arch/arm/plat-pxa/ssp.c

   1 /*
   2  *  linux/arch/arm/mach-pxa/ssp.c
   3  *
   4  *  based on linux/arch/arm/mach-sa1100/ssp.c by Russell King
   5  *
   6  *  Copyright (C) 2003 Russell King.
   7  *  Copyright (C) 2003 Wolfson Microelectronics PLC
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  *
  13  *  PXA2xx SSP driver.  This provides the generic core for simple
  14  *  IO-based SSP applications and allows easy port setup for DMA access.
  15  *
  16  *  Author: Liam Girdwood <liam.girdwood@wolfsonmicro.com>
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/kernel.h>
  21 #include <linux/sched.h>
  22 #include <linux/slab.h>
  23 #include <linux/errno.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/ioport.h>
  26 #include <linux/init.h>
  27 #include <linux/mutex.h>
  28 #include <linux/clk.h>
  29 #include <linux/err.h>
  30 #include <linux/platform_device.h>
  31 #include <linux/spi/pxa2xx_spi.h>
  32 #include <linux/io.h>
  33 #include <linux/of.h>
  34 #include <linux/of_device.h>
  35
  36 #include <asm/irq.h>
  37
  38 static DEFINE_MUTEX(ssp_lock);
  39 static LIST_HEAD(ssp_list);
  40
  41 struct ssp_device *pxa_ssp_request(int port, const char *label)
  42 {
  43         struct ssp_device *ssp = NULL;
  44
  45         mutex_lock(&ssp_lock);
  46
  47         list_for_each_entry(ssp, &ssp_list, node) {
  48                 if (ssp->port_id == port && ssp->use_count == 0) {
  49                         ssp->use_count++;
  50                         ssp->label = label;
  51                         break;
  52                 }
  53         }
  54
  55         mutex_unlock(&ssp_lock);
  56
  57         if (&ssp->node == &ssp_list)
  58                 return NULL;
  59
  60         return ssp;
  61 }
  62 EXPORT_SYMBOL(pxa_ssp_request);
  63
  64 struct ssp_device *pxa_ssp_request_of(const struct device_node *of_node,
  65                                       const char *label)
  66 {
  67         struct ssp_device *ssp = NULL;
  68
  69         mutex_lock(&ssp_lock);
  70
  71         list_for_each_entry(ssp, &ssp_list, node) {
  72                 if (ssp->of_node == of_node && ssp->use_count == 0) {
  73                         ssp->use_count++;
  74                         ssp->label = label;
  75                         break;
  76                 }
  77         }
  78
  79         mutex_unlock(&ssp_lock);
  80
  81         if (&ssp->node == &ssp_list)
  82                 return NULL;
  83
  84         return ssp;
  85 }
  86 EXPORT_SYMBOL(pxa_ssp_request_of);
  87
  88 void pxa_ssp_free(struct ssp_device *ssp)
  89 {
  90         mutex_lock(&ssp_lock);
  91         if (ssp->use_count) {
  92                 ssp->use_count--;
  93                 ssp->label = NULL;
  94         } else
  95                 dev_err(&ssp->pdev->dev, "device already free\n");
  96         mutex_unlock(&ssp_lock);
  97 }
  98 EXPORT_SYMBOL(pxa_ssp_free);
  99
 100 #ifdef CONFIG_OF
 101 static const struct of_device_id pxa_ssp_of_ids[] = {
 102         { .compatible = "mrvl,pxa25x-ssp",      .data = (void *) PXA25x_SSP },
 103         { .compatible = "mvrl,pxa25x-nssp",     .data = (void *) PXA25x_NSSP },
 104         { .compatible = "mrvl,pxa27x-ssp",      .data = (void *) PXA27x_SSP },
 105         { .compatible = "mrvl,pxa3xx-ssp",      .data = (void *) PXA3xx_SSP },
 106         { .compatible = "mvrl,pxa168-ssp",      .data = (void *) PXA168_SSP },
 107         { .compatible = "mrvl,pxa910-ssp",      .data = (void *) PXA910_SSP },
 108         { .compatible = "mrvl,ce4100-ssp",      .data = (void *) CE4100_SSP },
 109         { },
 110 };
 111 MODULE_DEVICE_TABLE(of, pxa_ssp_of_ids);
 112 #endif
 113
 114 static int pxa_ssp_probe(struct platform_device *pdev)
 115 {
 116         struct resource *res;
 117         struct ssp_device *ssp;
 118         struct device *dev = &pdev->dev;
 119
 120         ssp = devm_kzalloc(dev, sizeof(struct ssp_device), GFP_KERNEL);
 121         if (ssp == NULL)
 122                 return -ENOMEM;
 123
 124         ssp->pdev = pdev;
 125
 126         ssp->clk = devm_clk_get(dev, NULL);
 127         if (IS_ERR(ssp->clk))
 128                 return PTR_ERR(ssp->clk);
 129
 130         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 131         if (res == NULL) {
 132                 dev_err(dev, "no memory resource defined\n");
 133                 return -ENODEV;
 134         }
 135
 136         res = devm_request_mem_region(dev, res->start, resource_size(res),
 137                                       pdev->name);
 138         if (res == NULL) {
 139                 dev_err(dev, "failed to request memory resource\n");
 140                 return -EBUSY;
 141         }
 142
 143         ssp->phys_base = res->start;
 144
 145         ssp->mmio_base = devm_ioremap(dev, res->start, resource_size(res));
 146         if (ssp->mmio_base == NULL) {
 147                 dev_err(dev, "failed to ioremap() registers\n");
 148                 return -ENODEV;
 149         }
 150
 151         ssp->irq = platform_get_irq(pdev, 0);
 152         if (ssp->irq < 0) {
 153                 dev_err(dev, "no IRQ resource defined\n");
 154                 return -ENODEV;
 155         }
 156
 157         if (dev->of_node) {
 158                 const struct of_device_id *id =
 159                         of_match_device(of_match_ptr(pxa_ssp_of_ids), dev);
 160                 ssp->type = (int) id->data;
 161         } else {
 162                 const struct platform_device_id *id =
 163                         platform_get_device_id(pdev);
 164                 ssp->type = (int) id->driver_data;
 165
 166                 /* PXA2xx/3xx SSP ports starts from 1 and the internal pdev->id
 167                  * starts from 0, do a translation here
 168                  */
 169                 ssp->port_id = pdev->id + 1;
 170         }
 171
 172         ssp->use_count = 0;
 173         ssp->of_node = dev->of_node;
 174
 175         mutex_lock(&ssp_lock);
 176         list_add(&ssp->node, &ssp_list);
 177         mutex_unlock(&ssp_lock);
 178
 179         platform_set_drvdata(pdev, ssp);
 180
 181         return 0;
 182 }
 183
 184 static int pxa_ssp_remove(struct platform_device *pdev)
 185 {
 186         struct resource *res;
 187         struct ssp_device *ssp;
 188
 189         ssp = platform_get_drvdata(pdev);
 190         if (ssp == NULL)
 191                 return -ENODEV;
 192
 193         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 194         release_mem_region(res->start, resource_size(res));
 195
 196         clk_put(ssp->clk);
 197
 198         mutex_lock(&ssp_lock);
 199         list_del(&ssp->node);
 200         mutex_unlock(&ssp_lock);
 201
 202         return 0;
 203 }
 204
 205 static const struct platform_device_id ssp_id_table[] = {
 206         { "pxa25x-ssp",         PXA25x_SSP },
 207         { "pxa25x-nssp",        PXA25x_NSSP },
 208         { "pxa27x-ssp",         PXA27x_SSP },
 209         { "pxa3xx-ssp",         PXA3xx_SSP },
 210         { "pxa168-ssp",         PXA168_SSP },
 211         { "pxa910-ssp",         PXA910_SSP },
 212         { },
 213 };
 214
 215 static struct platform_driver pxa_ssp_driver = {
 216         .probe          = pxa_ssp_probe,
 217         .remove         = pxa_ssp_remove,
 218         .driver         = {
 219                 .name           = "pxa2xx-ssp",
 220                 .of_match_table = of_match_ptr(pxa_ssp_of_ids),
 221         },
 222         .id_table       = ssp_id_table,
 223 };
 224
 225 static int __init pxa_ssp_init(void)
 226 {
 227         return platform_driver_register(&pxa_ssp_driver);
 228 }
 229
 230 static void __exit pxa_ssp_exit(void)
 231 {
 232         platform_driver_unregister(&pxa_ssp_driver);
 233 }
 234
 235 arch_initcall(pxa_ssp_init);
 236 module_exit(pxa_ssp_exit);
 237
 238 MODULE_DESCRIPTION("PXA SSP driver");
 239 MODULE_AUTHOR("Liam Girdwood");
 240 MODULE_LICENSE("GPL");