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 #include <mach/hardware.h>
  38
  39 static DEFINE_MUTEX(ssp_lock);
  40 static LIST_HEAD(ssp_list);
  41
  42 struct ssp_device *pxa_ssp_request(int port, const char *label)
  43 {
  44         struct ssp_device *ssp = NULL;
  45
  46         mutex_lock(&ssp_lock);
  47
  48         list_for_each_entry(ssp, &ssp_list, node) {
  49                 if (ssp->port_id == port && ssp->use_count == 0) {
  50                         ssp->use_count++;
  51                         ssp->label = label;
  52                         break;
  53                 }
  54         }
  55
  56         mutex_unlock(&ssp_lock);
  57
  58         if (&ssp->node == &ssp_list)
  59                 return NULL;
  60
  61         return ssp;
  62 }
  63 EXPORT_SYMBOL(pxa_ssp_request);
  64
  65 struct ssp_device *pxa_ssp_request_of(const struct device_node *of_node,
  66                                       const char *label)
  67 {
  68         struct ssp_device *ssp = NULL;
  69
  70         mutex_lock(&ssp_lock);
  71
  72         list_for_each_entry(ssp, &ssp_list, node) {
  73                 if (ssp->of_node == of_node && ssp->use_count == 0) {
  74                         ssp->use_count++;
  75                         ssp->label = label;
  76                         break;
  77                 }
  78         }
  79
  80         mutex_unlock(&ssp_lock);
  81
  82         if (&ssp->node == &ssp_list)
  83                 return NULL;
  84
  85         return ssp;
  86 }
  87 EXPORT_SYMBOL(pxa_ssp_request_of);
  88
  89 void pxa_ssp_free(struct ssp_device *ssp)
  90 {
  91         mutex_lock(&ssp_lock);
  92         if (ssp->use_count) {
  93                 ssp->use_count--;
  94                 ssp->label = NULL;
  95         } else
  96                 dev_err(&ssp->pdev->dev, "device already free\n");
  97         mutex_unlock(&ssp_lock);
  98 }
  99 EXPORT_SYMBOL(pxa_ssp_free);
 100
 101 #ifdef CONFIG_OF
 102 static const struct of_device_id pxa_ssp_of_ids[] = {
 103         { .compatible = "mrvl,pxa25x-ssp",      .data = (void *) PXA25x_SSP },
 104         { .compatible = "mvrl,pxa25x-nssp",     .data = (void *) PXA25x_NSSP },
 105         { .compatible = "mrvl,pxa27x-ssp",      .data = (void *) PXA27x_SSP },
 106         { .compatible = "mrvl,pxa3xx-ssp",      .data = (void *) PXA3xx_SSP },
 107         { .compatible = "mvrl,pxa168-ssp",      .data = (void *) PXA168_SSP },
 108         { .compatible = "mrvl,pxa910-ssp",      .data = (void *) PXA910_SSP },
 109         { .compatible = "mrvl,ce4100-ssp",      .data = (void *) CE4100_SSP },
 110         { },
 111 };
 112 MODULE_DEVICE_TABLE(of, pxa_ssp_of_ids);
 113 #endif
 114
 115 static int pxa_ssp_probe(struct platform_device *pdev)
 116 {
 117         struct resource *res;
 118         struct ssp_device *ssp;
 119         struct device *dev = &pdev->dev;
 120
 121         ssp = devm_kzalloc(dev, sizeof(struct ssp_device), GFP_KERNEL);
 122         if (ssp == NULL)
 123                 return -ENOMEM;
 124
 125         ssp->pdev = pdev;
 126
 127         ssp->clk = devm_clk_get(dev, NULL);
 128         if (IS_ERR(ssp->clk))
 129                 return PTR_ERR(ssp->clk);
 130
 131         if (dev->of_node) {
 132                 struct of_phandle_args dma_spec;
 133                 struct device_node *np = dev->of_node;
 134                 int ret;
 135
 136                 /*
 137                  * FIXME: we should allocate the DMA channel from this
 138                  * context and pass the channel down to the ssp users.
 139                  * For now, we lookup the rx and tx indices manually
 140                  */
 141
 142                 /* rx */
 143                 ret = of_parse_phandle_with_args(np, "dmas", "#dma-cells",
 144                                                  0, &dma_spec);
 145
 146                 if (ret) {
 147                         dev_err(dev, "Can't parse dmas property\n");
 148                         return -ENODEV;
 149                 }
 150                 ssp->drcmr_rx = dma_spec.args[0];
 151                 of_node_put(dma_spec.np);
 152
 153                 /* tx */
 154                 ret = of_parse_phandle_with_args(np, "dmas", "#dma-cells",
 155                                                  1, &dma_spec);
 156                 if (ret) {
 157                         dev_err(dev, "Can't parse dmas property\n");
 158                         return -ENODEV;
 159                 }
 160                 ssp->drcmr_tx = dma_spec.args[0];
 161                 of_node_put(dma_spec.np);
 162         } else {
 163                 res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
 164                 if (res == NULL) {
 165                         dev_err(dev, "no SSP RX DRCMR defined\n");
 166                         return -ENODEV;
 167                 }
 168                 ssp->drcmr_rx = res->start;
 169
 170                 res = platform_get_resource(pdev, IORESOURCE_DMA, 1);
 171                 if (res == NULL) {
 172                         dev_err(dev, "no SSP TX DRCMR defined\n");
 173                         return -ENODEV;
 174                 }
 175                 ssp->drcmr_tx = res->start;
 176         }
 177
 178         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 179         if (res == NULL) {
 180                 dev_err(dev, "no memory resource defined\n");
 181                 return -ENODEV;
 182         }
 183
 184         res = devm_request_mem_region(dev, res->start, resource_size(res),
 185                                       pdev->name);
 186         if (res == NULL) {
 187                 dev_err(dev, "failed to request memory resource\n");
 188                 return -EBUSY;
 189         }
 190
 191         ssp->phys_base = res->start;
 192
 193         ssp->mmio_base = devm_ioremap(dev, res->start, resource_size(res));
 194         if (ssp->mmio_base == NULL) {
 195                 dev_err(dev, "failed to ioremap() registers\n");
 196                 return -ENODEV;
 197         }
 198
 199         ssp->irq = platform_get_irq(pdev, 0);
 200         if (ssp->irq < 0) {
 201                 dev_err(dev, "no IRQ resource defined\n");
 202                 return -ENODEV;
 203         }
 204
 205         if (dev->of_node) {
 206                 const struct of_device_id *id =
 207                         of_match_device(of_match_ptr(pxa_ssp_of_ids), dev);
 208                 ssp->type = (int) id->data;
 209         } else {
 210                 const struct platform_device_id *id =
 211                         platform_get_device_id(pdev);
 212                 ssp->type = (int) id->driver_data;
 213
 214                 /* PXA2xx/3xx SSP ports starts from 1 and the internal pdev->id
 215                  * starts from 0, do a translation here
 216                  */
 217                 ssp->port_id = pdev->id + 1;
 218         }
 219
 220         ssp->use_count = 0;
 221         ssp->of_node = dev->of_node;
 222
 223         mutex_lock(&ssp_lock);
 224         list_add(&ssp->node, &ssp_list);
 225         mutex_unlock(&ssp_lock);
 226
 227         platform_set_drvdata(pdev, ssp);
 228
 229         return 0;
 230 }
 231
 232 static int pxa_ssp_remove(struct platform_device *pdev)
 233 {
 234         struct resource *res;
 235         struct ssp_device *ssp;
 236
 237         ssp = platform_get_drvdata(pdev);
 238         if (ssp == NULL)
 239                 return -ENODEV;
 240
 241         iounmap(ssp->mmio_base);
 242
 243         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 244         release_mem_region(res->start, resource_size(res));
 245
 246         clk_put(ssp->clk);
 247
 248         mutex_lock(&ssp_lock);
 249         list_del(&ssp->node);
 250         mutex_unlock(&ssp_lock);
 251
 252         kfree(ssp);
 253         return 0;
 254 }
 255
 256 static const struct platform_device_id ssp_id_table[] = {
 257         { "pxa25x-ssp",         PXA25x_SSP },
 258         { "pxa25x-nssp",        PXA25x_NSSP },
 259         { "pxa27x-ssp",         PXA27x_SSP },
 260         { "pxa3xx-ssp",         PXA3xx_SSP },
 261         { "pxa168-ssp",         PXA168_SSP },
 262         { "pxa910-ssp",         PXA910_SSP },
 263         { },
 264 };
 265
 266 static struct platform_driver pxa_ssp_driver = {
 267         .probe          = pxa_ssp_probe,
 268         .remove         = pxa_ssp_remove,
 269         .driver         = {
 270                 .name           = "pxa2xx-ssp",
 271                 .of_match_table = of_match_ptr(pxa_ssp_of_ids),
 272         },
 273         .id_table       = ssp_id_table,
 274 };
 275
 276 static int __init pxa_ssp_init(void)
 277 {
 278         return platform_driver_register(&pxa_ssp_driver);
 279 }
 280
 281 static void __exit pxa_ssp_exit(void)
 282 {
 283         platform_driver_unregister(&pxa_ssp_driver);
 284 }
 285
 286 arch_initcall(pxa_ssp_init);
 287 module_exit(pxa_ssp_exit);
 288
 289 MODULE_DESCRIPTION("PXA SSP driver");
 290 MODULE_AUTHOR("Liam Girdwood");
 291 MODULE_LICENSE("GPL");