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03df0f62 CC |
1 | /* |
2 | * Sequencer Serial Port (SSP) driver for Texas Instruments' SoCs | |
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/errno.h> | |
22 | #include <linux/kernel.h> | |
23 | #include <linux/module.h> | |
24 | #include <linux/slab.h> | |
25 | #include <linux/err.h> | |
26 | #include <linux/init.h> | |
27 | #include <linux/wait.h> | |
28 | #include <linux/clk.h> | |
29 | #include <linux/interrupt.h> | |
30 | #include <linux/device.h> | |
31 | #include <linux/spinlock.h> | |
32 | #include <linux/platform_device.h> | |
33 | #include <linux/delay.h> | |
34 | #include <linux/io.h> | |
35 | #include <linux/mfd/core.h> | |
36 | #include <linux/mfd/ti_ssp.h> | |
37 | ||
38 | /* Register Offsets */ | |
39 | #define REG_REV 0x00 | |
40 | #define REG_IOSEL_1 0x04 | |
41 | #define REG_IOSEL_2 0x08 | |
42 | #define REG_PREDIV 0x0c | |
43 | #define REG_INTR_ST 0x10 | |
44 | #define REG_INTR_EN 0x14 | |
45 | #define REG_TEST_CTRL 0x18 | |
46 | ||
47 | /* Per port registers */ | |
48 | #define PORT_CFG_2 0x00 | |
49 | #define PORT_ADDR 0x04 | |
50 | #define PORT_DATA 0x08 | |
51 | #define PORT_CFG_1 0x0c | |
52 | #define PORT_STATE 0x10 | |
53 | ||
54 | #define SSP_PORT_CONFIG_MASK (SSP_EARLY_DIN | SSP_DELAY_DOUT) | |
55 | #define SSP_PORT_CLKRATE_MASK 0x0f | |
56 | ||
57 | #define SSP_SEQRAM_WR_EN BIT(4) | |
58 | #define SSP_SEQRAM_RD_EN BIT(5) | |
59 | #define SSP_START BIT(15) | |
60 | #define SSP_BUSY BIT(10) | |
61 | #define SSP_PORT_ASL BIT(7) | |
62 | #define SSP_PORT_CFO1 BIT(6) | |
63 | ||
64 | #define SSP_PORT_SEQRAM_SIZE 32 | |
65 | ||
66 | static const int ssp_port_base[] = {0x040, 0x080}; | |
67 | static const int ssp_port_seqram[] = {0x100, 0x180}; | |
68 | ||
69 | struct ti_ssp { | |
70 | struct resource *res; | |
71 | struct device *dev; | |
72 | void __iomem *regs; | |
73 | spinlock_t lock; | |
74 | struct clk *clk; | |
75 | int irq; | |
76 | wait_queue_head_t wqh; | |
77 | ||
78 | /* | |
79 | * Some of the iosel2 register bits always read-back as 0, we need to | |
80 | * remember these values so that we don't clobber previously set | |
81 | * values. | |
82 | */ | |
83 | u32 iosel2; | |
84 | }; | |
85 | ||
86 | static inline struct ti_ssp *dev_to_ssp(struct device *dev) | |
87 | { | |
88 | return dev_get_drvdata(dev->parent); | |
89 | } | |
90 | ||
91 | static inline int dev_to_port(struct device *dev) | |
92 | { | |
93 | return to_platform_device(dev)->id; | |
94 | } | |
95 | ||
96 | /* Register Access Helpers, rmw() functions need to run locked */ | |
97 | static inline u32 ssp_read(struct ti_ssp *ssp, int reg) | |
98 | { | |
99 | return __raw_readl(ssp->regs + reg); | |
100 | } | |
101 | ||
102 | static inline void ssp_write(struct ti_ssp *ssp, int reg, u32 val) | |
103 | { | |
104 | __raw_writel(val, ssp->regs + reg); | |
105 | } | |
106 | ||
107 | static inline void ssp_rmw(struct ti_ssp *ssp, int reg, u32 mask, u32 bits) | |
108 | { | |
109 | ssp_write(ssp, reg, (ssp_read(ssp, reg) & ~mask) | bits); | |
110 | } | |
111 | ||
112 | static inline u32 ssp_port_read(struct ti_ssp *ssp, int port, int reg) | |
113 | { | |
114 | return ssp_read(ssp, ssp_port_base[port] + reg); | |
115 | } | |
116 | ||
117 | static inline void ssp_port_write(struct ti_ssp *ssp, int port, int reg, | |
118 | u32 val) | |
119 | { | |
120 | ssp_write(ssp, ssp_port_base[port] + reg, val); | |
121 | } | |
122 | ||
123 | static inline void ssp_port_rmw(struct ti_ssp *ssp, int port, int reg, | |
124 | u32 mask, u32 bits) | |
125 | { | |
126 | ssp_rmw(ssp, ssp_port_base[port] + reg, mask, bits); | |
127 | } | |
128 | ||
129 | static inline void ssp_port_clr_bits(struct ti_ssp *ssp, int port, int reg, | |
130 | u32 bits) | |
131 | { | |
132 | ssp_port_rmw(ssp, port, reg, bits, 0); | |
133 | } | |
134 | ||
135 | static inline void ssp_port_set_bits(struct ti_ssp *ssp, int port, int reg, | |
136 | u32 bits) | |
137 | { | |
138 | ssp_port_rmw(ssp, port, reg, 0, bits); | |
139 | } | |
140 | ||
141 | /* Called to setup port clock mode, caller must hold ssp->lock */ | |
142 | static int __set_mode(struct ti_ssp *ssp, int port, int mode) | |
143 | { | |
144 | mode &= SSP_PORT_CONFIG_MASK; | |
145 | ssp_port_rmw(ssp, port, PORT_CFG_1, SSP_PORT_CONFIG_MASK, mode); | |
146 | ||
147 | return 0; | |
148 | } | |
149 | ||
150 | int ti_ssp_set_mode(struct device *dev, int mode) | |
151 | { | |
152 | struct ti_ssp *ssp = dev_to_ssp(dev); | |
153 | int port = dev_to_port(dev); | |
154 | int ret; | |
155 | ||
156 | spin_lock(&ssp->lock); | |
157 | ret = __set_mode(ssp, port, mode); | |
158 | spin_unlock(&ssp->lock); | |
159 | ||
160 | return ret; | |
161 | } | |
162 | EXPORT_SYMBOL(ti_ssp_set_mode); | |
163 | ||
164 | /* Called to setup iosel2, caller must hold ssp->lock */ | |
165 | static void __set_iosel2(struct ti_ssp *ssp, u32 mask, u32 val) | |
166 | { | |
167 | ssp->iosel2 = (ssp->iosel2 & ~mask) | val; | |
168 | ssp_write(ssp, REG_IOSEL_2, ssp->iosel2); | |
169 | } | |
170 | ||
171 | /* Called to setup port iosel, caller must hold ssp->lock */ | |
172 | static void __set_iosel(struct ti_ssp *ssp, int port, u32 iosel) | |
173 | { | |
174 | unsigned val, shift = port ? 16 : 0; | |
175 | ||
176 | /* IOSEL1 gets the least significant 16 bits */ | |
177 | val = ssp_read(ssp, REG_IOSEL_1); | |
178 | val &= 0xffff << (port ? 0 : 16); | |
179 | val |= (iosel & 0xffff) << (port ? 16 : 0); | |
180 | ssp_write(ssp, REG_IOSEL_1, val); | |
181 | ||
182 | /* IOSEL2 gets the most significant 16 bits */ | |
183 | val = (iosel >> 16) & 0x7; | |
184 | __set_iosel2(ssp, 0x7 << shift, val << shift); | |
185 | } | |
186 | ||
187 | int ti_ssp_set_iosel(struct device *dev, u32 iosel) | |
188 | { | |
189 | struct ti_ssp *ssp = dev_to_ssp(dev); | |
190 | int port = dev_to_port(dev); | |
191 | ||
192 | spin_lock(&ssp->lock); | |
193 | __set_iosel(ssp, port, iosel); | |
194 | spin_unlock(&ssp->lock); | |
195 | ||
196 | return 0; | |
197 | } | |
198 | EXPORT_SYMBOL(ti_ssp_set_iosel); | |
199 | ||
200 | int ti_ssp_load(struct device *dev, int offs, u32* prog, int len) | |
201 | { | |
202 | struct ti_ssp *ssp = dev_to_ssp(dev); | |
203 | int port = dev_to_port(dev); | |
204 | int i; | |
205 | ||
206 | if (len > SSP_PORT_SEQRAM_SIZE) | |
207 | return -ENOSPC; | |
208 | ||
209 | spin_lock(&ssp->lock); | |
210 | ||
211 | /* Enable SeqRAM access */ | |
212 | ssp_port_set_bits(ssp, port, PORT_CFG_2, SSP_SEQRAM_WR_EN); | |
213 | ||
214 | /* Copy code */ | |
215 | for (i = 0; i < len; i++) { | |
216 | __raw_writel(prog[i], ssp->regs + offs + 4*i + | |
217 | ssp_port_seqram[port]); | |
218 | } | |
219 | ||
220 | /* Disable SeqRAM access */ | |
221 | ssp_port_clr_bits(ssp, port, PORT_CFG_2, SSP_SEQRAM_WR_EN); | |
222 | ||
223 | spin_unlock(&ssp->lock); | |
224 | ||
225 | return 0; | |
226 | } | |
227 | EXPORT_SYMBOL(ti_ssp_load); | |
228 | ||
229 | int ti_ssp_raw_read(struct device *dev) | |
230 | { | |
231 | struct ti_ssp *ssp = dev_to_ssp(dev); | |
232 | int port = dev_to_port(dev); | |
233 | int shift = port ? 27 : 11; | |
234 | ||
235 | return (ssp_read(ssp, REG_IOSEL_2) >> shift) & 0xf; | |
236 | } | |
237 | EXPORT_SYMBOL(ti_ssp_raw_read); | |
238 | ||
239 | int ti_ssp_raw_write(struct device *dev, u32 val) | |
240 | { | |
241 | struct ti_ssp *ssp = dev_to_ssp(dev); | |
242 | int port = dev_to_port(dev), shift; | |
243 | ||
244 | spin_lock(&ssp->lock); | |
245 | ||
246 | shift = port ? 22 : 6; | |
247 | val &= 0xf; | |
248 | __set_iosel2(ssp, 0xf << shift, val << shift); | |
249 | ||
250 | spin_unlock(&ssp->lock); | |
251 | ||
252 | return 0; | |
253 | } | |
254 | EXPORT_SYMBOL(ti_ssp_raw_write); | |
255 | ||
256 | static inline int __xfer_done(struct ti_ssp *ssp, int port) | |
257 | { | |
258 | return !(ssp_port_read(ssp, port, PORT_CFG_1) & SSP_BUSY); | |
259 | } | |
260 | ||
261 | int ti_ssp_run(struct device *dev, u32 pc, u32 input, u32 *output) | |
262 | { | |
263 | struct ti_ssp *ssp = dev_to_ssp(dev); | |
264 | int port = dev_to_port(dev); | |
265 | int ret; | |
266 | ||
267 | if (pc & ~(0x3f)) | |
268 | return -EINVAL; | |
269 | ||
270 | /* Grab ssp->lock to serialize rmw on ssp registers */ | |
271 | spin_lock(&ssp->lock); | |
272 | ||
273 | ssp_port_write(ssp, port, PORT_ADDR, input >> 16); | |
274 | ssp_port_write(ssp, port, PORT_DATA, input & 0xffff); | |
275 | ssp_port_rmw(ssp, port, PORT_CFG_1, 0x3f, pc); | |
276 | ||
277 | /* grab wait queue head lock to avoid race with the isr */ | |
278 | spin_lock_irq(&ssp->wqh.lock); | |
279 | ||
280 | /* kick off sequence execution in hardware */ | |
281 | ssp_port_set_bits(ssp, port, PORT_CFG_1, SSP_START); | |
282 | ||
283 | /* drop ssp lock; no register writes beyond this */ | |
284 | spin_unlock(&ssp->lock); | |
285 | ||
286 | ret = wait_event_interruptible_locked_irq(ssp->wqh, | |
287 | __xfer_done(ssp, port)); | |
288 | spin_unlock_irq(&ssp->wqh.lock); | |
289 | ||
290 | if (ret < 0) | |
291 | return ret; | |
292 | ||
293 | if (output) { | |
294 | *output = (ssp_port_read(ssp, port, PORT_ADDR) << 16) | | |
295 | (ssp_port_read(ssp, port, PORT_DATA) & 0xffff); | |
296 | } | |
297 | ||
298 | ret = ssp_port_read(ssp, port, PORT_STATE) & 0x3f; /* stop address */ | |
299 | ||
300 | return ret; | |
301 | } | |
302 | EXPORT_SYMBOL(ti_ssp_run); | |
303 | ||
304 | static irqreturn_t ti_ssp_interrupt(int irq, void *dev_data) | |
305 | { | |
306 | struct ti_ssp *ssp = dev_data; | |
307 | ||
308 | spin_lock(&ssp->wqh.lock); | |
309 | ||
310 | ssp_write(ssp, REG_INTR_ST, 0x3); | |
311 | wake_up_locked(&ssp->wqh); | |
312 | ||
313 | spin_unlock(&ssp->wqh.lock); | |
314 | ||
315 | return IRQ_HANDLED; | |
316 | } | |
317 | ||
318 | static int __devinit ti_ssp_probe(struct platform_device *pdev) | |
319 | { | |
320 | static struct ti_ssp *ssp; | |
321 | const struct ti_ssp_data *pdata = pdev->dev.platform_data; | |
322 | int error = 0, prediv = 0xff, id; | |
323 | unsigned long sysclk; | |
324 | struct device *dev = &pdev->dev; | |
325 | struct mfd_cell cells[2]; | |
326 | ||
327 | ssp = kzalloc(sizeof(*ssp), GFP_KERNEL); | |
328 | if (!ssp) { | |
329 | dev_err(dev, "cannot allocate device info\n"); | |
330 | return -ENOMEM; | |
331 | } | |
332 | ||
333 | ssp->dev = dev; | |
334 | dev_set_drvdata(dev, ssp); | |
335 | ||
336 | ssp->res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
337 | if (!ssp->res) { | |
338 | error = -ENODEV; | |
339 | dev_err(dev, "cannot determine register area\n"); | |
340 | goto error_res; | |
341 | } | |
342 | ||
343 | if (!request_mem_region(ssp->res->start, resource_size(ssp->res), | |
344 | pdev->name)) { | |
345 | error = -ENOMEM; | |
346 | dev_err(dev, "cannot claim register memory\n"); | |
347 | goto error_res; | |
348 | } | |
349 | ||
350 | ssp->regs = ioremap(ssp->res->start, resource_size(ssp->res)); | |
351 | if (!ssp->regs) { | |
352 | error = -ENOMEM; | |
353 | dev_err(dev, "cannot map register memory\n"); | |
354 | goto error_map; | |
355 | } | |
356 | ||
357 | ssp->clk = clk_get(dev, NULL); | |
358 | if (IS_ERR(ssp->clk)) { | |
359 | error = PTR_ERR(ssp->clk); | |
360 | dev_err(dev, "cannot claim device clock\n"); | |
361 | goto error_clk; | |
362 | } | |
363 | ||
364 | ssp->irq = platform_get_irq(pdev, 0); | |
365 | if (ssp->irq < 0) { | |
366 | error = -ENODEV; | |
367 | dev_err(dev, "unknown irq\n"); | |
368 | goto error_irq; | |
369 | } | |
370 | ||
371 | error = request_threaded_irq(ssp->irq, NULL, ti_ssp_interrupt, 0, | |
372 | dev_name(dev), ssp); | |
373 | if (error < 0) { | |
374 | dev_err(dev, "cannot acquire irq\n"); | |
375 | goto error_irq; | |
376 | } | |
377 | ||
378 | spin_lock_init(&ssp->lock); | |
379 | init_waitqueue_head(&ssp->wqh); | |
380 | ||
381 | /* Power on and initialize SSP */ | |
382 | error = clk_enable(ssp->clk); | |
383 | if (error) { | |
384 | dev_err(dev, "cannot enable device clock\n"); | |
385 | goto error_enable; | |
386 | } | |
387 | ||
388 | /* Reset registers to a sensible known state */ | |
389 | ssp_write(ssp, REG_IOSEL_1, 0); | |
390 | ssp_write(ssp, REG_IOSEL_2, 0); | |
391 | ssp_write(ssp, REG_INTR_EN, 0x3); | |
392 | ssp_write(ssp, REG_INTR_ST, 0x3); | |
393 | ssp_write(ssp, REG_TEST_CTRL, 0); | |
394 | ssp_port_write(ssp, 0, PORT_CFG_1, SSP_PORT_ASL); | |
395 | ssp_port_write(ssp, 1, PORT_CFG_1, SSP_PORT_ASL); | |
396 | ssp_port_write(ssp, 0, PORT_CFG_2, SSP_PORT_CFO1); | |
397 | ssp_port_write(ssp, 1, PORT_CFG_2, SSP_PORT_CFO1); | |
398 | ||
399 | sysclk = clk_get_rate(ssp->clk); | |
400 | if (pdata && pdata->out_clock) | |
401 | prediv = (sysclk / pdata->out_clock) - 1; | |
402 | prediv = clamp(prediv, 0, 0xff); | |
403 | ssp_rmw(ssp, REG_PREDIV, 0xff, prediv); | |
404 | ||
405 | memset(cells, 0, sizeof(cells)); | |
406 | for (id = 0; id < 2; id++) { | |
407 | const struct ti_ssp_dev_data *data = &pdata->dev_data[id]; | |
408 | ||
409 | cells[id].id = id; | |
410 | cells[id].name = data->dev_name; | |
411 | cells[id].platform_data = data->pdata; | |
412 | cells[id].data_size = data->pdata_size; | |
413 | } | |
414 | ||
415 | error = mfd_add_devices(dev, 0, cells, 2, NULL, 0); | |
416 | if (error < 0) { | |
417 | dev_err(dev, "cannot add mfd cells\n"); | |
418 | goto error_enable; | |
419 | } | |
420 | ||
421 | return 0; | |
422 | ||
423 | error_enable: | |
424 | free_irq(ssp->irq, ssp); | |
425 | error_irq: | |
426 | clk_put(ssp->clk); | |
427 | error_clk: | |
428 | iounmap(ssp->regs); | |
429 | error_map: | |
430 | release_mem_region(ssp->res->start, resource_size(ssp->res)); | |
431 | error_res: | |
432 | kfree(ssp); | |
433 | return error; | |
434 | } | |
435 | ||
436 | static int __devexit ti_ssp_remove(struct platform_device *pdev) | |
437 | { | |
438 | struct device *dev = &pdev->dev; | |
439 | struct ti_ssp *ssp = dev_get_drvdata(dev); | |
440 | ||
441 | mfd_remove_devices(dev); | |
442 | clk_disable(ssp->clk); | |
443 | free_irq(ssp->irq, ssp); | |
444 | clk_put(ssp->clk); | |
445 | iounmap(ssp->regs); | |
446 | release_mem_region(ssp->res->start, resource_size(ssp->res)); | |
447 | kfree(ssp); | |
448 | dev_set_drvdata(dev, NULL); | |
449 | return 0; | |
450 | } | |
451 | ||
452 | static struct platform_driver ti_ssp_driver = { | |
453 | .probe = ti_ssp_probe, | |
454 | .remove = __devexit_p(ti_ssp_remove), | |
455 | .driver = { | |
456 | .name = "ti-ssp", | |
457 | .owner = THIS_MODULE, | |
458 | } | |
459 | }; | |
460 | ||
461 | static int __init ti_ssp_init(void) | |
462 | { | |
463 | return platform_driver_register(&ti_ssp_driver); | |
464 | } | |
465 | module_init(ti_ssp_init); | |
466 | ||
467 | static void __exit ti_ssp_exit(void) | |
468 | { | |
469 | platform_driver_unregister(&ti_ssp_driver); | |
470 | } | |
471 | module_exit(ti_ssp_exit); | |
472 | ||
473 | MODULE_DESCRIPTION("Sequencer Serial Port (SSP) Driver"); | |
474 | MODULE_AUTHOR("Cyril Chemparathy"); | |
475 | MODULE_LICENSE("GPL"); | |
476 | MODULE_ALIAS("platform:ti-ssp"); |