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c474b386 HK |
1 | /* |
2 | * Cadence SPI controller driver (master mode only) | |
3 | * | |
4 | * Copyright (C) 2008 - 2014 Xilinx, Inc. | |
5 | * | |
6 | * based on Blackfin On-Chip SPI Driver (spi_bfin5xx.c) | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify it under | |
9 | * the terms of the GNU General Public License version 2 as published by the | |
10 | * Free Software Foundation; either version 2 of the License, or (at your | |
11 | * option) any later version. | |
12 | */ | |
13 | ||
14 | #include <linux/clk.h> | |
15 | #include <linux/delay.h> | |
16 | #include <linux/interrupt.h> | |
17 | #include <linux/io.h> | |
18 | #include <linux/module.h> | |
19 | #include <linux/of_irq.h> | |
20 | #include <linux/of_address.h> | |
21 | #include <linux/platform_device.h> | |
22 | #include <linux/spi/spi.h> | |
23 | ||
24 | /* Name of this driver */ | |
25 | #define CDNS_SPI_NAME "cdns-spi" | |
26 | ||
27 | /* Register offset definitions */ | |
24746675 SD |
28 | #define CDNS_SPI_CR 0x00 /* Configuration Register, RW */ |
29 | #define CDNS_SPI_ISR 0x04 /* Interrupt Status Register, RO */ | |
30 | #define CDNS_SPI_IER 0x08 /* Interrupt Enable Register, WO */ | |
31 | #define CDNS_SPI_IDR 0x0c /* Interrupt Disable Register, WO */ | |
32 | #define CDNS_SPI_IMR 0x10 /* Interrupt Enabled Mask Register, RO */ | |
33 | #define CDNS_SPI_ER 0x14 /* Enable/Disable Register, RW */ | |
34 | #define CDNS_SPI_DR 0x18 /* Delay Register, RW */ | |
35 | #define CDNS_SPI_TXD 0x1C /* Data Transmit Register, WO */ | |
36 | #define CDNS_SPI_RXD 0x20 /* Data Receive Register, RO */ | |
37 | #define CDNS_SPI_SICR 0x24 /* Slave Idle Count Register, RW */ | |
38 | #define CDNS_SPI_THLD 0x28 /* Transmit FIFO Watermark Register,RW */ | |
c474b386 HK |
39 | |
40 | /* | |
41 | * SPI Configuration Register bit Masks | |
42 | * | |
43 | * This register contains various control bits that affect the operation | |
44 | * of the SPI controller | |
45 | */ | |
24746675 SD |
46 | #define CDNS_SPI_CR_MANSTRT 0x00010000 /* Manual TX Start */ |
47 | #define CDNS_SPI_CR_CPHA 0x00000004 /* Clock Phase Control */ | |
48 | #define CDNS_SPI_CR_CPOL 0x00000002 /* Clock Polarity Control */ | |
49 | #define CDNS_SPI_CR_SSCTRL 0x00003C00 /* Slave Select Mask */ | |
50 | #define CDNS_SPI_CR_PERI_SEL 0x00000200 /* Peripheral Select Decode */ | |
51 | #define CDNS_SPI_CR_BAUD_DIV 0x00000038 /* Baud Rate Divisor Mask */ | |
52 | #define CDNS_SPI_CR_MSTREN 0x00000001 /* Master Enable Mask */ | |
53 | #define CDNS_SPI_CR_MANSTRTEN 0x00008000 /* Manual TX Enable Mask */ | |
54 | #define CDNS_SPI_CR_SSFORCE 0x00004000 /* Manual SS Enable Mask */ | |
55 | #define CDNS_SPI_CR_BAUD_DIV_4 0x00000008 /* Default Baud Div Mask */ | |
56 | #define CDNS_SPI_CR_DEFAULT (CDNS_SPI_CR_MSTREN | \ | |
57 | CDNS_SPI_CR_SSCTRL | \ | |
58 | CDNS_SPI_CR_SSFORCE | \ | |
59 | CDNS_SPI_CR_BAUD_DIV_4) | |
c474b386 HK |
60 | |
61 | /* | |
62 | * SPI Configuration Register - Baud rate and slave select | |
63 | * | |
64 | * These are the values used in the calculation of baud rate divisor and | |
65 | * setting the slave select. | |
66 | */ | |
67 | ||
68 | #define CDNS_SPI_BAUD_DIV_MAX 7 /* Baud rate divisor maximum */ | |
69 | #define CDNS_SPI_BAUD_DIV_MIN 1 /* Baud rate divisor minimum */ | |
70 | #define CDNS_SPI_BAUD_DIV_SHIFT 3 /* Baud rate divisor shift in CR */ | |
71 | #define CDNS_SPI_SS_SHIFT 10 /* Slave Select field shift in CR */ | |
72 | #define CDNS_SPI_SS0 0x1 /* Slave Select zero */ | |
73 | ||
74 | /* | |
75 | * SPI Interrupt Registers bit Masks | |
76 | * | |
77 | * All the four interrupt registers (Status/Mask/Enable/Disable) have the same | |
78 | * bit definitions. | |
79 | */ | |
24746675 SD |
80 | #define CDNS_SPI_IXR_TXOW 0x00000004 /* SPI TX FIFO Overwater */ |
81 | #define CDNS_SPI_IXR_MODF 0x00000002 /* SPI Mode Fault */ | |
82 | #define CDNS_SPI_IXR_RXNEMTY 0x00000010 /* SPI RX FIFO Not Empty */ | |
83 | #define CDNS_SPI_IXR_DEFAULT (CDNS_SPI_IXR_TXOW | \ | |
84 | CDNS_SPI_IXR_MODF) | |
85 | #define CDNS_SPI_IXR_TXFULL 0x00000008 /* SPI TX Full */ | |
86 | #define CDNS_SPI_IXR_ALL 0x0000007F /* SPI all interrupts */ | |
c474b386 HK |
87 | |
88 | /* | |
89 | * SPI Enable Register bit Masks | |
90 | * | |
91 | * This register is used to enable or disable the SPI controller | |
92 | */ | |
24746675 SD |
93 | #define CDNS_SPI_ER_ENABLE 0x00000001 /* SPI Enable Bit Mask */ |
94 | #define CDNS_SPI_ER_DISABLE 0x0 /* SPI Disable Bit Mask */ | |
c474b386 HK |
95 | |
96 | /* SPI FIFO depth in bytes */ | |
97 | #define CDNS_SPI_FIFO_DEPTH 128 | |
98 | ||
99 | /* Default number of chip select lines */ | |
100 | #define CDNS_SPI_DEFAULT_NUM_CS 4 | |
101 | ||
102 | /** | |
103 | * struct cdns_spi - This definition defines spi driver instance | |
104 | * @regs: Virtual address of the SPI controller registers | |
105 | * @ref_clk: Pointer to the peripheral clock | |
106 | * @pclk: Pointer to the APB clock | |
107 | * @speed_hz: Current SPI bus clock speed in Hz | |
108 | * @txbuf: Pointer to the TX buffer | |
109 | * @rxbuf: Pointer to the RX buffer | |
110 | * @tx_bytes: Number of bytes left to transfer | |
111 | * @rx_bytes: Number of bytes requested | |
112 | * @dev_busy: Device busy flag | |
113 | * @is_decoded_cs: Flag for decoder property set or not | |
114 | */ | |
115 | struct cdns_spi { | |
116 | void __iomem *regs; | |
117 | struct clk *ref_clk; | |
118 | struct clk *pclk; | |
119 | u32 speed_hz; | |
120 | const u8 *txbuf; | |
121 | u8 *rxbuf; | |
122 | int tx_bytes; | |
123 | int rx_bytes; | |
124 | u8 dev_busy; | |
125 | u32 is_decoded_cs; | |
126 | }; | |
127 | ||
128 | /* Macros for the SPI controller read/write */ | |
129 | static inline u32 cdns_spi_read(struct cdns_spi *xspi, u32 offset) | |
130 | { | |
131 | return readl_relaxed(xspi->regs + offset); | |
132 | } | |
133 | ||
134 | static inline void cdns_spi_write(struct cdns_spi *xspi, u32 offset, u32 val) | |
135 | { | |
136 | writel_relaxed(val, xspi->regs + offset); | |
137 | } | |
138 | ||
139 | /** | |
140 | * cdns_spi_init_hw - Initialize the hardware and configure the SPI controller | |
141 | * @xspi: Pointer to the cdns_spi structure | |
142 | * | |
143 | * On reset the SPI controller is configured to be in master mode, baud rate | |
144 | * divisor is set to 4, threshold value for TX FIFO not full interrupt is set | |
145 | * to 1 and size of the word to be transferred as 8 bit. | |
146 | * This function initializes the SPI controller to disable and clear all the | |
147 | * interrupts, enable manual slave select and manual start, deselect all the | |
148 | * chip select lines, and enable the SPI controller. | |
149 | */ | |
150 | static void cdns_spi_init_hw(struct cdns_spi *xspi) | |
151 | { | |
24746675 | 152 | u32 ctrl_reg = CDNS_SPI_CR_DEFAULT; |
ee0ebe81 LPC |
153 | |
154 | if (xspi->is_decoded_cs) | |
24746675 | 155 | ctrl_reg |= CDNS_SPI_CR_PERI_SEL; |
ee0ebe81 | 156 | |
24746675 SD |
157 | cdns_spi_write(xspi, CDNS_SPI_ER, CDNS_SPI_ER_DISABLE); |
158 | cdns_spi_write(xspi, CDNS_SPI_IDR, CDNS_SPI_IXR_ALL); | |
c474b386 HK |
159 | |
160 | /* Clear the RX FIFO */ | |
24746675 SD |
161 | while (cdns_spi_read(xspi, CDNS_SPI_ISR) & CDNS_SPI_IXR_RXNEMTY) |
162 | cdns_spi_read(xspi, CDNS_SPI_RXD); | |
163 | ||
164 | cdns_spi_write(xspi, CDNS_SPI_ISR, CDNS_SPI_IXR_ALL); | |
165 | cdns_spi_write(xspi, CDNS_SPI_CR, ctrl_reg); | |
166 | cdns_spi_write(xspi, CDNS_SPI_ER, CDNS_SPI_ER_ENABLE); | |
c474b386 HK |
167 | } |
168 | ||
169 | /** | |
170 | * cdns_spi_chipselect - Select or deselect the chip select line | |
171 | * @spi: Pointer to the spi_device structure | |
172 | * @is_on: Select(0) or deselect (1) the chip select line | |
173 | */ | |
174 | static void cdns_spi_chipselect(struct spi_device *spi, bool is_high) | |
175 | { | |
176 | struct cdns_spi *xspi = spi_master_get_devdata(spi->master); | |
177 | u32 ctrl_reg; | |
178 | ||
24746675 | 179 | ctrl_reg = cdns_spi_read(xspi, CDNS_SPI_CR); |
c474b386 HK |
180 | |
181 | if (is_high) { | |
182 | /* Deselect the slave */ | |
24746675 | 183 | ctrl_reg |= CDNS_SPI_CR_SSCTRL; |
c474b386 HK |
184 | } else { |
185 | /* Select the slave */ | |
24746675 | 186 | ctrl_reg &= ~CDNS_SPI_CR_SSCTRL; |
c474b386 HK |
187 | if (!(xspi->is_decoded_cs)) |
188 | ctrl_reg |= ((~(CDNS_SPI_SS0 << spi->chip_select)) << | |
189 | CDNS_SPI_SS_SHIFT) & | |
24746675 | 190 | CDNS_SPI_CR_SSCTRL; |
c474b386 HK |
191 | else |
192 | ctrl_reg |= (spi->chip_select << CDNS_SPI_SS_SHIFT) & | |
24746675 | 193 | CDNS_SPI_CR_SSCTRL; |
c474b386 HK |
194 | } |
195 | ||
24746675 | 196 | cdns_spi_write(xspi, CDNS_SPI_CR, ctrl_reg); |
c474b386 HK |
197 | } |
198 | ||
199 | /** | |
200 | * cdns_spi_config_clock_mode - Sets clock polarity and phase | |
201 | * @spi: Pointer to the spi_device structure | |
202 | * | |
203 | * Sets the requested clock polarity and phase. | |
204 | */ | |
205 | static void cdns_spi_config_clock_mode(struct spi_device *spi) | |
206 | { | |
207 | struct cdns_spi *xspi = spi_master_get_devdata(spi->master); | |
a39e65e9 | 208 | u32 ctrl_reg, new_ctrl_reg; |
c474b386 | 209 | |
24746675 | 210 | new_ctrl_reg = ctrl_reg = cdns_spi_read(xspi, CDNS_SPI_CR); |
c474b386 HK |
211 | |
212 | /* Set the SPI clock phase and clock polarity */ | |
24746675 | 213 | new_ctrl_reg &= ~(CDNS_SPI_CR_CPHA | CDNS_SPI_CR_CPOL); |
c474b386 | 214 | if (spi->mode & SPI_CPHA) |
24746675 | 215 | new_ctrl_reg |= CDNS_SPI_CR_CPHA; |
c474b386 | 216 | if (spi->mode & SPI_CPOL) |
24746675 | 217 | new_ctrl_reg |= CDNS_SPI_CR_CPOL; |
a39e65e9 LPC |
218 | |
219 | if (new_ctrl_reg != ctrl_reg) { | |
220 | /* | |
221 | * Just writing the CR register does not seem to apply the clock | |
222 | * setting changes. This is problematic when changing the clock | |
223 | * polarity as it will cause the SPI slave to see spurious clock | |
224 | * transitions. To workaround the issue toggle the ER register. | |
225 | */ | |
24746675 SD |
226 | cdns_spi_write(xspi, CDNS_SPI_ER, CDNS_SPI_ER_DISABLE); |
227 | cdns_spi_write(xspi, CDNS_SPI_CR, new_ctrl_reg); | |
228 | cdns_spi_write(xspi, CDNS_SPI_ER, CDNS_SPI_ER_ENABLE); | |
a39e65e9 | 229 | } |
c474b386 HK |
230 | } |
231 | ||
232 | /** | |
233 | * cdns_spi_config_clock_freq - Sets clock frequency | |
234 | * @spi: Pointer to the spi_device structure | |
235 | * @transfer: Pointer to the spi_transfer structure which provides | |
236 | * information about next transfer setup parameters | |
237 | * | |
238 | * Sets the requested clock frequency. | |
239 | * Note: If the requested frequency is not an exact match with what can be | |
240 | * obtained using the prescalar value the driver sets the clock frequency which | |
241 | * is lower than the requested frequency (maximum lower) for the transfer. If | |
242 | * the requested frequency is higher or lower than that is supported by the SPI | |
243 | * controller the driver will set the highest or lowest frequency supported by | |
244 | * controller. | |
245 | */ | |
246 | static void cdns_spi_config_clock_freq(struct spi_device *spi, | |
247 | struct spi_transfer *transfer) | |
248 | { | |
249 | struct cdns_spi *xspi = spi_master_get_devdata(spi->master); | |
250 | u32 ctrl_reg, baud_rate_val; | |
251 | unsigned long frequency; | |
252 | ||
253 | frequency = clk_get_rate(xspi->ref_clk); | |
254 | ||
24746675 | 255 | ctrl_reg = cdns_spi_read(xspi, CDNS_SPI_CR); |
c474b386 HK |
256 | |
257 | /* Set the clock frequency */ | |
258 | if (xspi->speed_hz != transfer->speed_hz) { | |
259 | /* first valid value is 1 */ | |
260 | baud_rate_val = CDNS_SPI_BAUD_DIV_MIN; | |
261 | while ((baud_rate_val < CDNS_SPI_BAUD_DIV_MAX) && | |
262 | (frequency / (2 << baud_rate_val)) > transfer->speed_hz) | |
263 | baud_rate_val++; | |
264 | ||
24746675 | 265 | ctrl_reg &= ~CDNS_SPI_CR_BAUD_DIV; |
c474b386 HK |
266 | ctrl_reg |= baud_rate_val << CDNS_SPI_BAUD_DIV_SHIFT; |
267 | ||
268 | xspi->speed_hz = frequency / (2 << baud_rate_val); | |
269 | } | |
24746675 | 270 | cdns_spi_write(xspi, CDNS_SPI_CR, ctrl_reg); |
c474b386 HK |
271 | } |
272 | ||
273 | /** | |
274 | * cdns_spi_setup_transfer - Configure SPI controller for specified transfer | |
275 | * @spi: Pointer to the spi_device structure | |
276 | * @transfer: Pointer to the spi_transfer structure which provides | |
277 | * information about next transfer setup parameters | |
278 | * | |
279 | * Sets the operational mode of SPI controller for the next SPI transfer and | |
280 | * sets the requested clock frequency. | |
281 | * | |
282 | * Return: Always 0 | |
283 | */ | |
284 | static int cdns_spi_setup_transfer(struct spi_device *spi, | |
285 | struct spi_transfer *transfer) | |
286 | { | |
287 | struct cdns_spi *xspi = spi_master_get_devdata(spi->master); | |
288 | ||
289 | cdns_spi_config_clock_freq(spi, transfer); | |
290 | ||
291 | dev_dbg(&spi->dev, "%s, mode %d, %u bits/w, %u clock speed\n", | |
292 | __func__, spi->mode, spi->bits_per_word, | |
293 | xspi->speed_hz); | |
294 | ||
295 | return 0; | |
296 | } | |
297 | ||
298 | /** | |
299 | * cdns_spi_fill_tx_fifo - Fills the TX FIFO with as many bytes as possible | |
300 | * @xspi: Pointer to the cdns_spi structure | |
301 | */ | |
302 | static void cdns_spi_fill_tx_fifo(struct cdns_spi *xspi) | |
303 | { | |
304 | unsigned long trans_cnt = 0; | |
305 | ||
306 | while ((trans_cnt < CDNS_SPI_FIFO_DEPTH) && | |
307 | (xspi->tx_bytes > 0)) { | |
308 | if (xspi->txbuf) | |
24746675 | 309 | cdns_spi_write(xspi, CDNS_SPI_TXD, *xspi->txbuf++); |
c474b386 | 310 | else |
24746675 | 311 | cdns_spi_write(xspi, CDNS_SPI_TXD, 0); |
c474b386 HK |
312 | |
313 | xspi->tx_bytes--; | |
314 | trans_cnt++; | |
315 | } | |
316 | } | |
317 | ||
318 | /** | |
319 | * cdns_spi_irq - Interrupt service routine of the SPI controller | |
320 | * @irq: IRQ number | |
321 | * @dev_id: Pointer to the xspi structure | |
322 | * | |
323 | * This function handles TX empty and Mode Fault interrupts only. | |
324 | * On TX empty interrupt this function reads the received data from RX FIFO and | |
325 | * fills the TX FIFO if there is any data remaining to be transferred. | |
326 | * On Mode Fault interrupt this function indicates that transfer is completed, | |
327 | * the SPI subsystem will identify the error as the remaining bytes to be | |
328 | * transferred is non-zero. | |
329 | * | |
330 | * Return: IRQ_HANDLED when handled; IRQ_NONE otherwise. | |
331 | */ | |
332 | static irqreturn_t cdns_spi_irq(int irq, void *dev_id) | |
333 | { | |
334 | struct spi_master *master = dev_id; | |
335 | struct cdns_spi *xspi = spi_master_get_devdata(master); | |
336 | u32 intr_status, status; | |
337 | ||
338 | status = IRQ_NONE; | |
24746675 SD |
339 | intr_status = cdns_spi_read(xspi, CDNS_SPI_ISR); |
340 | cdns_spi_write(xspi, CDNS_SPI_ISR, intr_status); | |
c474b386 | 341 | |
24746675 | 342 | if (intr_status & CDNS_SPI_IXR_MODF) { |
c474b386 HK |
343 | /* Indicate that transfer is completed, the SPI subsystem will |
344 | * identify the error as the remaining bytes to be | |
345 | * transferred is non-zero | |
346 | */ | |
24746675 | 347 | cdns_spi_write(xspi, CDNS_SPI_IDR, CDNS_SPI_IXR_DEFAULT); |
c474b386 HK |
348 | spi_finalize_current_transfer(master); |
349 | status = IRQ_HANDLED; | |
24746675 | 350 | } else if (intr_status & CDNS_SPI_IXR_TXOW) { |
c474b386 HK |
351 | unsigned long trans_cnt; |
352 | ||
353 | trans_cnt = xspi->rx_bytes - xspi->tx_bytes; | |
354 | ||
355 | /* Read out the data from the RX FIFO */ | |
356 | while (trans_cnt) { | |
357 | u8 data; | |
358 | ||
24746675 | 359 | data = cdns_spi_read(xspi, CDNS_SPI_RXD); |
c474b386 HK |
360 | if (xspi->rxbuf) |
361 | *xspi->rxbuf++ = data; | |
362 | ||
363 | xspi->rx_bytes--; | |
364 | trans_cnt--; | |
365 | } | |
366 | ||
367 | if (xspi->tx_bytes) { | |
368 | /* There is more data to send */ | |
369 | cdns_spi_fill_tx_fifo(xspi); | |
370 | } else { | |
371 | /* Transfer is completed */ | |
24746675 SD |
372 | cdns_spi_write(xspi, CDNS_SPI_IDR, |
373 | CDNS_SPI_IXR_DEFAULT); | |
c474b386 HK |
374 | spi_finalize_current_transfer(master); |
375 | } | |
376 | status = IRQ_HANDLED; | |
377 | } | |
378 | ||
379 | return status; | |
380 | } | |
b48b9488 LPC |
381 | static int cdns_prepare_message(struct spi_master *master, |
382 | struct spi_message *msg) | |
383 | { | |
384 | cdns_spi_config_clock_mode(msg->spi); | |
385 | return 0; | |
386 | } | |
c474b386 HK |
387 | |
388 | /** | |
389 | * cdns_transfer_one - Initiates the SPI transfer | |
390 | * @master: Pointer to spi_master structure | |
391 | * @spi: Pointer to the spi_device structure | |
392 | * @transfer: Pointer to the spi_transfer structure which provides | |
393 | * information about next transfer parameters | |
394 | * | |
395 | * This function fills the TX FIFO, starts the SPI transfer and | |
396 | * returns a positive transfer count so that core will wait for completion. | |
397 | * | |
398 | * Return: Number of bytes transferred in the last transfer | |
399 | */ | |
400 | static int cdns_transfer_one(struct spi_master *master, | |
401 | struct spi_device *spi, | |
402 | struct spi_transfer *transfer) | |
403 | { | |
404 | struct cdns_spi *xspi = spi_master_get_devdata(master); | |
405 | ||
406 | xspi->txbuf = transfer->tx_buf; | |
407 | xspi->rxbuf = transfer->rx_buf; | |
408 | xspi->tx_bytes = transfer->len; | |
409 | xspi->rx_bytes = transfer->len; | |
410 | ||
411 | cdns_spi_setup_transfer(spi, transfer); | |
412 | ||
413 | cdns_spi_fill_tx_fifo(xspi); | |
414 | ||
24746675 | 415 | cdns_spi_write(xspi, CDNS_SPI_IER, CDNS_SPI_IXR_DEFAULT); |
c474b386 HK |
416 | return transfer->len; |
417 | } | |
418 | ||
419 | /** | |
420 | * cdns_prepare_transfer_hardware - Prepares hardware for transfer. | |
421 | * @master: Pointer to the spi_master structure which provides | |
422 | * information about the controller. | |
423 | * | |
424 | * This function enables SPI master controller. | |
425 | * | |
426 | * Return: 0 always | |
427 | */ | |
428 | static int cdns_prepare_transfer_hardware(struct spi_master *master) | |
429 | { | |
430 | struct cdns_spi *xspi = spi_master_get_devdata(master); | |
431 | ||
24746675 | 432 | cdns_spi_write(xspi, CDNS_SPI_ER, CDNS_SPI_ER_ENABLE); |
c474b386 HK |
433 | |
434 | return 0; | |
435 | } | |
436 | ||
437 | /** | |
438 | * cdns_unprepare_transfer_hardware - Relaxes hardware after transfer | |
439 | * @master: Pointer to the spi_master structure which provides | |
440 | * information about the controller. | |
441 | * | |
442 | * This function disables the SPI master controller. | |
443 | * | |
444 | * Return: 0 always | |
445 | */ | |
446 | static int cdns_unprepare_transfer_hardware(struct spi_master *master) | |
447 | { | |
448 | struct cdns_spi *xspi = spi_master_get_devdata(master); | |
449 | ||
24746675 | 450 | cdns_spi_write(xspi, CDNS_SPI_ER, CDNS_SPI_ER_DISABLE); |
c474b386 HK |
451 | |
452 | return 0; | |
453 | } | |
454 | ||
455 | /** | |
456 | * cdns_spi_probe - Probe method for the SPI driver | |
457 | * @pdev: Pointer to the platform_device structure | |
458 | * | |
459 | * This function initializes the driver data structures and the hardware. | |
460 | * | |
461 | * Return: 0 on success and error value on error | |
462 | */ | |
463 | static int cdns_spi_probe(struct platform_device *pdev) | |
464 | { | |
465 | int ret = 0, irq; | |
466 | struct spi_master *master; | |
467 | struct cdns_spi *xspi; | |
468 | struct resource *res; | |
469 | u32 num_cs; | |
470 | ||
471 | master = spi_alloc_master(&pdev->dev, sizeof(*xspi)); | |
15a1c503 | 472 | if (!master) |
c474b386 HK |
473 | return -ENOMEM; |
474 | ||
475 | xspi = spi_master_get_devdata(master); | |
476 | master->dev.of_node = pdev->dev.of_node; | |
477 | platform_set_drvdata(pdev, master); | |
478 | ||
479 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
480 | xspi->regs = devm_ioremap_resource(&pdev->dev, res); | |
481 | if (IS_ERR(xspi->regs)) { | |
482 | ret = PTR_ERR(xspi->regs); | |
483 | goto remove_master; | |
484 | } | |
485 | ||
486 | xspi->pclk = devm_clk_get(&pdev->dev, "pclk"); | |
487 | if (IS_ERR(xspi->pclk)) { | |
488 | dev_err(&pdev->dev, "pclk clock not found.\n"); | |
489 | ret = PTR_ERR(xspi->pclk); | |
490 | goto remove_master; | |
491 | } | |
492 | ||
493 | xspi->ref_clk = devm_clk_get(&pdev->dev, "ref_clk"); | |
494 | if (IS_ERR(xspi->ref_clk)) { | |
495 | dev_err(&pdev->dev, "ref_clk clock not found.\n"); | |
496 | ret = PTR_ERR(xspi->ref_clk); | |
497 | goto remove_master; | |
498 | } | |
499 | ||
500 | ret = clk_prepare_enable(xspi->pclk); | |
501 | if (ret) { | |
502 | dev_err(&pdev->dev, "Unable to enable APB clock.\n"); | |
503 | goto remove_master; | |
504 | } | |
505 | ||
506 | ret = clk_prepare_enable(xspi->ref_clk); | |
507 | if (ret) { | |
508 | dev_err(&pdev->dev, "Unable to enable device clock.\n"); | |
509 | goto clk_dis_apb; | |
510 | } | |
511 | ||
3cc29106 PC |
512 | ret = of_property_read_u32(pdev->dev.of_node, "num-cs", &num_cs); |
513 | if (ret < 0) | |
514 | master->num_chipselect = CDNS_SPI_DEFAULT_NUM_CS; | |
515 | else | |
516 | master->num_chipselect = num_cs; | |
517 | ||
518 | ret = of_property_read_u32(pdev->dev.of_node, "is-decoded-cs", | |
519 | &xspi->is_decoded_cs); | |
520 | if (ret < 0) | |
521 | xspi->is_decoded_cs = 0; | |
522 | ||
c474b386 HK |
523 | /* SPI controller initializations */ |
524 | cdns_spi_init_hw(xspi); | |
525 | ||
526 | irq = platform_get_irq(pdev, 0); | |
527 | if (irq <= 0) { | |
528 | ret = -ENXIO; | |
529 | dev_err(&pdev->dev, "irq number is invalid\n"); | |
50ac697b | 530 | goto clk_dis_all; |
c474b386 HK |
531 | } |
532 | ||
533 | ret = devm_request_irq(&pdev->dev, irq, cdns_spi_irq, | |
534 | 0, pdev->name, master); | |
535 | if (ret != 0) { | |
536 | ret = -ENXIO; | |
537 | dev_err(&pdev->dev, "request_irq failed\n"); | |
50ac697b | 538 | goto clk_dis_all; |
c474b386 HK |
539 | } |
540 | ||
c474b386 | 541 | master->prepare_transfer_hardware = cdns_prepare_transfer_hardware; |
b48b9488 | 542 | master->prepare_message = cdns_prepare_message; |
c474b386 HK |
543 | master->transfer_one = cdns_transfer_one; |
544 | master->unprepare_transfer_hardware = cdns_unprepare_transfer_hardware; | |
545 | master->set_cs = cdns_spi_chipselect; | |
546 | master->mode_bits = SPI_CPOL | SPI_CPHA; | |
547 | ||
548 | /* Set to default valid value */ | |
549 | master->max_speed_hz = clk_get_rate(xspi->ref_clk) / 4; | |
550 | xspi->speed_hz = master->max_speed_hz; | |
551 | ||
552 | master->bits_per_word_mask = SPI_BPW_MASK(8); | |
553 | ||
554 | ret = spi_register_master(master); | |
555 | if (ret) { | |
556 | dev_err(&pdev->dev, "spi_register_master failed\n"); | |
557 | goto clk_dis_all; | |
558 | } | |
559 | ||
560 | return ret; | |
561 | ||
562 | clk_dis_all: | |
563 | clk_disable_unprepare(xspi->ref_clk); | |
564 | clk_dis_apb: | |
565 | clk_disable_unprepare(xspi->pclk); | |
566 | remove_master: | |
567 | spi_master_put(master); | |
568 | return ret; | |
569 | } | |
570 | ||
571 | /** | |
572 | * cdns_spi_remove - Remove method for the SPI driver | |
573 | * @pdev: Pointer to the platform_device structure | |
574 | * | |
575 | * This function is called if a device is physically removed from the system or | |
576 | * if the driver module is being unloaded. It frees all resources allocated to | |
577 | * the device. | |
578 | * | |
579 | * Return: 0 on success and error value on error | |
580 | */ | |
581 | static int cdns_spi_remove(struct platform_device *pdev) | |
582 | { | |
583 | struct spi_master *master = platform_get_drvdata(pdev); | |
584 | struct cdns_spi *xspi = spi_master_get_devdata(master); | |
585 | ||
24746675 | 586 | cdns_spi_write(xspi, CDNS_SPI_ER, CDNS_SPI_ER_DISABLE); |
c474b386 HK |
587 | |
588 | clk_disable_unprepare(xspi->ref_clk); | |
589 | clk_disable_unprepare(xspi->pclk); | |
590 | ||
591 | spi_unregister_master(master); | |
592 | ||
593 | return 0; | |
594 | } | |
595 | ||
596 | /** | |
597 | * cdns_spi_suspend - Suspend method for the SPI driver | |
598 | * @dev: Address of the platform_device structure | |
599 | * | |
600 | * This function disables the SPI controller and | |
601 | * changes the driver state to "suspend" | |
602 | * | |
603 | * Return: Always 0 | |
604 | */ | |
605 | static int __maybe_unused cdns_spi_suspend(struct device *dev) | |
606 | { | |
9033a5f9 | 607 | struct platform_device *pdev = to_platform_device(dev); |
c474b386 HK |
608 | struct spi_master *master = platform_get_drvdata(pdev); |
609 | struct cdns_spi *xspi = spi_master_get_devdata(master); | |
610 | ||
611 | spi_master_suspend(master); | |
612 | ||
613 | clk_disable_unprepare(xspi->ref_clk); | |
614 | ||
615 | clk_disable_unprepare(xspi->pclk); | |
616 | ||
617 | return 0; | |
618 | } | |
619 | ||
620 | /** | |
621 | * cdns_spi_resume - Resume method for the SPI driver | |
622 | * @dev: Address of the platform_device structure | |
623 | * | |
624 | * This function changes the driver state to "ready" | |
625 | * | |
626 | * Return: 0 on success and error value on error | |
627 | */ | |
628 | static int __maybe_unused cdns_spi_resume(struct device *dev) | |
629 | { | |
9033a5f9 | 630 | struct platform_device *pdev = to_platform_device(dev); |
c474b386 HK |
631 | struct spi_master *master = platform_get_drvdata(pdev); |
632 | struct cdns_spi *xspi = spi_master_get_devdata(master); | |
633 | int ret = 0; | |
634 | ||
635 | ret = clk_prepare_enable(xspi->pclk); | |
636 | if (ret) { | |
637 | dev_err(dev, "Cannot enable APB clock.\n"); | |
638 | return ret; | |
639 | } | |
640 | ||
641 | ret = clk_prepare_enable(xspi->ref_clk); | |
642 | if (ret) { | |
643 | dev_err(dev, "Cannot enable device clock.\n"); | |
644 | clk_disable(xspi->pclk); | |
645 | return ret; | |
646 | } | |
647 | spi_master_resume(master); | |
648 | ||
649 | return 0; | |
650 | } | |
651 | ||
652 | static SIMPLE_DEV_PM_OPS(cdns_spi_dev_pm_ops, cdns_spi_suspend, | |
653 | cdns_spi_resume); | |
654 | ||
f7f994a4 | 655 | static const struct of_device_id cdns_spi_of_match[] = { |
c474b386 HK |
656 | { .compatible = "xlnx,zynq-spi-r1p6" }, |
657 | { .compatible = "cdns,spi-r1p6" }, | |
658 | { /* end of table */ } | |
659 | }; | |
660 | MODULE_DEVICE_TABLE(of, cdns_spi_of_match); | |
661 | ||
662 | /* cdns_spi_driver - This structure defines the SPI subsystem platform driver */ | |
663 | static struct platform_driver cdns_spi_driver = { | |
664 | .probe = cdns_spi_probe, | |
665 | .remove = cdns_spi_remove, | |
666 | .driver = { | |
667 | .name = CDNS_SPI_NAME, | |
c474b386 HK |
668 | .of_match_table = cdns_spi_of_match, |
669 | .pm = &cdns_spi_dev_pm_ops, | |
670 | }, | |
671 | }; | |
672 | ||
673 | module_platform_driver(cdns_spi_driver); | |
674 | ||
675 | MODULE_AUTHOR("Xilinx, Inc."); | |
676 | MODULE_DESCRIPTION("Cadence SPI driver"); | |
677 | MODULE_LICENSE("GPL"); |