[deliverable/linux.git] / arch / arm / mach-pxa / ssp.c

/*
 *  linux/arch/arm/mach-pxa/ssp.c
 *
 *  based on linux/arch/arm/mach-sa1100/ssp.c by Russell King
 *
 *  Copyright (C) 2003 Russell King.
 *  Copyright (C) 2003 Wolfson Microelectronics PLC
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 *  PXA2xx SSP driver.  This provides the generic core for simple
 *  IO-based SSP applications and allows easy port setup for DMA access.
 *
 *  Author: Liam Girdwood <liam.girdwood@wolfsonmicro.com>
 *
 *  Revision history:
 *   22nd Aug 2003 Initial version.
 *   20th Dec 2004 Added ssp_config for changing port config without
 *                 closing the port.
 *    4th Aug 2005 Added option to disable irq handler registration and
 *                 cleaned up irq and clock detection.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/mutex.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/hardware.h>
#include <asm/arch/ssp.h>
#include <asm/arch/pxa-regs.h>

#define PXA_SSP_PORTS 	3

struct ssp_info_ {
	int irq;
	u32 clock;
};

/*
 * SSP port clock and IRQ settings
 */
static const struct ssp_info_ ssp_info[PXA_SSP_PORTS] = {
#if defined (CONFIG_PXA27x)
	{IRQ_SSP,	CKEN23_SSP1},
	{IRQ_SSP2,	CKEN3_SSP2},
	{IRQ_SSP3,	CKEN4_SSP3},
#else
	{IRQ_SSP,	CKEN3_SSP},
	{IRQ_NSSP,	CKEN9_NSSP},
	{IRQ_ASSP,	CKEN10_ASSP},
#endif
};

static DEFINE_MUTEX(mutex);
static int use_count[PXA_SSP_PORTS] = {0, 0, 0};

static irqreturn_t ssp_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
	struct ssp_dev *dev = (struct ssp_dev*) dev_id;
	unsigned int status = SSSR_P(dev->port);

	SSSR_P(dev->port) = status; /* clear status bits */

	if (status & SSSR_ROR)
		printk(KERN_WARNING "SSP(%d): receiver overrun\n", dev->port);

	if (status & SSSR_TUR)
		printk(KERN_WARNING "SSP(%d): transmitter underrun\n", dev->port);

	if (status & SSSR_BCE)
		printk(KERN_WARNING "SSP(%d): bit count error\n", dev->port);

	return IRQ_HANDLED;
}

/**
 * ssp_write_word - write a word to the SSP port
 * @data: 32-bit, MSB justified data to write.
 *
 * Wait for a free entry in the SSP transmit FIFO, and write a data
 * word to the SSP port.
 *
 * The caller is expected to perform the necessary locking.
 *
 * Returns:
 *   %-ETIMEDOUT	timeout occurred (for future)
 *   0			success
 */
int ssp_write_word(struct ssp_dev *dev, u32 data)
{
	while (!(SSSR_P(dev->port) & SSSR_TNF))
		cpu_relax();

	SSDR_P(dev->port) = data;

	return 0;
}

/**
 * ssp_read_word - read a word from the SSP port
 *
 * Wait for a data word in the SSP receive FIFO, and return the
 * received data.  Data is LSB justified.
 *
 * Note: Currently, if data is not expected to be received, this
 * function will wait for ever.
 *
 * The caller is expected to perform the necessary locking.
 *
 * Returns:
 *   %-ETIMEDOUT	timeout occurred (for future)
 *   32-bit data	success
 */
int ssp_read_word(struct ssp_dev *dev)
{
	while (!(SSSR_P(dev->port) & SSSR_RNE))
		cpu_relax();

	return SSDR_P(dev->port);
}

/**
 * ssp_flush - flush the transmit and receive FIFOs
 *
 * Wait for the SSP to idle, and ensure that the receive FIFO
 * is empty.
 *
 * The caller is expected to perform the necessary locking.
 */
void ssp_flush(struct ssp_dev *dev)
{
	do {
		while (SSSR_P(dev->port) & SSSR_RNE) {
			(void) SSDR_P(dev->port);
		}
	} while (SSSR_P(dev->port) & SSSR_BSY);
}

/**
 * ssp_enable - enable the SSP port
 *
 * Turn on the SSP port.
 */
void ssp_enable(struct ssp_dev *dev)
{
	SSCR0_P(dev->port) |= SSCR0_SSE;
}

/**
 * ssp_disable - shut down the SSP port
 *
 * Turn off the SSP port, optionally powering it down.
 */
void ssp_disable(struct ssp_dev *dev)
{
	SSCR0_P(dev->port) &= ~SSCR0_SSE;
}

/**
 * ssp_save_state - save the SSP configuration
 * @ssp: pointer to structure to save SSP configuration
 *
 * Save the configured SSP state for suspend.
 */
void ssp_save_state(struct ssp_dev *dev, struct ssp_state *ssp)
{
	ssp->cr0 = SSCR0_P(dev->port);
	ssp->cr1 = SSCR1_P(dev->port);
	ssp->to = SSTO_P(dev->port);
	ssp->psp = SSPSP_P(dev->port);

	SSCR0_P(dev->port) &= ~SSCR0_SSE;
}

/**
 * ssp_restore_state - restore a previously saved SSP configuration
 * @ssp: pointer to configuration saved by ssp_save_state
 *
 * Restore the SSP configuration saved previously by ssp_save_state.
 */
void ssp_restore_state(struct ssp_dev *dev, struct ssp_state *ssp)
{
	SSSR_P(dev->port) = SSSR_ROR | SSSR_TUR | SSSR_BCE;

	SSCR0_P(dev->port) = ssp->cr0 & ~SSCR0_SSE;
	SSCR1_P(dev->port) = ssp->cr1;
	SSTO_P(dev->port) = ssp->to;
	SSPSP_P(dev->port) = ssp->psp;

	SSCR0_P(dev->port) = ssp->cr0;
}

/**
 * ssp_config - configure SSP port settings
 * @mode: port operating mode
 * @flags: port config flags
 * @psp_flags: port PSP config flags
 * @speed: port speed
 *
 * Port MUST be disabled by ssp_disable before making any config changes.
 */
int ssp_config(struct ssp_dev *dev, u32 mode, u32 flags, u32 psp_flags, u32 speed)
{
	dev->mode = mode;
	dev->flags = flags;
	dev->psp_flags = psp_flags;
	dev->speed = speed;

	/* set up port type, speed, port settings */
	SSCR0_P(dev->port) = (dev->speed | dev->mode);
	SSCR1_P(dev->port) = dev->flags;
	SSPSP_P(dev->port) = dev->psp_flags;

	return 0;
}

/**
 * ssp_init - setup the SSP port
 *
 * initialise and claim resources for the SSP port.
 *
 * Returns:
 *   %-ENODEV	if the SSP port is unavailable
 *   %-EBUSY	if the resources are already in use
 *   %0		on success
 */
int ssp_init(struct ssp_dev *dev, u32 port, u32 init_flags)
{
	int ret;

	if (port > PXA_SSP_PORTS || port == 0)
		return -ENODEV;

	mutex_lock(&mutex);
	if (use_count[port - 1]) {
		mutex_unlock(&mutex);
		return -EBUSY;
	}
	use_count[port - 1]++;

	if (!request_mem_region(__PREG(SSCR0_P(port)), 0x2c, "SSP")) {
		use_count[port - 1]--;
		mutex_unlock(&mutex);
		return -EBUSY;
	}
	dev->port = port;

	/* do we need to get irq */
	if (!(init_flags & SSP_NO_IRQ)) {
		ret = request_irq(ssp_info[port-1].irq, ssp_interrupt,
				0, "SSP", dev);
	    	if (ret)
			goto out_region;
	    	dev->irq = ssp_info[port-1].irq;
	} else
		dev->irq = 0;

	/* turn on SSP port clock */
	pxa_set_cken(ssp_info[port-1].clock, 1);
	mutex_unlock(&mutex);
	return 0;

out_region:
	release_mem_region(__PREG(SSCR0_P(port)), 0x2c);
	use_count[port - 1]--;
	mutex_unlock(&mutex);
	return ret;
}

/**
 * ssp_exit - undo the effects of ssp_init
 *
 * release and free resources for the SSP port.
 */
void ssp_exit(struct ssp_dev *dev)
{
	mutex_lock(&mutex);
	SSCR0_P(dev->port) &= ~SSCR0_SSE;

    	if (dev->port > PXA_SSP_PORTS || dev->port == 0) {
		printk(KERN_WARNING "SSP: tried to close invalid port\n");
		return;
	}

	pxa_set_cken(ssp_info[dev->port-1].clock, 0);
	if (dev->irq)
		free_irq(dev->irq, dev);
	release_mem_region(__PREG(SSCR0_P(dev->port)), 0x2c);
	use_count[dev->port - 1]--;
	mutex_unlock(&mutex);
}

EXPORT_SYMBOL(ssp_write_word);
EXPORT_SYMBOL(ssp_read_word);
EXPORT_SYMBOL(ssp_flush);
EXPORT_SYMBOL(ssp_enable);
EXPORT_SYMBOL(ssp_disable);
EXPORT_SYMBOL(ssp_save_state);
EXPORT_SYMBOL(ssp_restore_state);
EXPORT_SYMBOL(ssp_init);
EXPORT_SYMBOL(ssp_exit);
EXPORT_SYMBOL(ssp_config);

MODULE_DESCRIPTION("PXA SSP driver");
MODULE_AUTHOR("Liam Girdwood");
MODULE_LICENSE("GPL");
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.
b216c018 LG	22	* 4th Aug 2005 Added option to disable irq handler registration and
b216c018 LG	23	* cleaned up irq and clock detection.
1da177e4 LT	24	*/
	25
	26	#include <linux/module.h>
	27	#include <linux/kernel.h>
	28	#include <linux/sched.h>
	29	#include <linux/slab.h>
	30	#include <linux/errno.h>
	31	#include <linux/interrupt.h>
	32	#include <linux/ioport.h>
	33	#include <linux/init.h>
00431707	34	#include <linux/mutex.h>
1da177e4 LT	35	#include <asm/io.h>
	36	#include <asm/irq.h>
	37	#include <asm/hardware.h>
	38	#include <asm/arch/ssp.h>
	39	#include <asm/arch/pxa-regs.h>
	40
	41	#define PXA_SSP_PORTS 3
	42
b216c018 LG	43	struct ssp_info_ {
	44	int irq;
	45	u32 clock;
	46	};
	47
	48	/*
	49	* SSP port clock and IRQ settings
	50	*/
	51	static const struct ssp_info_ ssp_info[PXA_SSP_PORTS] = {
	52	#if defined (CONFIG_PXA27x)
	53	{IRQ_SSP, CKEN23_SSP1},
	54	{IRQ_SSP2, CKEN3_SSP2},
	55	{IRQ_SSP3, CKEN4_SSP3},
	56	#else
	57	{IRQ_SSP, CKEN3_SSP},
	58	{IRQ_NSSP, CKEN9_NSSP},
	59	{IRQ_ASSP, CKEN10_ASSP},
	60	#endif
	61	};
	62
00431707	63	static DEFINE_MUTEX(mutex);
1da177e4 LT	64	static int use_count[PXA_SSP_PORTS] = {0, 0, 0};
	65
	66	static irqreturn_t ssp_interrupt(int irq, void dev_id, struct pt_regs regs)
	67	{
	68	struct ssp_dev dev = (struct ssp_dev) dev_id;
	69	unsigned int status = SSSR_P(dev->port);
	70
	71	SSSR_P(dev->port) = status; /* clear status bits */
	72
	73	if (status & SSSR_ROR)
	74	printk(KERN_WARNING "SSP(%d): receiver overrun\n", dev->port);
	75
	76	if (status & SSSR_TUR)
	77	printk(KERN_WARNING "SSP(%d): transmitter underrun\n", dev->port);
	78
	79	if (status & SSSR_BCE)
	80	printk(KERN_WARNING "SSP(%d): bit count error\n", dev->port);
	81
	82	return IRQ_HANDLED;
	83	}
	84
	85	/**
	86	* ssp_write_word - write a word to the SSP port
	87	* @data: 32-bit, MSB justified data to write.
	88	*
	89	* Wait for a free entry in the SSP transmit FIFO, and write a data
	90	* word to the SSP port.
	91	*
	92	* The caller is expected to perform the necessary locking.
	93	*
	94	* Returns:
	95	* %-ETIMEDOUT timeout occurred (for future)
	96	* 0 success
	97	*/
	98	int ssp_write_word(struct ssp_dev *dev, u32 data)
	99	{
	100	while (!(SSSR_P(dev->port) & SSSR_TNF))
	101	cpu_relax();
	102
	103	SSDR_P(dev->port) = data;
	104
	105	return 0;
	106	}
	107
	108	/**
	109	* ssp_read_word - read a word from the SSP port
	110	*
	111	* Wait for a data word in the SSP receive FIFO, and return the
	112	* received data. Data is LSB justified.
	113	*
	114	* Note: Currently, if data is not expected to be received, this
	115	* function will wait for ever.
	116	*
	117	* The caller is expected to perform the necessary locking.
	118	*
	119	* Returns:
	120	* %-ETIMEDOUT timeout occurred (for future)
	121	* 32-bit data success
	122	*/
	123	int ssp_read_word(struct ssp_dev *dev)
	124	{
	125	while (!(SSSR_P(dev->port) & SSSR_RNE))
	126	cpu_relax();
	127
128	return SSDR_P(dev->port);
129	}
130
131	/**
132	* ssp_flush - flush the transmit and receive FIFOs
133	*
134	* Wait for the SSP to idle, and ensure that the receive FIFO
135	* is empty.
136	*
137	* The caller is expected to perform the necessary locking.
138	*/
139	void ssp_flush(struct ssp_dev *dev)
140	{
141	do {
142	while (SSSR_P(dev->port) & SSSR_RNE) {
143	(void) SSDR_P(dev->port);
144	}
145	} while (SSSR_P(dev->port) & SSSR_BSY);
146	}
147
148	/**
149	* ssp_enable - enable the SSP port
150	*
151	* Turn on the SSP port.
152	*/
153	void ssp_enable(struct ssp_dev *dev)
154	{
155	SSCR0_P(dev->port) \|= SSCR0_SSE;
156	}
157
158	/**
159	* ssp_disable - shut down the SSP port
160	*
161	* Turn off the SSP port, optionally powering it down.
162	*/
163	void ssp_disable(struct ssp_dev *dev)
164	{
165	SSCR0_P(dev->port) &= ~SSCR0_SSE;
166	}
167
168	/**
169	* ssp_save_state - save the SSP configuration
170	* @ssp: pointer to structure to save SSP configuration
171	*
172	* Save the configured SSP state for suspend.
173	*/
174	void ssp_save_state(struct ssp_dev dev, struct ssp_state ssp)
175	{
176	ssp->cr0 = SSCR0_P(dev->port);
177	ssp->cr1 = SSCR1_P(dev->port);
178	ssp->to = SSTO_P(dev->port);
179	ssp->psp = SSPSP_P(dev->port);
180
181	SSCR0_P(dev->port) &= ~SSCR0_SSE;
182	}
183
184	/**
185	* ssp_restore_state - restore a previously saved SSP configuration
186	* @ssp: pointer to configuration saved by ssp_save_state
187	*
188	* Restore the SSP configuration saved previously by ssp_save_state.
189	*/
190	void ssp_restore_state(struct ssp_dev dev, struct ssp_state ssp)
191	{
192	SSSR_P(dev->port) = SSSR_ROR \| SSSR_TUR \| SSSR_BCE;
193
194	SSCR0_P(dev->port) = ssp->cr0 & ~SSCR0_SSE;
195	SSCR1_P(dev->port) = ssp->cr1;
196	SSTO_P(dev->port) = ssp->to;
197	SSPSP_P(dev->port) = ssp->psp;
198
199	SSCR0_P(dev->port) = ssp->cr0;
200	}
201
202	/**
203	* ssp_config - configure SSP port settings
204	* @mode: port operating mode
205	* @flags: port config flags
206	* @psp_flags: port PSP config flags
207	* @speed: port speed
208	*
209	* Port MUST be disabled by ssp_disable before making any config changes.
210	*/
211	int ssp_config(struct ssp_dev *dev, u32 mode, u32 flags, u32 psp_flags, u32 speed)
212	{
213	dev->mode = mode;
214	dev->flags = flags;
215	dev->psp_flags = psp_flags;
216	dev->speed = speed;
217
218	/* set up port type, speed, port settings */
219	SSCR0_P(dev->port) = (dev->speed \| dev->mode);
220	SSCR1_P(dev->port) = dev->flags;
221	SSPSP_P(dev->port) = dev->psp_flags;
222
223	return 0;
224	}
225
226	/**
227	* ssp_init - setup the SSP port
228	*
229	* initialise and claim resources for the SSP port.
230	*
231	* Returns:
232	* %-ENODEV if the SSP port is unavailable
233	* %-EBUSY if the resources are already in use
234	* %0 on success
235	*/
b216c018	236	int ssp_init(struct ssp_dev *dev, u32 port, u32 init_flags)
1da177e4	237	{
b216c018	238	int ret;
1da177e4 LT	239
	240	if (port > PXA_SSP_PORTS \|\| port == 0)
	241	return -ENODEV;
	242
00431707	243	mutex_lock(&mutex);
1da177e4	244	if (use_count[port - 1]) {
00431707	245	mutex_unlock(&mutex);
1da177e4 LT	246	return -EBUSY;
	247	}
	248	use_count[port - 1]++;
	249
	250	if (!request_mem_region(__PREG(SSCR0_P(port)), 0x2c, "SSP")) {
	251	use_count[port - 1]--;
00431707	252	mutex_unlock(&mutex);
1da177e4 LT	253	return -EBUSY;
1da177e4 LT	254	}
1da177e4 LT	255	dev->port = port;
1da177e4 LT	256
b216c018 LG	257	/* do we need to get irq */
	258	if (!(init_flags & SSP_NO_IRQ)) {
	259	ret = request_irq(ssp_info[port-1].irq, ssp_interrupt,
	260	0, "SSP", dev);
	261	if (ret)
	262	goto out_region;
	263	dev->irq = ssp_info[port-1].irq;
	264	} else
	265	dev->irq = 0;
1da177e4 LT	266
1da177e4 LT	267	/* turn on SSP port clock */
b216c018	268	pxa_set_cken(ssp_info[port-1].clock, 1);
00431707	269	mutex_unlock(&mutex);
1da177e4 LT	270	return 0;
	271
	272	out_region:
	273	release_mem_region(__PREG(SSCR0_P(port)), 0x2c);
	274	use_count[port - 1]--;
00431707	275	mutex_unlock(&mutex);
1da177e4 LT	276	return ret;
	277	}
	278
	279	/**
	280	* ssp_exit - undo the effects of ssp_init
	281	*
	282	* release and free resources for the SSP port.
	283	*/
	284	void ssp_exit(struct ssp_dev *dev)
	285	{
00431707	286	mutex_lock(&mutex);
1da177e4 LT	287	SSCR0_P(dev->port) &= ~SSCR0_SSE;
1da177e4 LT	288
b216c018 LG	289	if (dev->port > PXA_SSP_PORTS \|\| dev->port == 0) {
	290	printk(KERN_WARNING "SSP: tried to close invalid port\n");
	291	return;
1da177e4 LT	292	}
1da177e4 LT	293
b216c018 LG	294	pxa_set_cken(ssp_info[dev->port-1].clock, 0);
	295	if (dev->irq)
	296	free_irq(dev->irq, dev);
1da177e4 LT	297	release_mem_region(__PREG(SSCR0_P(dev->port)), 0x2c);
1da177e4 LT	298	use_count[dev->port - 1]--;
00431707	299	mutex_unlock(&mutex);
1da177e4 LT	300	}
	301
	302	EXPORT_SYMBOL(ssp_write_word);
	303	EXPORT_SYMBOL(ssp_read_word);
	304	EXPORT_SYMBOL(ssp_flush);
	305	EXPORT_SYMBOL(ssp_enable);
	306	EXPORT_SYMBOL(ssp_disable);
	307	EXPORT_SYMBOL(ssp_save_state);
	308	EXPORT_SYMBOL(ssp_restore_state);
	309	EXPORT_SYMBOL(ssp_init);
	310	EXPORT_SYMBOL(ssp_exit);
	311	EXPORT_SYMBOL(ssp_config);
	312
	313	MODULE_DESCRIPTION("PXA SSP driver");
	314	MODULE_AUTHOR("Liam Girdwood");
	315	MODULE_LICENSE("GPL");
	316