| /* |
| * 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 <linux/clk.h> |
| #include <linux/err.h> |
| #include <linux/platform_device.h> |
| |
| #include <asm/io.h> |
| #include <asm/irq.h> |
| #include <asm/hardware.h> |
| #include <asm/arch/ssp.h> |
| #include <asm/arch/pxa-regs.h> |
| #include <asm/arch/regs-ssp.h> |
| |
| #define TIMEOUT 100000 |
| |
| static irqreturn_t ssp_interrupt(int irq, void *dev_id) |
| { |
| struct ssp_dev *dev = dev_id; |
| struct ssp_device *ssp = dev->ssp; |
| unsigned int status; |
| |
| status = __raw_readl(ssp->mmio_base + SSSR); |
| __raw_writel(status, ssp->mmio_base + SSSR); |
| |
| 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 |
| * 0 success |
| */ |
| int ssp_write_word(struct ssp_dev *dev, u32 data) |
| { |
| struct ssp_device *ssp = dev->ssp; |
| int timeout = TIMEOUT; |
| |
| while (!(__raw_readl(ssp->mmio_base + SSSR) & SSSR_TNF)) { |
| if (!--timeout) |
| return -ETIMEDOUT; |
| cpu_relax(); |
| } |
| |
| __raw_writel(data, ssp->mmio_base + SSDR); |
| |
| 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 |
| * 32-bit data success |
| */ |
| int ssp_read_word(struct ssp_dev *dev, u32 *data) |
| { |
| struct ssp_device *ssp = dev->ssp; |
| int timeout = TIMEOUT; |
| |
| while (!(__raw_readl(ssp->mmio_base + SSSR) & SSSR_RNE)) { |
| if (!--timeout) |
| return -ETIMEDOUT; |
| cpu_relax(); |
| } |
| |
| *data = __raw_readl(ssp->mmio_base + SSDR); |
| return 0; |
| } |
| |
| /** |
| * 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. |
| */ |
| int ssp_flush(struct ssp_dev *dev) |
| { |
| struct ssp_device *ssp = dev->ssp; |
| int timeout = TIMEOUT * 2; |
| |
| /* ensure TX FIFO is empty instead of not full */ |
| if (cpu_is_pxa3xx()) { |
| while (__raw_readl(ssp->mmio_base + SSSR) & 0xf00) { |
| if (!--timeout) |
| return -ETIMEDOUT; |
| cpu_relax(); |
| } |
| timeout = TIMEOUT * 2; |
| } |
| |
| do { |
| while (__raw_readl(ssp->mmio_base + SSSR) & SSSR_RNE) { |
| if (!--timeout) |
| return -ETIMEDOUT; |
| (void)__raw_readl(ssp->mmio_base + SSDR); |
| } |
| if (!--timeout) |
| return -ETIMEDOUT; |
| } while (__raw_readl(ssp->mmio_base + SSSR) & SSSR_BSY); |
| |
| return 0; |
| } |
| |
| /** |
| * ssp_enable - enable the SSP port |
| * |
| * Turn on the SSP port. |
| */ |
| void ssp_enable(struct ssp_dev *dev) |
| { |
| struct ssp_device *ssp = dev->ssp; |
| uint32_t sscr0; |
| |
| sscr0 = __raw_readl(ssp->mmio_base + SSCR0); |
| sscr0 |= SSCR0_SSE; |
| __raw_writel(sscr0, ssp->mmio_base + SSCR0); |
| } |
| |
| /** |
| * ssp_disable - shut down the SSP port |
| * |
| * Turn off the SSP port, optionally powering it down. |
| */ |
| void ssp_disable(struct ssp_dev *dev) |
| { |
| struct ssp_device *ssp = dev->ssp; |
| uint32_t sscr0; |
| |
| sscr0 = __raw_readl(ssp->mmio_base + SSCR0); |
| sscr0 &= ~SSCR0_SSE; |
| __raw_writel(sscr0, ssp->mmio_base + SSCR0); |
| } |
| |
| /** |
| * 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 *state) |
| { |
| struct ssp_device *ssp = dev->ssp; |
| |
| state->cr0 = __raw_readl(ssp->mmio_base + SSCR0); |
| state->cr1 = __raw_readl(ssp->mmio_base + SSCR1); |
| state->to = __raw_readl(ssp->mmio_base + SSTO); |
| state->psp = __raw_readl(ssp->mmio_base + SSPSP); |
| |
| ssp_disable(dev); |
| } |
| |
| /** |
| * 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 *state) |
| { |
| struct ssp_device *ssp = dev->ssp; |
| uint32_t sssr = SSSR_ROR | SSSR_TUR | SSSR_BCE; |
| |
| __raw_writel(sssr, ssp->mmio_base + SSSR); |
| |
| __raw_writel(state->cr0 & ~SSCR0_SSE, ssp->mmio_base + SSCR0); |
| __raw_writel(state->cr1, ssp->mmio_base + SSCR1); |
| __raw_writel(state->to, ssp->mmio_base + SSTO); |
| __raw_writel(state->psp, ssp->mmio_base + SSPSP); |
| __raw_writel(state->cr0, ssp->mmio_base + SSCR0); |
| } |
| |
| /** |
| * 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) |
| { |
| struct ssp_device *ssp = dev->ssp; |
| |
| dev->mode = mode; |
| dev->flags = flags; |
| dev->psp_flags = psp_flags; |
| dev->speed = speed; |
| |
| /* set up port type, speed, port settings */ |
| __raw_writel((dev->speed | dev->mode), ssp->mmio_base + SSCR0); |
| __raw_writel(dev->flags, ssp->mmio_base + SSCR1); |
| __raw_writel(dev->psp_flags, ssp->mmio_base + SSPSP); |
| |
| 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) |
| { |
| struct ssp_device *ssp; |
| int ret; |
| |
| ssp = ssp_request(port, "SSP"); |
| if (ssp == NULL) |
| return -ENODEV; |
| |
| dev->ssp = ssp; |
| dev->port = port; |
| |
| /* do we need to get irq */ |
| if (!(init_flags & SSP_NO_IRQ)) { |
| ret = request_irq(ssp->irq, ssp_interrupt, |
| 0, "SSP", dev); |
| if (ret) |
| goto out_region; |
| dev->irq = ssp->irq; |
| } else |
| dev->irq = 0; |
| |
| /* turn on SSP port clock */ |
| clk_enable(ssp->clk); |
| return 0; |
| |
| out_region: |
| ssp_free(ssp); |
| 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) |
| { |
| struct ssp_device *ssp = dev->ssp; |
| |
| ssp_disable(dev); |
| free_irq(dev->irq, dev); |
| clk_disable(ssp->clk); |
| ssp_free(ssp); |
| } |
| |
| static DEFINE_MUTEX(ssp_lock); |
| static LIST_HEAD(ssp_list); |
| |
| struct ssp_device *ssp_request(int port, const char *label) |
| { |
| struct ssp_device *ssp = NULL; |
| |
| mutex_lock(&ssp_lock); |
| |
| list_for_each_entry(ssp, &ssp_list, node) { |
| if (ssp->port_id == port && ssp->use_count == 0) { |
| ssp->use_count++; |
| ssp->label = label; |
| break; |
| } |
| } |
| |
| mutex_unlock(&ssp_lock); |
| |
| if (&ssp->node == &ssp_list) |
| return NULL; |
| |
| return ssp; |
| } |
| EXPORT_SYMBOL(ssp_request); |
| |
| void ssp_free(struct ssp_device *ssp) |
| { |
| mutex_lock(&ssp_lock); |
| if (ssp->use_count) { |
| ssp->use_count--; |
| ssp->label = NULL; |
| } else |
| dev_err(&ssp->pdev->dev, "device already free\n"); |
| mutex_unlock(&ssp_lock); |
| } |
| EXPORT_SYMBOL(ssp_free); |
| |
| static int __devinit ssp_probe(struct platform_device *pdev, int type) |
| { |
| struct resource *res; |
| struct ssp_device *ssp; |
| int ret = 0; |
| |
| ssp = kzalloc(sizeof(struct ssp_device), GFP_KERNEL); |
| if (ssp == NULL) { |
| dev_err(&pdev->dev, "failed to allocate memory"); |
| return -ENOMEM; |
| } |
| |
| ssp->clk = clk_get(&pdev->dev, "SSPCLK"); |
| if (IS_ERR(ssp->clk)) { |
| ret = PTR_ERR(ssp->clk); |
| goto err_free; |
| } |
| |
| res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| if (res == NULL) { |
| dev_err(&pdev->dev, "no memory resource defined\n"); |
| ret = -ENODEV; |
| goto err_free_clk; |
| } |
| |
| res = request_mem_region(res->start, res->end - res->start + 1, |
| pdev->name); |
| if (res == NULL) { |
| dev_err(&pdev->dev, "failed to request memory resource\n"); |
| ret = -EBUSY; |
| goto err_free_clk; |
| } |
| |
| ssp->phys_base = res->start; |
| |
| ssp->mmio_base = ioremap(res->start, res->end - res->start + 1); |
| if (ssp->mmio_base == NULL) { |
| dev_err(&pdev->dev, "failed to ioremap() registers\n"); |
| ret = -ENODEV; |
| goto err_free_mem; |
| } |
| |
| ssp->irq = platform_get_irq(pdev, 0); |
| if (ssp->irq < 0) { |
| dev_err(&pdev->dev, "no IRQ resource defined\n"); |
| ret = -ENODEV; |
| goto err_free_io; |
| } |
| |
| res = platform_get_resource(pdev, IORESOURCE_DMA, 0); |
| if (res == NULL) { |
| dev_err(&pdev->dev, "no SSP RX DRCMR defined\n"); |
| ret = -ENODEV; |
| goto err_free_io; |
| } |
| ssp->drcmr_rx = res->start; |
| |
| res = platform_get_resource(pdev, IORESOURCE_DMA, 1); |
| if (res == NULL) { |
| dev_err(&pdev->dev, "no SSP TX DRCMR defined\n"); |
| ret = -ENODEV; |
| goto err_free_io; |
| } |
| ssp->drcmr_tx = res->start; |
| |
| /* PXA2xx/3xx SSP ports starts from 1 and the internal pdev->id |
| * starts from 0, do a translation here |
| */ |
| ssp->port_id = pdev->id + 1; |
| ssp->use_count = 0; |
| ssp->type = type; |
| |
| mutex_lock(&ssp_lock); |
| list_add(&ssp->node, &ssp_list); |
| mutex_unlock(&ssp_lock); |
| |
| platform_set_drvdata(pdev, ssp); |
| return 0; |
| |
| err_free_io: |
| iounmap(ssp->mmio_base); |
| err_free_mem: |
| release_mem_region(res->start, res->end - res->start + 1); |
| err_free_clk: |
| clk_put(ssp->clk); |
| err_free: |
| kfree(ssp); |
| return ret; |
| } |
| |
| static int __devexit ssp_remove(struct platform_device *pdev) |
| { |
| struct resource *res; |
| struct ssp_device *ssp; |
| |
| ssp = platform_get_drvdata(pdev); |
| if (ssp == NULL) |
| return -ENODEV; |
| |
| iounmap(ssp->mmio_base); |
| |
| res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| release_mem_region(res->start, res->end - res->start + 1); |
| |
| clk_put(ssp->clk); |
| |
| mutex_lock(&ssp_lock); |
| list_del(&ssp->node); |
| mutex_unlock(&ssp_lock); |
| |
| kfree(ssp); |
| return 0; |
| } |
| |
| static int __devinit pxa25x_ssp_probe(struct platform_device *pdev) |
| { |
| return ssp_probe(pdev, PXA25x_SSP); |
| } |
| |
| static int __devinit pxa25x_nssp_probe(struct platform_device *pdev) |
| { |
| return ssp_probe(pdev, PXA25x_NSSP); |
| } |
| |
| static int __devinit pxa27x_ssp_probe(struct platform_device *pdev) |
| { |
| return ssp_probe(pdev, PXA27x_SSP); |
| } |
| |
| static struct platform_driver pxa25x_ssp_driver = { |
| .driver = { |
| .name = "pxa25x-ssp", |
| }, |
| .probe = pxa25x_ssp_probe, |
| .remove = __devexit_p(ssp_remove), |
| }; |
| |
| static struct platform_driver pxa25x_nssp_driver = { |
| .driver = { |
| .name = "pxa25x-nssp", |
| }, |
| .probe = pxa25x_nssp_probe, |
| .remove = __devexit_p(ssp_remove), |
| }; |
| |
| static struct platform_driver pxa27x_ssp_driver = { |
| .driver = { |
| .name = "pxa27x-ssp", |
| }, |
| .probe = pxa27x_ssp_probe, |
| .remove = __devexit_p(ssp_remove), |
| }; |
| |
| static int __init pxa_ssp_init(void) |
| { |
| int ret = 0; |
| |
| ret = platform_driver_register(&pxa25x_ssp_driver); |
| if (ret) { |
| printk(KERN_ERR "failed to register pxa25x_ssp_driver"); |
| return ret; |
| } |
| |
| ret = platform_driver_register(&pxa25x_nssp_driver); |
| if (ret) { |
| printk(KERN_ERR "failed to register pxa25x_nssp_driver"); |
| return ret; |
| } |
| |
| ret = platform_driver_register(&pxa27x_ssp_driver); |
| if (ret) { |
| printk(KERN_ERR "failed to register pxa27x_ssp_driver"); |
| return ret; |
| } |
| |
| return ret; |
| } |
| |
| static void __exit pxa_ssp_exit(void) |
| { |
| platform_driver_unregister(&pxa25x_ssp_driver); |
| platform_driver_unregister(&pxa25x_nssp_driver); |
| platform_driver_unregister(&pxa27x_ssp_driver); |
| } |
| |
| arch_initcall(pxa_ssp_init); |
| module_exit(pxa_ssp_exit); |
| |
| 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"); |
| |