1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright (C) 2019 Xilinx, Inc.
4 *
5 * Author: Naga Sureshkumar Relli <nagasure@xilinx.com>
6 */
7
8 #include <linux/clk.h>
9 #include <linux/delay.h>
10 #include <linux/interrupt.h>
11 #include <linux/io.h>
12 #include <linux/module.h>
13 #include <linux/of_irq.h>
14 #include <linux/of_address.h>
15 #include <linux/platform_device.h>
16 #include <linux/spi/spi.h>
17 #include <linux/workqueue.h>
18 #include <linux/spi/spi-mem.h>
19
20 /* Register offset definitions */
21 #define ZYNQ_QSPI_CONFIG_OFFSET 0x00 /* Configuration Register, RW */
22 #define ZYNQ_QSPI_STATUS_OFFSET 0x04 /* Interrupt Status Register, RO */
23 #define ZYNQ_QSPI_IEN_OFFSET 0x08 /* Interrupt Enable Register, WO */
24 #define ZYNQ_QSPI_IDIS_OFFSET 0x0C /* Interrupt Disable Reg, WO */
25 #define ZYNQ_QSPI_IMASK_OFFSET 0x10 /* Interrupt Enabled Mask Reg,RO */
26 #define ZYNQ_QSPI_ENABLE_OFFSET 0x14 /* Enable/Disable Register, RW */
27 #define ZYNQ_QSPI_DELAY_OFFSET 0x18 /* Delay Register, RW */
28 #define ZYNQ_QSPI_TXD_00_00_OFFSET 0x1C /* Transmit 4-byte inst, WO */
29 #define ZYNQ_QSPI_TXD_00_01_OFFSET 0x80 /* Transmit 1-byte inst, WO */
30 #define ZYNQ_QSPI_TXD_00_10_OFFSET 0x84 /* Transmit 2-byte inst, WO */
31 #define ZYNQ_QSPI_TXD_00_11_OFFSET 0x88 /* Transmit 3-byte inst, WO */
32 #define ZYNQ_QSPI_RXD_OFFSET 0x20 /* Data Receive Register, RO */
33 #define ZYNQ_QSPI_SIC_OFFSET 0x24 /* Slave Idle Count Register, RW */
34 #define ZYNQ_QSPI_TX_THRESH_OFFSET 0x28 /* TX FIFO Watermark Reg, RW */
35 #define ZYNQ_QSPI_RX_THRESH_OFFSET 0x2C /* RX FIFO Watermark Reg, RW */
36 #define ZYNQ_QSPI_GPIO_OFFSET 0x30 /* GPIO Register, RW */
37 #define ZYNQ_QSPI_LINEAR_CFG_OFFSET 0xA0 /* Linear Adapter Config Ref, RW */
38 #define ZYNQ_QSPI_MOD_ID_OFFSET 0xFC /* Module ID Register, RO */
39
40 /*
41 * QSPI Configuration Register bit Masks
42 *
43 * This register contains various control bits that effect the operation
44 * of the QSPI controller
45 */
46 #define ZYNQ_QSPI_CONFIG_IFMODE_MASK BIT(31) /* Flash Memory Interface */
47 #define ZYNQ_QSPI_CONFIG_MANSRT_MASK BIT(16) /* Manual TX Start */
48 #define ZYNQ_QSPI_CONFIG_MANSRTEN_MASK BIT(15) /* Enable Manual TX Mode */
49 #define ZYNQ_QSPI_CONFIG_SSFORCE_MASK BIT(14) /* Manual Chip Select */
50 #define ZYNQ_QSPI_CONFIG_BDRATE_MASK GENMASK(5, 3) /* Baud Rate Mask */
51 #define ZYNQ_QSPI_CONFIG_CPHA_MASK BIT(2) /* Clock Phase Control */
52 #define ZYNQ_QSPI_CONFIG_CPOL_MASK BIT(1) /* Clock Polarity Control */
53 #define ZYNQ_QSPI_CONFIG_FWIDTH_MASK GENMASK(7, 6) /* FIFO width */
54 #define ZYNQ_QSPI_CONFIG_MSTREN_MASK BIT(0) /* Master Mode */
55
56 /*
57 * QSPI Configuration Register - Baud rate and target select
58 *
59 * These are the values used in the calculation of baud rate divisor and
60 * setting the target select.
61 */
62 #define ZYNQ_QSPI_CONFIG_BAUD_DIV_MAX GENMASK(2, 0) /* Baud rate maximum */
63 #define ZYNQ_QSPI_CONFIG_BAUD_DIV_SHIFT 3 /* Baud rate divisor shift */
64 #define ZYNQ_QSPI_CONFIG_PCS BIT(10) /* Peripheral Chip Select */
65
66 /*
67 * QSPI Interrupt Registers bit Masks
68 *
69 * All the four interrupt registers (Status/Mask/Enable/Disable) have the same
70 * bit definitions.
71 */
72 #define ZYNQ_QSPI_IXR_RX_OVERFLOW_MASK BIT(0) /* QSPI RX FIFO Overflow */
73 #define ZYNQ_QSPI_IXR_TXNFULL_MASK BIT(2) /* QSPI TX FIFO Overflow */
74 #define ZYNQ_QSPI_IXR_TXFULL_MASK BIT(3) /* QSPI TX FIFO is full */
75 #define ZYNQ_QSPI_IXR_RXNEMTY_MASK BIT(4) /* QSPI RX FIFO Not Empty */
76 #define ZYNQ_QSPI_IXR_RXF_FULL_MASK BIT(5) /* QSPI RX FIFO is full */
77 #define ZYNQ_QSPI_IXR_TXF_UNDRFLOW_MASK BIT(6) /* QSPI TX FIFO Underflow */
78 #define ZYNQ_QSPI_IXR_ALL_MASK (ZYNQ_QSPI_IXR_RX_OVERFLOW_MASK | \
79 ZYNQ_QSPI_IXR_TXNFULL_MASK | \
80 ZYNQ_QSPI_IXR_TXFULL_MASK | \
81 ZYNQ_QSPI_IXR_RXNEMTY_MASK | \
82 ZYNQ_QSPI_IXR_RXF_FULL_MASK | \
83 ZYNQ_QSPI_IXR_TXF_UNDRFLOW_MASK)
84 #define ZYNQ_QSPI_IXR_RXTX_MASK (ZYNQ_QSPI_IXR_TXNFULL_MASK | \
85 ZYNQ_QSPI_IXR_RXNEMTY_MASK)
86
87 /*
88 * QSPI Enable Register bit Masks
89 *
90 * This register is used to enable or disable the QSPI controller
91 */
92 #define ZYNQ_QSPI_ENABLE_ENABLE_MASK BIT(0) /* QSPI Enable Bit Mask */
93
94 /*
95 * QSPI Linear Configuration Register
96 *
97 * It is named Linear Configuration but it controls other modes when not in
98 * linear mode also.
99 */
100 #define ZYNQ_QSPI_LCFG_TWO_MEM BIT(30) /* LQSPI Two memories */
101 #define ZYNQ_QSPI_LCFG_SEP_BUS BIT(29) /* LQSPI Separate bus */
102 #define ZYNQ_QSPI_LCFG_U_PAGE BIT(28) /* LQSPI Upper Page */
103
104 #define ZYNQ_QSPI_LCFG_DUMMY_SHIFT 8
105
106 #define ZYNQ_QSPI_FAST_READ_QOUT_CODE 0x6B /* read instruction code */
107 #define ZYNQ_QSPI_FIFO_DEPTH 63 /* FIFO depth in words */
108 #define ZYNQ_QSPI_RX_THRESHOLD 32 /* Rx FIFO threshold level */
109 #define ZYNQ_QSPI_TX_THRESHOLD 1 /* Tx FIFO threshold level */
110
111 /*
112 * The modebits configurable by the driver to make the SPI support different
113 * data formats
114 */
115 #define ZYNQ_QSPI_MODEBITS (SPI_CPOL | SPI_CPHA)
116
117 /* Maximum number of chip selects */
118 #define ZYNQ_QSPI_MAX_NUM_CS 2
119
120 /**
121 * struct zynq_qspi - Defines qspi driver instance
122 * @dev: Pointer to the this device's information
123 * @regs: Virtual address of the QSPI controller registers
124 * @refclk: Pointer to the peripheral clock
125 * @pclk: Pointer to the APB clock
126 * @irq: IRQ number
127 * @txbuf: Pointer to the TX buffer
128 * @rxbuf: Pointer to the RX buffer
129 * @tx_bytes: Number of bytes left to transfer
130 * @rx_bytes: Number of bytes left to receive
131 * @data_completion: completion structure
132 */
133 struct zynq_qspi {
134 struct device *dev;
135 void __iomem *regs;
136 struct clk *refclk;
137 struct clk *pclk;
138 int irq;
139 u8 *txbuf;
140 u8 *rxbuf;
141 int tx_bytes;
142 int rx_bytes;
143 struct completion data_completion;
144 };
145
146 /*
147 * Inline functions for the QSPI controller read/write
148 */
zynq_qspi_read(struct zynq_qspi * xqspi,u32 offset)149 static inline u32 zynq_qspi_read(struct zynq_qspi *xqspi, u32 offset)
150 {
151 return readl_relaxed(xqspi->regs + offset);
152 }
153
zynq_qspi_write(struct zynq_qspi * xqspi,u32 offset,u32 val)154 static inline void zynq_qspi_write(struct zynq_qspi *xqspi, u32 offset,
155 u32 val)
156 {
157 writel_relaxed(val, xqspi->regs + offset);
158 }
159
160 /**
161 * zynq_qspi_init_hw - Initialize the hardware
162 * @xqspi: Pointer to the zynq_qspi structure
163 * @num_cs: Number of connected CS (to enable dual memories if needed)
164 *
165 * The default settings of the QSPI controller's configurable parameters on
166 * reset are
167 * - Host mode
168 * - Baud rate divisor is set to 2
169 * - Tx threshold set to 1l Rx threshold set to 32
170 * - Flash memory interface mode enabled
171 * - Size of the word to be transferred as 8 bit
172 * This function performs the following actions
173 * - Disable and clear all the interrupts
174 * - Enable manual target select
175 * - Enable manual start
176 * - Deselect all the chip select lines
177 * - Set the size of the word to be transferred as 32 bit
178 * - Set the little endian mode of TX FIFO and
179 * - Enable the QSPI controller
180 */
zynq_qspi_init_hw(struct zynq_qspi * xqspi,unsigned int num_cs)181 static void zynq_qspi_init_hw(struct zynq_qspi *xqspi, unsigned int num_cs)
182 {
183 u32 config_reg;
184
185 zynq_qspi_write(xqspi, ZYNQ_QSPI_ENABLE_OFFSET, 0);
186 zynq_qspi_write(xqspi, ZYNQ_QSPI_IDIS_OFFSET, ZYNQ_QSPI_IXR_ALL_MASK);
187
188 /* Disable linear mode as the boot loader may have used it */
189 config_reg = 0;
190 /* At the same time, enable dual mode if more than 1 CS is available */
191 if (num_cs > 1)
192 config_reg |= ZYNQ_QSPI_LCFG_TWO_MEM;
193
194 zynq_qspi_write(xqspi, ZYNQ_QSPI_LINEAR_CFG_OFFSET, config_reg);
195
196 /* Clear the RX FIFO */
197 while (zynq_qspi_read(xqspi, ZYNQ_QSPI_STATUS_OFFSET) &
198 ZYNQ_QSPI_IXR_RXNEMTY_MASK)
199 zynq_qspi_read(xqspi, ZYNQ_QSPI_RXD_OFFSET);
200
201 zynq_qspi_write(xqspi, ZYNQ_QSPI_STATUS_OFFSET, ZYNQ_QSPI_IXR_ALL_MASK);
202 config_reg = zynq_qspi_read(xqspi, ZYNQ_QSPI_CONFIG_OFFSET);
203 config_reg &= ~(ZYNQ_QSPI_CONFIG_MSTREN_MASK |
204 ZYNQ_QSPI_CONFIG_CPOL_MASK |
205 ZYNQ_QSPI_CONFIG_CPHA_MASK |
206 ZYNQ_QSPI_CONFIG_BDRATE_MASK |
207 ZYNQ_QSPI_CONFIG_SSFORCE_MASK |
208 ZYNQ_QSPI_CONFIG_MANSRTEN_MASK |
209 ZYNQ_QSPI_CONFIG_MANSRT_MASK);
210 config_reg |= (ZYNQ_QSPI_CONFIG_MSTREN_MASK |
211 ZYNQ_QSPI_CONFIG_SSFORCE_MASK |
212 ZYNQ_QSPI_CONFIG_FWIDTH_MASK |
213 ZYNQ_QSPI_CONFIG_IFMODE_MASK);
214 zynq_qspi_write(xqspi, ZYNQ_QSPI_CONFIG_OFFSET, config_reg);
215
216 zynq_qspi_write(xqspi, ZYNQ_QSPI_RX_THRESH_OFFSET,
217 ZYNQ_QSPI_RX_THRESHOLD);
218 zynq_qspi_write(xqspi, ZYNQ_QSPI_TX_THRESH_OFFSET,
219 ZYNQ_QSPI_TX_THRESHOLD);
220
221 zynq_qspi_write(xqspi, ZYNQ_QSPI_ENABLE_OFFSET,
222 ZYNQ_QSPI_ENABLE_ENABLE_MASK);
223 }
224
zynq_qspi_supports_op(struct spi_mem * mem,const struct spi_mem_op * op)225 static bool zynq_qspi_supports_op(struct spi_mem *mem,
226 const struct spi_mem_op *op)
227 {
228 if (!spi_mem_default_supports_op(mem, op))
229 return false;
230
231 /*
232 * The number of address bytes should be equal to or less than 3 bytes.
233 */
234 if (op->addr.nbytes > 3)
235 return false;
236
237 return true;
238 }
239
240 /**
241 * zynq_qspi_rxfifo_op - Read 1..4 bytes from RxFIFO to RX buffer
242 * @xqspi: Pointer to the zynq_qspi structure
243 * @size: Number of bytes to be read (1..4)
244 */
zynq_qspi_rxfifo_op(struct zynq_qspi * xqspi,unsigned int size)245 static void zynq_qspi_rxfifo_op(struct zynq_qspi *xqspi, unsigned int size)
246 {
247 u32 data;
248
249 data = zynq_qspi_read(xqspi, ZYNQ_QSPI_RXD_OFFSET);
250
251 if (xqspi->rxbuf) {
252 memcpy(xqspi->rxbuf, ((u8 *)&data) + 4 - size, size);
253 xqspi->rxbuf += size;
254 }
255
256 xqspi->rx_bytes -= size;
257 if (xqspi->rx_bytes < 0)
258 xqspi->rx_bytes = 0;
259 }
260
261 /**
262 * zynq_qspi_txfifo_op - Write 1..4 bytes from TX buffer to TxFIFO
263 * @xqspi: Pointer to the zynq_qspi structure
264 * @size: Number of bytes to be written (1..4)
265 */
zynq_qspi_txfifo_op(struct zynq_qspi * xqspi,unsigned int size)266 static void zynq_qspi_txfifo_op(struct zynq_qspi *xqspi, unsigned int size)
267 {
268 static const unsigned int offset[4] = {
269 ZYNQ_QSPI_TXD_00_01_OFFSET, ZYNQ_QSPI_TXD_00_10_OFFSET,
270 ZYNQ_QSPI_TXD_00_11_OFFSET, ZYNQ_QSPI_TXD_00_00_OFFSET };
271 u32 data;
272
273 if (xqspi->txbuf) {
274 data = 0xffffffff;
275 memcpy(&data, xqspi->txbuf, size);
276 xqspi->txbuf += size;
277 } else {
278 data = 0;
279 }
280
281 xqspi->tx_bytes -= size;
282 zynq_qspi_write(xqspi, offset[size - 1], data);
283 }
284
285 /**
286 * zynq_qspi_chipselect - Select or deselect the chip select line
287 * @spi: Pointer to the spi_device structure
288 * @assert: 1 for select or 0 for deselect the chip select line
289 */
zynq_qspi_chipselect(struct spi_device * spi,bool assert)290 static void zynq_qspi_chipselect(struct spi_device *spi, bool assert)
291 {
292 struct spi_controller *ctlr = spi->controller;
293 struct zynq_qspi *xqspi = spi_controller_get_devdata(ctlr);
294 u32 config_reg;
295
296 /* Select the lower (CS0) or upper (CS1) memory */
297 if (ctlr->num_chipselect > 1) {
298 config_reg = zynq_qspi_read(xqspi, ZYNQ_QSPI_LINEAR_CFG_OFFSET);
299 if (!spi_get_chipselect(spi, 0))
300 config_reg &= ~ZYNQ_QSPI_LCFG_U_PAGE;
301 else
302 config_reg |= ZYNQ_QSPI_LCFG_U_PAGE;
303
304 zynq_qspi_write(xqspi, ZYNQ_QSPI_LINEAR_CFG_OFFSET, config_reg);
305 }
306
307 /* Ground the line to assert the CS */
308 config_reg = zynq_qspi_read(xqspi, ZYNQ_QSPI_CONFIG_OFFSET);
309 if (assert)
310 config_reg &= ~ZYNQ_QSPI_CONFIG_PCS;
311 else
312 config_reg |= ZYNQ_QSPI_CONFIG_PCS;
313
314 zynq_qspi_write(xqspi, ZYNQ_QSPI_CONFIG_OFFSET, config_reg);
315 }
316
317 /**
318 * zynq_qspi_config_op - Configure QSPI controller for specified transfer
319 * @xqspi: Pointer to the zynq_qspi structure
320 * @spi: Pointer to the spi_device structure
321 *
322 * Sets the operational mode of QSPI controller for the next QSPI transfer and
323 * sets the requested clock frequency.
324 *
325 * Return: 0 on success and -EINVAL on invalid input parameter
326 *
327 * Note: If the requested frequency is not an exact match with what can be
328 * obtained using the prescalar value, the driver sets the clock frequency which
329 * is lower than the requested frequency (maximum lower) for the transfer. If
330 * the requested frequency is higher or lower than that is supported by the QSPI
331 * controller the driver will set the highest or lowest frequency supported by
332 * controller.
333 */
zynq_qspi_config_op(struct zynq_qspi * xqspi,struct spi_device * spi)334 static int zynq_qspi_config_op(struct zynq_qspi *xqspi, struct spi_device *spi)
335 {
336 u32 config_reg, baud_rate_val = 0;
337
338 /*
339 * Set the clock frequency
340 * The baud rate divisor is not a direct mapping to the value written
341 * into the configuration register (config_reg[5:3])
342 * i.e. 000 - divide by 2
343 * 001 - divide by 4
344 * ----------------
345 * 111 - divide by 256
346 */
347 while ((baud_rate_val < ZYNQ_QSPI_CONFIG_BAUD_DIV_MAX) &&
348 (clk_get_rate(xqspi->refclk) / (2 << baud_rate_val)) >
349 spi->max_speed_hz)
350 baud_rate_val++;
351
352 config_reg = zynq_qspi_read(xqspi, ZYNQ_QSPI_CONFIG_OFFSET);
353
354 /* Set the QSPI clock phase and clock polarity */
355 config_reg &= (~ZYNQ_QSPI_CONFIG_CPHA_MASK) &
356 (~ZYNQ_QSPI_CONFIG_CPOL_MASK);
357 if (spi->mode & SPI_CPHA)
358 config_reg |= ZYNQ_QSPI_CONFIG_CPHA_MASK;
359 if (spi->mode & SPI_CPOL)
360 config_reg |= ZYNQ_QSPI_CONFIG_CPOL_MASK;
361
362 config_reg &= ~ZYNQ_QSPI_CONFIG_BDRATE_MASK;
363 config_reg |= (baud_rate_val << ZYNQ_QSPI_CONFIG_BAUD_DIV_SHIFT);
364 zynq_qspi_write(xqspi, ZYNQ_QSPI_CONFIG_OFFSET, config_reg);
365
366 return 0;
367 }
368
369 /**
370 * zynq_qspi_setup_op - Configure the QSPI controller
371 * @spi: Pointer to the spi_device structure
372 *
373 * Sets the operational mode of QSPI controller for the next QSPI transfer, baud
374 * rate and divisor value to setup the requested qspi clock.
375 *
376 * Return: 0 on success and error value on failure
377 */
zynq_qspi_setup_op(struct spi_device * spi)378 static int zynq_qspi_setup_op(struct spi_device *spi)
379 {
380 struct spi_controller *ctlr = spi->controller;
381 struct zynq_qspi *qspi = spi_controller_get_devdata(ctlr);
382
383 if (ctlr->busy)
384 return -EBUSY;
385
386 clk_enable(qspi->refclk);
387 clk_enable(qspi->pclk);
388 zynq_qspi_write(qspi, ZYNQ_QSPI_ENABLE_OFFSET,
389 ZYNQ_QSPI_ENABLE_ENABLE_MASK);
390
391 return 0;
392 }
393
394 /**
395 * zynq_qspi_write_op - Fills the TX FIFO with as many bytes as possible
396 * @xqspi: Pointer to the zynq_qspi structure
397 * @txcount: Maximum number of words to write
398 * @txempty: Indicates that TxFIFO is empty
399 */
zynq_qspi_write_op(struct zynq_qspi * xqspi,int txcount,bool txempty)400 static void zynq_qspi_write_op(struct zynq_qspi *xqspi, int txcount,
401 bool txempty)
402 {
403 int count, len, k;
404
405 len = xqspi->tx_bytes;
406 if (len && len < 4) {
407 /*
408 * We must empty the TxFIFO between accesses to TXD0,
409 * TXD1, TXD2, TXD3.
410 */
411 if (txempty)
412 zynq_qspi_txfifo_op(xqspi, len);
413
414 return;
415 }
416
417 count = len / 4;
418 if (count > txcount)
419 count = txcount;
420
421 if (xqspi->txbuf) {
422 iowrite32_rep(xqspi->regs + ZYNQ_QSPI_TXD_00_00_OFFSET,
423 xqspi->txbuf, count);
424 xqspi->txbuf += count * 4;
425 } else {
426 for (k = 0; k < count; k++)
427 writel_relaxed(0, xqspi->regs +
428 ZYNQ_QSPI_TXD_00_00_OFFSET);
429 }
430
431 xqspi->tx_bytes -= count * 4;
432 }
433
434 /**
435 * zynq_qspi_read_op - Drains the RX FIFO by as many bytes as possible
436 * @xqspi: Pointer to the zynq_qspi structure
437 * @rxcount: Maximum number of words to read
438 */
zynq_qspi_read_op(struct zynq_qspi * xqspi,int rxcount)439 static void zynq_qspi_read_op(struct zynq_qspi *xqspi, int rxcount)
440 {
441 int count, len, k;
442
443 len = xqspi->rx_bytes - xqspi->tx_bytes;
444 count = len / 4;
445 if (count > rxcount)
446 count = rxcount;
447 if (xqspi->rxbuf) {
448 ioread32_rep(xqspi->regs + ZYNQ_QSPI_RXD_OFFSET,
449 xqspi->rxbuf, count);
450 xqspi->rxbuf += count * 4;
451 } else {
452 for (k = 0; k < count; k++)
453 readl_relaxed(xqspi->regs + ZYNQ_QSPI_RXD_OFFSET);
454 }
455 xqspi->rx_bytes -= count * 4;
456 len -= count * 4;
457
458 if (len && len < 4 && count < rxcount)
459 zynq_qspi_rxfifo_op(xqspi, len);
460 }
461
462 /**
463 * zynq_qspi_irq - Interrupt service routine of the QSPI controller
464 * @irq: IRQ number
465 * @dev_id: Pointer to the xqspi structure
466 *
467 * This function handles TX empty only.
468 * On TX empty interrupt this function reads the received data from RX FIFO and
469 * fills the TX FIFO if there is any data remaining to be transferred.
470 *
471 * Return: IRQ_HANDLED when interrupt is handled; IRQ_NONE otherwise.
472 */
zynq_qspi_irq(int irq,void * dev_id)473 static irqreturn_t zynq_qspi_irq(int irq, void *dev_id)
474 {
475 u32 intr_status;
476 bool txempty;
477 struct zynq_qspi *xqspi = (struct zynq_qspi *)dev_id;
478
479 intr_status = zynq_qspi_read(xqspi, ZYNQ_QSPI_STATUS_OFFSET);
480 zynq_qspi_write(xqspi, ZYNQ_QSPI_STATUS_OFFSET, intr_status);
481
482 if ((intr_status & ZYNQ_QSPI_IXR_TXNFULL_MASK) ||
483 (intr_status & ZYNQ_QSPI_IXR_RXNEMTY_MASK)) {
484 /*
485 * This bit is set when Tx FIFO has < THRESHOLD entries.
486 * We have the THRESHOLD value set to 1,
487 * so this bit indicates Tx FIFO is empty.
488 */
489 txempty = !!(intr_status & ZYNQ_QSPI_IXR_TXNFULL_MASK);
490 /* Read out the data from the RX FIFO */
491 zynq_qspi_read_op(xqspi, ZYNQ_QSPI_RX_THRESHOLD);
492 if (xqspi->tx_bytes) {
493 /* There is more data to send */
494 zynq_qspi_write_op(xqspi, ZYNQ_QSPI_RX_THRESHOLD,
495 txempty);
496 } else {
497 /*
498 * If transfer and receive is completed then only send
499 * complete signal.
500 */
501 if (!xqspi->rx_bytes) {
502 zynq_qspi_write(xqspi,
503 ZYNQ_QSPI_IDIS_OFFSET,
504 ZYNQ_QSPI_IXR_RXTX_MASK);
505 complete(&xqspi->data_completion);
506 }
507 }
508 return IRQ_HANDLED;
509 }
510
511 return IRQ_NONE;
512 }
513
514 /**
515 * zynq_qspi_exec_mem_op() - Initiates the QSPI transfer
516 * @mem: the SPI memory
517 * @op: the memory operation to execute
518 *
519 * Executes a memory operation.
520 *
521 * This function first selects the chip and starts the memory operation.
522 *
523 * Return: 0 in case of success, a negative error code otherwise.
524 */
zynq_qspi_exec_mem_op(struct spi_mem * mem,const struct spi_mem_op * op)525 static int zynq_qspi_exec_mem_op(struct spi_mem *mem,
526 const struct spi_mem_op *op)
527 {
528 struct zynq_qspi *xqspi = spi_controller_get_devdata(mem->spi->controller);
529 int err = 0, i;
530 u8 *tmpbuf;
531
532 dev_dbg(xqspi->dev, "cmd:%#x mode:%d.%d.%d.%d\n",
533 op->cmd.opcode, op->cmd.buswidth, op->addr.buswidth,
534 op->dummy.buswidth, op->data.buswidth);
535
536 zynq_qspi_chipselect(mem->spi, true);
537 zynq_qspi_config_op(xqspi, mem->spi);
538
539 if (op->cmd.opcode) {
540 reinit_completion(&xqspi->data_completion);
541 xqspi->txbuf = (u8 *)&op->cmd.opcode;
542 xqspi->rxbuf = NULL;
543 xqspi->tx_bytes = op->cmd.nbytes;
544 xqspi->rx_bytes = op->cmd.nbytes;
545 zynq_qspi_write_op(xqspi, ZYNQ_QSPI_FIFO_DEPTH, true);
546 zynq_qspi_write(xqspi, ZYNQ_QSPI_IEN_OFFSET,
547 ZYNQ_QSPI_IXR_RXTX_MASK);
548 if (!wait_for_completion_timeout(&xqspi->data_completion,
549 msecs_to_jiffies(1000)))
550 err = -ETIMEDOUT;
551 }
552
553 if (op->addr.nbytes) {
554 for (i = 0; i < op->addr.nbytes; i++) {
555 xqspi->txbuf[i] = op->addr.val >>
556 (8 * (op->addr.nbytes - i - 1));
557 }
558
559 reinit_completion(&xqspi->data_completion);
560 xqspi->rxbuf = NULL;
561 xqspi->tx_bytes = op->addr.nbytes;
562 xqspi->rx_bytes = op->addr.nbytes;
563 zynq_qspi_write_op(xqspi, ZYNQ_QSPI_FIFO_DEPTH, true);
564 zynq_qspi_write(xqspi, ZYNQ_QSPI_IEN_OFFSET,
565 ZYNQ_QSPI_IXR_RXTX_MASK);
566 if (!wait_for_completion_timeout(&xqspi->data_completion,
567 msecs_to_jiffies(1000)))
568 err = -ETIMEDOUT;
569 }
570
571 if (op->dummy.nbytes) {
572 tmpbuf = kmalloc(op->dummy.nbytes, GFP_KERNEL);
573 if (!tmpbuf)
574 return -ENOMEM;
575
576 memset(tmpbuf, 0xff, op->dummy.nbytes);
577 reinit_completion(&xqspi->data_completion);
578 xqspi->txbuf = tmpbuf;
579 xqspi->rxbuf = NULL;
580 xqspi->tx_bytes = op->dummy.nbytes;
581 xqspi->rx_bytes = op->dummy.nbytes;
582 zynq_qspi_write_op(xqspi, ZYNQ_QSPI_FIFO_DEPTH, true);
583 zynq_qspi_write(xqspi, ZYNQ_QSPI_IEN_OFFSET,
584 ZYNQ_QSPI_IXR_RXTX_MASK);
585 if (!wait_for_completion_timeout(&xqspi->data_completion,
586 msecs_to_jiffies(1000)))
587 err = -ETIMEDOUT;
588
589 kfree(tmpbuf);
590 }
591
592 if (op->data.nbytes) {
593 reinit_completion(&xqspi->data_completion);
594 if (op->data.dir == SPI_MEM_DATA_OUT) {
595 xqspi->txbuf = (u8 *)op->data.buf.out;
596 xqspi->tx_bytes = op->data.nbytes;
597 xqspi->rxbuf = NULL;
598 xqspi->rx_bytes = op->data.nbytes;
599 } else {
600 xqspi->txbuf = NULL;
601 xqspi->rxbuf = (u8 *)op->data.buf.in;
602 xqspi->rx_bytes = op->data.nbytes;
603 xqspi->tx_bytes = op->data.nbytes;
604 }
605
606 zynq_qspi_write_op(xqspi, ZYNQ_QSPI_FIFO_DEPTH, true);
607 zynq_qspi_write(xqspi, ZYNQ_QSPI_IEN_OFFSET,
608 ZYNQ_QSPI_IXR_RXTX_MASK);
609 if (!wait_for_completion_timeout(&xqspi->data_completion,
610 msecs_to_jiffies(1000)))
611 err = -ETIMEDOUT;
612 }
613 zynq_qspi_chipselect(mem->spi, false);
614
615 return err;
616 }
617
618 static const struct spi_controller_mem_ops zynq_qspi_mem_ops = {
619 .supports_op = zynq_qspi_supports_op,
620 .exec_op = zynq_qspi_exec_mem_op,
621 };
622
623 /**
624 * zynq_qspi_probe - Probe method for the QSPI driver
625 * @pdev: Pointer to the platform_device structure
626 *
627 * This function initializes the driver data structures and the hardware.
628 *
629 * Return: 0 on success and error value on failure
630 */
zynq_qspi_probe(struct platform_device * pdev)631 static int zynq_qspi_probe(struct platform_device *pdev)
632 {
633 int ret = 0;
634 struct spi_controller *ctlr;
635 struct device *dev = &pdev->dev;
636 struct device_node *np = dev->of_node;
637 struct zynq_qspi *xqspi;
638 u32 num_cs;
639
640 ctlr = spi_alloc_host(&pdev->dev, sizeof(*xqspi));
641 if (!ctlr)
642 return -ENOMEM;
643
644 xqspi = spi_controller_get_devdata(ctlr);
645 xqspi->dev = dev;
646 platform_set_drvdata(pdev, xqspi);
647 xqspi->regs = devm_platform_ioremap_resource(pdev, 0);
648 if (IS_ERR(xqspi->regs)) {
649 ret = PTR_ERR(xqspi->regs);
650 goto remove_ctlr;
651 }
652
653 xqspi->pclk = devm_clk_get(&pdev->dev, "pclk");
654 if (IS_ERR(xqspi->pclk)) {
655 dev_err(&pdev->dev, "pclk clock not found.\n");
656 ret = PTR_ERR(xqspi->pclk);
657 goto remove_ctlr;
658 }
659
660 init_completion(&xqspi->data_completion);
661
662 xqspi->refclk = devm_clk_get(&pdev->dev, "ref_clk");
663 if (IS_ERR(xqspi->refclk)) {
664 dev_err(&pdev->dev, "ref_clk clock not found.\n");
665 ret = PTR_ERR(xqspi->refclk);
666 goto remove_ctlr;
667 }
668
669 ret = clk_prepare_enable(xqspi->pclk);
670 if (ret) {
671 dev_err(&pdev->dev, "Unable to enable APB clock.\n");
672 goto remove_ctlr;
673 }
674
675 ret = clk_prepare_enable(xqspi->refclk);
676 if (ret) {
677 dev_err(&pdev->dev, "Unable to enable device clock.\n");
678 goto clk_dis_pclk;
679 }
680
681 xqspi->irq = platform_get_irq(pdev, 0);
682 if (xqspi->irq < 0) {
683 ret = xqspi->irq;
684 goto clk_dis_all;
685 }
686 ret = devm_request_irq(&pdev->dev, xqspi->irq, zynq_qspi_irq,
687 0, pdev->name, xqspi);
688 if (ret != 0) {
689 ret = -ENXIO;
690 dev_err(&pdev->dev, "request_irq failed\n");
691 goto clk_dis_all;
692 }
693
694 ret = of_property_read_u32(np, "num-cs",
695 &num_cs);
696 if (ret < 0) {
697 ctlr->num_chipselect = 1;
698 } else if (num_cs > ZYNQ_QSPI_MAX_NUM_CS) {
699 ret = -EINVAL;
700 dev_err(&pdev->dev, "only 2 chip selects are available\n");
701 goto clk_dis_all;
702 } else {
703 ctlr->num_chipselect = num_cs;
704 }
705
706 ctlr->mode_bits = SPI_RX_DUAL | SPI_RX_QUAD |
707 SPI_TX_DUAL | SPI_TX_QUAD;
708 ctlr->mem_ops = &zynq_qspi_mem_ops;
709 ctlr->setup = zynq_qspi_setup_op;
710 ctlr->max_speed_hz = clk_get_rate(xqspi->refclk) / 2;
711 ctlr->dev.of_node = np;
712
713 /* QSPI controller initializations */
714 zynq_qspi_init_hw(xqspi, ctlr->num_chipselect);
715
716 ret = devm_spi_register_controller(&pdev->dev, ctlr);
717 if (ret) {
718 dev_err(&pdev->dev, "devm_spi_register_controller failed\n");
719 goto clk_dis_all;
720 }
721
722 return ret;
723
724 clk_dis_all:
725 clk_disable_unprepare(xqspi->refclk);
726 clk_dis_pclk:
727 clk_disable_unprepare(xqspi->pclk);
728 remove_ctlr:
729 spi_controller_put(ctlr);
730
731 return ret;
732 }
733
734 /**
735 * zynq_qspi_remove - Remove method for the QSPI driver
736 * @pdev: Pointer to the platform_device structure
737 *
738 * This function is called if a device is physically removed from the system or
739 * if the driver module is being unloaded. It frees all resources allocated to
740 * the device.
741 *
742 * Return: 0 on success and error value on failure
743 */
zynq_qspi_remove(struct platform_device * pdev)744 static void zynq_qspi_remove(struct platform_device *pdev)
745 {
746 struct zynq_qspi *xqspi = platform_get_drvdata(pdev);
747
748 zynq_qspi_write(xqspi, ZYNQ_QSPI_ENABLE_OFFSET, 0);
749
750 clk_disable_unprepare(xqspi->refclk);
751 clk_disable_unprepare(xqspi->pclk);
752 }
753
754 static const struct of_device_id zynq_qspi_of_match[] = {
755 { .compatible = "xlnx,zynq-qspi-1.0", },
756 { /* end of table */ }
757 };
758
759 MODULE_DEVICE_TABLE(of, zynq_qspi_of_match);
760
761 /*
762 * zynq_qspi_driver - This structure defines the QSPI platform driver
763 */
764 static struct platform_driver zynq_qspi_driver = {
765 .probe = zynq_qspi_probe,
766 .remove = zynq_qspi_remove,
767 .driver = {
768 .name = "zynq-qspi",
769 .of_match_table = zynq_qspi_of_match,
770 },
771 };
772
773 module_platform_driver(zynq_qspi_driver);
774
775 MODULE_AUTHOR("Xilinx, Inc.");
776 MODULE_DESCRIPTION("Xilinx Zynq QSPI driver");
777 MODULE_LICENSE("GPL");
778