450157b9394SAndrei Pistirica } 451157b9394SAndrei Pistirica 452157b9394SAndrei Pistirica /* serial core request to initialize uart and start rx operation */ 453157b9394SAndrei Pistirica static int pic32_uart_startup(struct uart_port *port) 454157b9394SAndrei Pistirica { 455157b9394SAndrei Pistirica struct pic32_sport *sport = to_pic32_sport(port); 456157b9394SAndrei Pistirica u32 dflt_baud = (port->uartclk / PIC32_UART_DFLT_BRATE / 16) - 1; 457157b9394SAndrei Pistirica unsigned long flags; 458157b9394SAndrei Pistirica int ret; 459157b9394SAndrei Pistirica 460157b9394SAndrei Pistirica local_irq_save(flags); 461157b9394SAndrei Pistirica 462bb2cff41SJiri Slaby ret = clk_prepare_enable(sport->clk); 463157b9394SAndrei Pistirica if (ret) { 464157b9394SAndrei Pistirica local_irq_restore(flags); 465157b9394SAndrei Pistirica goto out_done; 466157b9394SAndrei Pistirica } 467157b9394SAndrei Pistirica 468157b9394SAndrei Pistirica /* clear status and mode registers */ 469157b9394SAndrei Pistirica pic32_uart_writel(sport, PIC32_UART_MODE, 0); 470157b9394SAndrei Pistirica pic32_uart_writel(sport, PIC32_UART_STA, 0); 471157b9394SAndrei Pistirica 472157b9394SAndrei Pistirica /* disable uart and mask all interrupts */ 473157b9394SAndrei Pistirica pic32_uart_dsbl_and_mask(port); 474157b9394SAndrei Pistirica 475157b9394SAndrei Pistirica /* set default baud */ 476157b9394SAndrei Pistirica pic32_uart_writel(sport, PIC32_UART_BRG, dflt_baud); 477157b9394SAndrei Pistirica 478157b9394SAndrei Pistirica local_irq_restore(flags); 479157b9394SAndrei Pistirica 480157b9394SAndrei Pistirica /* Each UART of a PIC32 has three interrupts therefore, 481157b9394SAndrei Pistirica * we setup driver to register the 3 irqs for the device. 482157b9394SAndrei Pistirica * 483157b9394SAndrei Pistirica * For each irq request_irq() is called with interrupt disabled. 484157b9394SAndrei Pistirica * And the irq is enabled as soon as we are ready to handle them. 485157b9394SAndrei Pistirica */ 486e8616bd0SJiri Slaby sport->enable_tx_irq = false; 487157b9394SAndrei Pistirica 488157b9394SAndrei Pistirica sport->irq_fault_name = kasprintf(GFP_KERNEL, "%s%d-fault", 489157b9394SAndrei Pistirica pic32_uart_type(port), 490157b9394SAndrei Pistirica sport->idx); 491157b9394SAndrei Pistirica if (!sport->irq_fault_name) { 492157b9394SAndrei Pistirica dev_err(port->dev, "%s: kasprintf err!", __func__); 493157b9394SAndrei Pistirica ret = -ENOMEM; 4946f3cdf2bSYang Yingliang goto out_disable_clk; 495157b9394SAndrei Pistirica } 496157b9394SAndrei Pistirica irq_set_status_flags(sport->irq_fault, IRQ_NOAUTOEN); 497157b9394SAndrei Pistirica ret = request_irq(sport->irq_fault, pic32_uart_fault_interrupt, 49808f643e0SJiri Slaby IRQF_NO_THREAD, sport->irq_fault_name, port); 499157b9394SAndrei Pistirica if (ret) { 500157b9394SAndrei Pistirica dev_err(port->dev, "%s: request irq(%d) err! ret:%d name:%s\n", 501157b9394SAndrei Pistirica __func__, sport->irq_fault, ret, 502157b9394SAndrei Pistirica pic32_uart_type(port)); 503157b9394SAndrei Pistirica goto out_f; 504157b9394SAndrei Pistirica } 505157b9394SAndrei Pistirica 506157b9394SAndrei Pistirica sport->irq_rx_name = kasprintf(GFP_KERNEL, "%s%d-rx", 507157b9394SAndrei Pistirica pic32_uart_type(port), 508157b9394SAndrei Pistirica sport->idx); 509157b9394SAndrei Pistirica if (!sport->irq_rx_name) { 510157b9394SAndrei Pistirica dev_err(port->dev, "%s: kasprintf err!", __func__); 511157b9394SAndrei Pistirica ret = -ENOMEM; 512157b9394SAndrei Pistirica goto out_f; 513157b9394SAndrei Pistirica } 514157b9394SAndrei Pistirica irq_set_status_flags(sport->irq_rx, IRQ_NOAUTOEN); 515157b9394SAndrei Pistirica ret = request_irq(sport->irq_rx, pic32_uart_rx_interrupt, 51608f643e0SJiri Slaby IRQF_NO_THREAD, sport->irq_rx_name, port); 517157b9394SAndrei Pistirica if (ret) { 518157b9394SAndrei Pistirica dev_err(port->dev, "%s: request irq(%d) err! ret:%d name:%s\n", 519157b9394SAndrei Pistirica __func__, sport->irq_rx, ret, 520157b9394SAndrei Pistirica pic32_uart_type(port)); 521157b9394SAndrei Pistirica goto out_r; 522157b9394SAndrei Pistirica } 523157b9394SAndrei Pistirica 524157b9394SAndrei Pistirica sport->irq_tx_name = kasprintf(GFP_KERNEL, "%s%d-tx", 525157b9394SAndrei Pistirica pic32_uart_type(port), 526157b9394SAndrei Pistirica sport->idx); 527157b9394SAndrei Pistirica if (!sport->irq_tx_name) { 528157b9394SAndrei Pistirica dev_err(port->dev, "%s: kasprintf err!", __func__); 529157b9394SAndrei Pistirica ret = -ENOMEM; 530157b9394SAndrei Pistirica goto out_r; 531157b9394SAndrei Pistirica } 532157b9394SAndrei Pistirica irq_set_status_flags(sport->irq_tx, IRQ_NOAUTOEN); 533157b9394SAndrei Pistirica ret = request_irq(sport->irq_tx, pic32_uart_tx_interrupt, 53408f643e0SJiri Slaby IRQF_NO_THREAD, sport->irq_tx_name, port); 535157b9394SAndrei Pistirica if (ret) { 536157b9394SAndrei Pistirica dev_err(port->dev, "%s: request irq(%d) err! ret:%d name:%s\n", 537157b9394SAndrei Pistirica __func__, sport->irq_tx, ret, 538157b9394SAndrei Pistirica pic32_uart_type(port)); 539157b9394SAndrei Pistirica goto out_t; 540157b9394SAndrei Pistirica } 541157b9394SAndrei Pistirica 542157b9394SAndrei Pistirica local_irq_save(flags); 543157b9394SAndrei Pistirica 544157b9394SAndrei Pistirica /* set rx interrupt on first receive */ 545157b9394SAndrei Pistirica pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_STA), 546157b9394SAndrei Pistirica PIC32_UART_STA_URXISEL1 | PIC32_UART_STA_URXISEL0); 547157b9394SAndrei Pistirica 548157b9394SAndrei Pistirica /* set interrupt on empty */ 549157b9394SAndrei Pistirica pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_STA), 550157b9394SAndrei Pistirica PIC32_UART_STA_UTXISEL1); 551157b9394SAndrei Pistirica 552157b9394SAndrei Pistirica /* enable all interrupts and eanable uart */ 553157b9394SAndrei Pistirica pic32_uart_en_and_unmask(port); 554157b9394SAndrei Pistirica 555dfb9afb6SJiri Slaby local_irq_restore(flags); 556dfb9afb6SJiri Slaby 557157b9394SAndrei Pistirica enable_irq(sport->irq_rx); 558157b9394SAndrei Pistirica 559157b9394SAndrei Pistirica return 0; 560157b9394SAndrei Pistirica 561157b9394SAndrei Pistirica out_t: 5622aaa9573SChristophe JAILLET free_irq(sport->irq_tx, port); 563fe36fa18SJiri Slaby kfree(sport->irq_tx_name); 564157b9394SAndrei Pistirica out_r: 5652aaa9573SChristophe JAILLET free_irq(sport->irq_rx, port); 566fe36fa18SJiri Slaby kfree(sport->irq_rx_name); 567157b9394SAndrei Pistirica out_f: 5682aaa9573SChristophe JAILLET free_irq(sport->irq_fault, port); 569fe36fa18SJiri Slaby kfree(sport->irq_fault_name); 5706f3cdf2bSYang Yingliang out_disable_clk: 5716f3cdf2bSYang Yingliang clk_disable_unprepare(sport->clk); 572157b9394SAndrei Pistirica out_done: 573157b9394SAndrei Pistirica return ret; 574157b9394SAndrei Pistirica } 575157b9394SAndrei Pistirica 576157b9394SAndrei Pistirica /* serial core request to flush & disable uart */ 577157b9394SAndrei Pistirica static void pic32_uart_shutdown(struct uart_port *port) 578157b9394SAndrei Pistirica { 579157b9394SAndrei Pistirica struct pic32_sport *sport = to_pic32_sport(port); 580157b9394SAndrei Pistirica unsigned long flags; 581157b9394SAndrei Pistirica 582157b9394SAndrei Pistirica /* disable uart */ 5838975ed8cSThomas Gleixner uart_port_lock_irqsave(port, &flags); 584157b9394SAndrei Pistirica pic32_uart_dsbl_and_mask(port); 5858975ed8cSThomas Gleixner uart_port_unlock_irqrestore(port, flags); 586bb2cff41SJiri Slaby clk_disable_unprepare(sport->clk); 587157b9394SAndrei Pistirica 588157b9394SAndrei Pistirica /* free all 3 interrupts for this UART */ 589157b9394SAndrei Pistirica free_irq(sport->irq_fault, port); 590fe36fa18SJiri Slaby kfree(sport->irq_fault_name); 591157b9394SAndrei Pistirica free_irq(sport->irq_tx, port); 592fe36fa18SJiri Slaby kfree(sport->irq_tx_name); 593157b9394SAndrei Pistirica free_irq(sport->irq_rx, port); 594fe36fa18SJiri Slaby kfree(sport->irq_rx_name); 595157b9394SAndrei Pistirica } 596157b9394SAndrei Pistirica 597157b9394SAndrei Pistirica /* serial core request to change current uart setting */ 598157b9394SAndrei Pistirica static void pic32_uart_set_termios(struct uart_port *port, 599157b9394SAndrei Pistirica struct ktermios *new, 600bec5b814SIlpo Järvinen const struct ktermios *old) 601157b9394SAndrei Pistirica { 602157b9394SAndrei Pistirica struct pic32_sport *sport = to_pic32_sport(port); 603157b9394SAndrei Pistirica unsigned int baud; 604157b9394SAndrei Pistirica unsigned int quot; 605157b9394SAndrei Pistirica unsigned long flags; 606157b9394SAndrei Pistirica 6078975ed8cSThomas Gleixner uart_port_lock_irqsave(port, &flags); 608157b9394SAndrei Pistirica 609157b9394SAndrei Pistirica /* disable uart and mask all interrupts while changing speed */ 610157b9394SAndrei Pistirica pic32_uart_dsbl_and_mask(port); 611157b9394SAndrei Pistirica 612157b9394SAndrei Pistirica /* stop bit options */ 613157b9394SAndrei Pistirica if (new->c_cflag & CSTOPB) 614157b9394SAndrei Pistirica pic32_uart_writel(sport, PIC32_SET(PIC32_UART_MODE), 615157b9394SAndrei Pistirica PIC32_UART_MODE_STSEL); 616157b9394SAndrei Pistirica else 617157b9394SAndrei Pistirica pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_MODE), 618157b9394SAndrei Pistirica PIC32_UART_MODE_STSEL); 619157b9394SAndrei Pistirica 620157b9394SAndrei Pistirica /* parity options */ 621157b9394SAndrei Pistirica if (new->c_cflag & PARENB) { 622157b9394SAndrei Pistirica if (new->c_cflag & PARODD) { 623157b9394SAndrei Pistirica pic32_uart_writel(sport, PIC32_SET(PIC32_UART_MODE), 624157b9394SAndrei Pistirica PIC32_UART_MODE_PDSEL1); 625157b9394SAndrei Pistirica pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_MODE), 626157b9394SAndrei Pistirica PIC32_UART_MODE_PDSEL0); 627157b9394SAndrei Pistirica } else { 628157b9394SAndrei Pistirica pic32_uart_writel(sport, PIC32_SET(PIC32_UART_MODE), 629157b9394SAndrei Pistirica PIC32_UART_MODE_PDSEL0); 630157b9394SAndrei Pistirica pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_MODE), 631157b9394SAndrei Pistirica PIC32_UART_MODE_PDSEL1); 632157b9394SAndrei Pistirica } 633157b9394SAndrei Pistirica } else { 634157b9394SAndrei Pistirica pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_MODE), 635157b9394SAndrei Pistirica PIC32_UART_MODE_PDSEL1 | 636157b9394SAndrei Pistirica PIC32_UART_MODE_PDSEL0); 637157b9394SAndrei Pistirica } 638157b9394SAndrei Pistirica /* if hw flow ctrl, then the pins must be specified in device tree */ 639e9c9d3bbSAndy Shevchenko if ((new->c_cflag & CRTSCTS) && sport->cts_gpiod) { 640157b9394SAndrei Pistirica /* enable hardware flow control */ 641157b9394SAndrei Pistirica pic32_uart_writel(sport, PIC32_SET(PIC32_UART_MODE), 642157b9394SAndrei Pistirica PIC32_UART_MODE_UEN1); 643157b9394SAndrei Pistirica pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_MODE), 644157b9394SAndrei Pistirica PIC32_UART_MODE_UEN0); 645157b9394SAndrei Pistirica pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_MODE), 646157b9394SAndrei Pistirica PIC32_UART_MODE_RTSMD); 647157b9394SAndrei Pistirica } else { 648157b9394SAndrei Pistirica /* disable hardware flow control */ 649157b9394SAndrei Pistirica pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_MODE), 650157b9394SAndrei Pistirica PIC32_UART_MODE_UEN1); 651157b9394SAndrei Pistirica pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_MODE), 652157b9394SAndrei Pistirica PIC32_UART_MODE_UEN0); 653157b9394SAndrei Pistirica pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_MODE), 654157b9394SAndrei Pistirica PIC32_UART_MODE_RTSMD); 655157b9394SAndrei Pistirica } 656157b9394SAndrei Pistirica 657157b9394SAndrei Pistirica /* Always 8-bit */ 658157b9394SAndrei Pistirica new->c_cflag |= CS8; 659157b9394SAndrei Pistirica 660157b9394SAndrei Pistirica /* Mark/Space parity is not supported */ 661157b9394SAndrei Pistirica new->c_cflag &= ~CMSPAR; 662157b9394SAndrei Pistirica 663157b9394SAndrei Pistirica /* update baud */ 664157b9394SAndrei Pistirica baud = uart_get_baud_rate(port, new, old, 0, port->uartclk / 16); 665157b9394SAndrei Pistirica quot = uart_get_divisor(port, baud) - 1; 666157b9394SAndrei Pistirica pic32_uart_writel(sport, PIC32_UART_BRG, quot); 667157b9394SAndrei Pistirica uart_update_timeout(port, new->c_cflag, baud); 668157b9394SAndrei Pistirica 669157b9394SAndrei Pistirica if (tty_termios_baud_rate(new)) 670157b9394SAndrei Pistirica tty_termios_encode_baud_rate(new, baud, baud); 671157b9394SAndrei Pistirica 672157b9394SAndrei Pistirica /* enable uart */ 673157b9394SAndrei Pistirica pic32_uart_en_and_unmask(port); 674157b9394SAndrei Pistirica 6758975ed8cSThomas Gleixner uart_port_unlock_irqrestore(port, flags); 676157b9394SAndrei Pistirica } 677157b9394SAndrei Pistirica 678157b9394SAndrei Pistirica /* serial core request to claim uart iomem */ 679157b9394SAndrei Pistirica static int pic32_uart_request_port(struct uart_port *port) 680157b9394SAndrei Pistirica { 681157b9394SAndrei Pistirica struct platform_device *pdev = to_platform_device(port->dev); 682157b9394SAndrei Pistirica struct resource *res_mem; 683157b9394SAndrei Pistirica 684157b9394SAndrei Pistirica res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 685157b9394SAndrei Pistirica if (unlikely(!res_mem)) 686157b9394SAndrei Pistirica return -EINVAL; 687157b9394SAndrei Pistirica 688157b9394SAndrei Pistirica if (!request_mem_region(port->mapbase, resource_size(res_mem), 689157b9394SAndrei Pistirica "pic32_uart_mem")) 690157b9394SAndrei Pistirica return -EBUSY; 691157b9394SAndrei Pistirica 6924bdc0d67SChristoph Hellwig port->membase = devm_ioremap(port->dev, port->mapbase, 693157b9394SAndrei Pistirica resource_size(res_mem)); 694157b9394SAndrei Pistirica if (!port->membase) { 695157b9394SAndrei Pistirica dev_err(port->dev, "Unable to map registers\n"); 696157b9394SAndrei Pistirica release_mem_region(port->mapbase, resource_size(res_mem)); 697157b9394SAndrei Pistirica return -ENOMEM; 698157b9394SAndrei Pistirica } 699157b9394SAndrei Pistirica 700157b9394SAndrei Pistirica return 0; 701157b9394SAndrei Pistirica } 702157b9394SAndrei Pistirica 703157b9394SAndrei Pistirica /* serial core request to release uart iomem */ 704157b9394SAndrei Pistirica static void pic32_uart_release_port(struct uart_port *port) 705157b9394SAndrei Pistirica { 706157b9394SAndrei Pistirica struct platform_device *pdev = to_platform_device(port->dev); 707157b9394SAndrei Pistirica struct resource *res_mem; 708157b9394SAndrei Pistirica unsigned int res_size; 709157b9394SAndrei Pistirica 710157b9394SAndrei Pistirica res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 711157b9394SAndrei Pistirica if (unlikely(!res_mem)) 712157b9394SAndrei Pistirica return; 713157b9394SAndrei Pistirica res_size = resource_size(res_mem); 714157b9394SAndrei Pistirica 715157b9394SAndrei Pistirica release_mem_region(port->mapbase, res_size); 716157b9394SAndrei Pistirica } 717157b9394SAndrei Pistirica 718157b9394SAndrei Pistirica /* serial core request to do any port required auto-configuration */ 719157b9394SAndrei Pistirica static void pic32_uart_config_port(struct uart_port *port, int flags) 720157b9394SAndrei Pistirica { 721157b9394SAndrei Pistirica if (flags & UART_CONFIG_TYPE) { 722157b9394SAndrei Pistirica if (pic32_uart_request_port(port)) 723157b9394SAndrei Pistirica return; 724157b9394SAndrei Pistirica port->type = PORT_PIC32; 725157b9394SAndrei Pistirica } 726157b9394SAndrei Pistirica } 727157b9394SAndrei Pistirica 728157b9394SAndrei Pistirica /* serial core request to check that port information in serinfo are suitable */ 729157b9394SAndrei Pistirica static int pic32_uart_verify_port(struct uart_port *port, 730157b9394SAndrei Pistirica struct serial_struct *serinfo) 731157b9394SAndrei Pistirica { 732157b9394SAndrei Pistirica if (port->type != PORT_PIC32) 733157b9394SAndrei Pistirica return -EINVAL; 734157b9394SAndrei Pistirica if (port->irq != serinfo->irq) 735157b9394SAndrei Pistirica return -EINVAL; 736157b9394SAndrei Pistirica if (port->iotype != serinfo->io_type) 737157b9394SAndrei Pistirica return -EINVAL; 738157b9394SAndrei Pistirica if (port->mapbase != (unsigned long)serinfo->iomem_base) 739157b9394SAndrei Pistirica return -EINVAL; 740157b9394SAndrei Pistirica 741157b9394SAndrei Pistirica return 0; 742157b9394SAndrei Pistirica } 743157b9394SAndrei Pistirica 744157b9394SAndrei Pistirica /* serial core callbacks */ 745157b9394SAndrei Pistirica static const struct uart_ops pic32_uart_ops = { 746157b9394SAndrei Pistirica .tx_empty = pic32_uart_tx_empty, 747157b9394SAndrei Pistirica .get_mctrl = pic32_uart_get_mctrl, 748157b9394SAndrei Pistirica .set_mctrl = pic32_uart_set_mctrl, 749157b9394SAndrei Pistirica .start_tx = pic32_uart_start_tx, 750157b9394SAndrei Pistirica .stop_tx = pic32_uart_stop_tx, 751157b9394SAndrei Pistirica .stop_rx = pic32_uart_stop_rx, 752157b9394SAndrei Pistirica .break_ctl = pic32_uart_break_ctl, 753157b9394SAndrei Pistirica .startup = pic32_uart_startup, 754157b9394SAndrei Pistirica .shutdown = pic32_uart_shutdown, 755157b9394SAndrei Pistirica .set_termios = pic32_uart_set_termios, 756157b9394SAndrei Pistirica .type = pic32_uart_type, 757157b9394SAndrei Pistirica .release_port = pic32_uart_release_port, 758157b9394SAndrei Pistirica .request_port = pic32_uart_request_port, 759157b9394SAndrei Pistirica .config_port = pic32_uart_config_port, 760157b9394SAndrei Pistirica .verify_port = pic32_uart_verify_port, 761157b9394SAndrei Pistirica }; 762157b9394SAndrei Pistirica 763157b9394SAndrei Pistirica #ifdef CONFIG_SERIAL_PIC32_CONSOLE 764157b9394SAndrei Pistirica /* output given char */ 7653f8bab17SJiri Slaby static void pic32_console_putchar(struct uart_port *port, unsigned char ch) 766157b9394SAndrei Pistirica { 767157b9394SAndrei Pistirica struct pic32_sport *sport = to_pic32_sport(port); 768157b9394SAndrei Pistirica 769157b9394SAndrei Pistirica if (!(pic32_uart_readl(sport, PIC32_UART_MODE) & PIC32_UART_MODE_ON)) 770157b9394SAndrei Pistirica return; 771157b9394SAndrei Pistirica 772157b9394SAndrei Pistirica if (!(pic32_uart_readl(sport, PIC32_UART_STA) & PIC32_UART_STA_UTXEN)) 773157b9394SAndrei Pistirica return; 774157b9394SAndrei Pistirica 775157b9394SAndrei Pistirica /* wait for tx empty */ 776157b9394SAndrei Pistirica pic32_wait_deplete_txbuf(sport); 777157b9394SAndrei Pistirica 778157b9394SAndrei Pistirica pic32_uart_writel(sport, PIC32_UART_TX, ch & 0xff); 779157b9394SAndrei Pistirica } 780157b9394SAndrei Pistirica 781157b9394SAndrei Pistirica /* console core request to output given string */ 782157b9394SAndrei Pistirica static void pic32_console_write(struct console *co, const char *s, 783157b9394SAndrei Pistirica unsigned int count) 784157b9394SAndrei Pistirica { 785157b9394SAndrei Pistirica struct pic32_sport *sport = pic32_sports[co->index]; 786157b9394SAndrei Pistirica 787157b9394SAndrei Pistirica /* call uart helper to deal with \r\n */ 788343f23cfSJiri Slaby uart_console_write(&sport->port, s, count, pic32_console_putchar); 789157b9394SAndrei Pistirica } 790157b9394SAndrei Pistirica 791157b9394SAndrei Pistirica /* console core request to setup given console, find matching uart 792157b9394SAndrei Pistirica * port and setup it. 793157b9394SAndrei Pistirica */ 794157b9394SAndrei Pistirica static int pic32_console_setup(struct console *co, char *options) 795157b9394SAndrei Pistirica { 796157b9394SAndrei Pistirica struct pic32_sport *sport; 797157b9394SAndrei Pistirica int baud = 115200; 798157b9394SAndrei Pistirica int bits = 8; 799157b9394SAndrei Pistirica int parity = 'n'; 800157b9394SAndrei Pistirica int flow = 'n'; 801157b9394SAndrei Pistirica int ret = 0; 802157b9394SAndrei Pistirica 803157b9394SAndrei Pistirica if (unlikely(co->index < 0 || co->index >= PIC32_MAX_UARTS)) 804157b9394SAndrei Pistirica return -ENODEV; 805157b9394SAndrei Pistirica 806157b9394SAndrei Pistirica sport = pic32_sports[co->index]; 807157b9394SAndrei Pistirica if (!sport) 808157b9394SAndrei Pistirica return -ENODEV; 809157b9394SAndrei Pistirica 810bb2cff41SJiri Slaby ret = clk_prepare_enable(sport->clk); 811157b9394SAndrei Pistirica if (ret) 812157b9394SAndrei Pistirica return ret; 813157b9394SAndrei Pistirica 814157b9394SAndrei Pistirica if (options) 815157b9394SAndrei Pistirica uart_parse_options(options, &baud, &parity, &bits, &flow); 816157b9394SAndrei Pistirica 817343f23cfSJiri Slaby return uart_set_options(&sport->port, co, baud, parity, bits, flow); 818157b9394SAndrei Pistirica } 819157b9394SAndrei Pistirica 820157b9394SAndrei Pistirica static struct uart_driver pic32_uart_driver; 821157b9394SAndrei Pistirica static struct console pic32_console = { 822157b9394SAndrei Pistirica .name = PIC32_SDEV_NAME, 823157b9394SAndrei Pistirica .write = pic32_console_write, 824157b9394SAndrei Pistirica .device = uart_console_device, 825157b9394SAndrei Pistirica .setup = pic32_console_setup, 826157b9394SAndrei Pistirica .flags = CON_PRINTBUFFER, 827157b9394SAndrei Pistirica .index = -1, 828157b9394SAndrei Pistirica .data = &pic32_uart_driver, 829157b9394SAndrei Pistirica }; 830157b9394SAndrei Pistirica #define PIC32_SCONSOLE (&pic32_console) 831157b9394SAndrei Pistirica 832157b9394SAndrei Pistirica static int __init pic32_console_init(void) 833157b9394SAndrei Pistirica { 834157b9394SAndrei Pistirica register_console(&pic32_console); 835157b9394SAndrei Pistirica return 0; 836157b9394SAndrei Pistirica } 837157b9394SAndrei Pistirica console_initcall(pic32_console_init); 838157b9394SAndrei Pistirica 839157b9394SAndrei Pistirica /* 840157b9394SAndrei Pistirica * Late console initialization. 841157b9394SAndrei Pistirica */ 842157b9394SAndrei Pistirica static int __init pic32_late_console_init(void) 843157b9394SAndrei Pistirica { 844f5bea480SJohn Ogness if (!console_is_registered(&pic32_console)) 845157b9394SAndrei Pistirica register_console(&pic32_console); 846157b9394SAndrei Pistirica 847157b9394SAndrei Pistirica return 0; 848157b9394SAndrei Pistirica } 849157b9394SAndrei Pistirica 850157b9394SAndrei Pistirica core_initcall(pic32_late_console_init); 851157b9394SAndrei Pistirica 852157b9394SAndrei Pistirica #else 853157b9394SAndrei Pistirica #define PIC32_SCONSOLE NULL 854157b9394SAndrei Pistirica #endif 855157b9394SAndrei Pistirica 856157b9394SAndrei Pistirica static struct uart_driver pic32_uart_driver = { 857157b9394SAndrei Pistirica .owner = THIS_MODULE, 858157b9394SAndrei Pistirica .driver_name = PIC32_DEV_NAME, 859157b9394SAndrei Pistirica .dev_name = PIC32_SDEV_NAME, 860157b9394SAndrei Pistirica .nr = PIC32_MAX_UARTS, 861157b9394SAndrei Pistirica .cons = PIC32_SCONSOLE, 862157b9394SAndrei Pistirica }; 863157b9394SAndrei Pistirica 864157b9394SAndrei Pistirica static int pic32_uart_probe(struct platform_device *pdev) 865157b9394SAndrei Pistirica { 866e9c9d3bbSAndy Shevchenko struct device *dev = &pdev->dev; 867e9c9d3bbSAndy Shevchenko struct device_node *np = dev->of_node; 868157b9394SAndrei Pistirica struct pic32_sport *sport; 869157b9394SAndrei Pistirica int uart_idx = 0; 870157b9394SAndrei Pistirica struct resource *res_mem; 871157b9394SAndrei Pistirica struct uart_port *port; 872157b9394SAndrei Pistirica int ret; 873157b9394SAndrei Pistirica 874157b9394SAndrei Pistirica uart_idx = of_alias_get_id(np, "serial"); 875157b9394SAndrei Pistirica if (uart_idx < 0 || uart_idx >= PIC32_MAX_UARTS) 876157b9394SAndrei Pistirica return -EINVAL; 877157b9394SAndrei Pistirica 878157b9394SAndrei Pistirica res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 879157b9394SAndrei Pistirica if (!res_mem) 880157b9394SAndrei Pistirica return -EINVAL; 881157b9394SAndrei Pistirica 882157b9394SAndrei Pistirica sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL); 883157b9394SAndrei Pistirica if (!sport) 884157b9394SAndrei Pistirica return -ENOMEM; 885157b9394SAndrei Pistirica 886157b9394SAndrei Pistirica sport->idx = uart_idx; 887157b9394SAndrei Pistirica sport->irq_fault = irq_of_parse_and_map(np, 0); 888157b9394SAndrei Pistirica sport->irq_rx = irq_of_parse_and_map(np, 1); 889157b9394SAndrei Pistirica sport->irq_tx = irq_of_parse_and_map(np, 2); 890157b9394SAndrei Pistirica sport->clk = devm_clk_get(&pdev->dev, NULL); 8913bec2f77SYuan Can if (IS_ERR(sport->clk)) 8923bec2f77SYuan Can return PTR_ERR(sport->clk); 893157b9394SAndrei Pistirica sport->dev = &pdev->dev; 894157b9394SAndrei Pistirica 895157b9394SAndrei Pistirica /* Hardware flow control: gpios 896157b9394SAndrei Pistirica * !Note: Basically, CTS is needed for reading the status. 897157b9394SAndrei Pistirica */ 898e9c9d3bbSAndy Shevchenko sport->cts_gpiod = devm_gpiod_get_optional(dev, "cts", GPIOD_IN); 899e9c9d3bbSAndy Shevchenko if (IS_ERR(sport->cts_gpiod)) 900e9c9d3bbSAndy Shevchenko return dev_err_probe(dev, PTR_ERR(sport->cts_gpiod), "error requesting CTS GPIO\n"); 901e9c9d3bbSAndy Shevchenko gpiod_set_consumer_name(sport->cts_gpiod, "CTS"); 902157b9394SAndrei Pistirica 903157b9394SAndrei Pistirica pic32_sports[uart_idx] = sport; 904157b9394SAndrei Pistirica port = &sport->port; 905157b9394SAndrei Pistirica port->iotype = UPIO_MEM; 906157b9394SAndrei Pistirica port->mapbase = res_mem->start; 907157b9394SAndrei Pistirica port->ops = &pic32_uart_ops; 908157b9394SAndrei Pistirica port->flags = UPF_BOOT_AUTOCONF; 909157b9394SAndrei Pistirica port->dev = &pdev->dev; 910157b9394SAndrei Pistirica port->fifosize = PIC32_UART_TX_FIFO_DEPTH; 911157b9394SAndrei Pistirica port->uartclk = clk_get_rate(sport->clk); 912157b9394SAndrei Pistirica port->line = uart_idx; 913157b9394SAndrei Pistirica 914157b9394SAndrei Pistirica ret = uart_add_one_port(&pic32_uart_driver, port); 915157b9394SAndrei Pistirica if (ret) { 916157b9394SAndrei Pistirica port->membase = NULL; 917157b9394SAndrei Pistirica dev_err(port->dev, "%s: uart add port error!\n", __func__); 918157b9394SAndrei Pistirica goto err; 919157b9394SAndrei Pistirica } 920157b9394SAndrei Pistirica 921157b9394SAndrei Pistirica #ifdef CONFIG_SERIAL_PIC32_CONSOLE 922452b9b24SJohn Ogness if (uart_console_registered(port)) { 923157b9394SAndrei Pistirica /* The peripheral clock has been enabled by console_setup, 924157b9394SAndrei Pistirica * so disable it till the port is used. 925157b9394SAndrei Pistirica */ 926bb2cff41SJiri Slaby clk_disable_unprepare(sport->clk); 927157b9394SAndrei Pistirica } 928157b9394SAndrei Pistirica #endif 929157b9394SAndrei Pistirica 930157b9394SAndrei Pistirica platform_set_drvdata(pdev, port); 931157b9394SAndrei Pistirica 932157b9394SAndrei Pistirica dev_info(&pdev->dev, "%s: uart(%d) driver initialized.\n", 933157b9394SAndrei Pistirica __func__, uart_idx); 934157b9394SAndrei Pistirica 935157b9394SAndrei Pistirica return 0; 936157b9394SAndrei Pistirica err: 937157b9394SAndrei Pistirica /* automatic unroll of sport and gpios */ 938157b9394SAndrei Pistirica return ret; 939157b9394SAndrei Pistirica } 940157b9394SAndrei Pistirica 941*915fd7f3SUwe Kleine-König static void pic32_uart_remove(struct platform_device *pdev) 942157b9394SAndrei Pistirica { 943157b9394SAndrei Pistirica struct uart_port *port = platform_get_drvdata(pdev); 944157b9394SAndrei Pistirica struct pic32_sport *sport = to_pic32_sport(port); 945157b9394SAndrei Pistirica 946157b9394SAndrei Pistirica uart_remove_one_port(&pic32_uart_driver, port); 947bb2cff41SJiri Slaby clk_disable_unprepare(sport->clk); 948157b9394SAndrei Pistirica platform_set_drvdata(pdev, NULL); 949157b9394SAndrei Pistirica pic32_sports[sport->idx] = NULL; 950157b9394SAndrei Pistirica } 951157b9394SAndrei Pistirica 952157b9394SAndrei Pistirica static const struct of_device_id pic32_serial_dt_ids[] = { 953157b9394SAndrei Pistirica { .compatible = "microchip,pic32mzda-uart" }, 954157b9394SAndrei Pistirica { /* sentinel */ } 955157b9394SAndrei Pistirica }; 956157b9394SAndrei Pistirica MODULE_DEVICE_TABLE(of, pic32_serial_dt_ids); 957157b9394SAndrei Pistirica 958157b9394SAndrei Pistirica static struct platform_driver pic32_uart_platform_driver = { 959157b9394SAndrei Pistirica .probe = pic32_uart_probe, 960*915fd7f3SUwe Kleine-König .remove_new = pic32_uart_remove, 961157b9394SAndrei Pistirica .driver = { 962157b9394SAndrei Pistirica .name = PIC32_DEV_NAME, 963157b9394SAndrei Pistirica .of_match_table = of_match_ptr(pic32_serial_dt_ids), 96464609794SAnders Roxell .suppress_bind_attrs = IS_BUILTIN(CONFIG_SERIAL_PIC32), 965157b9394SAndrei Pistirica }, 966157b9394SAndrei Pistirica }; 967157b9394SAndrei Pistirica 968157b9394SAndrei Pistirica static int __init pic32_uart_init(void) 969157b9394SAndrei Pistirica { 970157b9394SAndrei Pistirica int ret; 971157b9394SAndrei Pistirica 972157b9394SAndrei Pistirica ret = uart_register_driver(&pic32_uart_driver); 973157b9394SAndrei Pistirica if (ret) { 974157b9394SAndrei Pistirica pr_err("failed to register %s:%d\n", 975157b9394SAndrei Pistirica pic32_uart_driver.driver_name, ret); 976157b9394SAndrei Pistirica return ret; 977157b9394SAndrei Pistirica } 978157b9394SAndrei Pistirica 979157b9394SAndrei Pistirica ret = platform_driver_register(&pic32_uart_platform_driver); 980157b9394SAndrei Pistirica if (ret) { 981157b9394SAndrei Pistirica pr_err("fail to register pic32 uart\n"); 982157b9394SAndrei Pistirica uart_unregister_driver(&pic32_uart_driver); 983157b9394SAndrei Pistirica } 984157b9394SAndrei Pistirica 985157b9394SAndrei Pistirica return ret; 986157b9394SAndrei Pistirica } 987157b9394SAndrei Pistirica arch_initcall(pic32_uart_init); 988157b9394SAndrei Pistirica 989157b9394SAndrei Pistirica static void __exit pic32_uart_exit(void) 990157b9394SAndrei Pistirica { 991157b9394SAndrei Pistirica #ifdef CONFIG_SERIAL_PIC32_CONSOLE 992157b9394SAndrei Pistirica unregister_console(&pic32_console); 993157b9394SAndrei Pistirica #endif 994157b9394SAndrei Pistirica platform_driver_unregister(&pic32_uart_platform_driver); 995157b9394SAndrei Pistirica uart_unregister_driver(&pic32_uart_driver); 996157b9394SAndrei Pistirica } 997157b9394SAndrei Pistirica module_exit(pic32_uart_exit); 998157b9394SAndrei Pistirica 999157b9394SAndrei Pistirica MODULE_AUTHOR("Sorin-Andrei Pistirica <andrei.pistirica@microchip.com>"); 1000157b9394SAndrei Pistirica MODULE_DESCRIPTION("Microchip PIC32 integrated serial port driver"); 1001157b9394SAndrei Pistirica MODULE_LICENSE("GPL v2"); 1002