diff options
author | Cyril Chemparathy <cyril@ti.com> | 2011-01-18 14:21:36 -0500 |
---|---|---|
committer | Kevin Hilman <khilman@ti.com> | 2011-03-15 11:17:22 -0400 |
commit | a72aeefebe6545ad5c9c699e1121019c1709ca77 (patch) | |
tree | dfa765108f3582182ea25c22311e4e0dc7903130 | |
parent | 03df0f629483f941f83ee2fbb180a4425e99dd23 (diff) |
spi: add ti-ssp spi master driver
This patch adds an SPI master implementation that operates on top of an
underlying TI-SSP port.
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Cyril Chemparathy <cyril@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>
-rw-r--r-- | drivers/spi/Kconfig | 10 | ||||
-rw-r--r-- | drivers/spi/Makefile | 1 | ||||
-rw-r--r-- | drivers/spi/ti-ssp-spi.c | 402 | ||||
-rw-r--r-- | include/linux/mfd/ti_ssp.h | 6 |
4 files changed, 419 insertions, 0 deletions
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index bb233a9cbad2..42f5a8d7c817 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig | |||
@@ -350,6 +350,16 @@ config SPI_TEGRA | |||
350 | help | 350 | help |
351 | SPI driver for NVidia Tegra SoCs | 351 | SPI driver for NVidia Tegra SoCs |
352 | 352 | ||
353 | config SPI_TI_SSP | ||
354 | tristate "TI Sequencer Serial Port - SPI Support" | ||
355 | depends on MFD_TI_SSP | ||
356 | help | ||
357 | This selects an SPI master implementation using a TI sequencer | ||
358 | serial port. | ||
359 | |||
360 | To compile this driver as a module, choose M here: the | ||
361 | module will be called ti-ssp-spi. | ||
362 | |||
353 | config SPI_TOPCLIFF_PCH | 363 | config SPI_TOPCLIFF_PCH |
354 | tristate "Topcliff PCH SPI Controller" | 364 | tristate "Topcliff PCH SPI Controller" |
355 | depends on PCI | 365 | depends on PCI |
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile index 86d1b5f9bbd9..f3f31d988358 100644 --- a/drivers/spi/Makefile +++ b/drivers/spi/Makefile | |||
@@ -43,6 +43,7 @@ obj-$(CONFIG_SPI_S3C24XX_GPIO) += spi_s3c24xx_gpio.o | |||
43 | obj-$(CONFIG_SPI_S3C24XX) += spi_s3c24xx_hw.o | 43 | obj-$(CONFIG_SPI_S3C24XX) += spi_s3c24xx_hw.o |
44 | obj-$(CONFIG_SPI_S3C64XX) += spi_s3c64xx.o | 44 | obj-$(CONFIG_SPI_S3C64XX) += spi_s3c64xx.o |
45 | obj-$(CONFIG_SPI_TEGRA) += spi_tegra.o | 45 | obj-$(CONFIG_SPI_TEGRA) += spi_tegra.o |
46 | obj-$(CONFIG_SPI_TI_SSP) += ti-ssp-spi.o | ||
46 | obj-$(CONFIG_SPI_TOPCLIFF_PCH) += spi_topcliff_pch.o | 47 | obj-$(CONFIG_SPI_TOPCLIFF_PCH) += spi_topcliff_pch.o |
47 | obj-$(CONFIG_SPI_TXX9) += spi_txx9.o | 48 | obj-$(CONFIG_SPI_TXX9) += spi_txx9.o |
48 | obj-$(CONFIG_SPI_XILINX) += xilinx_spi.o | 49 | obj-$(CONFIG_SPI_XILINX) += xilinx_spi.o |
diff --git a/drivers/spi/ti-ssp-spi.c b/drivers/spi/ti-ssp-spi.c new file mode 100644 index 000000000000..ee22795c7973 --- /dev/null +++ b/drivers/spi/ti-ssp-spi.c | |||
@@ -0,0 +1,402 @@ | |||
1 | /* | ||
2 | * Sequencer Serial Port (SSP) based SPI master driver | ||
3 | * | ||
4 | * Copyright (C) 2010 Texas Instruments Inc | ||
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/completion.h> | ||
24 | #include <linux/delay.h> | ||
25 | #include <linux/platform_device.h> | ||
26 | #include <linux/spi/spi.h> | ||
27 | #include <linux/mfd/ti_ssp.h> | ||
28 | |||
29 | #define MODE_BITS (SPI_CPHA | SPI_CPOL | SPI_CS_HIGH) | ||
30 | |||
31 | struct ti_ssp_spi { | ||
32 | struct spi_master *master; | ||
33 | struct device *dev; | ||
34 | spinlock_t lock; | ||
35 | struct list_head msg_queue; | ||
36 | struct completion complete; | ||
37 | bool shutdown; | ||
38 | struct workqueue_struct *workqueue; | ||
39 | struct work_struct work; | ||
40 | u8 mode, bpw; | ||
41 | int cs_active; | ||
42 | u32 pc_en, pc_dis, pc_wr, pc_rd; | ||
43 | void (*select)(int cs); | ||
44 | }; | ||
45 | |||
46 | static u32 ti_ssp_spi_rx(struct ti_ssp_spi *hw) | ||
47 | { | ||
48 | u32 ret; | ||
49 | |||
50 | ti_ssp_run(hw->dev, hw->pc_rd, 0, &ret); | ||
51 | return ret; | ||
52 | } | ||
53 | |||
54 | static void ti_ssp_spi_tx(struct ti_ssp_spi *hw, u32 data) | ||
55 | { | ||
56 | ti_ssp_run(hw->dev, hw->pc_wr, data << (32 - hw->bpw), NULL); | ||
57 | } | ||
58 | |||
59 | static int ti_ssp_spi_txrx(struct ti_ssp_spi *hw, struct spi_message *msg, | ||
60 | struct spi_transfer *t) | ||
61 | { | ||
62 | int count; | ||
63 | |||
64 | if (hw->bpw <= 8) { | ||
65 | u8 *rx = t->rx_buf; | ||
66 | const u8 *tx = t->tx_buf; | ||
67 | |||
68 | for (count = 0; count < t->len; count += 1) { | ||
69 | if (t->tx_buf) | ||
70 | ti_ssp_spi_tx(hw, *tx++); | ||
71 | if (t->rx_buf) | ||
72 | *rx++ = ti_ssp_spi_rx(hw); | ||
73 | } | ||
74 | } else if (hw->bpw <= 16) { | ||
75 | u16 *rx = t->rx_buf; | ||
76 | const u16 *tx = t->tx_buf; | ||
77 | |||
78 | for (count = 0; count < t->len; count += 2) { | ||
79 | if (t->tx_buf) | ||
80 | ti_ssp_spi_tx(hw, *tx++); | ||
81 | if (t->rx_buf) | ||
82 | *rx++ = ti_ssp_spi_rx(hw); | ||
83 | } | ||
84 | } else { | ||
85 | u32 *rx = t->rx_buf; | ||
86 | const u32 *tx = t->tx_buf; | ||
87 | |||
88 | for (count = 0; count < t->len; count += 4) { | ||
89 | if (t->tx_buf) | ||
90 | ti_ssp_spi_tx(hw, *tx++); | ||
91 | if (t->rx_buf) | ||
92 | *rx++ = ti_ssp_spi_rx(hw); | ||
93 | } | ||
94 | } | ||
95 | |||
96 | msg->actual_length += count; /* bytes transferred */ | ||
97 | |||
98 | dev_dbg(&msg->spi->dev, "xfer %s%s, %d bytes, %d bpw, count %d%s\n", | ||
99 | t->tx_buf ? "tx" : "", t->rx_buf ? "rx" : "", t->len, | ||
100 | hw->bpw, count, (count < t->len) ? " (under)" : ""); | ||
101 | |||
102 | return (count < t->len) ? -EIO : 0; /* left over data */ | ||
103 | } | ||
104 | |||
105 | static void ti_ssp_spi_chip_select(struct ti_ssp_spi *hw, int cs_active) | ||
106 | { | ||
107 | cs_active = !!cs_active; | ||
108 | if (cs_active == hw->cs_active) | ||
109 | return; | ||
110 | ti_ssp_run(hw->dev, cs_active ? hw->pc_en : hw->pc_dis, 0, NULL); | ||
111 | hw->cs_active = cs_active; | ||
112 | } | ||
113 | |||
114 | #define __SHIFT_OUT(bits) (SSP_OPCODE_SHIFT | SSP_OUT_MODE | \ | ||
115 | cs_en | clk | SSP_COUNT((bits) * 2 - 1)) | ||
116 | #define __SHIFT_IN(bits) (SSP_OPCODE_SHIFT | SSP_IN_MODE | \ | ||
117 | cs_en | clk | SSP_COUNT((bits) * 2 - 1)) | ||
118 | |||
119 | static int ti_ssp_spi_setup_transfer(struct ti_ssp_spi *hw, u8 bpw, u8 mode) | ||
120 | { | ||
121 | int error, idx = 0; | ||
122 | u32 seqram[16]; | ||
123 | u32 cs_en, cs_dis, clk; | ||
124 | u32 topbits, botbits; | ||
125 | |||
126 | mode &= MODE_BITS; | ||
127 | if (mode == hw->mode && bpw == hw->bpw) | ||
128 | return 0; | ||
129 | |||
130 | cs_en = (mode & SPI_CS_HIGH) ? SSP_CS_HIGH : SSP_CS_LOW; | ||
131 | cs_dis = (mode & SPI_CS_HIGH) ? SSP_CS_LOW : SSP_CS_HIGH; | ||
132 | clk = (mode & SPI_CPOL) ? SSP_CLK_HIGH : SSP_CLK_LOW; | ||
133 | |||
134 | /* Construct instructions */ | ||
135 | |||
136 | /* Disable Chip Select */ | ||
137 | hw->pc_dis = idx; | ||
138 | seqram[idx++] = SSP_OPCODE_DIRECT | SSP_OUT_MODE | cs_dis | clk; | ||
139 | seqram[idx++] = SSP_OPCODE_STOP | SSP_OUT_MODE | cs_dis | clk; | ||
140 | |||
141 | /* Enable Chip Select */ | ||
142 | hw->pc_en = idx; | ||
143 | seqram[idx++] = SSP_OPCODE_DIRECT | SSP_OUT_MODE | cs_en | clk; | ||
144 | seqram[idx++] = SSP_OPCODE_STOP | SSP_OUT_MODE | cs_en | clk; | ||
145 | |||
146 | /* Reads and writes need to be split for bpw > 16 */ | ||
147 | topbits = (bpw > 16) ? 16 : bpw; | ||
148 | botbits = bpw - topbits; | ||
149 | |||
150 | /* Write */ | ||
151 | hw->pc_wr = idx; | ||
152 | seqram[idx++] = __SHIFT_OUT(topbits) | SSP_ADDR_REG; | ||
153 | if (botbits) | ||
154 | seqram[idx++] = __SHIFT_OUT(botbits) | SSP_DATA_REG; | ||
155 | seqram[idx++] = SSP_OPCODE_STOP | SSP_OUT_MODE | cs_en | clk; | ||
156 | |||
157 | /* Read */ | ||
158 | hw->pc_rd = idx; | ||
159 | if (botbits) | ||
160 | seqram[idx++] = __SHIFT_IN(botbits) | SSP_ADDR_REG; | ||
161 | seqram[idx++] = __SHIFT_IN(topbits) | SSP_DATA_REG; | ||
162 | seqram[idx++] = SSP_OPCODE_STOP | SSP_OUT_MODE | cs_en | clk; | ||
163 | |||
164 | error = ti_ssp_load(hw->dev, 0, seqram, idx); | ||
165 | if (error < 0) | ||
166 | return error; | ||
167 | |||
168 | error = ti_ssp_set_mode(hw->dev, ((mode & SPI_CPHA) ? | ||
169 | 0 : SSP_EARLY_DIN)); | ||
170 | if (error < 0) | ||
171 | return error; | ||
172 | |||
173 | hw->bpw = bpw; | ||
174 | hw->mode = mode; | ||
175 | |||
176 | return error; | ||
177 | } | ||
178 | |||
179 | static void ti_ssp_spi_work(struct work_struct *work) | ||
180 | { | ||
181 | struct ti_ssp_spi *hw = container_of(work, struct ti_ssp_spi, work); | ||
182 | |||
183 | spin_lock(&hw->lock); | ||
184 | |||
185 | while (!list_empty(&hw->msg_queue)) { | ||
186 | struct spi_message *m; | ||
187 | struct spi_device *spi; | ||
188 | struct spi_transfer *t = NULL; | ||
189 | int status = 0; | ||
190 | |||
191 | m = container_of(hw->msg_queue.next, struct spi_message, | ||
192 | queue); | ||
193 | |||
194 | list_del_init(&m->queue); | ||
195 | |||
196 | spin_unlock(&hw->lock); | ||
197 | |||
198 | spi = m->spi; | ||
199 | |||
200 | if (hw->select) | ||
201 | hw->select(spi->chip_select); | ||
202 | |||
203 | list_for_each_entry(t, &m->transfers, transfer_list) { | ||
204 | int bpw = spi->bits_per_word; | ||
205 | int xfer_status; | ||
206 | |||
207 | if (t->bits_per_word) | ||
208 | bpw = t->bits_per_word; | ||
209 | |||
210 | if (ti_ssp_spi_setup_transfer(hw, bpw, spi->mode) < 0) | ||
211 | break; | ||
212 | |||
213 | ti_ssp_spi_chip_select(hw, 1); | ||
214 | |||
215 | xfer_status = ti_ssp_spi_txrx(hw, m, t); | ||
216 | if (xfer_status < 0) | ||
217 | status = xfer_status; | ||
218 | |||
219 | if (t->delay_usecs) | ||
220 | udelay(t->delay_usecs); | ||
221 | |||
222 | if (t->cs_change) | ||
223 | ti_ssp_spi_chip_select(hw, 0); | ||
224 | } | ||
225 | |||
226 | ti_ssp_spi_chip_select(hw, 0); | ||
227 | m->status = status; | ||
228 | m->complete(m->context); | ||
229 | |||
230 | spin_lock(&hw->lock); | ||
231 | } | ||
232 | |||
233 | if (hw->shutdown) | ||
234 | complete(&hw->complete); | ||
235 | |||
236 | spin_unlock(&hw->lock); | ||
237 | } | ||
238 | |||
239 | static int ti_ssp_spi_setup(struct spi_device *spi) | ||
240 | { | ||
241 | if (spi->bits_per_word > 32) | ||
242 | return -EINVAL; | ||
243 | |||
244 | return 0; | ||
245 | } | ||
246 | |||
247 | static int ti_ssp_spi_transfer(struct spi_device *spi, struct spi_message *m) | ||
248 | { | ||
249 | struct ti_ssp_spi *hw; | ||
250 | struct spi_transfer *t; | ||
251 | int error = 0; | ||
252 | |||
253 | m->actual_length = 0; | ||
254 | m->status = -EINPROGRESS; | ||
255 | |||
256 | hw = spi_master_get_devdata(spi->master); | ||
257 | |||
258 | if (list_empty(&m->transfers) || !m->complete) | ||
259 | return -EINVAL; | ||
260 | |||
261 | list_for_each_entry(t, &m->transfers, transfer_list) { | ||
262 | if (t->len && !(t->rx_buf || t->tx_buf)) { | ||
263 | dev_err(&spi->dev, "invalid xfer, no buffer\n"); | ||
264 | return -EINVAL; | ||
265 | } | ||
266 | |||
267 | if (t->len && t->rx_buf && t->tx_buf) { | ||
268 | dev_err(&spi->dev, "invalid xfer, full duplex\n"); | ||
269 | return -EINVAL; | ||
270 | } | ||
271 | |||
272 | if (t->bits_per_word > 32) { | ||
273 | dev_err(&spi->dev, "invalid xfer width %d\n", | ||
274 | t->bits_per_word); | ||
275 | return -EINVAL; | ||
276 | } | ||
277 | } | ||
278 | |||
279 | spin_lock(&hw->lock); | ||
280 | if (hw->shutdown) { | ||
281 | error = -ESHUTDOWN; | ||
282 | goto error_unlock; | ||
283 | } | ||
284 | list_add_tail(&m->queue, &hw->msg_queue); | ||
285 | queue_work(hw->workqueue, &hw->work); | ||
286 | error_unlock: | ||
287 | spin_unlock(&hw->lock); | ||
288 | return error; | ||
289 | } | ||
290 | |||
291 | static int __devinit ti_ssp_spi_probe(struct platform_device *pdev) | ||
292 | { | ||
293 | const struct ti_ssp_spi_data *pdata; | ||
294 | struct ti_ssp_spi *hw; | ||
295 | struct spi_master *master; | ||
296 | struct device *dev = &pdev->dev; | ||
297 | int error = 0; | ||
298 | |||
299 | pdata = dev->platform_data; | ||
300 | if (!pdata) { | ||
301 | dev_err(dev, "platform data not found\n"); | ||
302 | return -EINVAL; | ||
303 | } | ||
304 | |||
305 | master = spi_alloc_master(dev, sizeof(struct ti_ssp_spi)); | ||
306 | if (!master) { | ||
307 | dev_err(dev, "cannot allocate SPI master\n"); | ||
308 | return -ENOMEM; | ||
309 | } | ||
310 | |||
311 | hw = spi_master_get_devdata(master); | ||
312 | platform_set_drvdata(pdev, hw); | ||
313 | |||
314 | hw->master = master; | ||
315 | hw->dev = dev; | ||
316 | hw->select = pdata->select; | ||
317 | |||
318 | spin_lock_init(&hw->lock); | ||
319 | init_completion(&hw->complete); | ||
320 | INIT_LIST_HEAD(&hw->msg_queue); | ||
321 | INIT_WORK(&hw->work, ti_ssp_spi_work); | ||
322 | |||
323 | hw->workqueue = create_singlethread_workqueue(dev_name(dev)); | ||
324 | if (!hw->workqueue) { | ||
325 | error = -ENOMEM; | ||
326 | dev_err(dev, "work queue creation failed\n"); | ||
327 | goto error_wq; | ||
328 | } | ||
329 | |||
330 | error = ti_ssp_set_iosel(hw->dev, pdata->iosel); | ||
331 | if (error < 0) { | ||
332 | dev_err(dev, "io setup failed\n"); | ||
333 | goto error_iosel; | ||
334 | } | ||
335 | |||
336 | master->bus_num = pdev->id; | ||
337 | master->num_chipselect = pdata->num_cs; | ||
338 | master->mode_bits = MODE_BITS; | ||
339 | master->flags = SPI_MASTER_HALF_DUPLEX; | ||
340 | master->setup = ti_ssp_spi_setup; | ||
341 | master->transfer = ti_ssp_spi_transfer; | ||
342 | |||
343 | error = spi_register_master(master); | ||
344 | if (error) { | ||
345 | dev_err(dev, "master registration failed\n"); | ||
346 | goto error_reg; | ||
347 | } | ||
348 | |||
349 | return 0; | ||
350 | |||
351 | error_reg: | ||
352 | error_iosel: | ||
353 | destroy_workqueue(hw->workqueue); | ||
354 | error_wq: | ||
355 | spi_master_put(master); | ||
356 | return error; | ||
357 | } | ||
358 | |||
359 | static int __devexit ti_ssp_spi_remove(struct platform_device *pdev) | ||
360 | { | ||
361 | struct ti_ssp_spi *hw = platform_get_drvdata(pdev); | ||
362 | int error; | ||
363 | |||
364 | hw->shutdown = 1; | ||
365 | while (!list_empty(&hw->msg_queue)) { | ||
366 | error = wait_for_completion_interruptible(&hw->complete); | ||
367 | if (error < 0) { | ||
368 | hw->shutdown = 0; | ||
369 | return error; | ||
370 | } | ||
371 | } | ||
372 | destroy_workqueue(hw->workqueue); | ||
373 | spi_unregister_master(hw->master); | ||
374 | |||
375 | return 0; | ||
376 | } | ||
377 | |||
378 | static struct platform_driver ti_ssp_spi_driver = { | ||
379 | .probe = ti_ssp_spi_probe, | ||
380 | .remove = __devexit_p(ti_ssp_spi_remove), | ||
381 | .driver = { | ||
382 | .name = "ti-ssp-spi", | ||
383 | .owner = THIS_MODULE, | ||
384 | }, | ||
385 | }; | ||
386 | |||
387 | static int __init ti_ssp_spi_init(void) | ||
388 | { | ||
389 | return platform_driver_register(&ti_ssp_spi_driver); | ||
390 | } | ||
391 | module_init(ti_ssp_spi_init); | ||
392 | |||
393 | static void __exit ti_ssp_spi_exit(void) | ||
394 | { | ||
395 | platform_driver_unregister(&ti_ssp_spi_driver); | ||
396 | } | ||
397 | module_exit(ti_ssp_spi_exit); | ||
398 | |||
399 | MODULE_DESCRIPTION("SSP SPI Master"); | ||
400 | MODULE_AUTHOR("Cyril Chemparathy"); | ||
401 | MODULE_LICENSE("GPL"); | ||
402 | MODULE_ALIAS("platform:ti-ssp-spi"); | ||
diff --git a/include/linux/mfd/ti_ssp.h b/include/linux/mfd/ti_ssp.h index 021fe0912435..dbb4b43bd20e 100644 --- a/include/linux/mfd/ti_ssp.h +++ b/include/linux/mfd/ti_ssp.h | |||
@@ -32,6 +32,12 @@ struct ti_ssp_data { | |||
32 | struct ti_ssp_dev_data dev_data[2]; | 32 | struct ti_ssp_dev_data dev_data[2]; |
33 | }; | 33 | }; |
34 | 34 | ||
35 | struct ti_ssp_spi_data { | ||
36 | unsigned long iosel; | ||
37 | int num_cs; | ||
38 | void (*select)(int cs); | ||
39 | }; | ||
40 | |||
35 | /* | 41 | /* |
36 | * Sequencer port IO pin configuration bits. These do not correlate 1-1 with | 42 | * Sequencer port IO pin configuration bits. These do not correlate 1-1 with |
37 | * the hardware. The iosel field in the port data combines iosel1 and iosel2, | 43 | * the hardware. The iosel field in the port data combines iosel1 and iosel2, |