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d1c8bbd7 KM |
1 | /* |
2 | * SuperH HSPI bus driver | |
3 | * | |
4 | * Copyright (C) 2011 Kuninori Morimoto | |
5 | * | |
6 | * Based on spi-sh.c: | |
7 | * Based on pxa2xx_spi.c: | |
8 | * Copyright (C) 2011 Renesas Solutions Corp. | |
9 | * Copyright (C) 2005 Stephen Street / StreetFire Sound Labs | |
10 | * | |
11 | * This program is free software; you can redistribute it and/or modify | |
12 | * it under the terms of the GNU General Public License as published by | |
13 | * the Free Software Foundation; version 2 of the License. | |
14 | * | |
15 | * This program is distributed in the hope that it will be useful, | |
16 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
18 | * GNU General Public License for more details. | |
19 | * | |
20 | * You should have received a copy of the GNU General Public License | |
21 | * along with this program; if not, write to the Free Software | |
22 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
23 | * | |
24 | */ | |
49e599b8 KM |
25 | |
26 | #include <linux/clk.h> | |
d1c8bbd7 KM |
27 | #include <linux/module.h> |
28 | #include <linux/kernel.h> | |
29 | #include <linux/timer.h> | |
30 | #include <linux/delay.h> | |
31 | #include <linux/list.h> | |
d1c8bbd7 KM |
32 | #include <linux/interrupt.h> |
33 | #include <linux/platform_device.h> | |
34 | #include <linux/pm_runtime.h> | |
35 | #include <linux/io.h> | |
36 | #include <linux/spi/spi.h> | |
37 | #include <linux/spi/sh_hspi.h> | |
38 | ||
39 | #define SPCR 0x00 | |
40 | #define SPSR 0x04 | |
41 | #define SPSCR 0x08 | |
42 | #define SPTBR 0x0C | |
43 | #define SPRBR 0x10 | |
44 | #define SPCR2 0x14 | |
45 | ||
46 | /* SPSR */ | |
47 | #define RXFL (1 << 2) | |
48 | ||
49 | #define hspi2info(h) (h->dev->platform_data) | |
50 | ||
51 | struct hspi_priv { | |
52 | void __iomem *addr; | |
53 | struct spi_master *master; | |
d1c8bbd7 | 54 | struct device *dev; |
49e599b8 | 55 | struct clk *clk; |
d1c8bbd7 KM |
56 | }; |
57 | ||
58 | /* | |
59 | * basic function | |
60 | */ | |
61 | static void hspi_write(struct hspi_priv *hspi, int reg, u32 val) | |
62 | { | |
63 | iowrite32(val, hspi->addr + reg); | |
64 | } | |
65 | ||
66 | static u32 hspi_read(struct hspi_priv *hspi, int reg) | |
67 | { | |
68 | return ioread32(hspi->addr + reg); | |
69 | } | |
70 | ||
ce329305 PE |
71 | static void hspi_bit_set(struct hspi_priv *hspi, int reg, u32 mask, u32 set) |
72 | { | |
73 | u32 val = hspi_read(hspi, reg); | |
74 | ||
75 | val &= ~mask; | |
76 | val |= set & mask; | |
77 | ||
78 | hspi_write(hspi, reg, val); | |
79 | } | |
80 | ||
d1c8bbd7 KM |
81 | /* |
82 | * transfer function | |
83 | */ | |
84 | static int hspi_status_check_timeout(struct hspi_priv *hspi, u32 mask, u32 val) | |
85 | { | |
86 | int t = 256; | |
87 | ||
88 | while (t--) { | |
89 | if ((mask & hspi_read(hspi, SPSR)) == val) | |
90 | return 0; | |
91 | ||
92 | msleep(20); | |
93 | } | |
94 | ||
95 | dev_err(hspi->dev, "timeout\n"); | |
96 | return -ETIMEDOUT; | |
97 | } | |
98 | ||
ec139b67 KM |
99 | /* |
100 | * spi master function | |
101 | */ | |
102 | static int hspi_prepare_transfer(struct spi_master *master) | |
d1c8bbd7 | 103 | { |
ec139b67 | 104 | struct hspi_priv *hspi = spi_master_get_devdata(master); |
d1c8bbd7 | 105 | |
d1c8bbd7 | 106 | pm_runtime_get_sync(hspi->dev); |
ec139b67 KM |
107 | return 0; |
108 | } | |
d1c8bbd7 | 109 | |
ec139b67 KM |
110 | static int hspi_unprepare_transfer(struct spi_master *master) |
111 | { | |
112 | struct hspi_priv *hspi = spi_master_get_devdata(master); | |
d1c8bbd7 | 113 | |
ec139b67 KM |
114 | pm_runtime_put_sync(hspi->dev); |
115 | return 0; | |
116 | } | |
d1c8bbd7 | 117 | |
ce329305 PE |
118 | #define hspi_hw_cs_enable(hspi) hspi_hw_cs_ctrl(hspi, 0) |
119 | #define hspi_hw_cs_disable(hspi) hspi_hw_cs_ctrl(hspi, 1) | |
120 | static void hspi_hw_cs_ctrl(struct hspi_priv *hspi, int hi) | |
121 | { | |
122 | hspi_bit_set(hspi, SPSCR, (1 << 6), (hi) << 6); | |
123 | } | |
124 | ||
49e599b8 KM |
125 | static void hspi_hw_setup(struct hspi_priv *hspi, |
126 | struct spi_message *msg, | |
127 | struct spi_transfer *t) | |
128 | { | |
129 | struct spi_device *spi = msg->spi; | |
130 | struct device *dev = hspi->dev; | |
131 | u32 target_rate; | |
132 | u32 spcr, idiv_clk; | |
133 | u32 rate, best_rate, min, tmp; | |
134 | ||
135 | target_rate = t ? t->speed_hz : 0; | |
136 | if (!target_rate) | |
137 | target_rate = spi->max_speed_hz; | |
138 | ||
139 | /* | |
140 | * find best IDIV/CLKCx settings | |
141 | */ | |
142 | min = ~0; | |
143 | best_rate = 0; | |
144 | spcr = 0; | |
145 | for (idiv_clk = 0x00; idiv_clk <= 0x3F; idiv_clk++) { | |
146 | rate = clk_get_rate(hspi->clk); | |
147 | ||
148 | /* IDIV calculation */ | |
149 | if (idiv_clk & (1 << 5)) | |
150 | rate /= 128; | |
151 | else | |
152 | rate /= 16; | |
153 | ||
154 | /* CLKCx calculation */ | |
155 | rate /= (((idiv_clk & 0x1F) + 1) * 2) ; | |
156 | ||
157 | /* save best settings */ | |
158 | tmp = abs(target_rate - rate); | |
159 | if (tmp < min) { | |
160 | min = tmp; | |
161 | spcr = idiv_clk; | |
162 | best_rate = rate; | |
163 | } | |
164 | } | |
165 | ||
166 | if (spi->mode & SPI_CPHA) | |
167 | spcr |= 1 << 7; | |
168 | if (spi->mode & SPI_CPOL) | |
169 | spcr |= 1 << 6; | |
170 | ||
171 | dev_dbg(dev, "speed %d/%d\n", target_rate, best_rate); | |
172 | ||
173 | hspi_write(hspi, SPCR, spcr); | |
174 | hspi_write(hspi, SPSR, 0x0); | |
ce329305 | 175 | hspi_write(hspi, SPSCR, 0x21); /* master mode / CS control */ |
49e599b8 KM |
176 | } |
177 | ||
ec139b67 KM |
178 | static int hspi_transfer_one_message(struct spi_master *master, |
179 | struct spi_message *msg) | |
180 | { | |
181 | struct hspi_priv *hspi = spi_master_get_devdata(master); | |
182 | struct spi_transfer *t; | |
bb9c5687 KM |
183 | u32 tx; |
184 | u32 rx; | |
185 | int ret, i; | |
ce329305 PE |
186 | unsigned int cs_change; |
187 | const int nsecs = 50; | |
d1c8bbd7 | 188 | |
ec139b67 | 189 | dev_dbg(hspi->dev, "%s\n", __func__); |
d1c8bbd7 | 190 | |
ce329305 | 191 | cs_change = 1; |
ec139b67 KM |
192 | ret = 0; |
193 | list_for_each_entry(t, &msg->transfers, transfer_list) { | |
ce329305 PE |
194 | |
195 | if (cs_change) { | |
196 | hspi_hw_setup(hspi, msg, t); | |
197 | hspi_hw_cs_enable(hspi); | |
198 | ndelay(nsecs); | |
199 | } | |
200 | cs_change = t->cs_change; | |
49e599b8 | 201 | |
bb9c5687 KM |
202 | for (i = 0; i < t->len; i++) { |
203 | ||
204 | /* wait remains */ | |
205 | ret = hspi_status_check_timeout(hspi, 0x1, 0); | |
ec139b67 | 206 | if (ret < 0) |
bb9c5687 KM |
207 | break; |
208 | ||
209 | tx = 0; | |
210 | if (t->tx_buf) | |
211 | tx = (u32)((u8 *)t->tx_buf)[i]; | |
212 | ||
213 | hspi_write(hspi, SPTBR, tx); | |
214 | ||
215 | /* wait recive */ | |
216 | ret = hspi_status_check_timeout(hspi, 0x4, 0x4); | |
ec139b67 | 217 | if (ret < 0) |
bb9c5687 KM |
218 | break; |
219 | ||
220 | rx = hspi_read(hspi, SPRBR); | |
221 | if (t->rx_buf) | |
222 | ((u8 *)t->rx_buf)[i] = (u8)rx; | |
223 | ||
d1c8bbd7 | 224 | } |
bb9c5687 | 225 | |
ec139b67 | 226 | msg->actual_length += t->len; |
ce329305 PE |
227 | |
228 | if (t->delay_usecs) | |
229 | udelay(t->delay_usecs); | |
230 | ||
231 | if (cs_change) { | |
232 | ndelay(nsecs); | |
233 | hspi_hw_cs_disable(hspi); | |
234 | ndelay(nsecs); | |
235 | } | |
d1c8bbd7 KM |
236 | } |
237 | ||
ec139b67 | 238 | msg->status = ret; |
ce329305 PE |
239 | if (!cs_change) { |
240 | ndelay(nsecs); | |
241 | hspi_hw_cs_disable(hspi); | |
242 | } | |
ec139b67 | 243 | spi_finalize_current_message(master); |
d1c8bbd7 | 244 | |
ec139b67 | 245 | return ret; |
d1c8bbd7 KM |
246 | } |
247 | ||
d1c8bbd7 KM |
248 | static int hspi_setup(struct spi_device *spi) |
249 | { | |
250 | struct hspi_priv *hspi = spi_master_get_devdata(spi->master); | |
251 | struct device *dev = hspi->dev; | |
252 | ||
253 | if (8 != spi->bits_per_word) { | |
254 | dev_err(dev, "bits_per_word should be 8\n"); | |
255 | return -EIO; | |
256 | } | |
257 | ||
258 | dev_dbg(dev, "%s setup\n", spi->modalias); | |
259 | ||
260 | return 0; | |
261 | } | |
262 | ||
263 | static void hspi_cleanup(struct spi_device *spi) | |
264 | { | |
265 | struct hspi_priv *hspi = spi_master_get_devdata(spi->master); | |
266 | struct device *dev = hspi->dev; | |
267 | ||
268 | dev_dbg(dev, "%s cleanup\n", spi->modalias); | |
269 | } | |
270 | ||
fd4a319b | 271 | static int hspi_probe(struct platform_device *pdev) |
d1c8bbd7 KM |
272 | { |
273 | struct resource *res; | |
274 | struct spi_master *master; | |
275 | struct hspi_priv *hspi; | |
49e599b8 | 276 | struct clk *clk; |
d1c8bbd7 KM |
277 | int ret; |
278 | ||
279 | /* get base addr */ | |
280 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
281 | if (!res) { | |
282 | dev_err(&pdev->dev, "invalid resource\n"); | |
283 | return -EINVAL; | |
284 | } | |
285 | ||
286 | master = spi_alloc_master(&pdev->dev, sizeof(*hspi)); | |
287 | if (!master) { | |
288 | dev_err(&pdev->dev, "spi_alloc_master error.\n"); | |
289 | return -ENOMEM; | |
290 | } | |
291 | ||
49e599b8 KM |
292 | clk = clk_get(NULL, "shyway_clk"); |
293 | if (!clk) { | |
294 | dev_err(&pdev->dev, "shyway_clk is required\n"); | |
295 | ret = -EINVAL; | |
296 | goto error0; | |
297 | } | |
298 | ||
d1c8bbd7 KM |
299 | hspi = spi_master_get_devdata(master); |
300 | dev_set_drvdata(&pdev->dev, hspi); | |
301 | ||
302 | /* init hspi */ | |
303 | hspi->master = master; | |
304 | hspi->dev = &pdev->dev; | |
49e599b8 | 305 | hspi->clk = clk; |
d1c8bbd7 KM |
306 | hspi->addr = devm_ioremap(hspi->dev, |
307 | res->start, resource_size(res)); | |
308 | if (!hspi->addr) { | |
309 | dev_err(&pdev->dev, "ioremap error.\n"); | |
310 | ret = -ENOMEM; | |
311 | goto error1; | |
312 | } | |
d1c8bbd7 KM |
313 | |
314 | master->num_chipselect = 1; | |
315 | master->bus_num = pdev->id; | |
316 | master->setup = hspi_setup; | |
d1c8bbd7 KM |
317 | master->cleanup = hspi_cleanup; |
318 | master->mode_bits = SPI_CPOL | SPI_CPHA; | |
ec139b67 KM |
319 | master->prepare_transfer_hardware = hspi_prepare_transfer; |
320 | master->transfer_one_message = hspi_transfer_one_message; | |
321 | master->unprepare_transfer_hardware = hspi_unprepare_transfer; | |
d1c8bbd7 KM |
322 | ret = spi_register_master(master); |
323 | if (ret < 0) { | |
324 | dev_err(&pdev->dev, "spi_register_master error.\n"); | |
78bfee0e | 325 | goto error1; |
d1c8bbd7 KM |
326 | } |
327 | ||
328 | pm_runtime_enable(&pdev->dev); | |
329 | ||
330 | dev_info(&pdev->dev, "probed\n"); | |
331 | ||
332 | return 0; | |
333 | ||
d1c8bbd7 | 334 | error1: |
49e599b8 KM |
335 | clk_put(clk); |
336 | error0: | |
d1c8bbd7 KM |
337 | spi_master_put(master); |
338 | ||
339 | return ret; | |
340 | } | |
341 | ||
fd4a319b | 342 | static int hspi_remove(struct platform_device *pdev) |
d1c8bbd7 KM |
343 | { |
344 | struct hspi_priv *hspi = dev_get_drvdata(&pdev->dev); | |
345 | ||
346 | pm_runtime_disable(&pdev->dev); | |
347 | ||
49e599b8 | 348 | clk_put(hspi->clk); |
d1c8bbd7 | 349 | spi_unregister_master(hspi->master); |
d1c8bbd7 KM |
350 | |
351 | return 0; | |
352 | } | |
353 | ||
354 | static struct platform_driver hspi_driver = { | |
355 | .probe = hspi_probe, | |
fd4a319b | 356 | .remove = hspi_remove, |
d1c8bbd7 KM |
357 | .driver = { |
358 | .name = "sh-hspi", | |
359 | .owner = THIS_MODULE, | |
360 | }, | |
361 | }; | |
362 | module_platform_driver(hspi_driver); | |
363 | ||
364 | MODULE_DESCRIPTION("SuperH HSPI bus driver"); | |
365 | MODULE_LICENSE("GPL"); | |
366 | MODULE_AUTHOR("Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>"); | |
367 | MODULE_ALIAS("platform:sh_spi"); |