2 * linux/arch/arm/mach-pxa/ssp.c
4 * based on linux/arch/arm/mach-sa1100/ssp.c by Russell King
6 * Copyright (C) 2003 Russell King.
7 * Copyright (C) 2003 Wolfson Microelectronics PLC
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.
13 * PXA2xx SSP driver. This provides the generic core for simple
14 * IO-based SSP applications and allows easy port setup for DMA access.
16 * Author: Liam Girdwood <liam.girdwood@wolfsonmicro.com>
19 #include <linux/module.h>
20 #include <linux/kernel.h>
21 #include <linux/sched.h>
22 #include <linux/slab.h>
23 #include <linux/errno.h>
24 #include <linux/interrupt.h>
25 #include <linux/ioport.h>
26 #include <linux/init.h>
27 #include <linux/mutex.h>
28 #include <linux/clk.h>
29 #include <linux/err.h>
30 #include <linux/platform_device.h>
34 #include <mach/hardware.h>
36 #include <mach/regs-ssp.h>
38 #ifdef CONFIG_PXA_SSP_LEGACY
40 #define TIMEOUT 100000
42 static irqreturn_t ssp_interrupt(int irq, void *dev_id)
44 struct ssp_dev *dev = dev_id;
45 struct ssp_device *ssp = dev->ssp;
48 status = __raw_readl(ssp->mmio_base + SSSR);
49 __raw_writel(status, ssp->mmio_base + SSSR);
51 if (status & SSSR_ROR)
52 printk(KERN_WARNING "SSP(%d): receiver overrun\n", dev->port);
54 if (status & SSSR_TUR)
55 printk(KERN_WARNING "SSP(%d): transmitter underrun\n", dev->port);
57 if (status & SSSR_BCE)
58 printk(KERN_WARNING "SSP(%d): bit count error\n", dev->port);
64 * ssp_write_word - write a word to the SSP port
65 * @data: 32-bit, MSB justified data to write.
67 * Wait for a free entry in the SSP transmit FIFO, and write a data
68 * word to the SSP port.
70 * The caller is expected to perform the necessary locking.
73 * %-ETIMEDOUT timeout occurred
76 int ssp_write_word(struct ssp_dev *dev, u32 data)
78 struct ssp_device *ssp = dev->ssp;
79 int timeout = TIMEOUT;
81 while (!(__raw_readl(ssp->mmio_base + SSSR) & SSSR_TNF)) {
87 __raw_writel(data, ssp->mmio_base + SSDR);
93 * ssp_read_word - read a word from the SSP port
95 * Wait for a data word in the SSP receive FIFO, and return the
96 * received data. Data is LSB justified.
98 * Note: Currently, if data is not expected to be received, this
99 * function will wait for ever.
101 * The caller is expected to perform the necessary locking.
104 * %-ETIMEDOUT timeout occurred
105 * 32-bit data success
107 int ssp_read_word(struct ssp_dev *dev, u32 *data)
109 struct ssp_device *ssp = dev->ssp;
110 int timeout = TIMEOUT;
112 while (!(__raw_readl(ssp->mmio_base + SSSR) & SSSR_RNE)) {
118 *data = __raw_readl(ssp->mmio_base + SSDR);
123 * ssp_flush - flush the transmit and receive FIFOs
125 * Wait for the SSP to idle, and ensure that the receive FIFO
128 * The caller is expected to perform the necessary locking.
130 int ssp_flush(struct ssp_dev *dev)
132 struct ssp_device *ssp = dev->ssp;
133 int timeout = TIMEOUT * 2;
135 /* ensure TX FIFO is empty instead of not full */
136 if (cpu_is_pxa3xx()) {
137 while (__raw_readl(ssp->mmio_base + SSSR) & 0xf00) {
142 timeout = TIMEOUT * 2;
146 while (__raw_readl(ssp->mmio_base + SSSR) & SSSR_RNE) {
149 (void)__raw_readl(ssp->mmio_base + SSDR);
153 } while (__raw_readl(ssp->mmio_base + SSSR) & SSSR_BSY);
159 * ssp_enable - enable the SSP port
161 * Turn on the SSP port.
163 void ssp_enable(struct ssp_dev *dev)
165 struct ssp_device *ssp = dev->ssp;
168 sscr0 = __raw_readl(ssp->mmio_base + SSCR0);
170 __raw_writel(sscr0, ssp->mmio_base + SSCR0);
174 * ssp_disable - shut down the SSP port
176 * Turn off the SSP port, optionally powering it down.
178 void ssp_disable(struct ssp_dev *dev)
180 struct ssp_device *ssp = dev->ssp;
183 sscr0 = __raw_readl(ssp->mmio_base + SSCR0);
185 __raw_writel(sscr0, ssp->mmio_base + SSCR0);
189 * ssp_save_state - save the SSP configuration
190 * @ssp: pointer to structure to save SSP configuration
192 * Save the configured SSP state for suspend.
194 void ssp_save_state(struct ssp_dev *dev, struct ssp_state *state)
196 struct ssp_device *ssp = dev->ssp;
198 state->cr0 = __raw_readl(ssp->mmio_base + SSCR0);
199 state->cr1 = __raw_readl(ssp->mmio_base + SSCR1);
200 state->to = __raw_readl(ssp->mmio_base + SSTO);
201 state->psp = __raw_readl(ssp->mmio_base + SSPSP);
207 * ssp_restore_state - restore a previously saved SSP configuration
208 * @ssp: pointer to configuration saved by ssp_save_state
210 * Restore the SSP configuration saved previously by ssp_save_state.
212 void ssp_restore_state(struct ssp_dev *dev, struct ssp_state *state)
214 struct ssp_device *ssp = dev->ssp;
215 uint32_t sssr = SSSR_ROR | SSSR_TUR | SSSR_BCE;
217 __raw_writel(sssr, ssp->mmio_base + SSSR);
219 __raw_writel(state->cr0 & ~SSCR0_SSE, ssp->mmio_base + SSCR0);
220 __raw_writel(state->cr1, ssp->mmio_base + SSCR1);
221 __raw_writel(state->to, ssp->mmio_base + SSTO);
222 __raw_writel(state->psp, ssp->mmio_base + SSPSP);
223 __raw_writel(state->cr0, ssp->mmio_base + SSCR0);
227 * ssp_config - configure SSP port settings
228 * @mode: port operating mode
229 * @flags: port config flags
230 * @psp_flags: port PSP config flags
233 * Port MUST be disabled by ssp_disable before making any config changes.
235 int ssp_config(struct ssp_dev *dev, u32 mode, u32 flags, u32 psp_flags, u32 speed)
237 struct ssp_device *ssp = dev->ssp;
241 dev->psp_flags = psp_flags;
244 /* set up port type, speed, port settings */
245 __raw_writel((dev->speed | dev->mode), ssp->mmio_base + SSCR0);
246 __raw_writel(dev->flags, ssp->mmio_base + SSCR1);
247 __raw_writel(dev->psp_flags, ssp->mmio_base + SSPSP);
253 * ssp_init - setup the SSP port
255 * initialise and claim resources for the SSP port.
258 * %-ENODEV if the SSP port is unavailable
259 * %-EBUSY if the resources are already in use
262 int ssp_init(struct ssp_dev *dev, u32 port, u32 init_flags)
264 struct ssp_device *ssp;
267 ssp = ssp_request(port, "SSP");
274 /* do we need to get irq */
275 if (!(init_flags & SSP_NO_IRQ)) {
276 ret = request_irq(ssp->irq, ssp_interrupt,
284 /* turn on SSP port clock */
285 clk_enable(ssp->clk);
294 * ssp_exit - undo the effects of ssp_init
296 * release and free resources for the SSP port.
298 void ssp_exit(struct ssp_dev *dev)
300 struct ssp_device *ssp = dev->ssp;
303 if (dev->irq != NO_IRQ)
304 free_irq(dev->irq, dev);
305 clk_disable(ssp->clk);
308 #endif /* CONFIG_PXA_SSP_LEGACY */
310 static DEFINE_MUTEX(ssp_lock);
311 static LIST_HEAD(ssp_list);
313 struct ssp_device *ssp_request(int port, const char *label)
315 struct ssp_device *ssp = NULL;
317 mutex_lock(&ssp_lock);
319 list_for_each_entry(ssp, &ssp_list, node) {
320 if (ssp->port_id == port && ssp->use_count == 0) {
327 mutex_unlock(&ssp_lock);
329 if (&ssp->node == &ssp_list)
334 EXPORT_SYMBOL(ssp_request);
336 void ssp_free(struct ssp_device *ssp)
338 mutex_lock(&ssp_lock);
339 if (ssp->use_count) {
343 dev_err(&ssp->pdev->dev, "device already free\n");
344 mutex_unlock(&ssp_lock);
346 EXPORT_SYMBOL(ssp_free);
348 static int __devinit ssp_probe(struct platform_device *pdev)
350 const struct platform_device_id *id = platform_get_device_id(pdev);
351 struct resource *res;
352 struct ssp_device *ssp;
355 ssp = kzalloc(sizeof(struct ssp_device), GFP_KERNEL);
357 dev_err(&pdev->dev, "failed to allocate memory");
362 ssp->clk = clk_get(&pdev->dev, NULL);
363 if (IS_ERR(ssp->clk)) {
364 ret = PTR_ERR(ssp->clk);
368 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
370 dev_err(&pdev->dev, "no memory resource defined\n");
375 res = request_mem_region(res->start, res->end - res->start + 1,
378 dev_err(&pdev->dev, "failed to request memory resource\n");
383 ssp->phys_base = res->start;
385 ssp->mmio_base = ioremap(res->start, res->end - res->start + 1);
386 if (ssp->mmio_base == NULL) {
387 dev_err(&pdev->dev, "failed to ioremap() registers\n");
392 ssp->irq = platform_get_irq(pdev, 0);
394 dev_err(&pdev->dev, "no IRQ resource defined\n");
399 res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
401 dev_err(&pdev->dev, "no SSP RX DRCMR defined\n");
405 ssp->drcmr_rx = res->start;
407 res = platform_get_resource(pdev, IORESOURCE_DMA, 1);
409 dev_err(&pdev->dev, "no SSP TX DRCMR defined\n");
413 ssp->drcmr_tx = res->start;
415 /* PXA2xx/3xx SSP ports starts from 1 and the internal pdev->id
416 * starts from 0, do a translation here
418 ssp->port_id = pdev->id + 1;
420 ssp->type = (int)id->driver_data;
422 mutex_lock(&ssp_lock);
423 list_add(&ssp->node, &ssp_list);
424 mutex_unlock(&ssp_lock);
426 platform_set_drvdata(pdev, ssp);
430 iounmap(ssp->mmio_base);
432 release_mem_region(res->start, res->end - res->start + 1);
440 static int __devexit ssp_remove(struct platform_device *pdev)
442 struct resource *res;
443 struct ssp_device *ssp;
445 ssp = platform_get_drvdata(pdev);
449 iounmap(ssp->mmio_base);
451 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
452 release_mem_region(res->start, res->end - res->start + 1);
456 mutex_lock(&ssp_lock);
457 list_del(&ssp->node);
458 mutex_unlock(&ssp_lock);
464 static const struct platform_device_id ssp_id_table[] = {
465 { "pxa25x-ssp", PXA25x_SSP },
466 { "pxa25x-nssp", PXA25x_NSSP },
467 { "pxa27x-ssp", PXA27x_SSP },
471 static struct platform_driver ssp_driver = {
473 .remove = __devexit_p(ssp_remove),
475 .owner = THIS_MODULE,
476 .name = "pxa2xx-ssp",
478 .id_table = ssp_id_table,
481 static int __init pxa_ssp_init(void)
483 return platform_driver_register(&ssp_driver);
486 static void __exit pxa_ssp_exit(void)
488 platform_driver_unregister(&ssp_driver);
491 arch_initcall(pxa_ssp_init);
492 module_exit(pxa_ssp_exit);
494 #ifdef CONFIG_PXA_SSP_LEGACY
495 EXPORT_SYMBOL(ssp_write_word);
496 EXPORT_SYMBOL(ssp_read_word);
497 EXPORT_SYMBOL(ssp_flush);
498 EXPORT_SYMBOL(ssp_enable);
499 EXPORT_SYMBOL(ssp_disable);
500 EXPORT_SYMBOL(ssp_save_state);
501 EXPORT_SYMBOL(ssp_restore_state);
502 EXPORT_SYMBOL(ssp_init);
503 EXPORT_SYMBOL(ssp_exit);
504 EXPORT_SYMBOL(ssp_config);
507 MODULE_DESCRIPTION("PXA SSP driver");
508 MODULE_AUTHOR("Liam Girdwood");
509 MODULE_LICENSE("GPL");