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1 /*
2  * Xilinx Zynq UltraScale+ MPSoC Quad-SPI (QSPI) controller driver
3  * (master mode only)
4  *
5  * Copyright (C) 2009 - 2015 Xilinx, Inc.
6  *
7  * This program is free software; you can redistribute it and/or modify it
8  * under the terms of the GNU General Public License version 2 as published
9  * by the Free Software Foundation; either version 2 of the License, or
10  * (at your option) any later version.
11  */
12 
13 #include <linux/clk.h>
14 #include <linux/delay.h>
15 #include <linux/dma-mapping.h>
16 #include <linux/dmaengine.h>
17 #include <linux/interrupt.h>
18 #include <linux/io.h>
19 #include <linux/module.h>
20 #include <linux/of_irq.h>
21 #include <linux/of_address.h>
22 #include <linux/platform_device.h>
23 #include <linux/spi/spi.h>
24 #include <linux/spinlock.h>
25 #include <linux/workqueue.h>
26 
27 /* Generic QSPI register offsets */
28 #define GQSPI_CONFIG_OFST		0x00000100
29 #define GQSPI_ISR_OFST			0x00000104
30 #define GQSPI_IDR_OFST			0x0000010C
31 #define GQSPI_IER_OFST			0x00000108
32 #define GQSPI_IMASK_OFST		0x00000110
33 #define GQSPI_EN_OFST			0x00000114
34 #define GQSPI_TXD_OFST			0x0000011C
35 #define GQSPI_RXD_OFST			0x00000120
36 #define GQSPI_TX_THRESHOLD_OFST		0x00000128
37 #define GQSPI_RX_THRESHOLD_OFST		0x0000012C
38 #define GQSPI_LPBK_DLY_ADJ_OFST		0x00000138
39 #define GQSPI_GEN_FIFO_OFST		0x00000140
40 #define GQSPI_SEL_OFST			0x00000144
41 #define GQSPI_GF_THRESHOLD_OFST		0x00000150
42 #define GQSPI_FIFO_CTRL_OFST		0x0000014C
43 #define GQSPI_QSPIDMA_DST_CTRL_OFST	0x0000080C
44 #define GQSPI_QSPIDMA_DST_SIZE_OFST	0x00000804
45 #define GQSPI_QSPIDMA_DST_STS_OFST	0x00000808
46 #define GQSPI_QSPIDMA_DST_I_STS_OFST	0x00000814
47 #define GQSPI_QSPIDMA_DST_I_EN_OFST	0x00000818
48 #define GQSPI_QSPIDMA_DST_I_DIS_OFST	0x0000081C
49 #define GQSPI_QSPIDMA_DST_I_MASK_OFST	0x00000820
50 #define GQSPI_QSPIDMA_DST_ADDR_OFST	0x00000800
51 #define GQSPI_QSPIDMA_DST_ADDR_MSB_OFST 0x00000828
52 
53 /* GQSPI register bit masks */
54 #define GQSPI_SEL_MASK				0x00000001
55 #define GQSPI_EN_MASK				0x00000001
56 #define GQSPI_LPBK_DLY_ADJ_USE_LPBK_MASK	0x00000020
57 #define GQSPI_ISR_WR_TO_CLR_MASK		0x00000002
58 #define GQSPI_IDR_ALL_MASK			0x00000FBE
59 #define GQSPI_CFG_MODE_EN_MASK			0xC0000000
60 #define GQSPI_CFG_GEN_FIFO_START_MODE_MASK	0x20000000
61 #define GQSPI_CFG_ENDIAN_MASK			0x04000000
62 #define GQSPI_CFG_EN_POLL_TO_MASK		0x00100000
63 #define GQSPI_CFG_WP_HOLD_MASK			0x00080000
64 #define GQSPI_CFG_BAUD_RATE_DIV_MASK		0x00000038
65 #define GQSPI_CFG_CLK_PHA_MASK			0x00000004
66 #define GQSPI_CFG_CLK_POL_MASK			0x00000002
67 #define GQSPI_CFG_START_GEN_FIFO_MASK		0x10000000
68 #define GQSPI_GENFIFO_IMM_DATA_MASK		0x000000FF
69 #define GQSPI_GENFIFO_DATA_XFER			0x00000100
70 #define GQSPI_GENFIFO_EXP			0x00000200
71 #define GQSPI_GENFIFO_MODE_SPI			0x00000400
72 #define GQSPI_GENFIFO_MODE_DUALSPI		0x00000800
73 #define GQSPI_GENFIFO_MODE_QUADSPI		0x00000C00
74 #define GQSPI_GENFIFO_MODE_MASK			0x00000C00
75 #define GQSPI_GENFIFO_CS_LOWER			0x00001000
76 #define GQSPI_GENFIFO_CS_UPPER			0x00002000
77 #define GQSPI_GENFIFO_BUS_LOWER			0x00004000
78 #define GQSPI_GENFIFO_BUS_UPPER			0x00008000
79 #define GQSPI_GENFIFO_BUS_BOTH			0x0000C000
80 #define GQSPI_GENFIFO_BUS_MASK			0x0000C000
81 #define GQSPI_GENFIFO_TX			0x00010000
82 #define GQSPI_GENFIFO_RX			0x00020000
83 #define GQSPI_GENFIFO_STRIPE			0x00040000
84 #define GQSPI_GENFIFO_POLL			0x00080000
85 #define GQSPI_GENFIFO_EXP_START			0x00000100
86 #define GQSPI_FIFO_CTRL_RST_RX_FIFO_MASK	0x00000004
87 #define GQSPI_FIFO_CTRL_RST_TX_FIFO_MASK	0x00000002
88 #define GQSPI_FIFO_CTRL_RST_GEN_FIFO_MASK	0x00000001
89 #define GQSPI_ISR_RXEMPTY_MASK			0x00000800
90 #define GQSPI_ISR_GENFIFOFULL_MASK		0x00000400
91 #define GQSPI_ISR_GENFIFONOT_FULL_MASK		0x00000200
92 #define GQSPI_ISR_TXEMPTY_MASK			0x00000100
93 #define GQSPI_ISR_GENFIFOEMPTY_MASK		0x00000080
94 #define GQSPI_ISR_RXFULL_MASK			0x00000020
95 #define GQSPI_ISR_RXNEMPTY_MASK			0x00000010
96 #define GQSPI_ISR_TXFULL_MASK			0x00000008
97 #define GQSPI_ISR_TXNOT_FULL_MASK		0x00000004
98 #define GQSPI_ISR_POLL_TIME_EXPIRE_MASK		0x00000002
99 #define GQSPI_IER_TXNOT_FULL_MASK		0x00000004
100 #define GQSPI_IER_RXEMPTY_MASK			0x00000800
101 #define GQSPI_IER_POLL_TIME_EXPIRE_MASK		0x00000002
102 #define GQSPI_IER_RXNEMPTY_MASK			0x00000010
103 #define GQSPI_IER_GENFIFOEMPTY_MASK		0x00000080
104 #define GQSPI_IER_TXEMPTY_MASK			0x00000100
105 #define GQSPI_QSPIDMA_DST_INTR_ALL_MASK		0x000000FE
106 #define GQSPI_QSPIDMA_DST_STS_WTC		0x0000E000
107 #define GQSPI_CFG_MODE_EN_DMA_MASK		0x80000000
108 #define GQSPI_ISR_IDR_MASK			0x00000994
109 #define GQSPI_QSPIDMA_DST_I_EN_DONE_MASK	0x00000002
110 #define GQSPI_QSPIDMA_DST_I_STS_DONE_MASK	0x00000002
111 #define GQSPI_IRQ_MASK				0x00000980
112 
113 #define GQSPI_CFG_BAUD_RATE_DIV_SHIFT		3
114 #define GQSPI_GENFIFO_CS_SETUP			0x4
115 #define GQSPI_GENFIFO_CS_HOLD			0x3
116 #define GQSPI_TXD_DEPTH				64
117 #define GQSPI_RX_FIFO_THRESHOLD			32
118 #define GQSPI_RX_FIFO_FILL	(GQSPI_RX_FIFO_THRESHOLD * 4)
119 #define GQSPI_TX_FIFO_THRESHOLD_RESET_VAL	32
120 #define GQSPI_TX_FIFO_FILL	(GQSPI_TXD_DEPTH -\
121 				GQSPI_TX_FIFO_THRESHOLD_RESET_VAL)
122 #define GQSPI_GEN_FIFO_THRESHOLD_RESET_VAL	0X10
123 #define GQSPI_QSPIDMA_DST_CTRL_RESET_VAL	0x803FFA00
124 #define GQSPI_SELECT_FLASH_CS_LOWER		0x1
125 #define GQSPI_SELECT_FLASH_CS_UPPER		0x2
126 #define GQSPI_SELECT_FLASH_CS_BOTH		0x3
127 #define GQSPI_SELECT_FLASH_BUS_LOWER		0x1
128 #define GQSPI_SELECT_FLASH_BUS_UPPER		0x2
129 #define GQSPI_SELECT_FLASH_BUS_BOTH		0x3
130 #define GQSPI_BAUD_DIV_MAX	7	/* Baud rate divisor maximum */
131 #define GQSPI_BAUD_DIV_SHIFT	2	/* Baud rate divisor shift */
132 #define GQSPI_SELECT_MODE_SPI		0x1
133 #define GQSPI_SELECT_MODE_DUALSPI	0x2
134 #define GQSPI_SELECT_MODE_QUADSPI	0x4
135 #define GQSPI_DMA_UNALIGN		0x3
136 #define GQSPI_DEFAULT_NUM_CS	1	/* Default number of chip selects */
137 
138 enum mode_type {GQSPI_MODE_IO, GQSPI_MODE_DMA};
139 
140 /**
141  * struct zynqmp_qspi - Defines qspi driver instance
142  * @regs:		Virtual address of the QSPI controller registers
143  * @refclk:		Pointer to the peripheral clock
144  * @pclk:		Pointer to the APB clock
145  * @irq:		IRQ number
146  * @dev:		Pointer to struct device
147  * @txbuf:		Pointer to the TX buffer
148  * @rxbuf:		Pointer to the RX buffer
149  * @bytes_to_transfer:	Number of bytes left to transfer
150  * @bytes_to_receive:	Number of bytes left to receive
151  * @genfifocs:		Used for chip select
152  * @genfifobus:		Used to select the upper or lower bus
153  * @dma_rx_bytes:	Remaining bytes to receive by DMA mode
154  * @dma_addr:		DMA address after mapping the kernel buffer
155  * @genfifoentry:	Used for storing the genfifoentry instruction.
156  * @mode:		Defines the mode in which QSPI is operating
157  */
158 struct zynqmp_qspi {
159 	void __iomem *regs;
160 	struct clk *refclk;
161 	struct clk *pclk;
162 	int irq;
163 	struct device *dev;
164 	const void *txbuf;
165 	void *rxbuf;
166 	int bytes_to_transfer;
167 	int bytes_to_receive;
168 	u32 genfifocs;
169 	u32 genfifobus;
170 	u32 dma_rx_bytes;
171 	dma_addr_t dma_addr;
172 	u32 genfifoentry;
173 	enum mode_type mode;
174 };
175 
176 /**
177  * zynqmp_gqspi_read:	For GQSPI controller read operation
178  * @xqspi:	Pointer to the zynqmp_qspi structure
179  * @offset:	Offset from where to read
180  */
zynqmp_gqspi_read(struct zynqmp_qspi * xqspi,u32 offset)181 static u32 zynqmp_gqspi_read(struct zynqmp_qspi *xqspi, u32 offset)
182 {
183 	return readl_relaxed(xqspi->regs + offset);
184 }
185 
186 /**
187  * zynqmp_gqspi_write:	For GQSPI controller write operation
188  * @xqspi:	Pointer to the zynqmp_qspi structure
189  * @offset:	Offset where to write
190  * @val:	Value to be written
191  */
zynqmp_gqspi_write(struct zynqmp_qspi * xqspi,u32 offset,u32 val)192 static inline void zynqmp_gqspi_write(struct zynqmp_qspi *xqspi, u32 offset,
193 				      u32 val)
194 {
195 	writel_relaxed(val, (xqspi->regs + offset));
196 }
197 
198 /**
199  * zynqmp_gqspi_selectslave:	For selection of slave device
200  * @instanceptr:	Pointer to the zynqmp_qspi structure
201  * @flashcs:	For chip select
202  * @flashbus:	To check which bus is selected- upper or lower
203  */
zynqmp_gqspi_selectslave(struct zynqmp_qspi * instanceptr,u8 slavecs,u8 slavebus)204 static void zynqmp_gqspi_selectslave(struct zynqmp_qspi *instanceptr,
205 				     u8 slavecs, u8 slavebus)
206 {
207 	/*
208 	 * Bus and CS lines selected here will be updated in the instance and
209 	 * used for subsequent GENFIFO entries during transfer.
210 	 */
211 
212 	/* Choose slave select line */
213 	switch (slavecs) {
214 	case GQSPI_SELECT_FLASH_CS_BOTH:
215 		instanceptr->genfifocs = GQSPI_GENFIFO_CS_LOWER |
216 			GQSPI_GENFIFO_CS_UPPER;
217 		break;
218 	case GQSPI_SELECT_FLASH_CS_UPPER:
219 		instanceptr->genfifocs = GQSPI_GENFIFO_CS_UPPER;
220 		break;
221 	case GQSPI_SELECT_FLASH_CS_LOWER:
222 		instanceptr->genfifocs = GQSPI_GENFIFO_CS_LOWER;
223 		break;
224 	default:
225 		dev_warn(instanceptr->dev, "Invalid slave select\n");
226 	}
227 
228 	/* Choose the bus */
229 	switch (slavebus) {
230 	case GQSPI_SELECT_FLASH_BUS_BOTH:
231 		instanceptr->genfifobus = GQSPI_GENFIFO_BUS_LOWER |
232 			GQSPI_GENFIFO_BUS_UPPER;
233 		break;
234 	case GQSPI_SELECT_FLASH_BUS_UPPER:
235 		instanceptr->genfifobus = GQSPI_GENFIFO_BUS_UPPER;
236 		break;
237 	case GQSPI_SELECT_FLASH_BUS_LOWER:
238 		instanceptr->genfifobus = GQSPI_GENFIFO_BUS_LOWER;
239 		break;
240 	default:
241 		dev_warn(instanceptr->dev, "Invalid slave bus\n");
242 	}
243 }
244 
245 /**
246  * zynqmp_qspi_init_hw:	Initialize the hardware
247  * @xqspi:	Pointer to the zynqmp_qspi structure
248  *
249  * The default settings of the QSPI controller's configurable parameters on
250  * reset are
251  *	- Master mode
252  *	- TX threshold set to 1
253  *	- RX threshold set to 1
254  *	- Flash memory interface mode enabled
255  * This function performs the following actions
256  *	- Disable and clear all the interrupts
257  *	- Enable manual slave select
258  *	- Enable manual start
259  *	- Deselect all the chip select lines
260  *	- Set the little endian mode of TX FIFO and
261  *	- Enable the QSPI controller
262  */
zynqmp_qspi_init_hw(struct zynqmp_qspi * xqspi)263 static void zynqmp_qspi_init_hw(struct zynqmp_qspi *xqspi)
264 {
265 	u32 config_reg;
266 
267 	/* Select the GQSPI mode */
268 	zynqmp_gqspi_write(xqspi, GQSPI_SEL_OFST, GQSPI_SEL_MASK);
269 	/* Clear and disable interrupts */
270 	zynqmp_gqspi_write(xqspi, GQSPI_ISR_OFST,
271 			   zynqmp_gqspi_read(xqspi, GQSPI_ISR_OFST) |
272 			   GQSPI_ISR_WR_TO_CLR_MASK);
273 	/* Clear the DMA STS */
274 	zynqmp_gqspi_write(xqspi, GQSPI_QSPIDMA_DST_I_STS_OFST,
275 			   zynqmp_gqspi_read(xqspi,
276 					     GQSPI_QSPIDMA_DST_I_STS_OFST));
277 	zynqmp_gqspi_write(xqspi, GQSPI_QSPIDMA_DST_STS_OFST,
278 			   zynqmp_gqspi_read(xqspi,
279 					     GQSPI_QSPIDMA_DST_STS_OFST) |
280 					     GQSPI_QSPIDMA_DST_STS_WTC);
281 	zynqmp_gqspi_write(xqspi, GQSPI_IDR_OFST, GQSPI_IDR_ALL_MASK);
282 	zynqmp_gqspi_write(xqspi,
283 			   GQSPI_QSPIDMA_DST_I_DIS_OFST,
284 			   GQSPI_QSPIDMA_DST_INTR_ALL_MASK);
285 	/* Disable the GQSPI */
286 	zynqmp_gqspi_write(xqspi, GQSPI_EN_OFST, 0x0);
287 	config_reg = zynqmp_gqspi_read(xqspi, GQSPI_CONFIG_OFST);
288 	config_reg &= ~GQSPI_CFG_MODE_EN_MASK;
289 	/* Manual start */
290 	config_reg |= GQSPI_CFG_GEN_FIFO_START_MODE_MASK;
291 	/* Little endian by default */
292 	config_reg &= ~GQSPI_CFG_ENDIAN_MASK;
293 	/* Disable poll time out */
294 	config_reg &= ~GQSPI_CFG_EN_POLL_TO_MASK;
295 	/* Set hold bit */
296 	config_reg |= GQSPI_CFG_WP_HOLD_MASK;
297 	/* Clear pre-scalar by default */
298 	config_reg &= ~GQSPI_CFG_BAUD_RATE_DIV_MASK;
299 	/* CPHA 0 */
300 	config_reg &= ~GQSPI_CFG_CLK_PHA_MASK;
301 	/* CPOL 0 */
302 	config_reg &= ~GQSPI_CFG_CLK_POL_MASK;
303 	zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST, config_reg);
304 
305 	/* Clear the TX and RX FIFO */
306 	zynqmp_gqspi_write(xqspi, GQSPI_FIFO_CTRL_OFST,
307 			   GQSPI_FIFO_CTRL_RST_RX_FIFO_MASK |
308 			   GQSPI_FIFO_CTRL_RST_TX_FIFO_MASK |
309 			   GQSPI_FIFO_CTRL_RST_GEN_FIFO_MASK);
310 	/* Set by default to allow for high frequencies */
311 	zynqmp_gqspi_write(xqspi, GQSPI_LPBK_DLY_ADJ_OFST,
312 			   zynqmp_gqspi_read(xqspi, GQSPI_LPBK_DLY_ADJ_OFST) |
313 			   GQSPI_LPBK_DLY_ADJ_USE_LPBK_MASK);
314 	/* Reset thresholds */
315 	zynqmp_gqspi_write(xqspi, GQSPI_TX_THRESHOLD_OFST,
316 			   GQSPI_TX_FIFO_THRESHOLD_RESET_VAL);
317 	zynqmp_gqspi_write(xqspi, GQSPI_RX_THRESHOLD_OFST,
318 			   GQSPI_RX_FIFO_THRESHOLD);
319 	zynqmp_gqspi_write(xqspi, GQSPI_GF_THRESHOLD_OFST,
320 			   GQSPI_GEN_FIFO_THRESHOLD_RESET_VAL);
321 	zynqmp_gqspi_selectslave(xqspi,
322 				 GQSPI_SELECT_FLASH_CS_LOWER,
323 				 GQSPI_SELECT_FLASH_BUS_LOWER);
324 	/* Initialize DMA */
325 	zynqmp_gqspi_write(xqspi,
326 			GQSPI_QSPIDMA_DST_CTRL_OFST,
327 			GQSPI_QSPIDMA_DST_CTRL_RESET_VAL);
328 
329 	/* Enable the GQSPI */
330 	zynqmp_gqspi_write(xqspi, GQSPI_EN_OFST, GQSPI_EN_MASK);
331 }
332 
333 /**
334  * zynqmp_qspi_copy_read_data:	Copy data to RX buffer
335  * @xqspi:	Pointer to the zynqmp_qspi structure
336  * @data:	The variable where data is stored
337  * @size:	Number of bytes to be copied from data to RX buffer
338  */
zynqmp_qspi_copy_read_data(struct zynqmp_qspi * xqspi,ulong data,u8 size)339 static void zynqmp_qspi_copy_read_data(struct zynqmp_qspi *xqspi,
340 				       ulong data, u8 size)
341 {
342 	memcpy(xqspi->rxbuf, &data, size);
343 	xqspi->rxbuf += size;
344 	xqspi->bytes_to_receive -= size;
345 }
346 
347 /**
348  * zynqmp_prepare_transfer_hardware:	Prepares hardware for transfer.
349  * @master:	Pointer to the spi_master structure which provides
350  *		information about the controller.
351  *
352  * This function enables SPI master controller.
353  *
354  * Return:	0 on success; error value otherwise
355  */
zynqmp_prepare_transfer_hardware(struct spi_master * master)356 static int zynqmp_prepare_transfer_hardware(struct spi_master *master)
357 {
358 	struct zynqmp_qspi *xqspi = spi_master_get_devdata(master);
359 	int ret;
360 
361 	ret = clk_enable(xqspi->refclk);
362 	if (ret)
363 		goto clk_err;
364 
365 	ret = clk_enable(xqspi->pclk);
366 	if (ret)
367 		goto clk_err;
368 
369 	zynqmp_gqspi_write(xqspi, GQSPI_EN_OFST, GQSPI_EN_MASK);
370 	return 0;
371 clk_err:
372 	return ret;
373 }
374 
375 /**
376  * zynqmp_unprepare_transfer_hardware:	Relaxes hardware after transfer
377  * @master:	Pointer to the spi_master structure which provides
378  *		information about the controller.
379  *
380  * This function disables the SPI master controller.
381  *
382  * Return:	Always 0
383  */
zynqmp_unprepare_transfer_hardware(struct spi_master * master)384 static int zynqmp_unprepare_transfer_hardware(struct spi_master *master)
385 {
386 	struct zynqmp_qspi *xqspi = spi_master_get_devdata(master);
387 
388 	zynqmp_gqspi_write(xqspi, GQSPI_EN_OFST, 0x0);
389 	clk_disable(xqspi->refclk);
390 	clk_disable(xqspi->pclk);
391 	return 0;
392 }
393 
394 /**
395  * zynqmp_qspi_chipselect:	Select or deselect the chip select line
396  * @qspi:	Pointer to the spi_device structure
397  * @is_high:	Select(0) or deselect (1) the chip select line
398  */
zynqmp_qspi_chipselect(struct spi_device * qspi,bool is_high)399 static void zynqmp_qspi_chipselect(struct spi_device *qspi, bool is_high)
400 {
401 	struct zynqmp_qspi *xqspi = spi_master_get_devdata(qspi->master);
402 	ulong timeout;
403 	u32 genfifoentry = 0x0, statusreg;
404 
405 	genfifoentry |= GQSPI_GENFIFO_MODE_SPI;
406 	genfifoentry |= xqspi->genfifobus;
407 
408 	if (!is_high) {
409 		genfifoentry |= xqspi->genfifocs;
410 		genfifoentry |= GQSPI_GENFIFO_CS_SETUP;
411 	} else {
412 		genfifoentry |= GQSPI_GENFIFO_CS_HOLD;
413 	}
414 
415 	zynqmp_gqspi_write(xqspi, GQSPI_GEN_FIFO_OFST, genfifoentry);
416 
417 	/* Manually start the generic FIFO command */
418 	zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST,
419 			zynqmp_gqspi_read(xqspi, GQSPI_CONFIG_OFST) |
420 			GQSPI_CFG_START_GEN_FIFO_MASK);
421 
422 	timeout = jiffies + msecs_to_jiffies(1000);
423 
424 	/* Wait until the generic FIFO command is empty */
425 	do {
426 		statusreg = zynqmp_gqspi_read(xqspi, GQSPI_ISR_OFST);
427 
428 		if ((statusreg & GQSPI_ISR_GENFIFOEMPTY_MASK) &&
429 			(statusreg & GQSPI_ISR_TXEMPTY_MASK))
430 			break;
431 		else
432 			cpu_relax();
433 	} while (!time_after_eq(jiffies, timeout));
434 
435 	if (time_after_eq(jiffies, timeout))
436 		dev_err(xqspi->dev, "Chip select timed out\n");
437 }
438 
439 /**
440  * zynqmp_qspi_setup_transfer:	Configure QSPI controller for specified
441  *				transfer
442  * @qspi:	Pointer to the spi_device structure
443  * @transfer:	Pointer to the spi_transfer structure which provides
444  *		information about next transfer setup parameters
445  *
446  * Sets the operational mode of QSPI controller for the next QSPI transfer and
447  * sets the requested clock frequency.
448  *
449  * Return:	Always 0
450  *
451  * Note:
452  *	If the requested frequency is not an exact match with what can be
453  *	obtained using the pre-scalar value, the driver sets the clock
454  *	frequency which is lower than the requested frequency (maximum lower)
455  *	for the transfer.
456  *
457  *	If the requested frequency is higher or lower than that is supported
458  *	by the QSPI controller the driver will set the highest or lowest
459  *	frequency supported by controller.
460  */
zynqmp_qspi_setup_transfer(struct spi_device * qspi,struct spi_transfer * transfer)461 static int zynqmp_qspi_setup_transfer(struct spi_device *qspi,
462 				      struct spi_transfer *transfer)
463 {
464 	struct zynqmp_qspi *xqspi = spi_master_get_devdata(qspi->master);
465 	ulong clk_rate;
466 	u32 config_reg, req_hz, baud_rate_val = 0;
467 
468 	if (transfer)
469 		req_hz = transfer->speed_hz;
470 	else
471 		req_hz = qspi->max_speed_hz;
472 
473 	/* Set the clock frequency */
474 	/* If req_hz == 0, default to lowest speed */
475 	clk_rate = clk_get_rate(xqspi->refclk);
476 
477 	while ((baud_rate_val < GQSPI_BAUD_DIV_MAX) &&
478 	       (clk_rate /
479 		(GQSPI_BAUD_DIV_SHIFT << baud_rate_val)) > req_hz)
480 		baud_rate_val++;
481 
482 	config_reg = zynqmp_gqspi_read(xqspi, GQSPI_CONFIG_OFST);
483 
484 	/* Set the QSPI clock phase and clock polarity */
485 	config_reg &= (~GQSPI_CFG_CLK_PHA_MASK) & (~GQSPI_CFG_CLK_POL_MASK);
486 
487 	if (qspi->mode & SPI_CPHA)
488 		config_reg |= GQSPI_CFG_CLK_PHA_MASK;
489 	if (qspi->mode & SPI_CPOL)
490 		config_reg |= GQSPI_CFG_CLK_POL_MASK;
491 
492 	config_reg &= ~GQSPI_CFG_BAUD_RATE_DIV_MASK;
493 	config_reg |= (baud_rate_val << GQSPI_CFG_BAUD_RATE_DIV_SHIFT);
494 	zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST, config_reg);
495 	return 0;
496 }
497 
498 /**
499  * zynqmp_qspi_setup:	Configure the QSPI controller
500  * @qspi:	Pointer to the spi_device structure
501  *
502  * Sets the operational mode of QSPI controller for the next QSPI transfer,
503  * baud rate and divisor value to setup the requested qspi clock.
504  *
505  * Return:	0 on success; error value otherwise.
506  */
zynqmp_qspi_setup(struct spi_device * qspi)507 static int zynqmp_qspi_setup(struct spi_device *qspi)
508 {
509 	if (qspi->master->busy)
510 		return -EBUSY;
511 	return 0;
512 }
513 
514 /**
515  * zynqmp_qspi_filltxfifo:	Fills the TX FIFO as long as there is room in
516  *				the FIFO or the bytes required to be
517  *				transmitted.
518  * @xqspi:	Pointer to the zynqmp_qspi structure
519  * @size:	Number of bytes to be copied from TX buffer to TX FIFO
520  */
zynqmp_qspi_filltxfifo(struct zynqmp_qspi * xqspi,int size)521 static void zynqmp_qspi_filltxfifo(struct zynqmp_qspi *xqspi, int size)
522 {
523 	u32 count = 0, intermediate;
524 
525 	while ((xqspi->bytes_to_transfer > 0) && (count < size)) {
526 		memcpy(&intermediate, xqspi->txbuf, 4);
527 		zynqmp_gqspi_write(xqspi, GQSPI_TXD_OFST, intermediate);
528 
529 		if (xqspi->bytes_to_transfer >= 4) {
530 			xqspi->txbuf += 4;
531 			xqspi->bytes_to_transfer -= 4;
532 		} else {
533 			xqspi->txbuf += xqspi->bytes_to_transfer;
534 			xqspi->bytes_to_transfer = 0;
535 		}
536 		count++;
537 	}
538 }
539 
540 /**
541  * zynqmp_qspi_readrxfifo:	Fills the RX FIFO as long as there is room in
542  *				the FIFO.
543  * @xqspi:	Pointer to the zynqmp_qspi structure
544  * @size:	Number of bytes to be copied from RX buffer to RX FIFO
545  */
zynqmp_qspi_readrxfifo(struct zynqmp_qspi * xqspi,u32 size)546 static void zynqmp_qspi_readrxfifo(struct zynqmp_qspi *xqspi, u32 size)
547 {
548 	ulong data;
549 	int count = 0;
550 
551 	while ((count < size) && (xqspi->bytes_to_receive > 0)) {
552 		if (xqspi->bytes_to_receive >= 4) {
553 			(*(u32 *) xqspi->rxbuf) =
554 			zynqmp_gqspi_read(xqspi, GQSPI_RXD_OFST);
555 			xqspi->rxbuf += 4;
556 			xqspi->bytes_to_receive -= 4;
557 			count += 4;
558 		} else {
559 			data = zynqmp_gqspi_read(xqspi, GQSPI_RXD_OFST);
560 			count += xqspi->bytes_to_receive;
561 			zynqmp_qspi_copy_read_data(xqspi, data,
562 						   xqspi->bytes_to_receive);
563 			xqspi->bytes_to_receive = 0;
564 		}
565 	}
566 }
567 
568 /**
569  * zynqmp_process_dma_irq:	Handler for DMA done interrupt of QSPI
570  *				controller
571  * @xqspi:	zynqmp_qspi instance pointer
572  *
573  * This function handles DMA interrupt only.
574  */
zynqmp_process_dma_irq(struct zynqmp_qspi * xqspi)575 static void zynqmp_process_dma_irq(struct zynqmp_qspi *xqspi)
576 {
577 	u32 config_reg, genfifoentry;
578 
579 	dma_unmap_single(xqspi->dev, xqspi->dma_addr,
580 				xqspi->dma_rx_bytes, DMA_FROM_DEVICE);
581 	xqspi->rxbuf += xqspi->dma_rx_bytes;
582 	xqspi->bytes_to_receive -= xqspi->dma_rx_bytes;
583 	xqspi->dma_rx_bytes = 0;
584 
585 	/* Disabling the DMA interrupts */
586 	zynqmp_gqspi_write(xqspi, GQSPI_QSPIDMA_DST_I_DIS_OFST,
587 					GQSPI_QSPIDMA_DST_I_EN_DONE_MASK);
588 
589 	if (xqspi->bytes_to_receive > 0) {
590 		/* Switch to IO mode,for remaining bytes to receive */
591 		config_reg = zynqmp_gqspi_read(xqspi, GQSPI_CONFIG_OFST);
592 		config_reg &= ~GQSPI_CFG_MODE_EN_MASK;
593 		zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST, config_reg);
594 
595 		/* Initiate the transfer of remaining bytes */
596 		genfifoentry = xqspi->genfifoentry;
597 		genfifoentry |= xqspi->bytes_to_receive;
598 		zynqmp_gqspi_write(xqspi, GQSPI_GEN_FIFO_OFST, genfifoentry);
599 
600 		/* Dummy generic FIFO entry */
601 		zynqmp_gqspi_write(xqspi, GQSPI_GEN_FIFO_OFST, 0x0);
602 
603 		/* Manual start */
604 		zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST,
605 			(zynqmp_gqspi_read(xqspi, GQSPI_CONFIG_OFST) |
606 			GQSPI_CFG_START_GEN_FIFO_MASK));
607 
608 		/* Enable the RX interrupts for IO mode */
609 		zynqmp_gqspi_write(xqspi, GQSPI_IER_OFST,
610 				GQSPI_IER_GENFIFOEMPTY_MASK |
611 				GQSPI_IER_RXNEMPTY_MASK |
612 				GQSPI_IER_RXEMPTY_MASK);
613 	}
614 }
615 
616 /**
617  * zynqmp_qspi_irq:	Interrupt service routine of the QSPI controller
618  * @irq:	IRQ number
619  * @dev_id:	Pointer to the xqspi structure
620  *
621  * This function handles TX empty only.
622  * On TX empty interrupt this function reads the received data from RX FIFO
623  * and fills the TX FIFO if there is any data remaining to be transferred.
624  *
625  * Return:	IRQ_HANDLED when interrupt is handled
626  *		IRQ_NONE otherwise.
627  */
zynqmp_qspi_irq(int irq,void * dev_id)628 static irqreturn_t zynqmp_qspi_irq(int irq, void *dev_id)
629 {
630 	struct spi_master *master = dev_id;
631 	struct zynqmp_qspi *xqspi = spi_master_get_devdata(master);
632 	int ret = IRQ_NONE;
633 	u32 status, mask, dma_status = 0;
634 
635 	status = zynqmp_gqspi_read(xqspi, GQSPI_ISR_OFST);
636 	zynqmp_gqspi_write(xqspi, GQSPI_ISR_OFST, status);
637 	mask = (status & ~(zynqmp_gqspi_read(xqspi, GQSPI_IMASK_OFST)));
638 
639 	/* Read and clear DMA status */
640 	if (xqspi->mode == GQSPI_MODE_DMA) {
641 		dma_status =
642 			zynqmp_gqspi_read(xqspi, GQSPI_QSPIDMA_DST_I_STS_OFST);
643 		zynqmp_gqspi_write(xqspi, GQSPI_QSPIDMA_DST_I_STS_OFST,
644 								dma_status);
645 	}
646 
647 	if (mask & GQSPI_ISR_TXNOT_FULL_MASK) {
648 		zynqmp_qspi_filltxfifo(xqspi, GQSPI_TX_FIFO_FILL);
649 		ret = IRQ_HANDLED;
650 	}
651 
652 	if (dma_status & GQSPI_QSPIDMA_DST_I_STS_DONE_MASK) {
653 		zynqmp_process_dma_irq(xqspi);
654 		ret = IRQ_HANDLED;
655 	} else if (!(mask & GQSPI_IER_RXEMPTY_MASK) &&
656 			(mask & GQSPI_IER_GENFIFOEMPTY_MASK)) {
657 		zynqmp_qspi_readrxfifo(xqspi, GQSPI_RX_FIFO_FILL);
658 		ret = IRQ_HANDLED;
659 	}
660 
661 	if ((xqspi->bytes_to_receive == 0) && (xqspi->bytes_to_transfer == 0)
662 			&& ((status & GQSPI_IRQ_MASK) == GQSPI_IRQ_MASK)) {
663 		zynqmp_gqspi_write(xqspi, GQSPI_IDR_OFST, GQSPI_ISR_IDR_MASK);
664 		spi_finalize_current_transfer(master);
665 		ret = IRQ_HANDLED;
666 	}
667 	return ret;
668 }
669 
670 /**
671  * zynqmp_qspi_selectspimode:	Selects SPI mode - x1 or x2 or x4.
672  * @xqspi:	xqspi is a pointer to the GQSPI instance
673  * @spimode:	spimode - SPI or DUAL or QUAD.
674  * Return:	Mask to set desired SPI mode in GENFIFO entry.
675  */
zynqmp_qspi_selectspimode(struct zynqmp_qspi * xqspi,u8 spimode)676 static inline u32 zynqmp_qspi_selectspimode(struct zynqmp_qspi *xqspi,
677 						u8 spimode)
678 {
679 	u32 mask = 0;
680 
681 	switch (spimode) {
682 	case GQSPI_SELECT_MODE_DUALSPI:
683 		mask = GQSPI_GENFIFO_MODE_DUALSPI;
684 		break;
685 	case GQSPI_SELECT_MODE_QUADSPI:
686 		mask = GQSPI_GENFIFO_MODE_QUADSPI;
687 		break;
688 	case GQSPI_SELECT_MODE_SPI:
689 		mask = GQSPI_GENFIFO_MODE_SPI;
690 		break;
691 	default:
692 		dev_warn(xqspi->dev, "Invalid SPI mode\n");
693 	}
694 
695 	return mask;
696 }
697 
698 /**
699  * zynq_qspi_setuprxdma:	This function sets up the RX DMA operation
700  * @xqspi:	xqspi is a pointer to the GQSPI instance.
701  */
zynq_qspi_setuprxdma(struct zynqmp_qspi * xqspi)702 static void zynq_qspi_setuprxdma(struct zynqmp_qspi *xqspi)
703 {
704 	u32 rx_bytes, rx_rem, config_reg;
705 	dma_addr_t addr;
706 	u64 dma_align =  (u64)(uintptr_t)xqspi->rxbuf;
707 
708 	if ((xqspi->bytes_to_receive < 8) ||
709 		((dma_align & GQSPI_DMA_UNALIGN) != 0x0)) {
710 		/* Setting to IO mode */
711 		config_reg = zynqmp_gqspi_read(xqspi, GQSPI_CONFIG_OFST);
712 		config_reg &= ~GQSPI_CFG_MODE_EN_MASK;
713 		zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST, config_reg);
714 		xqspi->mode = GQSPI_MODE_IO;
715 		xqspi->dma_rx_bytes = 0;
716 		return;
717 	}
718 
719 	rx_rem = xqspi->bytes_to_receive % 4;
720 	rx_bytes = (xqspi->bytes_to_receive - rx_rem);
721 
722 	addr = dma_map_single(xqspi->dev, (void *)xqspi->rxbuf,
723 						rx_bytes, DMA_FROM_DEVICE);
724 	if (dma_mapping_error(xqspi->dev, addr))
725 		dev_err(xqspi->dev, "ERR:rxdma:memory not mapped\n");
726 
727 	xqspi->dma_rx_bytes = rx_bytes;
728 	xqspi->dma_addr = addr;
729 	zynqmp_gqspi_write(xqspi, GQSPI_QSPIDMA_DST_ADDR_OFST,
730 				(u32)(addr & 0xffffffff));
731 	addr = ((addr >> 16) >> 16);
732 	zynqmp_gqspi_write(xqspi, GQSPI_QSPIDMA_DST_ADDR_MSB_OFST,
733 				((u32)addr) & 0xfff);
734 
735 	/* Enabling the DMA mode */
736 	config_reg = zynqmp_gqspi_read(xqspi, GQSPI_CONFIG_OFST);
737 	config_reg &= ~GQSPI_CFG_MODE_EN_MASK;
738 	config_reg |= GQSPI_CFG_MODE_EN_DMA_MASK;
739 	zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST, config_reg);
740 
741 	/* Switch to DMA mode */
742 	xqspi->mode = GQSPI_MODE_DMA;
743 
744 	/* Write the number of bytes to transfer */
745 	zynqmp_gqspi_write(xqspi, GQSPI_QSPIDMA_DST_SIZE_OFST, rx_bytes);
746 }
747 
748 /**
749  * zynqmp_qspi_txrxsetup:	This function checks the TX/RX buffers in
750  *				the transfer and sets up the GENFIFO entries,
751  *				TX FIFO as required.
752  * @xqspi:	xqspi is a pointer to the GQSPI instance.
753  * @transfer:	It is a pointer to the structure containing transfer data.
754  * @genfifoentry:	genfifoentry is pointer to the variable in which
755  *			GENFIFO	mask is returned to calling function
756  */
zynqmp_qspi_txrxsetup(struct zynqmp_qspi * xqspi,struct spi_transfer * transfer,u32 * genfifoentry)757 static void zynqmp_qspi_txrxsetup(struct zynqmp_qspi *xqspi,
758 				  struct spi_transfer *transfer,
759 				  u32 *genfifoentry)
760 {
761 	u32 config_reg;
762 
763 	/* Transmit */
764 	if ((xqspi->txbuf != NULL) && (xqspi->rxbuf == NULL)) {
765 		/* Setup data to be TXed */
766 		*genfifoentry &= ~GQSPI_GENFIFO_RX;
767 		*genfifoentry |= GQSPI_GENFIFO_DATA_XFER;
768 		*genfifoentry |= GQSPI_GENFIFO_TX;
769 		*genfifoentry |=
770 			zynqmp_qspi_selectspimode(xqspi, transfer->tx_nbits);
771 		xqspi->bytes_to_transfer = transfer->len;
772 		if (xqspi->mode == GQSPI_MODE_DMA) {
773 			config_reg = zynqmp_gqspi_read(xqspi,
774 							GQSPI_CONFIG_OFST);
775 			config_reg &= ~GQSPI_CFG_MODE_EN_MASK;
776 			zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST,
777 								config_reg);
778 			xqspi->mode = GQSPI_MODE_IO;
779 		}
780 		zynqmp_qspi_filltxfifo(xqspi, GQSPI_TXD_DEPTH);
781 		/* Discard RX data */
782 		xqspi->bytes_to_receive = 0;
783 	} else if ((xqspi->txbuf == NULL) && (xqspi->rxbuf != NULL)) {
784 		/* Receive */
785 
786 		/* TX auto fill */
787 		*genfifoentry &= ~GQSPI_GENFIFO_TX;
788 		/* Setup RX */
789 		*genfifoentry |= GQSPI_GENFIFO_DATA_XFER;
790 		*genfifoentry |= GQSPI_GENFIFO_RX;
791 		*genfifoentry |=
792 			zynqmp_qspi_selectspimode(xqspi, transfer->rx_nbits);
793 		xqspi->bytes_to_transfer = 0;
794 		xqspi->bytes_to_receive = transfer->len;
795 		zynq_qspi_setuprxdma(xqspi);
796 	}
797 }
798 
799 /**
800  * zynqmp_qspi_start_transfer:	Initiates the QSPI transfer
801  * @master:	Pointer to the spi_master structure which provides
802  *		information about the controller.
803  * @qspi:	Pointer to the spi_device structure
804  * @transfer:	Pointer to the spi_transfer structure which provide information
805  *		about next transfer parameters
806  *
807  * This function fills the TX FIFO, starts the QSPI transfer, and waits for the
808  * transfer to be completed.
809  *
810  * Return:	Number of bytes transferred in the last transfer
811  */
zynqmp_qspi_start_transfer(struct spi_master * master,struct spi_device * qspi,struct spi_transfer * transfer)812 static int zynqmp_qspi_start_transfer(struct spi_master *master,
813 				      struct spi_device *qspi,
814 				      struct spi_transfer *transfer)
815 {
816 	struct zynqmp_qspi *xqspi = spi_master_get_devdata(master);
817 	u32 genfifoentry = 0x0, transfer_len;
818 
819 	xqspi->txbuf = transfer->tx_buf;
820 	xqspi->rxbuf = transfer->rx_buf;
821 
822 	zynqmp_qspi_setup_transfer(qspi, transfer);
823 
824 	genfifoentry |= xqspi->genfifocs;
825 	genfifoentry |= xqspi->genfifobus;
826 
827 	zynqmp_qspi_txrxsetup(xqspi, transfer, &genfifoentry);
828 
829 	if (xqspi->mode == GQSPI_MODE_DMA)
830 		transfer_len = xqspi->dma_rx_bytes;
831 	else
832 		transfer_len = transfer->len;
833 
834 	xqspi->genfifoentry = genfifoentry;
835 	if ((transfer_len) < GQSPI_GENFIFO_IMM_DATA_MASK) {
836 		genfifoentry &= ~GQSPI_GENFIFO_IMM_DATA_MASK;
837 		genfifoentry |= transfer_len;
838 		zynqmp_gqspi_write(xqspi, GQSPI_GEN_FIFO_OFST, genfifoentry);
839 	} else {
840 		int tempcount = transfer_len;
841 		u32 exponent = 8;	/* 2^8 = 256 */
842 		u8 imm_data = tempcount & 0xFF;
843 
844 		tempcount &= ~(tempcount & 0xFF);
845 		/* Immediate entry */
846 		if (tempcount != 0) {
847 			/* Exponent entries */
848 			genfifoentry |= GQSPI_GENFIFO_EXP;
849 			while (tempcount != 0) {
850 				if (tempcount & GQSPI_GENFIFO_EXP_START) {
851 					genfifoentry &=
852 					    ~GQSPI_GENFIFO_IMM_DATA_MASK;
853 					genfifoentry |= exponent;
854 					zynqmp_gqspi_write(xqspi,
855 							   GQSPI_GEN_FIFO_OFST,
856 							   genfifoentry);
857 				}
858 				tempcount = tempcount >> 1;
859 				exponent++;
860 			}
861 		}
862 		if (imm_data != 0) {
863 			genfifoentry &= ~GQSPI_GENFIFO_EXP;
864 			genfifoentry &= ~GQSPI_GENFIFO_IMM_DATA_MASK;
865 			genfifoentry |= (u8) (imm_data & 0xFF);
866 			zynqmp_gqspi_write(xqspi,
867 					   GQSPI_GEN_FIFO_OFST, genfifoentry);
868 		}
869 	}
870 
871 	if ((xqspi->mode == GQSPI_MODE_IO) &&
872 			(xqspi->rxbuf != NULL)) {
873 		/* Dummy generic FIFO entry */
874 		zynqmp_gqspi_write(xqspi, GQSPI_GEN_FIFO_OFST, 0x0);
875 	}
876 
877 	/* Since we are using manual mode */
878 	zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST,
879 			   zynqmp_gqspi_read(xqspi, GQSPI_CONFIG_OFST) |
880 			   GQSPI_CFG_START_GEN_FIFO_MASK);
881 
882 	if (xqspi->txbuf != NULL)
883 		/* Enable interrupts for TX */
884 		zynqmp_gqspi_write(xqspi, GQSPI_IER_OFST,
885 				   GQSPI_IER_TXEMPTY_MASK |
886 					GQSPI_IER_GENFIFOEMPTY_MASK |
887 					GQSPI_IER_TXNOT_FULL_MASK);
888 
889 	if (xqspi->rxbuf != NULL) {
890 		/* Enable interrupts for RX */
891 		if (xqspi->mode == GQSPI_MODE_DMA) {
892 			/* Enable DMA interrupts */
893 			zynqmp_gqspi_write(xqspi,
894 					GQSPI_QSPIDMA_DST_I_EN_OFST,
895 					GQSPI_QSPIDMA_DST_I_EN_DONE_MASK);
896 		} else {
897 			zynqmp_gqspi_write(xqspi, GQSPI_IER_OFST,
898 					GQSPI_IER_GENFIFOEMPTY_MASK |
899 					GQSPI_IER_RXNEMPTY_MASK |
900 					GQSPI_IER_RXEMPTY_MASK);
901 		}
902 	}
903 
904 	return transfer->len;
905 }
906 
907 /**
908  * zynqmp_qspi_suspend:	Suspend method for the QSPI driver
909  * @_dev:	Address of the platform_device structure
910  *
911  * This function stops the QSPI driver queue and disables the QSPI controller
912  *
913  * Return:	Always 0
914  */
zynqmp_qspi_suspend(struct device * dev)915 static int __maybe_unused zynqmp_qspi_suspend(struct device *dev)
916 {
917 	struct platform_device *pdev = container_of(dev,
918 						    struct platform_device,
919 						    dev);
920 	struct spi_master *master = platform_get_drvdata(pdev);
921 
922 	spi_master_suspend(master);
923 
924 	zynqmp_unprepare_transfer_hardware(master);
925 
926 	return 0;
927 }
928 
929 /**
930  * zynqmp_qspi_resume:	Resume method for the QSPI driver
931  * @dev:	Address of the platform_device structure
932  *
933  * The function starts the QSPI driver queue and initializes the QSPI
934  * controller
935  *
936  * Return:	0 on success; error value otherwise
937  */
zynqmp_qspi_resume(struct device * dev)938 static int __maybe_unused zynqmp_qspi_resume(struct device *dev)
939 {
940 	struct platform_device *pdev = container_of(dev,
941 						    struct platform_device,
942 						    dev);
943 	struct spi_master *master = platform_get_drvdata(pdev);
944 	struct zynqmp_qspi *xqspi = spi_master_get_devdata(master);
945 	int ret = 0;
946 
947 	ret = clk_enable(xqspi->pclk);
948 	if (ret) {
949 		dev_err(dev, "Cannot enable APB clock.\n");
950 		return ret;
951 	}
952 
953 	ret = clk_enable(xqspi->refclk);
954 	if (ret) {
955 		dev_err(dev, "Cannot enable device clock.\n");
956 		clk_disable(xqspi->pclk);
957 		return ret;
958 	}
959 
960 	spi_master_resume(master);
961 
962 	return 0;
963 }
964 
965 static SIMPLE_DEV_PM_OPS(zynqmp_qspi_dev_pm_ops, zynqmp_qspi_suspend,
966 			 zynqmp_qspi_resume);
967 
968 /**
969  * zynqmp_qspi_probe:	Probe method for the QSPI driver
970  * @pdev:	Pointer to the platform_device structure
971  *
972  * This function initializes the driver data structures and the hardware.
973  *
974  * Return:	0 on success; error value otherwise
975  */
zynqmp_qspi_probe(struct platform_device * pdev)976 static int zynqmp_qspi_probe(struct platform_device *pdev)
977 {
978 	int ret = 0;
979 	struct spi_master *master;
980 	struct zynqmp_qspi *xqspi;
981 	struct resource *res;
982 	struct device *dev = &pdev->dev;
983 
984 	master = spi_alloc_master(&pdev->dev, sizeof(*xqspi));
985 	if (!master)
986 		return -ENOMEM;
987 
988 	xqspi = spi_master_get_devdata(master);
989 	master->dev.of_node = pdev->dev.of_node;
990 	platform_set_drvdata(pdev, master);
991 
992 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
993 	xqspi->regs = devm_ioremap_resource(&pdev->dev, res);
994 	if (IS_ERR(xqspi->regs)) {
995 		ret = PTR_ERR(xqspi->regs);
996 		goto remove_master;
997 	}
998 
999 	xqspi->dev = dev;
1000 	xqspi->pclk = devm_clk_get(&pdev->dev, "pclk");
1001 	if (IS_ERR(xqspi->pclk)) {
1002 		dev_err(dev, "pclk clock not found.\n");
1003 		ret = PTR_ERR(xqspi->pclk);
1004 		goto remove_master;
1005 	}
1006 
1007 	ret = clk_prepare_enable(xqspi->pclk);
1008 	if (ret) {
1009 		dev_err(dev, "Unable to enable APB clock.\n");
1010 		goto remove_master;
1011 	}
1012 
1013 	xqspi->refclk = devm_clk_get(&pdev->dev, "ref_clk");
1014 	if (IS_ERR(xqspi->refclk)) {
1015 		dev_err(dev, "ref_clk clock not found.\n");
1016 		ret = PTR_ERR(xqspi->refclk);
1017 		goto clk_dis_pclk;
1018 	}
1019 
1020 	ret = clk_prepare_enable(xqspi->refclk);
1021 	if (ret) {
1022 		dev_err(dev, "Unable to enable device clock.\n");
1023 		goto clk_dis_pclk;
1024 	}
1025 
1026 	/* QSPI controller initializations */
1027 	zynqmp_qspi_init_hw(xqspi);
1028 
1029 	xqspi->irq = platform_get_irq(pdev, 0);
1030 	if (xqspi->irq <= 0) {
1031 		ret = -ENXIO;
1032 		dev_err(dev, "irq resource not found\n");
1033 		goto clk_dis_all;
1034 	}
1035 	ret = devm_request_irq(&pdev->dev, xqspi->irq, zynqmp_qspi_irq,
1036 			       0, pdev->name, master);
1037 	if (ret != 0) {
1038 		ret = -ENXIO;
1039 		dev_err(dev, "request_irq failed\n");
1040 		goto clk_dis_all;
1041 	}
1042 
1043 	master->num_chipselect = GQSPI_DEFAULT_NUM_CS;
1044 
1045 	master->setup = zynqmp_qspi_setup;
1046 	master->set_cs = zynqmp_qspi_chipselect;
1047 	master->transfer_one = zynqmp_qspi_start_transfer;
1048 	master->prepare_transfer_hardware = zynqmp_prepare_transfer_hardware;
1049 	master->unprepare_transfer_hardware =
1050 					zynqmp_unprepare_transfer_hardware;
1051 	master->max_speed_hz = clk_get_rate(xqspi->refclk) / 2;
1052 	master->bits_per_word_mask = SPI_BPW_MASK(8);
1053 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_RX_DUAL | SPI_RX_QUAD |
1054 			    SPI_TX_DUAL | SPI_TX_QUAD;
1055 
1056 	if (master->dev.parent == NULL)
1057 		master->dev.parent = &master->dev;
1058 
1059 	ret = spi_register_master(master);
1060 	if (ret)
1061 		goto clk_dis_all;
1062 
1063 	return 0;
1064 
1065 clk_dis_all:
1066 	clk_disable_unprepare(xqspi->refclk);
1067 clk_dis_pclk:
1068 	clk_disable_unprepare(xqspi->pclk);
1069 remove_master:
1070 	spi_master_put(master);
1071 
1072 	return ret;
1073 }
1074 
1075 /**
1076  * zynqmp_qspi_remove:	Remove method for the QSPI driver
1077  * @pdev:	Pointer to the platform_device structure
1078  *
1079  * This function is called if a device is physically removed from the system or
1080  * if the driver module is being unloaded. It frees all resources allocated to
1081  * the device.
1082  *
1083  * Return:	0 Always
1084  */
zynqmp_qspi_remove(struct platform_device * pdev)1085 static int zynqmp_qspi_remove(struct platform_device *pdev)
1086 {
1087 	struct spi_master *master = platform_get_drvdata(pdev);
1088 	struct zynqmp_qspi *xqspi = spi_master_get_devdata(master);
1089 
1090 	zynqmp_gqspi_write(xqspi, GQSPI_EN_OFST, 0x0);
1091 	clk_disable_unprepare(xqspi->refclk);
1092 	clk_disable_unprepare(xqspi->pclk);
1093 
1094 	spi_unregister_master(master);
1095 
1096 	return 0;
1097 }
1098 
1099 static const struct of_device_id zynqmp_qspi_of_match[] = {
1100 	{ .compatible = "xlnx,zynqmp-qspi-1.0", },
1101 	{ /* End of table */ }
1102 };
1103 
1104 MODULE_DEVICE_TABLE(of, zynqmp_qspi_of_match);
1105 
1106 static struct platform_driver zynqmp_qspi_driver = {
1107 	.probe = zynqmp_qspi_probe,
1108 	.remove = zynqmp_qspi_remove,
1109 	.driver = {
1110 		.name = "zynqmp-qspi",
1111 		.of_match_table = zynqmp_qspi_of_match,
1112 		.pm = &zynqmp_qspi_dev_pm_ops,
1113 	},
1114 };
1115 
1116 module_platform_driver(zynqmp_qspi_driver);
1117 
1118 MODULE_AUTHOR("Xilinx, Inc.");
1119 MODULE_DESCRIPTION("Xilinx Zynqmp QSPI driver");
1120 MODULE_LICENSE("GPL");
1121