diff options
Diffstat (limited to 'kernel/arch/arm/plat-pxa/ssp.c')
| -rw-r--r-- | kernel/arch/arm/plat-pxa/ssp.c | 292 |
1 files changed, 292 insertions, 0 deletions
diff --git a/kernel/arch/arm/plat-pxa/ssp.c b/kernel/arch/arm/plat-pxa/ssp.c new file mode 100644 index 000000000..ad9529cc4 --- /dev/null +++ b/kernel/arch/arm/plat-pxa/ssp.c @@ -0,0 +1,292 @@ +/* + * 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/spi/pxa2xx_spi.h> +#include <linux/io.h> +#include <linux/of.h> +#include <linux/of_device.h> + +#include <asm/irq.h> +#include <mach/hardware.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); + +struct ssp_device *pxa_ssp_request_of(const struct device_node *of_node, + const char *label) +{ + struct ssp_device *ssp = NULL; + + mutex_lock(&ssp_lock); + + list_for_each_entry(ssp, &ssp_list, node) { + if (ssp->of_node == of_node && 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_of); + +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); + +#ifdef CONFIG_OF +static const struct of_device_id pxa_ssp_of_ids[] = { + { .compatible = "mrvl,pxa25x-ssp", .data = (void *) PXA25x_SSP }, + { .compatible = "mvrl,pxa25x-nssp", .data = (void *) PXA25x_NSSP }, + { .compatible = "mrvl,pxa27x-ssp", .data = (void *) PXA27x_SSP }, + { .compatible = "mrvl,pxa3xx-ssp", .data = (void *) PXA3xx_SSP }, + { .compatible = "mvrl,pxa168-ssp", .data = (void *) PXA168_SSP }, + { .compatible = "mrvl,pxa910-ssp", .data = (void *) PXA910_SSP }, + { .compatible = "mrvl,ce4100-ssp", .data = (void *) CE4100_SSP }, + { .compatible = "mrvl,lpss-ssp", .data = (void *) LPSS_SSP }, + { }, +}; +MODULE_DEVICE_TABLE(of, pxa_ssp_of_ids); +#endif + +static int pxa_ssp_probe(struct platform_device *pdev) +{ + struct resource *res; + struct ssp_device *ssp; + struct device *dev = &pdev->dev; + + ssp = devm_kzalloc(dev, sizeof(struct ssp_device), GFP_KERNEL); + if (ssp == NULL) + return -ENOMEM; + + ssp->pdev = pdev; + + ssp->clk = devm_clk_get(dev, NULL); + if (IS_ERR(ssp->clk)) + return PTR_ERR(ssp->clk); + + if (dev->of_node) { + struct of_phandle_args dma_spec; + struct device_node *np = dev->of_node; + int ret; + + /* + * FIXME: we should allocate the DMA channel from this + * context and pass the channel down to the ssp users. + * For now, we lookup the rx and tx indices manually + */ + + /* rx */ + ret = of_parse_phandle_with_args(np, "dmas", "#dma-cells", + 0, &dma_spec); + + if (ret) { + dev_err(dev, "Can't parse dmas property\n"); + return -ENODEV; + } + ssp->drcmr_rx = dma_spec.args[0]; + of_node_put(dma_spec.np); + + /* tx */ + ret = of_parse_phandle_with_args(np, "dmas", "#dma-cells", + 1, &dma_spec); + if (ret) { + dev_err(dev, "Can't parse dmas property\n"); + return -ENODEV; + } + ssp->drcmr_tx = dma_spec.args[0]; + of_node_put(dma_spec.np); + } else { + res = platform_get_resource(pdev, IORESOURCE_DMA, 0); + if (res == NULL) { + dev_err(dev, "no SSP RX DRCMR defined\n"); + return -ENODEV; + } + ssp->drcmr_rx = res->start; + + res = platform_get_resource(pdev, IORESOURCE_DMA, 1); + if (res == NULL) { + dev_err(dev, "no SSP TX DRCMR defined\n"); + return -ENODEV; + } + ssp->drcmr_tx = res->start; + } + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (res == NULL) { + dev_err(dev, "no memory resource defined\n"); + return -ENODEV; + } + + res = devm_request_mem_region(dev, res->start, resource_size(res), + pdev->name); + if (res == NULL) { + dev_err(dev, "failed to request memory resource\n"); + return -EBUSY; + } + + ssp->phys_base = res->start; + + ssp->mmio_base = devm_ioremap(dev, res->start, resource_size(res)); + if (ssp->mmio_base == NULL) { + dev_err(dev, "failed to ioremap() registers\n"); + return -ENODEV; + } + + ssp->irq = platform_get_irq(pdev, 0); + if (ssp->irq < 0) { + dev_err(dev, "no IRQ resource defined\n"); + return -ENODEV; + } + + if (dev->of_node) { + const struct of_device_id *id = + of_match_device(of_match_ptr(pxa_ssp_of_ids), dev); + ssp->type = (int) id->data; + } else { + const struct platform_device_id *id = + platform_get_device_id(pdev); + ssp->type = (int) id->driver_data; + + /* 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->of_node = dev->of_node; + + mutex_lock(&ssp_lock); + list_add(&ssp->node, &ssp_list); + mutex_unlock(&ssp_lock); + + platform_set_drvdata(pdev, ssp); + + return 0; +} + +static int 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 }, + { "pxa3xx-ssp", PXA3xx_SSP }, + { "pxa168-ssp", PXA168_SSP }, + { "pxa910-ssp", PXA910_SSP }, + { }, +}; + +static struct platform_driver pxa_ssp_driver = { + .probe = pxa_ssp_probe, + .remove = pxa_ssp_remove, + .driver = { + .name = "pxa2xx-ssp", + .of_match_table = of_match_ptr(pxa_ssp_of_ids), + }, + .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"); |