gpu: nvgpu: Increase PBDMA timeout
[linux-3.10.git] / drivers / spi / spi-sc18is602.c
1 /*
2  * NXP SC18IS602/603 SPI driver
3  *
4  * Copyright (C) Guenter Roeck <linux@roeck-us.net>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
19  */
20
21 #include <linux/kernel.h>
22 #include <linux/err.h>
23 #include <linux/module.h>
24 #include <linux/spi/spi.h>
25 #include <linux/i2c.h>
26 #include <linux/delay.h>
27 #include <linux/pm_runtime.h>
28 #include <linux/of.h>
29 #include <linux/platform_data/sc18is602.h>
30
31 enum chips { sc18is602, sc18is602b, sc18is603 };
32
33 #define SC18IS602_BUFSIZ                200
34 #define SC18IS602_CLOCK                 7372000
35
36 #define SC18IS602_MODE_CPHA             BIT(2)
37 #define SC18IS602_MODE_CPOL             BIT(3)
38 #define SC18IS602_MODE_LSB_FIRST        BIT(5)
39 #define SC18IS602_MODE_CLOCK_DIV_4      0x0
40 #define SC18IS602_MODE_CLOCK_DIV_16     0x1
41 #define SC18IS602_MODE_CLOCK_DIV_64     0x2
42 #define SC18IS602_MODE_CLOCK_DIV_128    0x3
43
44 struct sc18is602 {
45         struct spi_master       *master;
46         struct device           *dev;
47         u8                      ctrl;
48         u32                     freq;
49         u32                     speed;
50
51         /* I2C data */
52         struct i2c_client       *client;
53         enum chips              id;
54         u8                      buffer[SC18IS602_BUFSIZ + 1];
55         int                     tlen;   /* Data queued for tx in buffer */
56         int                     rindex; /* Receive data index in buffer */
57 };
58
59 static int sc18is602_wait_ready(struct sc18is602 *hw, int len)
60 {
61         int i, err;
62         int usecs = 1000000 * len / hw->speed + 1;
63         u8 dummy[1];
64
65         for (i = 0; i < 10; i++) {
66                 err = i2c_master_recv(hw->client, dummy, 1);
67                 if (err >= 0)
68                         return 0;
69                 usleep_range(usecs, usecs * 2);
70         }
71         return -ETIMEDOUT;
72 }
73
74 static int sc18is602_txrx(struct sc18is602 *hw, struct spi_message *msg,
75                           struct spi_transfer *t, bool do_transfer)
76 {
77         unsigned int len = t->len;
78         int ret;
79
80         if (hw->tlen == 0) {
81                 /* First byte (I2C command) is chip select */
82                 hw->buffer[0] = 1 << msg->spi->chip_select;
83                 hw->tlen = 1;
84                 hw->rindex = 0;
85         }
86         /*
87          * We can not immediately send data to the chip, since each I2C message
88          * resembles a full SPI message (from CS active to CS inactive).
89          * Enqueue messages up to the first read or until do_transfer is true.
90          */
91         if (t->tx_buf) {
92                 memcpy(&hw->buffer[hw->tlen], t->tx_buf, len);
93                 hw->tlen += len;
94                 if (t->rx_buf)
95                         do_transfer = true;
96                 else
97                         hw->rindex = hw->tlen - 1;
98         } else if (t->rx_buf) {
99                 /*
100                  * For receive-only transfers we still need to perform a dummy
101                  * write to receive data from the SPI chip.
102                  * Read data starts at the end of transmit data (minus 1 to
103                  * account for CS).
104                  */
105                 hw->rindex = hw->tlen - 1;
106                 memset(&hw->buffer[hw->tlen], 0, len);
107                 hw->tlen += len;
108                 do_transfer = true;
109         }
110
111         if (do_transfer && hw->tlen > 1) {
112                 ret = sc18is602_wait_ready(hw, SC18IS602_BUFSIZ);
113                 if (ret < 0)
114                         return ret;
115                 ret = i2c_master_send(hw->client, hw->buffer, hw->tlen);
116                 if (ret < 0)
117                         return ret;
118                 if (ret != hw->tlen)
119                         return -EIO;
120
121                 if (t->rx_buf) {
122                         int rlen = hw->rindex + len;
123
124                         ret = sc18is602_wait_ready(hw, hw->tlen);
125                         if (ret < 0)
126                                 return ret;
127                         ret = i2c_master_recv(hw->client, hw->buffer, rlen);
128                         if (ret < 0)
129                                 return ret;
130                         if (ret != rlen)
131                                 return -EIO;
132                         memcpy(t->rx_buf, &hw->buffer[hw->rindex], len);
133                 }
134                 hw->tlen = 0;
135         }
136         return len;
137 }
138
139 static int sc18is602_setup_transfer(struct sc18is602 *hw, u32 hz, u8 mode)
140 {
141         u8 ctrl = 0;
142         int ret;
143
144         if (mode & SPI_CPHA)
145                 ctrl |= SC18IS602_MODE_CPHA;
146         if (mode & SPI_CPOL)
147                 ctrl |= SC18IS602_MODE_CPOL;
148         if (mode & SPI_LSB_FIRST)
149                 ctrl |= SC18IS602_MODE_LSB_FIRST;
150
151         /* Find the closest clock speed */
152         if (hz >= hw->freq / 4) {
153                 ctrl |= SC18IS602_MODE_CLOCK_DIV_4;
154                 hw->speed = hw->freq / 4;
155         } else if (hz >= hw->freq / 16) {
156                 ctrl |= SC18IS602_MODE_CLOCK_DIV_16;
157                 hw->speed = hw->freq / 16;
158         } else if (hz >= hw->freq / 64) {
159                 ctrl |= SC18IS602_MODE_CLOCK_DIV_64;
160                 hw->speed = hw->freq / 64;
161         } else {
162                 ctrl |= SC18IS602_MODE_CLOCK_DIV_128;
163                 hw->speed = hw->freq / 128;
164         }
165
166         /*
167          * Don't do anything if the control value did not change. The initial
168          * value of 0xff for hw->ctrl ensures that the correct mode will be set
169          * with the first call to this function.
170          */
171         if (ctrl == hw->ctrl)
172                 return 0;
173
174         ret = i2c_smbus_write_byte_data(hw->client, 0xf0, ctrl);
175         if (ret < 0)
176                 return ret;
177
178         hw->ctrl = ctrl;
179
180         return 0;
181 }
182
183 static int sc18is602_check_transfer(struct spi_device *spi,
184                                     struct spi_transfer *t, int tlen)
185 {
186         int bpw;
187         uint32_t hz;
188
189         if (t && t->len + tlen > SC18IS602_BUFSIZ)
190                 return -EINVAL;
191
192         bpw = spi->bits_per_word;
193         if (t && t->bits_per_word)
194                 bpw = t->bits_per_word;
195         if (bpw != 8)
196                 return -EINVAL;
197
198         hz = spi->max_speed_hz;
199         if (t && t->speed_hz)
200                 hz = t->speed_hz;
201         if (hz == 0)
202                 return -EINVAL;
203
204         return 0;
205 }
206
207 static int sc18is602_transfer_one(struct spi_master *master,
208                                   struct spi_message *m)
209 {
210         struct sc18is602 *hw = spi_master_get_devdata(master);
211         struct spi_device *spi = m->spi;
212         struct spi_transfer *t;
213         int status = 0;
214
215         /* SC18IS602 does not support CS2 */
216         if (hw->id == sc18is602 && spi->chip_select == 2) {
217                 status = -ENXIO;
218                 goto error;
219         }
220
221         hw->tlen = 0;
222         list_for_each_entry(t, &m->transfers, transfer_list) {
223                 u32 hz = t->speed_hz ? : spi->max_speed_hz;
224                 bool do_transfer;
225
226                 status = sc18is602_check_transfer(spi, t, hw->tlen);
227                 if (status < 0)
228                         break;
229
230                 status = sc18is602_setup_transfer(hw, hz, spi->mode);
231                 if (status < 0)
232                         break;
233
234                 do_transfer = t->cs_change || list_is_last(&t->transfer_list,
235                                                            &m->transfers);
236
237                 if (t->len) {
238                         status = sc18is602_txrx(hw, m, t, do_transfer);
239                         if (status < 0)
240                                 break;
241                         m->actual_length += status;
242                 }
243                 status = 0;
244
245                 if (t->delay_usecs)
246                         udelay(t->delay_usecs);
247         }
248 error:
249         m->status = status;
250         spi_finalize_current_message(master);
251
252         return status;
253 }
254
255 static int sc18is602_setup(struct spi_device *spi)
256 {
257         if (!spi->bits_per_word)
258                 spi->bits_per_word = 8;
259
260         if (spi->mode & ~(SPI_CPHA | SPI_CPOL | SPI_LSB_FIRST))
261                 return -EINVAL;
262
263         return sc18is602_check_transfer(spi, NULL, 0);
264 }
265
266 static int sc18is602_probe(struct i2c_client *client,
267                            const struct i2c_device_id *id)
268 {
269         struct device *dev = &client->dev;
270         struct device_node *np = dev->of_node;
271         struct sc18is602_platform_data *pdata = dev_get_platdata(dev);
272         struct sc18is602 *hw;
273         struct spi_master *master;
274         int error;
275
276         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
277                                      I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
278                 return -EINVAL;
279
280         master = spi_alloc_master(dev, sizeof(struct sc18is602));
281         if (!master)
282                 return -ENOMEM;
283
284         hw = spi_master_get_devdata(master);
285         i2c_set_clientdata(client, hw);
286
287         hw->master = master;
288         hw->client = client;
289         hw->dev = dev;
290         hw->ctrl = 0xff;
291
292         hw->id = id->driver_data;
293
294         switch (hw->id) {
295         case sc18is602:
296         case sc18is602b:
297                 master->num_chipselect = 4;
298                 hw->freq = SC18IS602_CLOCK;
299                 break;
300         case sc18is603:
301                 master->num_chipselect = 2;
302                 if (pdata) {
303                         hw->freq = pdata->clock_frequency;
304                 } else {
305                         const __be32 *val;
306                         int len;
307
308                         val = of_get_property(np, "clock-frequency", &len);
309                         if (val && len >= sizeof(__be32))
310                                 hw->freq = be32_to_cpup(val);
311                 }
312                 if (!hw->freq)
313                         hw->freq = SC18IS602_CLOCK;
314                 break;
315         }
316         master->bus_num = client->adapter->nr;
317         master->mode_bits = SPI_CPHA | SPI_CPOL | SPI_LSB_FIRST;
318         master->setup = sc18is602_setup;
319         master->transfer_one_message = sc18is602_transfer_one;
320         master->dev.of_node = np;
321
322         error = spi_register_master(master);
323         if (error)
324                 goto error_reg;
325
326         return 0;
327
328 error_reg:
329         spi_master_put(master);
330         return error;
331 }
332
333 static int sc18is602_remove(struct i2c_client *client)
334 {
335         struct sc18is602 *hw = i2c_get_clientdata(client);
336         struct spi_master *master = hw->master;
337
338         spi_unregister_master(master);
339
340         return 0;
341 }
342
343 static const struct i2c_device_id sc18is602_id[] = {
344         { "sc18is602", sc18is602 },
345         { "sc18is602b", sc18is602b },
346         { "sc18is603", sc18is603 },
347         { }
348 };
349 MODULE_DEVICE_TABLE(i2c, sc18is602_id);
350
351 static struct i2c_driver sc18is602_driver = {
352         .driver = {
353                 .name = "sc18is602",
354         },
355         .probe = sc18is602_probe,
356         .remove = sc18is602_remove,
357         .id_table = sc18is602_id,
358 };
359
360 module_i2c_driver(sc18is602_driver);
361
362 MODULE_DESCRIPTION("SC18IC602/603 SPI Master Driver");
363 MODULE_AUTHOR("Guenter Roeck");
364 MODULE_LICENSE("GPL");