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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/arm/plat-pxa/ssp.c
Initial import
Diffstat (limited to 'arch/arm/plat-pxa/ssp.c')
-rw-r--r--arch/arm/plat-pxa/ssp.c292
1 files changed, 292 insertions, 0 deletions
diff --git a/arch/arm/plat-pxa/ssp.c b/arch/arm/plat-pxa/ssp.c
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+++ b/arch/arm/plat-pxa/ssp.c
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+/*
+ * 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");