1 /* 2 * Copyright (C) 2013 Aeroflex Gaisler 3 * 4 * This driver supports the APBPS2 PS/2 core available in the GRLIB 5 * VHDL IP core library. 6 * 7 * Full documentation of the APBPS2 core can be found here: 8 * http://www.gaisler.com/products/grlib/grip.pdf 9 * 10 * See "Documentation/devicetree/bindings/input/ps2keyb-mouse-apbps2.txt" for 11 * information on open firmware properties. 12 * 13 * This program is free software; you can redistribute it and/or modify 14 * it under the terms of the GNU General Public License as published by 15 * the Free Software Foundation; either version 2 of the License, or 16 * (at your option) any later version. 17 * 18 * Contributors: Daniel Hellstrom <daniel@gaisler.com> 19 */ 20 #include <linux/platform_device.h> 21 #include <linux/of_device.h> 22 #include <linux/module.h> 23 #include <linux/serio.h> 24 #include <linux/errno.h> 25 #include <linux/interrupt.h> 26 #include <linux/of_irq.h> 27 #include <linux/device.h> 28 #include <linux/delay.h> 29 #include <linux/err.h> 30 #include <linux/slab.h> 31 #include <linux/string.h> 32 #include <linux/kernel.h> 33 #include <linux/io.h> 34 35 struct apbps2_regs { 36 u32 __iomem data; /* 0x00 */ 37 u32 __iomem status; /* 0x04 */ 38 u32 __iomem ctrl; /* 0x08 */ 39 u32 __iomem reload; /* 0x0c */ 40 }; 41 42 #define APBPS2_STATUS_DR (1<<0) 43 #define APBPS2_STATUS_PE (1<<1) 44 #define APBPS2_STATUS_FE (1<<2) 45 #define APBPS2_STATUS_KI (1<<3) 46 #define APBPS2_STATUS_RF (1<<4) 47 #define APBPS2_STATUS_TF (1<<5) 48 #define APBPS2_STATUS_TCNT (0x1f<<22) 49 #define APBPS2_STATUS_RCNT (0x1f<<27) 50 51 #define APBPS2_CTRL_RE (1<<0) 52 #define APBPS2_CTRL_TE (1<<1) 53 #define APBPS2_CTRL_RI (1<<2) 54 #define APBPS2_CTRL_TI (1<<3) 55 56 struct apbps2_priv { 57 struct serio *io; 58 struct apbps2_regs *regs; 59 }; 60 61 static int apbps2_idx; 62 63 static irqreturn_t apbps2_isr(int irq, void *dev_id) 64 { 65 struct apbps2_priv *priv = dev_id; 66 unsigned long status, data, rxflags; 67 irqreturn_t ret = IRQ_NONE; 68 69 while ((status = ioread32be(&priv->regs->status)) & APBPS2_STATUS_DR) { 70 data = ioread32be(&priv->regs->data); 71 rxflags = (status & APBPS2_STATUS_PE) ? SERIO_PARITY : 0; 72 rxflags |= (status & APBPS2_STATUS_FE) ? SERIO_FRAME : 0; 73 74 /* clear error bits? */ 75 if (rxflags) 76 iowrite32be(0, &priv->regs->status); 77 78 serio_interrupt(priv->io, data, rxflags); 79 80 ret = IRQ_HANDLED; 81 } 82 83 return ret; 84 } 85 86 static int apbps2_write(struct serio *io, unsigned char val) 87 { 88 struct apbps2_priv *priv = io->port_data; 89 unsigned int tleft = 10000; /* timeout in 100ms */ 90 91 /* delay until PS/2 controller has room for more chars */ 92 while ((ioread32be(&priv->regs->status) & APBPS2_STATUS_TF) && tleft--) 93 udelay(10); 94 95 if ((ioread32be(&priv->regs->status) & APBPS2_STATUS_TF) == 0) { 96 iowrite32be(val, &priv->regs->data); 97 98 iowrite32be(APBPS2_CTRL_RE | APBPS2_CTRL_RI | APBPS2_CTRL_TE, 99 &priv->regs->ctrl); 100 return 0; 101 } 102 103 return -ETIMEDOUT; 104 } 105 106 static int apbps2_open(struct serio *io) 107 { 108 struct apbps2_priv *priv = io->port_data; 109 int limit; 110 unsigned long tmp; 111 112 /* clear error flags */ 113 iowrite32be(0, &priv->regs->status); 114 115 /* Clear old data if available (unlikely) */ 116 limit = 1024; 117 while ((ioread32be(&priv->regs->status) & APBPS2_STATUS_DR) && --limit) 118 tmp = ioread32be(&priv->regs->data); 119 120 /* Enable reciever and it's interrupt */ 121 iowrite32be(APBPS2_CTRL_RE | APBPS2_CTRL_RI, &priv->regs->ctrl); 122 123 return 0; 124 } 125 126 static void apbps2_close(struct serio *io) 127 { 128 struct apbps2_priv *priv = io->port_data; 129 130 /* stop interrupts at PS/2 HW level */ 131 iowrite32be(0, &priv->regs->ctrl); 132 } 133 134 /* Initialize one APBPS2 PS/2 core */ 135 static int apbps2_of_probe(struct platform_device *ofdev) 136 { 137 struct apbps2_priv *priv; 138 int irq, err; 139 u32 freq_hz; 140 struct resource *res; 141 142 priv = devm_kzalloc(&ofdev->dev, sizeof(*priv), GFP_KERNEL); 143 if (!priv) { 144 dev_err(&ofdev->dev, "memory allocation failed\n"); 145 return -ENOMEM; 146 } 147 148 /* Find Device Address */ 149 res = platform_get_resource(ofdev, IORESOURCE_MEM, 0); 150 priv->regs = devm_ioremap_resource(&ofdev->dev, res); 151 if (IS_ERR(priv->regs)) 152 return PTR_ERR(priv->regs); 153 154 /* Reset hardware, disable interrupt */ 155 iowrite32be(0, &priv->regs->ctrl); 156 157 /* IRQ */ 158 irq = irq_of_parse_and_map(ofdev->dev.of_node, 0); 159 err = devm_request_irq(&ofdev->dev, irq, apbps2_isr, 160 IRQF_SHARED, "apbps2", priv); 161 if (err) { 162 dev_err(&ofdev->dev, "request IRQ%d failed\n", irq); 163 return err; 164 } 165 166 /* Get core frequency */ 167 if (of_property_read_u32(ofdev->dev.of_node, "freq", &freq_hz)) { 168 dev_err(&ofdev->dev, "unable to get core frequency\n"); 169 return -EINVAL; 170 } 171 172 /* Set reload register to core freq in kHz/10 */ 173 iowrite32be(freq_hz / 10000, &priv->regs->reload); 174 175 priv->io = kzalloc(sizeof(struct serio), GFP_KERNEL); 176 if (!priv->io) 177 return -ENOMEM; 178 179 priv->io->id.type = SERIO_8042; 180 priv->io->open = apbps2_open; 181 priv->io->close = apbps2_close; 182 priv->io->write = apbps2_write; 183 priv->io->port_data = priv; 184 strlcpy(priv->io->name, "APBPS2 PS/2", sizeof(priv->io->name)); 185 snprintf(priv->io->phys, sizeof(priv->io->phys), 186 "apbps2_%d", apbps2_idx++); 187 188 dev_info(&ofdev->dev, "irq = %d, base = 0x%p\n", irq, priv->regs); 189 190 serio_register_port(priv->io); 191 192 platform_set_drvdata(ofdev, priv); 193 194 return 0; 195 } 196 197 static int apbps2_of_remove(struct platform_device *of_dev) 198 { 199 struct apbps2_priv *priv = platform_get_drvdata(of_dev); 200 201 serio_unregister_port(priv->io); 202 203 return 0; 204 } 205 206 static const struct of_device_id apbps2_of_match[] = { 207 { .name = "GAISLER_APBPS2", }, 208 { .name = "01_060", }, 209 {} 210 }; 211 212 MODULE_DEVICE_TABLE(of, apbps2_of_match); 213 214 static struct platform_driver apbps2_of_driver = { 215 .driver = { 216 .name = "grlib-apbps2", 217 .of_match_table = apbps2_of_match, 218 }, 219 .probe = apbps2_of_probe, 220 .remove = apbps2_of_remove, 221 }; 222 223 module_platform_driver(apbps2_of_driver); 224 225 MODULE_AUTHOR("Aeroflex Gaisler AB."); 226 MODULE_DESCRIPTION("GRLIB APBPS2 PS/2 serial I/O"); 227 MODULE_LICENSE("GPL"); 228