diff options
Diffstat (limited to 'arch/arm/plat-pxa/ssp.c')
| -rw-r--r-- | arch/arm/plat-pxa/ssp.c | 224 |
1 files changed, 224 insertions, 0 deletions
diff --git a/arch/arm/plat-pxa/ssp.c b/arch/arm/plat-pxa/ssp.c new file mode 100644 index 000000000000..c6357e554aba --- /dev/null +++ b/arch/arm/plat-pxa/ssp.c @@ -0,0 +1,224 @@ +/* + * 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 <plat/ssp.h> + +static DEFINE_MUTEX(ssp_lock); +static LIST_HEAD(ssp_list); + +struct ssp_device *pxa_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(pxa_ssp_request); + +void pxa_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(pxa_ssp_free); + +static int __devinit pxa_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_DMA, 0); + if (res == NULL) { + dev_err(&pdev->dev, "no SSP RX DRCMR defined\n"); + ret = -ENODEV; + goto err_free_clk; + } + 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_clk; + } + ssp->drcmr_tx = res->start; + + 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, resource_size(res), + 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, resource_size(res)); + 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; + } + + /* 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, resource_size(res)); +err_free_clk: + clk_put(ssp->clk); +err_free: + kfree(ssp); + return ret; +} + +static int __devexit pxa_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, resource_size(res)); + + 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 }, + { "pxa168-ssp", PXA168_SSP }, + { }, +}; + +static struct platform_driver pxa_ssp_driver = { + .probe = pxa_ssp_probe, + .remove = __devexit_p(pxa_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(&pxa_ssp_driver); +} + +static void __exit pxa_ssp_exit(void) +{ + platform_driver_unregister(&pxa_ssp_driver); +} + +arch_initcall(pxa_ssp_init); +module_exit(pxa_ssp_exit); + +MODULE_DESCRIPTION("PXA SSP driver"); +MODULE_AUTHOR("Liam Girdwood"); +MODULE_LICENSE("GPL"); |