Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/arch/arm/mach-pxa/ssp.c | |
3 | * | |
4 | * based on linux/arch/arm/mach-sa1100/ssp.c by Russell King | |
5 | * | |
6 | * Copyright (C) 2003 Russell King. | |
7 | * Copyright (C) 2003 Wolfson Microelectronics PLC | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License version 2 as | |
11 | * published by the Free Software Foundation. | |
12 | * | |
13 | * PXA2xx SSP driver. This provides the generic core for simple | |
14 | * IO-based SSP applications and allows easy port setup for DMA access. | |
15 | * | |
16 | * Author: Liam Girdwood <liam.girdwood@wolfsonmicro.com> | |
17 | * | |
18 | * Revision history: | |
19 | * 22nd Aug 2003 Initial version. | |
20 | * 20th Dec 2004 Added ssp_config for changing port config without | |
21 | * closing the port. | |
22 | */ | |
23 | ||
24 | #include <linux/module.h> | |
25 | #include <linux/kernel.h> | |
26 | #include <linux/sched.h> | |
27 | #include <linux/slab.h> | |
28 | #include <linux/errno.h> | |
29 | #include <linux/interrupt.h> | |
30 | #include <linux/ioport.h> | |
31 | #include <linux/init.h> | |
32 | #include <asm/io.h> | |
33 | #include <asm/irq.h> | |
34 | #include <asm/hardware.h> | |
35 | #include <asm/arch/ssp.h> | |
36 | #include <asm/arch/pxa-regs.h> | |
37 | ||
38 | #define PXA_SSP_PORTS 3 | |
39 | ||
40 | static DECLARE_MUTEX(sem); | |
41 | static int use_count[PXA_SSP_PORTS] = {0, 0, 0}; | |
42 | ||
43 | static irqreturn_t ssp_interrupt(int irq, void *dev_id, struct pt_regs *regs) | |
44 | { | |
45 | struct ssp_dev *dev = (struct ssp_dev*) dev_id; | |
46 | unsigned int status = SSSR_P(dev->port); | |
47 | ||
48 | SSSR_P(dev->port) = status; /* clear status bits */ | |
49 | ||
50 | if (status & SSSR_ROR) | |
51 | printk(KERN_WARNING "SSP(%d): receiver overrun\n", dev->port); | |
52 | ||
53 | if (status & SSSR_TUR) | |
54 | printk(KERN_WARNING "SSP(%d): transmitter underrun\n", dev->port); | |
55 | ||
56 | if (status & SSSR_BCE) | |
57 | printk(KERN_WARNING "SSP(%d): bit count error\n", dev->port); | |
58 | ||
59 | return IRQ_HANDLED; | |
60 | } | |
61 | ||
62 | /** | |
63 | * ssp_write_word - write a word to the SSP port | |
64 | * @data: 32-bit, MSB justified data to write. | |
65 | * | |
66 | * Wait for a free entry in the SSP transmit FIFO, and write a data | |
67 | * word to the SSP port. | |
68 | * | |
69 | * The caller is expected to perform the necessary locking. | |
70 | * | |
71 | * Returns: | |
72 | * %-ETIMEDOUT timeout occurred (for future) | |
73 | * 0 success | |
74 | */ | |
75 | int ssp_write_word(struct ssp_dev *dev, u32 data) | |
76 | { | |
77 | while (!(SSSR_P(dev->port) & SSSR_TNF)) | |
78 | cpu_relax(); | |
79 | ||
80 | SSDR_P(dev->port) = data; | |
81 | ||
82 | return 0; | |
83 | } | |
84 | ||
85 | /** | |
86 | * ssp_read_word - read a word from the SSP port | |
87 | * | |
88 | * Wait for a data word in the SSP receive FIFO, and return the | |
89 | * received data. Data is LSB justified. | |
90 | * | |
91 | * Note: Currently, if data is not expected to be received, this | |
92 | * function will wait for ever. | |
93 | * | |
94 | * The caller is expected to perform the necessary locking. | |
95 | * | |
96 | * Returns: | |
97 | * %-ETIMEDOUT timeout occurred (for future) | |
98 | * 32-bit data success | |
99 | */ | |
100 | int ssp_read_word(struct ssp_dev *dev) | |
101 | { | |
102 | while (!(SSSR_P(dev->port) & SSSR_RNE)) | |
103 | cpu_relax(); | |
104 | ||
105 | return SSDR_P(dev->port); | |
106 | } | |
107 | ||
108 | /** | |
109 | * ssp_flush - flush the transmit and receive FIFOs | |
110 | * | |
111 | * Wait for the SSP to idle, and ensure that the receive FIFO | |
112 | * is empty. | |
113 | * | |
114 | * The caller is expected to perform the necessary locking. | |
115 | */ | |
116 | void ssp_flush(struct ssp_dev *dev) | |
117 | { | |
118 | do { | |
119 | while (SSSR_P(dev->port) & SSSR_RNE) { | |
120 | (void) SSDR_P(dev->port); | |
121 | } | |
122 | } while (SSSR_P(dev->port) & SSSR_BSY); | |
123 | } | |
124 | ||
125 | /** | |
126 | * ssp_enable - enable the SSP port | |
127 | * | |
128 | * Turn on the SSP port. | |
129 | */ | |
130 | void ssp_enable(struct ssp_dev *dev) | |
131 | { | |
132 | SSCR0_P(dev->port) |= SSCR0_SSE; | |
133 | } | |
134 | ||
135 | /** | |
136 | * ssp_disable - shut down the SSP port | |
137 | * | |
138 | * Turn off the SSP port, optionally powering it down. | |
139 | */ | |
140 | void ssp_disable(struct ssp_dev *dev) | |
141 | { | |
142 | SSCR0_P(dev->port) &= ~SSCR0_SSE; | |
143 | } | |
144 | ||
145 | /** | |
146 | * ssp_save_state - save the SSP configuration | |
147 | * @ssp: pointer to structure to save SSP configuration | |
148 | * | |
149 | * Save the configured SSP state for suspend. | |
150 | */ | |
151 | void ssp_save_state(struct ssp_dev *dev, struct ssp_state *ssp) | |
152 | { | |
153 | ssp->cr0 = SSCR0_P(dev->port); | |
154 | ssp->cr1 = SSCR1_P(dev->port); | |
155 | ssp->to = SSTO_P(dev->port); | |
156 | ssp->psp = SSPSP_P(dev->port); | |
157 | ||
158 | SSCR0_P(dev->port) &= ~SSCR0_SSE; | |
159 | } | |
160 | ||
161 | /** | |
162 | * ssp_restore_state - restore a previously saved SSP configuration | |
163 | * @ssp: pointer to configuration saved by ssp_save_state | |
164 | * | |
165 | * Restore the SSP configuration saved previously by ssp_save_state. | |
166 | */ | |
167 | void ssp_restore_state(struct ssp_dev *dev, struct ssp_state *ssp) | |
168 | { | |
169 | SSSR_P(dev->port) = SSSR_ROR | SSSR_TUR | SSSR_BCE; | |
170 | ||
171 | SSCR0_P(dev->port) = ssp->cr0 & ~SSCR0_SSE; | |
172 | SSCR1_P(dev->port) = ssp->cr1; | |
173 | SSTO_P(dev->port) = ssp->to; | |
174 | SSPSP_P(dev->port) = ssp->psp; | |
175 | ||
176 | SSCR0_P(dev->port) = ssp->cr0; | |
177 | } | |
178 | ||
179 | /** | |
180 | * ssp_config - configure SSP port settings | |
181 | * @mode: port operating mode | |
182 | * @flags: port config flags | |
183 | * @psp_flags: port PSP config flags | |
184 | * @speed: port speed | |
185 | * | |
186 | * Port MUST be disabled by ssp_disable before making any config changes. | |
187 | */ | |
188 | int ssp_config(struct ssp_dev *dev, u32 mode, u32 flags, u32 psp_flags, u32 speed) | |
189 | { | |
190 | dev->mode = mode; | |
191 | dev->flags = flags; | |
192 | dev->psp_flags = psp_flags; | |
193 | dev->speed = speed; | |
194 | ||
195 | /* set up port type, speed, port settings */ | |
196 | SSCR0_P(dev->port) = (dev->speed | dev->mode); | |
197 | SSCR1_P(dev->port) = dev->flags; | |
198 | SSPSP_P(dev->port) = dev->psp_flags; | |
199 | ||
200 | return 0; | |
201 | } | |
202 | ||
203 | /** | |
204 | * ssp_init - setup the SSP port | |
205 | * | |
206 | * initialise and claim resources for the SSP port. | |
207 | * | |
208 | * Returns: | |
209 | * %-ENODEV if the SSP port is unavailable | |
210 | * %-EBUSY if the resources are already in use | |
211 | * %0 on success | |
212 | */ | |
213 | int ssp_init(struct ssp_dev *dev, u32 port) | |
214 | { | |
215 | int ret, irq; | |
216 | ||
217 | if (port > PXA_SSP_PORTS || port == 0) | |
218 | return -ENODEV; | |
219 | ||
220 | down(&sem); | |
221 | if (use_count[port - 1]) { | |
222 | up(&sem); | |
223 | return -EBUSY; | |
224 | } | |
225 | use_count[port - 1]++; | |
226 | ||
227 | if (!request_mem_region(__PREG(SSCR0_P(port)), 0x2c, "SSP")) { | |
228 | use_count[port - 1]--; | |
229 | up(&sem); | |
230 | return -EBUSY; | |
231 | } | |
232 | ||
233 | switch (port) { | |
234 | case 1: | |
235 | irq = IRQ_SSP; | |
236 | break; | |
237 | #if defined (CONFIG_PXA27x) | |
238 | case 2: | |
239 | irq = IRQ_SSP2; | |
240 | break; | |
241 | case 3: | |
242 | irq = IRQ_SSP3; | |
243 | break; | |
244 | #else | |
245 | case 2: | |
246 | irq = IRQ_NSSP; | |
247 | break; | |
248 | case 3: | |
249 | irq = IRQ_ASSP; | |
250 | break; | |
251 | #endif | |
252 | default: | |
253 | return -ENODEV; | |
254 | } | |
255 | ||
256 | dev->port = port; | |
257 | ||
258 | ret = request_irq(irq, ssp_interrupt, 0, "SSP", dev); | |
259 | if (ret) | |
260 | goto out_region; | |
261 | ||
262 | /* turn on SSP port clock */ | |
263 | switch (dev->port) { | |
264 | #if defined (CONFIG_PXA27x) | |
265 | case 1: | |
266 | pxa_set_cken(CKEN23_SSP1, 1); | |
267 | break; | |
268 | case 2: | |
269 | pxa_set_cken(CKEN3_SSP2, 1); | |
270 | break; | |
271 | case 3: | |
272 | pxa_set_cken(CKEN4_SSP3, 1); | |
273 | break; | |
274 | #else | |
275 | case 1: | |
276 | pxa_set_cken(CKEN3_SSP, 1); | |
277 | break; | |
278 | case 2: | |
279 | pxa_set_cken(CKEN9_NSSP, 1); | |
280 | break; | |
281 | case 3: | |
282 | pxa_set_cken(CKEN10_ASSP, 1); | |
283 | break; | |
284 | #endif | |
285 | } | |
286 | ||
287 | up(&sem); | |
288 | return 0; | |
289 | ||
290 | out_region: | |
291 | release_mem_region(__PREG(SSCR0_P(port)), 0x2c); | |
292 | use_count[port - 1]--; | |
293 | up(&sem); | |
294 | return ret; | |
295 | } | |
296 | ||
297 | /** | |
298 | * ssp_exit - undo the effects of ssp_init | |
299 | * | |
300 | * release and free resources for the SSP port. | |
301 | */ | |
302 | void ssp_exit(struct ssp_dev *dev) | |
303 | { | |
304 | int irq; | |
305 | ||
306 | down(&sem); | |
307 | SSCR0_P(dev->port) &= ~SSCR0_SSE; | |
308 | ||
309 | /* find irq, save power and turn off SSP port clock */ | |
310 | switch (dev->port) { | |
311 | #if defined (CONFIG_PXA27x) | |
312 | case 1: | |
313 | irq = IRQ_SSP; | |
314 | pxa_set_cken(CKEN23_SSP1, 0); | |
315 | break; | |
316 | case 2: | |
317 | irq = IRQ_SSP2; | |
318 | pxa_set_cken(CKEN3_SSP2, 0); | |
319 | break; | |
320 | case 3: | |
321 | irq = IRQ_SSP3; | |
322 | pxa_set_cken(CKEN4_SSP3, 0); | |
323 | break; | |
324 | #else | |
325 | case 1: | |
326 | irq = IRQ_SSP; | |
327 | pxa_set_cken(CKEN3_SSP, 0); | |
328 | break; | |
329 | case 2: | |
330 | irq = IRQ_NSSP; | |
331 | pxa_set_cken(CKEN9_NSSP, 0); | |
332 | break; | |
333 | case 3: | |
334 | irq = IRQ_ASSP; | |
335 | pxa_set_cken(CKEN10_ASSP, 0); | |
336 | break; | |
337 | #endif | |
338 | default: | |
339 | printk(KERN_WARNING "SSP: tried to close invalid port\n"); | |
340 | return; | |
341 | } | |
342 | ||
343 | free_irq(irq, dev); | |
344 | release_mem_region(__PREG(SSCR0_P(dev->port)), 0x2c); | |
345 | use_count[dev->port - 1]--; | |
346 | up(&sem); | |
347 | } | |
348 | ||
349 | EXPORT_SYMBOL(ssp_write_word); | |
350 | EXPORT_SYMBOL(ssp_read_word); | |
351 | EXPORT_SYMBOL(ssp_flush); | |
352 | EXPORT_SYMBOL(ssp_enable); | |
353 | EXPORT_SYMBOL(ssp_disable); | |
354 | EXPORT_SYMBOL(ssp_save_state); | |
355 | EXPORT_SYMBOL(ssp_restore_state); | |
356 | EXPORT_SYMBOL(ssp_init); | |
357 | EXPORT_SYMBOL(ssp_exit); | |
358 | EXPORT_SYMBOL(ssp_config); | |
359 | ||
360 | MODULE_DESCRIPTION("PXA SSP driver"); | |
361 | MODULE_AUTHOR("Liam Girdwood"); | |
362 | MODULE_LICENSE("GPL"); | |
363 |