/* * 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> */ #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 <linux/io.h> #include <asm/irq.h> #include <mach/hardware.h> #include <mach/ssp.h> #include <mach/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 = NO_IRQ; /* 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); if (dev->irq != NO_IRQ) 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) { const struct platform_device_id *id = platform_get_device_id(pdev); 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->pdev = pdev; ssp->clk = clk_get(&pdev->dev, NULL); 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 = (int)id->driver_data; 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 const struct platform_device_id ssp_id_table[] = { { "pxa25x-ssp", PXA25x_SSP }, { "pxa25x-nssp", PXA25x_NSSP }, { "pxa27x-ssp", PXA27x_SSP }, { }, }; static struct platform_driver ssp_driver = { .probe = ssp_probe, .remove = __devexit_p(ssp_remove), .driver = { .owner = THIS_MODULE, .name = "pxa2xx-ssp", }, .id_table = ssp_id_table, }; static int __init pxa_ssp_init(void) { return platform_driver_register(&ssp_driver); } static void __exit pxa_ssp_exit(void) { platform_driver_unregister(&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");