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Stefan Roese5bef6fd2014-11-07 13:50:31 +01001/*
2 * Designware master SPI core controller driver
3 *
4 * Copyright (C) 2014 Stefan Roese <sr@denx.de>
5 *
Stefan Roesea72f8022014-11-16 12:47:01 +01006 * Very loosely based on the Linux driver:
7 * drivers/spi/spi-dw.c, which is:
Stefan Roese5bef6fd2014-11-07 13:50:31 +01008 * Copyright (c) 2009, Intel Corporation.
9 *
10 * SPDX-License-Identifier: GPL-2.0
11 */
12
13#include <common.h>
14#include <dm.h>
15#include <errno.h>
16#include <malloc.h>
17#include <spi.h>
18#include <fdtdec.h>
19#include <linux/compat.h>
20#include <asm/io.h>
Stefan Roesea72f8022014-11-16 12:47:01 +010021#include <asm/arch/clock_manager.h>
Stefan Roese5bef6fd2014-11-07 13:50:31 +010022
23DECLARE_GLOBAL_DATA_PTR;
24
25/* Register offsets */
26#define DW_SPI_CTRL0 0x00
27#define DW_SPI_CTRL1 0x04
28#define DW_SPI_SSIENR 0x08
29#define DW_SPI_MWCR 0x0c
30#define DW_SPI_SER 0x10
31#define DW_SPI_BAUDR 0x14
32#define DW_SPI_TXFLTR 0x18
33#define DW_SPI_RXFLTR 0x1c
34#define DW_SPI_TXFLR 0x20
35#define DW_SPI_RXFLR 0x24
36#define DW_SPI_SR 0x28
37#define DW_SPI_IMR 0x2c
38#define DW_SPI_ISR 0x30
39#define DW_SPI_RISR 0x34
40#define DW_SPI_TXOICR 0x38
41#define DW_SPI_RXOICR 0x3c
42#define DW_SPI_RXUICR 0x40
43#define DW_SPI_MSTICR 0x44
44#define DW_SPI_ICR 0x48
45#define DW_SPI_DMACR 0x4c
46#define DW_SPI_DMATDLR 0x50
47#define DW_SPI_DMARDLR 0x54
48#define DW_SPI_IDR 0x58
49#define DW_SPI_VERSION 0x5c
50#define DW_SPI_DR 0x60
51
52/* Bit fields in CTRLR0 */
53#define SPI_DFS_OFFSET 0
54
55#define SPI_FRF_OFFSET 4
56#define SPI_FRF_SPI 0x0
57#define SPI_FRF_SSP 0x1
58#define SPI_FRF_MICROWIRE 0x2
59#define SPI_FRF_RESV 0x3
60
61#define SPI_MODE_OFFSET 6
62#define SPI_SCPH_OFFSET 6
63#define SPI_SCOL_OFFSET 7
64
65#define SPI_TMOD_OFFSET 8
66#define SPI_TMOD_MASK (0x3 << SPI_TMOD_OFFSET)
67#define SPI_TMOD_TR 0x0 /* xmit & recv */
68#define SPI_TMOD_TO 0x1 /* xmit only */
69#define SPI_TMOD_RO 0x2 /* recv only */
70#define SPI_TMOD_EPROMREAD 0x3 /* eeprom read mode */
71
72#define SPI_SLVOE_OFFSET 10
73#define SPI_SRL_OFFSET 11
74#define SPI_CFS_OFFSET 12
75
76/* Bit fields in SR, 7 bits */
77#define SR_MASK 0x7f /* cover 7 bits */
78#define SR_BUSY (1 << 0)
79#define SR_TF_NOT_FULL (1 << 1)
80#define SR_TF_EMPT (1 << 2)
81#define SR_RF_NOT_EMPT (1 << 3)
82#define SR_RF_FULL (1 << 4)
83#define SR_TX_ERR (1 << 5)
84#define SR_DCOL (1 << 6)
85
Stefan Roesea72f8022014-11-16 12:47:01 +010086#define RX_TIMEOUT 1000 /* timeout in ms */
Stefan Roese5bef6fd2014-11-07 13:50:31 +010087
88struct dw_spi_platdata {
89 s32 frequency; /* Default clock frequency, -1 for none */
90 void __iomem *regs;
91};
92
93struct dw_spi_priv {
94 void __iomem *regs;
95 unsigned int freq; /* Default frequency */
96 unsigned int mode;
97
98 int bits_per_word;
99 u8 cs; /* chip select pin */
Stefan Roese5bef6fd2014-11-07 13:50:31 +0100100 u8 tmode; /* TR/TO/RO/EEPROM */
101 u8 type; /* SPI/SSP/MicroWire */
102 int len;
103
104 u32 fifo_len; /* depth of the FIFO buffer */
105 void *tx;
106 void *tx_end;
107 void *rx;
108 void *rx_end;
109};
110
111static inline u32 dw_readl(struct dw_spi_priv *priv, u32 offset)
112{
113 return __raw_readl(priv->regs + offset);
114}
115
116static inline void dw_writel(struct dw_spi_priv *priv, u32 offset, u32 val)
117{
118 __raw_writel(val, priv->regs + offset);
119}
120
121static inline u16 dw_readw(struct dw_spi_priv *priv, u32 offset)
122{
123 return __raw_readw(priv->regs + offset);
124}
125
126static inline void dw_writew(struct dw_spi_priv *priv, u32 offset, u16 val)
127{
128 __raw_writew(val, priv->regs + offset);
129}
130
131static int dw_spi_ofdata_to_platdata(struct udevice *bus)
132{
133 struct dw_spi_platdata *plat = bus->platdata;
134 const void *blob = gd->fdt_blob;
135 int node = bus->of_offset;
136
137 plat->regs = (struct dw_spi *)fdtdec_get_addr(blob, node, "reg");
138
139 /* Use 500KHz as a suitable default */
140 plat->frequency = fdtdec_get_int(blob, node, "spi-max-frequency",
141 500000);
142 debug("%s: regs=%p max-frequency=%d\n", __func__, plat->regs,
143 plat->frequency);
144
145 return 0;
146}
147
148static inline void spi_enable_chip(struct dw_spi_priv *priv, int enable)
149{
150 dw_writel(priv, DW_SPI_SSIENR, (enable ? 1 : 0));
151}
152
153/* Restart the controller, disable all interrupts, clean rx fifo */
154static void spi_hw_init(struct dw_spi_priv *priv)
155{
156 spi_enable_chip(priv, 0);
157 dw_writel(priv, DW_SPI_IMR, 0xff);
158 spi_enable_chip(priv, 1);
159
160 /*
161 * Try to detect the FIFO depth if not set by interface driver,
162 * the depth could be from 2 to 256 from HW spec
163 */
164 if (!priv->fifo_len) {
165 u32 fifo;
166
Axel Lin52091ad2015-02-26 10:45:22 +0800167 for (fifo = 1; fifo < 256; fifo++) {
Stefan Roese5bef6fd2014-11-07 13:50:31 +0100168 dw_writew(priv, DW_SPI_TXFLTR, fifo);
169 if (fifo != dw_readw(priv, DW_SPI_TXFLTR))
170 break;
171 }
172
Axel Lin52091ad2015-02-26 10:45:22 +0800173 priv->fifo_len = (fifo == 1) ? 0 : fifo;
Stefan Roese5bef6fd2014-11-07 13:50:31 +0100174 dw_writew(priv, DW_SPI_TXFLTR, 0);
175 }
176 debug("%s: fifo_len=%d\n", __func__, priv->fifo_len);
177}
178
179static int dw_spi_probe(struct udevice *bus)
180{
181 struct dw_spi_platdata *plat = dev_get_platdata(bus);
182 struct dw_spi_priv *priv = dev_get_priv(bus);
183
184 priv->regs = plat->regs;
185 priv->freq = plat->frequency;
186
187 /* Currently only bits_per_word == 8 supported */
188 priv->bits_per_word = 8;
Stefan Roese5bef6fd2014-11-07 13:50:31 +0100189
190 priv->tmode = 0; /* Tx & Rx */
191
192 /* Basic HW init */
193 spi_hw_init(priv);
194
195 return 0;
196}
197
198/* Return the max entries we can fill into tx fifo */
199static inline u32 tx_max(struct dw_spi_priv *priv)
200{
201 u32 tx_left, tx_room, rxtx_gap;
202
Stefan Roesea72f8022014-11-16 12:47:01 +0100203 tx_left = (priv->tx_end - priv->tx) / (priv->bits_per_word >> 3);
Stefan Roese5bef6fd2014-11-07 13:50:31 +0100204 tx_room = priv->fifo_len - dw_readw(priv, DW_SPI_TXFLR);
205
206 /*
207 * Another concern is about the tx/rx mismatch, we
Stefan Roesea72f8022014-11-16 12:47:01 +0100208 * thought about using (priv->fifo_len - rxflr - txflr) as
Stefan Roese5bef6fd2014-11-07 13:50:31 +0100209 * one maximum value for tx, but it doesn't cover the
210 * data which is out of tx/rx fifo and inside the
211 * shift registers. So a control from sw point of
212 * view is taken.
213 */
214 rxtx_gap = ((priv->rx_end - priv->rx) - (priv->tx_end - priv->tx)) /
Stefan Roesea72f8022014-11-16 12:47:01 +0100215 (priv->bits_per_word >> 3);
Stefan Roese5bef6fd2014-11-07 13:50:31 +0100216
217 return min3(tx_left, tx_room, (u32)(priv->fifo_len - rxtx_gap));
218}
219
220/* Return the max entries we should read out of rx fifo */
221static inline u32 rx_max(struct dw_spi_priv *priv)
222{
Stefan Roesea72f8022014-11-16 12:47:01 +0100223 u32 rx_left = (priv->rx_end - priv->rx) / (priv->bits_per_word >> 3);
Stefan Roese5bef6fd2014-11-07 13:50:31 +0100224
225 return min_t(u32, rx_left, dw_readw(priv, DW_SPI_RXFLR));
226}
227
228static void dw_writer(struct dw_spi_priv *priv)
229{
230 u32 max = tx_max(priv);
231 u16 txw = 0;
232
233 while (max--) {
234 /* Set the tx word if the transfer's original "tx" is not null */
235 if (priv->tx_end - priv->len) {
Stefan Roesea72f8022014-11-16 12:47:01 +0100236 if (priv->bits_per_word == 8)
Stefan Roese5bef6fd2014-11-07 13:50:31 +0100237 txw = *(u8 *)(priv->tx);
238 else
239 txw = *(u16 *)(priv->tx);
240 }
241 dw_writew(priv, DW_SPI_DR, txw);
242 debug("%s: tx=0x%02x\n", __func__, txw);
Stefan Roesea72f8022014-11-16 12:47:01 +0100243 priv->tx += priv->bits_per_word >> 3;
Stefan Roese5bef6fd2014-11-07 13:50:31 +0100244 }
245}
246
247static int dw_reader(struct dw_spi_priv *priv)
248{
249 unsigned start = get_timer(0);
250 u32 max;
251 u16 rxw;
252
253 /* Wait for rx data to be ready */
254 while (rx_max(priv) == 0) {
255 if (get_timer(start) > RX_TIMEOUT)
256 return -ETIMEDOUT;
257 }
258
259 max = rx_max(priv);
260
261 while (max--) {
262 rxw = dw_readw(priv, DW_SPI_DR);
263 debug("%s: rx=0x%02x\n", __func__, rxw);
Stefan Roesea72f8022014-11-16 12:47:01 +0100264
265 /*
266 * Care about rx only if the transfer's original "rx" is
267 * not null
268 */
Stefan Roese5bef6fd2014-11-07 13:50:31 +0100269 if (priv->rx_end - priv->len) {
Stefan Roesea72f8022014-11-16 12:47:01 +0100270 if (priv->bits_per_word == 8)
Stefan Roese5bef6fd2014-11-07 13:50:31 +0100271 *(u8 *)(priv->rx) = rxw;
272 else
273 *(u16 *)(priv->rx) = rxw;
274 }
Stefan Roesea72f8022014-11-16 12:47:01 +0100275 priv->rx += priv->bits_per_word >> 3;
Stefan Roese5bef6fd2014-11-07 13:50:31 +0100276 }
277
278 return 0;
279}
280
281static int poll_transfer(struct dw_spi_priv *priv)
282{
283 int ret;
284
285 do {
286 dw_writer(priv);
287 ret = dw_reader(priv);
288 if (ret < 0)
289 return ret;
290 } while (priv->rx_end > priv->rx);
291
292 return 0;
293}
294
295static int dw_spi_xfer(struct udevice *dev, unsigned int bitlen,
296 const void *dout, void *din, unsigned long flags)
297{
298 struct udevice *bus = dev->parent;
299 struct dw_spi_priv *priv = dev_get_priv(bus);
300 const u8 *tx = dout;
301 u8 *rx = din;
302 int ret = 0;
303 u32 cr0 = 0;
Stefan Roese5bef6fd2014-11-07 13:50:31 +0100304 u32 cs;
305
306 /* spi core configured to do 8 bit transfers */
307 if (bitlen % 8) {
308 debug("Non byte aligned SPI transfer.\n");
309 return -1;
310 }
311
Stefan Roesea72f8022014-11-16 12:47:01 +0100312 cr0 = (priv->bits_per_word - 1) | (priv->type << SPI_FRF_OFFSET) |
Stefan Roese5bef6fd2014-11-07 13:50:31 +0100313 (priv->mode << SPI_MODE_OFFSET) |
314 (priv->tmode << SPI_TMOD_OFFSET);
315
316 if (rx && tx)
317 priv->tmode = SPI_TMOD_TR;
318 else if (rx)
319 priv->tmode = SPI_TMOD_RO;
320 else
321 priv->tmode = SPI_TMOD_TO;
322
323 cr0 &= ~SPI_TMOD_MASK;
324 cr0 |= (priv->tmode << SPI_TMOD_OFFSET);
325
Stefan Roesea72f8022014-11-16 12:47:01 +0100326 priv->len = bitlen >> 3;
Stefan Roese5bef6fd2014-11-07 13:50:31 +0100327 debug("%s: rx=%p tx=%p len=%d [bytes]\n", __func__, rx, tx, priv->len);
328
329 priv->tx = (void *)tx;
330 priv->tx_end = priv->tx + priv->len;
331 priv->rx = rx;
332 priv->rx_end = priv->rx + priv->len;
333
334 /* Disable controller before writing control registers */
335 spi_enable_chip(priv, 0);
336
337 debug("%s: cr0=%08x\n", __func__, cr0);
338 /* Reprogram cr0 only if changed */
339 if (dw_readw(priv, DW_SPI_CTRL0) != cr0)
340 dw_writew(priv, DW_SPI_CTRL0, cr0);
341
342 /*
343 * Configure the desired SS (slave select 0...3) in the controller
344 * The DW SPI controller will activate and deactivate this CS
345 * automatically. So no cs_activate() etc is needed in this driver.
346 */
347 cs = spi_chip_select(dev);
348 dw_writel(priv, DW_SPI_SER, 1 << cs);
349
350 /* Enable controller after writing control registers */
351 spi_enable_chip(priv, 1);
352
353 /* Start transfer in a polling loop */
354 ret = poll_transfer(priv);
355
356 return ret;
357}
358
359static int dw_spi_set_speed(struct udevice *bus, uint speed)
360{
361 struct dw_spi_platdata *plat = bus->platdata;
362 struct dw_spi_priv *priv = dev_get_priv(bus);
363 u16 clk_div;
364
365 if (speed > plat->frequency)
366 speed = plat->frequency;
367
368 /* Disable controller before writing control registers */
369 spi_enable_chip(priv, 0);
370
371 /* clk_div doesn't support odd number */
Stefan Roesea72f8022014-11-16 12:47:01 +0100372 clk_div = cm_get_spi_controller_clk_hz() / speed;
Stefan Roese5bef6fd2014-11-07 13:50:31 +0100373 clk_div = (clk_div + 1) & 0xfffe;
374 dw_writel(priv, DW_SPI_BAUDR, clk_div);
375
376 /* Enable controller after writing control registers */
377 spi_enable_chip(priv, 1);
378
379 priv->freq = speed;
380 debug("%s: regs=%p speed=%d clk_div=%d\n", __func__, priv->regs,
381 priv->freq, clk_div);
382
383 return 0;
384}
385
386static int dw_spi_set_mode(struct udevice *bus, uint mode)
387{
388 struct dw_spi_priv *priv = dev_get_priv(bus);
389
390 /*
391 * Can't set mode yet. Since this depends on if rx, tx, or
392 * rx & tx is requested. So we have to defer this to the
393 * real transfer function.
394 */
395 priv->mode = mode;
396 debug("%s: regs=%p, mode=%d\n", __func__, priv->regs, priv->mode);
397
398 return 0;
399}
400
401static const struct dm_spi_ops dw_spi_ops = {
402 .xfer = dw_spi_xfer,
403 .set_speed = dw_spi_set_speed,
404 .set_mode = dw_spi_set_mode,
405 /*
406 * cs_info is not needed, since we require all chip selects to be
407 * in the device tree explicitly
408 */
409};
410
411static const struct udevice_id dw_spi_ids[] = {
Marek Vasut74114862014-12-31 20:14:55 +0100412 { .compatible = "snps,dw-apb-ssi" },
Stefan Roese5bef6fd2014-11-07 13:50:31 +0100413 { }
414};
415
416U_BOOT_DRIVER(dw_spi) = {
417 .name = "dw_spi",
418 .id = UCLASS_SPI,
419 .of_match = dw_spi_ids,
420 .ops = &dw_spi_ops,
421 .ofdata_to_platdata = dw_spi_ofdata_to_platdata,
422 .platdata_auto_alloc_size = sizeof(struct dw_spi_platdata),
423 .priv_auto_alloc_size = sizeof(struct dw_spi_priv),
Stefan Roese5bef6fd2014-11-07 13:50:31 +0100424 .probe = dw_spi_probe,
425};