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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 */ | |
28 | #define CDNS_SPI_CR_OFFSET 0x00 /* Configuration Register, RW */ | |
29 | #define CDNS_SPI_ISR_OFFSET 0x04 /* Interrupt Status Register, RO */ | |
30 | #define CDNS_SPI_IER_OFFSET 0x08 /* Interrupt Enable Register, WO */ | |
31 | #define CDNS_SPI_IDR_OFFSET 0x0c /* Interrupt Disable Register, WO */ | |
32 | #define CDNS_SPI_IMR_OFFSET 0x10 /* Interrupt Enabled Mask Register, RO */ | |
33 | #define CDNS_SPI_ER_OFFSET 0x14 /* Enable/Disable Register, RW */ | |
34 | #define CDNS_SPI_DR_OFFSET 0x18 /* Delay Register, RW */ | |
35 | #define CDNS_SPI_TXD_OFFSET 0x1C /* Data Transmit Register, WO */ | |
36 | #define CDNS_SPI_RXD_OFFSET 0x20 /* Data Receive Register, RO */ | |
37 | #define CDNS_SPI_SICR_OFFSET 0x24 /* Slave Idle Count Register, RW */ | |
38 | #define CDNS_SPI_THLD_OFFSET 0x28 /* Transmit FIFO Watermark Register,RW */ | |
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 | */ | |
46 | #define CDNS_SPI_CR_MANSTRT_MASK 0x00010000 /* Manual TX Start */ | |
47 | #define CDNS_SPI_CR_CPHA_MASK 0x00000004 /* Clock Phase Control */ | |
48 | #define CDNS_SPI_CR_CPOL_MASK 0x00000002 /* Clock Polarity Control */ | |
49 | #define CDNS_SPI_CR_SSCTRL_MASK 0x00003C00 /* Slave Select Mask */ | |
50 | #define CDNS_SPI_CR_BAUD_DIV_MASK 0x00000038 /* Baud Rate Divisor Mask */ | |
51 | #define CDNS_SPI_CR_MSTREN_MASK 0x00000001 /* Master Enable Mask */ | |
52 | #define CDNS_SPI_CR_MANSTRTEN_MASK 0x00008000 /* Manual TX Enable Mask */ | |
53 | #define CDNS_SPI_CR_SSFORCE_MASK 0x00004000 /* Manual SS Enable Mask */ | |
54 | #define CDNS_SPI_CR_BAUD_DIV_4_MASK 0x00000008 /* Default Baud Div Mask */ | |
55 | #define CDNS_SPI_CR_DEFAULT_MASK (CDNS_SPI_CR_MSTREN_MASK | \ | |
56 | CDNS_SPI_CR_SSCTRL_MASK | \ | |
57 | CDNS_SPI_CR_SSFORCE_MASK | \ | |
58 | CDNS_SPI_CR_BAUD_DIV_4_MASK) | |
59 | ||
60 | /* | |
61 | * SPI Configuration Register - Baud rate and slave select | |
62 | * | |
63 | * These are the values used in the calculation of baud rate divisor and | |
64 | * setting the slave select. | |
65 | */ | |
66 | ||
67 | #define CDNS_SPI_BAUD_DIV_MAX 7 /* Baud rate divisor maximum */ | |
68 | #define CDNS_SPI_BAUD_DIV_MIN 1 /* Baud rate divisor minimum */ | |
69 | #define CDNS_SPI_BAUD_DIV_SHIFT 3 /* Baud rate divisor shift in CR */ | |
70 | #define CDNS_SPI_SS_SHIFT 10 /* Slave Select field shift in CR */ | |
71 | #define CDNS_SPI_SS0 0x1 /* Slave Select zero */ | |
72 | ||
73 | /* | |
74 | * SPI Interrupt Registers bit Masks | |
75 | * | |
76 | * All the four interrupt registers (Status/Mask/Enable/Disable) have the same | |
77 | * bit definitions. | |
78 | */ | |
79 | #define CDNS_SPI_IXR_TXOW_MASK 0x00000004 /* SPI TX FIFO Overwater */ | |
80 | #define CDNS_SPI_IXR_MODF_MASK 0x00000002 /* SPI Mode Fault */ | |
81 | #define CDNS_SPI_IXR_RXNEMTY_MASK 0x00000010 /* SPI RX FIFO Not Empty */ | |
82 | #define CDNS_SPI_IXR_DEFAULT_MASK (CDNS_SPI_IXR_TXOW_MASK | \ | |
83 | CDNS_SPI_IXR_MODF_MASK) | |
84 | #define CDNS_SPI_IXR_TXFULL_MASK 0x00000008 /* SPI TX Full */ | |
85 | #define CDNS_SPI_IXR_ALL_MASK 0x0000007F /* SPI all interrupts */ | |
86 | ||
87 | /* | |
88 | * SPI Enable Register bit Masks | |
89 | * | |
90 | * This register is used to enable or disable the SPI controller | |
91 | */ | |
92 | #define CDNS_SPI_ER_ENABLE_MASK 0x00000001 /* SPI Enable Bit Mask */ | |
93 | #define CDNS_SPI_ER_DISABLE_MASK 0x0 /* SPI Disable Bit Mask */ | |
94 | ||
95 | /* SPI FIFO depth in bytes */ | |
96 | #define CDNS_SPI_FIFO_DEPTH 128 | |
97 | ||
98 | /* Default number of chip select lines */ | |
99 | #define CDNS_SPI_DEFAULT_NUM_CS 4 | |
100 | ||
101 | /** | |
102 | * struct cdns_spi - This definition defines spi driver instance | |
103 | * @regs: Virtual address of the SPI controller registers | |
104 | * @ref_clk: Pointer to the peripheral clock | |
105 | * @pclk: Pointer to the APB clock | |
106 | * @speed_hz: Current SPI bus clock speed in Hz | |
107 | * @txbuf: Pointer to the TX buffer | |
108 | * @rxbuf: Pointer to the RX buffer | |
109 | * @tx_bytes: Number of bytes left to transfer | |
110 | * @rx_bytes: Number of bytes requested | |
111 | * @dev_busy: Device busy flag | |
112 | * @is_decoded_cs: Flag for decoder property set or not | |
113 | */ | |
114 | struct cdns_spi { | |
115 | void __iomem *regs; | |
116 | struct clk *ref_clk; | |
117 | struct clk *pclk; | |
118 | u32 speed_hz; | |
119 | const u8 *txbuf; | |
120 | u8 *rxbuf; | |
121 | int tx_bytes; | |
122 | int rx_bytes; | |
123 | u8 dev_busy; | |
124 | u32 is_decoded_cs; | |
125 | }; | |
126 | ||
127 | /* Macros for the SPI controller read/write */ | |
128 | static inline u32 cdns_spi_read(struct cdns_spi *xspi, u32 offset) | |
129 | { | |
130 | return readl_relaxed(xspi->regs + offset); | |
131 | } | |
132 | ||
133 | static inline void cdns_spi_write(struct cdns_spi *xspi, u32 offset, u32 val) | |
134 | { | |
135 | writel_relaxed(val, xspi->regs + offset); | |
136 | } | |
137 | ||
138 | /** | |
139 | * cdns_spi_init_hw - Initialize the hardware and configure the SPI controller | |
140 | * @xspi: Pointer to the cdns_spi structure | |
141 | * | |
142 | * On reset the SPI controller is configured to be in master mode, baud rate | |
143 | * divisor is set to 4, threshold value for TX FIFO not full interrupt is set | |
144 | * to 1 and size of the word to be transferred as 8 bit. | |
145 | * This function initializes the SPI controller to disable and clear all the | |
146 | * interrupts, enable manual slave select and manual start, deselect all the | |
147 | * chip select lines, and enable the SPI controller. | |
148 | */ | |
149 | static void cdns_spi_init_hw(struct cdns_spi *xspi) | |
150 | { | |
151 | cdns_spi_write(xspi, CDNS_SPI_ER_OFFSET, | |
152 | CDNS_SPI_ER_DISABLE_MASK); | |
153 | cdns_spi_write(xspi, CDNS_SPI_IDR_OFFSET, | |
154 | CDNS_SPI_IXR_ALL_MASK); | |
155 | ||
156 | /* Clear the RX FIFO */ | |
157 | while (cdns_spi_read(xspi, CDNS_SPI_ISR_OFFSET) & | |
158 | CDNS_SPI_IXR_RXNEMTY_MASK) | |
159 | cdns_spi_read(xspi, CDNS_SPI_RXD_OFFSET); | |
160 | ||
161 | cdns_spi_write(xspi, CDNS_SPI_ISR_OFFSET, | |
162 | CDNS_SPI_IXR_ALL_MASK); | |
163 | cdns_spi_write(xspi, CDNS_SPI_CR_OFFSET, | |
164 | CDNS_SPI_CR_DEFAULT_MASK); | |
165 | cdns_spi_write(xspi, CDNS_SPI_ER_OFFSET, | |
166 | CDNS_SPI_ER_ENABLE_MASK); | |
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 | ||
179 | ctrl_reg = cdns_spi_read(xspi, CDNS_SPI_CR_OFFSET); | |
180 | ||
181 | if (is_high) { | |
182 | /* Deselect the slave */ | |
183 | ctrl_reg |= CDNS_SPI_CR_SSCTRL_MASK; | |
184 | } else { | |
185 | /* Select the slave */ | |
186 | ctrl_reg &= ~CDNS_SPI_CR_SSCTRL_MASK; | |
187 | if (!(xspi->is_decoded_cs)) | |
188 | ctrl_reg |= ((~(CDNS_SPI_SS0 << spi->chip_select)) << | |
189 | CDNS_SPI_SS_SHIFT) & | |
190 | CDNS_SPI_CR_SSCTRL_MASK; | |
191 | else | |
192 | ctrl_reg |= (spi->chip_select << CDNS_SPI_SS_SHIFT) & | |
193 | CDNS_SPI_CR_SSCTRL_MASK; | |
194 | } | |
195 | ||
196 | cdns_spi_write(xspi, CDNS_SPI_CR_OFFSET, ctrl_reg); | |
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 | |
a39e65e9 | 210 | new_ctrl_reg = ctrl_reg = cdns_spi_read(xspi, CDNS_SPI_CR_OFFSET); |
c474b386 HK |
211 | |
212 | /* Set the SPI clock phase and clock polarity */ | |
a39e65e9 | 213 | new_ctrl_reg &= ~(CDNS_SPI_CR_CPHA_MASK | CDNS_SPI_CR_CPOL_MASK); |
c474b386 | 214 | if (spi->mode & SPI_CPHA) |
a39e65e9 | 215 | new_ctrl_reg |= CDNS_SPI_CR_CPHA_MASK; |
c474b386 | 216 | if (spi->mode & SPI_CPOL) |
a39e65e9 LPC |
217 | new_ctrl_reg |= CDNS_SPI_CR_CPOL_MASK; |
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 | */ | |
226 | cdns_spi_write(xspi, CDNS_SPI_ER_OFFSET, | |
227 | CDNS_SPI_ER_DISABLE_MASK); | |
228 | cdns_spi_write(xspi, CDNS_SPI_CR_OFFSET, new_ctrl_reg); | |
229 | cdns_spi_write(xspi, CDNS_SPI_ER_OFFSET, | |
230 | CDNS_SPI_ER_ENABLE_MASK); | |
231 | } | |
c474b386 HK |
232 | } |
233 | ||
234 | /** | |
235 | * cdns_spi_config_clock_freq - Sets clock frequency | |
236 | * @spi: Pointer to the spi_device structure | |
237 | * @transfer: Pointer to the spi_transfer structure which provides | |
238 | * information about next transfer setup parameters | |
239 | * | |
240 | * Sets the requested clock frequency. | |
241 | * Note: If the requested frequency is not an exact match with what can be | |
242 | * obtained using the prescalar value the driver sets the clock frequency which | |
243 | * is lower than the requested frequency (maximum lower) for the transfer. If | |
244 | * the requested frequency is higher or lower than that is supported by the SPI | |
245 | * controller the driver will set the highest or lowest frequency supported by | |
246 | * controller. | |
247 | */ | |
248 | static void cdns_spi_config_clock_freq(struct spi_device *spi, | |
249 | struct spi_transfer *transfer) | |
250 | { | |
251 | struct cdns_spi *xspi = spi_master_get_devdata(spi->master); | |
252 | u32 ctrl_reg, baud_rate_val; | |
253 | unsigned long frequency; | |
254 | ||
255 | frequency = clk_get_rate(xspi->ref_clk); | |
256 | ||
257 | ctrl_reg = cdns_spi_read(xspi, CDNS_SPI_CR_OFFSET); | |
258 | ||
259 | /* Set the clock frequency */ | |
260 | if (xspi->speed_hz != transfer->speed_hz) { | |
261 | /* first valid value is 1 */ | |
262 | baud_rate_val = CDNS_SPI_BAUD_DIV_MIN; | |
263 | while ((baud_rate_val < CDNS_SPI_BAUD_DIV_MAX) && | |
264 | (frequency / (2 << baud_rate_val)) > transfer->speed_hz) | |
265 | baud_rate_val++; | |
266 | ||
267 | ctrl_reg &= ~CDNS_SPI_CR_BAUD_DIV_MASK; | |
268 | ctrl_reg |= baud_rate_val << CDNS_SPI_BAUD_DIV_SHIFT; | |
269 | ||
270 | xspi->speed_hz = frequency / (2 << baud_rate_val); | |
271 | } | |
272 | cdns_spi_write(xspi, CDNS_SPI_CR_OFFSET, ctrl_reg); | |
273 | } | |
274 | ||
275 | /** | |
276 | * cdns_spi_setup_transfer - Configure SPI controller for specified transfer | |
277 | * @spi: Pointer to the spi_device structure | |
278 | * @transfer: Pointer to the spi_transfer structure which provides | |
279 | * information about next transfer setup parameters | |
280 | * | |
281 | * Sets the operational mode of SPI controller for the next SPI transfer and | |
282 | * sets the requested clock frequency. | |
283 | * | |
284 | * Return: Always 0 | |
285 | */ | |
286 | static int cdns_spi_setup_transfer(struct spi_device *spi, | |
287 | struct spi_transfer *transfer) | |
288 | { | |
289 | struct cdns_spi *xspi = spi_master_get_devdata(spi->master); | |
290 | ||
291 | cdns_spi_config_clock_freq(spi, transfer); | |
292 | ||
293 | dev_dbg(&spi->dev, "%s, mode %d, %u bits/w, %u clock speed\n", | |
294 | __func__, spi->mode, spi->bits_per_word, | |
295 | xspi->speed_hz); | |
296 | ||
297 | return 0; | |
298 | } | |
299 | ||
300 | /** | |
301 | * cdns_spi_fill_tx_fifo - Fills the TX FIFO with as many bytes as possible | |
302 | * @xspi: Pointer to the cdns_spi structure | |
303 | */ | |
304 | static void cdns_spi_fill_tx_fifo(struct cdns_spi *xspi) | |
305 | { | |
306 | unsigned long trans_cnt = 0; | |
307 | ||
308 | while ((trans_cnt < CDNS_SPI_FIFO_DEPTH) && | |
309 | (xspi->tx_bytes > 0)) { | |
310 | if (xspi->txbuf) | |
311 | cdns_spi_write(xspi, CDNS_SPI_TXD_OFFSET, | |
312 | *xspi->txbuf++); | |
313 | else | |
314 | cdns_spi_write(xspi, CDNS_SPI_TXD_OFFSET, 0); | |
315 | ||
316 | xspi->tx_bytes--; | |
317 | trans_cnt++; | |
318 | } | |
319 | } | |
320 | ||
321 | /** | |
322 | * cdns_spi_irq - Interrupt service routine of the SPI controller | |
323 | * @irq: IRQ number | |
324 | * @dev_id: Pointer to the xspi structure | |
325 | * | |
326 | * This function handles TX empty and Mode Fault interrupts only. | |
327 | * On TX empty interrupt this function reads the received data from RX FIFO and | |
328 | * fills the TX FIFO if there is any data remaining to be transferred. | |
329 | * On Mode Fault interrupt this function indicates that transfer is completed, | |
330 | * the SPI subsystem will identify the error as the remaining bytes to be | |
331 | * transferred is non-zero. | |
332 | * | |
333 | * Return: IRQ_HANDLED when handled; IRQ_NONE otherwise. | |
334 | */ | |
335 | static irqreturn_t cdns_spi_irq(int irq, void *dev_id) | |
336 | { | |
337 | struct spi_master *master = dev_id; | |
338 | struct cdns_spi *xspi = spi_master_get_devdata(master); | |
339 | u32 intr_status, status; | |
340 | ||
341 | status = IRQ_NONE; | |
342 | intr_status = cdns_spi_read(xspi, CDNS_SPI_ISR_OFFSET); | |
343 | cdns_spi_write(xspi, CDNS_SPI_ISR_OFFSET, intr_status); | |
344 | ||
345 | if (intr_status & CDNS_SPI_IXR_MODF_MASK) { | |
346 | /* Indicate that transfer is completed, the SPI subsystem will | |
347 | * identify the error as the remaining bytes to be | |
348 | * transferred is non-zero | |
349 | */ | |
350 | cdns_spi_write(xspi, CDNS_SPI_IDR_OFFSET, | |
351 | CDNS_SPI_IXR_DEFAULT_MASK); | |
352 | spi_finalize_current_transfer(master); | |
353 | status = IRQ_HANDLED; | |
354 | } else if (intr_status & CDNS_SPI_IXR_TXOW_MASK) { | |
355 | unsigned long trans_cnt; | |
356 | ||
357 | trans_cnt = xspi->rx_bytes - xspi->tx_bytes; | |
358 | ||
359 | /* Read out the data from the RX FIFO */ | |
360 | while (trans_cnt) { | |
361 | u8 data; | |
362 | ||
363 | data = cdns_spi_read(xspi, CDNS_SPI_RXD_OFFSET); | |
364 | if (xspi->rxbuf) | |
365 | *xspi->rxbuf++ = data; | |
366 | ||
367 | xspi->rx_bytes--; | |
368 | trans_cnt--; | |
369 | } | |
370 | ||
371 | if (xspi->tx_bytes) { | |
372 | /* There is more data to send */ | |
373 | cdns_spi_fill_tx_fifo(xspi); | |
374 | } else { | |
375 | /* Transfer is completed */ | |
376 | cdns_spi_write(xspi, CDNS_SPI_IDR_OFFSET, | |
377 | CDNS_SPI_IXR_DEFAULT_MASK); | |
378 | spi_finalize_current_transfer(master); | |
379 | } | |
380 | status = IRQ_HANDLED; | |
381 | } | |
382 | ||
383 | return status; | |
384 | } | |
b48b9488 LPC |
385 | static int cdns_prepare_message(struct spi_master *master, |
386 | struct spi_message *msg) | |
387 | { | |
388 | cdns_spi_config_clock_mode(msg->spi); | |
389 | return 0; | |
390 | } | |
c474b386 HK |
391 | |
392 | /** | |
393 | * cdns_transfer_one - Initiates the SPI transfer | |
394 | * @master: Pointer to spi_master structure | |
395 | * @spi: Pointer to the spi_device structure | |
396 | * @transfer: Pointer to the spi_transfer structure which provides | |
397 | * information about next transfer parameters | |
398 | * | |
399 | * This function fills the TX FIFO, starts the SPI transfer and | |
400 | * returns a positive transfer count so that core will wait for completion. | |
401 | * | |
402 | * Return: Number of bytes transferred in the last transfer | |
403 | */ | |
404 | static int cdns_transfer_one(struct spi_master *master, | |
405 | struct spi_device *spi, | |
406 | struct spi_transfer *transfer) | |
407 | { | |
408 | struct cdns_spi *xspi = spi_master_get_devdata(master); | |
409 | ||
410 | xspi->txbuf = transfer->tx_buf; | |
411 | xspi->rxbuf = transfer->rx_buf; | |
412 | xspi->tx_bytes = transfer->len; | |
413 | xspi->rx_bytes = transfer->len; | |
414 | ||
415 | cdns_spi_setup_transfer(spi, transfer); | |
416 | ||
417 | cdns_spi_fill_tx_fifo(xspi); | |
418 | ||
419 | cdns_spi_write(xspi, CDNS_SPI_IER_OFFSET, | |
420 | CDNS_SPI_IXR_DEFAULT_MASK); | |
421 | return transfer->len; | |
422 | } | |
423 | ||
424 | /** | |
425 | * cdns_prepare_transfer_hardware - Prepares hardware for transfer. | |
426 | * @master: Pointer to the spi_master structure which provides | |
427 | * information about the controller. | |
428 | * | |
429 | * This function enables SPI master controller. | |
430 | * | |
431 | * Return: 0 always | |
432 | */ | |
433 | static int cdns_prepare_transfer_hardware(struct spi_master *master) | |
434 | { | |
435 | struct cdns_spi *xspi = spi_master_get_devdata(master); | |
436 | ||
c474b386 HK |
437 | cdns_spi_write(xspi, CDNS_SPI_ER_OFFSET, |
438 | CDNS_SPI_ER_ENABLE_MASK); | |
439 | ||
440 | return 0; | |
441 | } | |
442 | ||
443 | /** | |
444 | * cdns_unprepare_transfer_hardware - Relaxes hardware after transfer | |
445 | * @master: Pointer to the spi_master structure which provides | |
446 | * information about the controller. | |
447 | * | |
448 | * This function disables the SPI master controller. | |
449 | * | |
450 | * Return: 0 always | |
451 | */ | |
452 | static int cdns_unprepare_transfer_hardware(struct spi_master *master) | |
453 | { | |
454 | struct cdns_spi *xspi = spi_master_get_devdata(master); | |
455 | ||
456 | cdns_spi_write(xspi, CDNS_SPI_ER_OFFSET, | |
457 | CDNS_SPI_ER_DISABLE_MASK); | |
458 | ||
459 | return 0; | |
460 | } | |
461 | ||
462 | /** | |
463 | * cdns_spi_probe - Probe method for the SPI driver | |
464 | * @pdev: Pointer to the platform_device structure | |
465 | * | |
466 | * This function initializes the driver data structures and the hardware. | |
467 | * | |
468 | * Return: 0 on success and error value on error | |
469 | */ | |
470 | static int cdns_spi_probe(struct platform_device *pdev) | |
471 | { | |
472 | int ret = 0, irq; | |
473 | struct spi_master *master; | |
474 | struct cdns_spi *xspi; | |
475 | struct resource *res; | |
476 | u32 num_cs; | |
477 | ||
478 | master = spi_alloc_master(&pdev->dev, sizeof(*xspi)); | |
479 | if (master == NULL) | |
480 | return -ENOMEM; | |
481 | ||
482 | xspi = spi_master_get_devdata(master); | |
483 | master->dev.of_node = pdev->dev.of_node; | |
484 | platform_set_drvdata(pdev, master); | |
485 | ||
486 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
487 | xspi->regs = devm_ioremap_resource(&pdev->dev, res); | |
488 | if (IS_ERR(xspi->regs)) { | |
489 | ret = PTR_ERR(xspi->regs); | |
490 | goto remove_master; | |
491 | } | |
492 | ||
493 | xspi->pclk = devm_clk_get(&pdev->dev, "pclk"); | |
494 | if (IS_ERR(xspi->pclk)) { | |
495 | dev_err(&pdev->dev, "pclk clock not found.\n"); | |
496 | ret = PTR_ERR(xspi->pclk); | |
497 | goto remove_master; | |
498 | } | |
499 | ||
500 | xspi->ref_clk = devm_clk_get(&pdev->dev, "ref_clk"); | |
501 | if (IS_ERR(xspi->ref_clk)) { | |
502 | dev_err(&pdev->dev, "ref_clk clock not found.\n"); | |
503 | ret = PTR_ERR(xspi->ref_clk); | |
504 | goto remove_master; | |
505 | } | |
506 | ||
507 | ret = clk_prepare_enable(xspi->pclk); | |
508 | if (ret) { | |
509 | dev_err(&pdev->dev, "Unable to enable APB clock.\n"); | |
510 | goto remove_master; | |
511 | } | |
512 | ||
513 | ret = clk_prepare_enable(xspi->ref_clk); | |
514 | if (ret) { | |
515 | dev_err(&pdev->dev, "Unable to enable device clock.\n"); | |
516 | goto clk_dis_apb; | |
517 | } | |
518 | ||
519 | /* SPI controller initializations */ | |
520 | cdns_spi_init_hw(xspi); | |
521 | ||
522 | irq = platform_get_irq(pdev, 0); | |
523 | if (irq <= 0) { | |
524 | ret = -ENXIO; | |
525 | dev_err(&pdev->dev, "irq number is invalid\n"); | |
526 | goto remove_master; | |
527 | } | |
528 | ||
529 | ret = devm_request_irq(&pdev->dev, irq, cdns_spi_irq, | |
530 | 0, pdev->name, master); | |
531 | if (ret != 0) { | |
532 | ret = -ENXIO; | |
533 | dev_err(&pdev->dev, "request_irq failed\n"); | |
534 | goto remove_master; | |
535 | } | |
536 | ||
537 | ret = of_property_read_u32(pdev->dev.of_node, "num-cs", &num_cs); | |
538 | ||
539 | if (ret < 0) | |
540 | master->num_chipselect = CDNS_SPI_DEFAULT_NUM_CS; | |
541 | else | |
542 | master->num_chipselect = num_cs; | |
543 | ||
544 | ret = of_property_read_u32(pdev->dev.of_node, "is-decoded-cs", | |
545 | &xspi->is_decoded_cs); | |
546 | ||
547 | if (ret < 0) | |
548 | xspi->is_decoded_cs = 0; | |
549 | ||
550 | master->prepare_transfer_hardware = cdns_prepare_transfer_hardware; | |
b48b9488 | 551 | master->prepare_message = cdns_prepare_message; |
c474b386 HK |
552 | master->transfer_one = cdns_transfer_one; |
553 | master->unprepare_transfer_hardware = cdns_unprepare_transfer_hardware; | |
554 | master->set_cs = cdns_spi_chipselect; | |
555 | master->mode_bits = SPI_CPOL | SPI_CPHA; | |
556 | ||
557 | /* Set to default valid value */ | |
558 | master->max_speed_hz = clk_get_rate(xspi->ref_clk) / 4; | |
559 | xspi->speed_hz = master->max_speed_hz; | |
560 | ||
561 | master->bits_per_word_mask = SPI_BPW_MASK(8); | |
562 | ||
563 | ret = spi_register_master(master); | |
564 | if (ret) { | |
565 | dev_err(&pdev->dev, "spi_register_master failed\n"); | |
566 | goto clk_dis_all; | |
567 | } | |
568 | ||
569 | return ret; | |
570 | ||
571 | clk_dis_all: | |
572 | clk_disable_unprepare(xspi->ref_clk); | |
573 | clk_dis_apb: | |
574 | clk_disable_unprepare(xspi->pclk); | |
575 | remove_master: | |
576 | spi_master_put(master); | |
577 | return ret; | |
578 | } | |
579 | ||
580 | /** | |
581 | * cdns_spi_remove - Remove method for the SPI driver | |
582 | * @pdev: Pointer to the platform_device structure | |
583 | * | |
584 | * This function is called if a device is physically removed from the system or | |
585 | * if the driver module is being unloaded. It frees all resources allocated to | |
586 | * the device. | |
587 | * | |
588 | * Return: 0 on success and error value on error | |
589 | */ | |
590 | static int cdns_spi_remove(struct platform_device *pdev) | |
591 | { | |
592 | struct spi_master *master = platform_get_drvdata(pdev); | |
593 | struct cdns_spi *xspi = spi_master_get_devdata(master); | |
594 | ||
595 | cdns_spi_write(xspi, CDNS_SPI_ER_OFFSET, | |
596 | CDNS_SPI_ER_DISABLE_MASK); | |
597 | ||
598 | clk_disable_unprepare(xspi->ref_clk); | |
599 | clk_disable_unprepare(xspi->pclk); | |
600 | ||
601 | spi_unregister_master(master); | |
602 | ||
603 | return 0; | |
604 | } | |
605 | ||
606 | /** | |
607 | * cdns_spi_suspend - Suspend method for the SPI driver | |
608 | * @dev: Address of the platform_device structure | |
609 | * | |
610 | * This function disables the SPI controller and | |
611 | * changes the driver state to "suspend" | |
612 | * | |
613 | * Return: Always 0 | |
614 | */ | |
615 | static int __maybe_unused cdns_spi_suspend(struct device *dev) | |
616 | { | |
617 | struct platform_device *pdev = container_of(dev, | |
618 | struct platform_device, dev); | |
619 | struct spi_master *master = platform_get_drvdata(pdev); | |
620 | struct cdns_spi *xspi = spi_master_get_devdata(master); | |
621 | ||
622 | spi_master_suspend(master); | |
623 | ||
624 | clk_disable_unprepare(xspi->ref_clk); | |
625 | ||
626 | clk_disable_unprepare(xspi->pclk); | |
627 | ||
628 | return 0; | |
629 | } | |
630 | ||
631 | /** | |
632 | * cdns_spi_resume - Resume method for the SPI driver | |
633 | * @dev: Address of the platform_device structure | |
634 | * | |
635 | * This function changes the driver state to "ready" | |
636 | * | |
637 | * Return: 0 on success and error value on error | |
638 | */ | |
639 | static int __maybe_unused cdns_spi_resume(struct device *dev) | |
640 | { | |
641 | struct platform_device *pdev = container_of(dev, | |
642 | struct platform_device, dev); | |
643 | struct spi_master *master = platform_get_drvdata(pdev); | |
644 | struct cdns_spi *xspi = spi_master_get_devdata(master); | |
645 | int ret = 0; | |
646 | ||
647 | ret = clk_prepare_enable(xspi->pclk); | |
648 | if (ret) { | |
649 | dev_err(dev, "Cannot enable APB clock.\n"); | |
650 | return ret; | |
651 | } | |
652 | ||
653 | ret = clk_prepare_enable(xspi->ref_clk); | |
654 | if (ret) { | |
655 | dev_err(dev, "Cannot enable device clock.\n"); | |
656 | clk_disable(xspi->pclk); | |
657 | return ret; | |
658 | } | |
659 | spi_master_resume(master); | |
660 | ||
661 | return 0; | |
662 | } | |
663 | ||
664 | static SIMPLE_DEV_PM_OPS(cdns_spi_dev_pm_ops, cdns_spi_suspend, | |
665 | cdns_spi_resume); | |
666 | ||
f7f994a4 | 667 | static const struct of_device_id cdns_spi_of_match[] = { |
c474b386 HK |
668 | { .compatible = "xlnx,zynq-spi-r1p6" }, |
669 | { .compatible = "cdns,spi-r1p6" }, | |
670 | { /* end of table */ } | |
671 | }; | |
672 | MODULE_DEVICE_TABLE(of, cdns_spi_of_match); | |
673 | ||
674 | /* cdns_spi_driver - This structure defines the SPI subsystem platform driver */ | |
675 | static struct platform_driver cdns_spi_driver = { | |
676 | .probe = cdns_spi_probe, | |
677 | .remove = cdns_spi_remove, | |
678 | .driver = { | |
679 | .name = CDNS_SPI_NAME, | |
c474b386 HK |
680 | .of_match_table = cdns_spi_of_match, |
681 | .pm = &cdns_spi_dev_pm_ops, | |
682 | }, | |
683 | }; | |
684 | ||
685 | module_platform_driver(cdns_spi_driver); | |
686 | ||
687 | MODULE_AUTHOR("Xilinx, Inc."); | |
688 | MODULE_DESCRIPTION("Cadence SPI driver"); | |
689 | MODULE_LICENSE("GPL"); |