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
  34 #include <asm/irq.h>
  35 #include <mach/hardware.h>
  36
  37 static DEFINE_MUTEX(ssp_lock);
  38 static LIST_HEAD(ssp_list);
  39
  40 struct ssp_device *pxa_ssp_request(int port, const char *label)
  41 {
  42         struct ssp_device *ssp = NULL;
  43
  44         mutex_lock(&ssp_lock);
  45
  46         list_for_each_entry(ssp, &ssp_list, node) {
  47                 if (ssp->port_id == port && ssp->use_count == 0) {
  48                         ssp->use_count++;
  49                         ssp->label = label;
  50                         break;
  51                 }
  52         }
  53
  54         mutex_unlock(&ssp_lock);
  55
  56         if (&ssp->node == &ssp_list)
  57                 return NULL;
  58
  59         return ssp;
  60 }
  61 EXPORT_SYMBOL(pxa_ssp_request);
  62
  63 void pxa_ssp_free(struct ssp_device *ssp)
  64 {
  65         mutex_lock(&ssp_lock);
  66         if (ssp->use_count) {
  67                 ssp->use_count--;
  68                 ssp->label = NULL;
  69         } else
  70                 dev_err(&ssp->pdev->dev, "device already free\n");
  71         mutex_unlock(&ssp_lock);
  72 }
  73 EXPORT_SYMBOL(pxa_ssp_free);
  74
  75 static int pxa_ssp_probe(struct platform_device *pdev)
  76 {
  77         const struct platform_device_id *id = platform_get_device_id(pdev);
  78         struct resource *res;
  79         struct ssp_device *ssp;
  80         int ret = 0;
  81
  82         ssp = kzalloc(sizeof(struct ssp_device), GFP_KERNEL);
  83         if (ssp == NULL) {
  84                 dev_err(&pdev->dev, "failed to allocate memory");
  85                 return -ENOMEM;
  86         }
  87         ssp->pdev = pdev;
  88
  89         ssp->clk = clk_get(&pdev->dev, NULL);
  90         if (IS_ERR(ssp->clk)) {
  91                 ret = PTR_ERR(ssp->clk);
  92                 goto err_free;
  93         }
  94
  95         res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
  96         if (res == NULL) {
  97                 dev_err(&pdev->dev, "no SSP RX DRCMR defined\n");
  98                 ret = -ENODEV;
  99                 goto err_free_clk;
 100         }
 101         ssp->drcmr_rx = res->start;
 102
 103         res = platform_get_resource(pdev, IORESOURCE_DMA, 1);
 104         if (res == NULL) {
 105                 dev_err(&pdev->dev, "no SSP TX DRCMR defined\n");
 106                 ret = -ENODEV;
 107                 goto err_free_clk;
 108         }
 109         ssp->drcmr_tx = res->start;
 110
 111         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 112         if (res == NULL) {
 113                 dev_err(&pdev->dev, "no memory resource defined\n");
 114                 ret = -ENODEV;
 115                 goto err_free_clk;
 116         }
 117
 118         res = request_mem_region(res->start, resource_size(res),
 119                         pdev->name);
 120         if (res == NULL) {
 121                 dev_err(&pdev->dev, "failed to request memory resource\n");
 122                 ret = -EBUSY;
 123                 goto err_free_clk;
 124         }
 125
 126         ssp->phys_base = res->start;
 127
 128         ssp->mmio_base = ioremap(res->start, resource_size(res));
 129         if (ssp->mmio_base == NULL) {
 130                 dev_err(&pdev->dev, "failed to ioremap() registers\n");
 131                 ret = -ENODEV;
 132                 goto err_free_mem;
 133         }
 134
 135         ssp->irq = platform_get_irq(pdev, 0);
 136         if (ssp->irq < 0) {
 137                 dev_err(&pdev->dev, "no IRQ resource defined\n");
 138                 ret = -ENODEV;
 139                 goto err_free_io;
 140         }
 141
 142         /* PXA2xx/3xx SSP ports starts from 1 and the internal pdev->id
 143          * starts from 0, do a translation here
 144          */
 145         ssp->port_id = pdev->id + 1;
 146         ssp->use_count = 0;
 147         ssp->type = (int)id->driver_data;
 148
 149         mutex_lock(&ssp_lock);
 150         list_add(&ssp->node, &ssp_list);
 151         mutex_unlock(&ssp_lock);
 152
 153         platform_set_drvdata(pdev, ssp);
 154         return 0;
 155
 156 err_free_io:
 157         iounmap(ssp->mmio_base);
 158 err_free_mem:
 159         release_mem_region(res->start, resource_size(res));
 160 err_free_clk:
 161         clk_put(ssp->clk);
 162 err_free:
 163         kfree(ssp);
 164         return ret;
 165 }
 166
 167 static int pxa_ssp_remove(struct platform_device *pdev)
 168 {
 169         struct resource *res;
 170         struct ssp_device *ssp;
 171
 172         ssp = platform_get_drvdata(pdev);
 173         if (ssp == NULL)
 174                 return -ENODEV;
 175
 176         iounmap(ssp->mmio_base);
 177
 178         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 179         release_mem_region(res->start, resource_size(res));
 180
 181         clk_put(ssp->clk);
 182
 183         mutex_lock(&ssp_lock);
 184         list_del(&ssp->node);
 185         mutex_unlock(&ssp_lock);
 186
 187         kfree(ssp);
 188         return 0;
 189 }
 190
 191 static const struct platform_device_id ssp_id_table[] = {
 192         { "pxa25x-ssp",         PXA25x_SSP },
 193         { "pxa25x-nssp",        PXA25x_NSSP },
 194         { "pxa27x-ssp",         PXA27x_SSP },
 195         { "pxa168-ssp",         PXA168_SSP },
 196         { "pxa910-ssp",         PXA910_SSP },
 197         { },
 198 };
 199
 200 static struct platform_driver pxa_ssp_driver = {
 201         .probe          = pxa_ssp_probe,
 202         .remove         = pxa_ssp_remove,
 203         .driver         = {
 204                 .owner  = THIS_MODULE,
 205                 .name   = "pxa2xx-ssp",
 206         },
 207         .id_table       = ssp_id_table,
 208 };
 209
 210 static int __init pxa_ssp_init(void)
 211 {
 212         return platform_driver_register(&pxa_ssp_driver);
 213 }
 214
 215 static void __exit pxa_ssp_exit(void)
 216 {
 217         platform_driver_unregister(&pxa_ssp_driver);
 218 }
 219
 220 arch_initcall(pxa_ssp_init);
 221 module_exit(pxa_ssp_exit);
 222
 223 MODULE_DESCRIPTION("PXA SSP driver");
 224 MODULE_AUTHOR("Liam Girdwood");
 225 MODULE_LICENSE("GPL");