drivers/dma/dw/platform.c

   1 /*
   2  * Platform driver for the Synopsys DesignWare DMA Controller
   3  *
   4  * Copyright (C) 2007-2008 Atmel Corporation
   5  * Copyright (C) 2010-2011 ST Microelectronics
   6  * Copyright (C) 2013 Intel Corporation
   7  *
   8  * Some parts of this driver are derived from the original dw_dmac.
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  */
  14
  15 #include <linux/module.h>
  16 #include <linux/device.h>
  17 #include <linux/clk.h>
  18 #include <linux/pm_runtime.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/dmaengine.h>
  21 #include <linux/dma-mapping.h>
  22 #include <linux/of.h>
  23 #include <linux/of_dma.h>
  24 #include <linux/acpi.h>
  25 #include <linux/acpi_dma.h>
  26
  27 #include "internal.h"
  28
  29 #define DRV_NAME        "dw_dmac"
  30
  31 static struct dma_chan *dw_dma_of_xlate(struct of_phandle_args *dma_spec,
  32                                         struct of_dma *ofdma)
  33 {
  34         struct dw_dma *dw = ofdma->of_dma_data;
  35         struct dw_dma_slave slave = {
  36                 .dma_dev = dw->dma.dev,
  37         };
  38         dma_cap_mask_t cap;
  39
  40         if (dma_spec->args_count != 3)
  41                 return NULL;
  42
  43         slave.src_id = dma_spec->args[0];
  44         slave.dst_id = dma_spec->args[0];
  45         slave.m_master = dma_spec->args[1];
  46         slave.p_master = dma_spec->args[2];
  47
  48         if (WARN_ON(slave.src_id >= DW_DMA_MAX_NR_REQUESTS ||
  49                     slave.dst_id >= DW_DMA_MAX_NR_REQUESTS ||
  50                     slave.m_master >= dw->pdata->nr_masters ||
  51                     slave.p_master >= dw->pdata->nr_masters))
  52                 return NULL;
  53
  54         dma_cap_zero(cap);
  55         dma_cap_set(DMA_SLAVE, cap);
  56
  57         /* TODO: there should be a simpler way to do this */
  58         return dma_request_channel(cap, dw_dma_filter, &slave);
  59 }
  60
  61 #ifdef CONFIG_ACPI
  62 static bool dw_dma_acpi_filter(struct dma_chan *chan, void *param)
  63 {
  64         struct acpi_dma_spec *dma_spec = param;
  65         struct dw_dma_slave slave = {
  66                 .dma_dev = dma_spec->dev,
  67                 .src_id = dma_spec->slave_id,
  68                 .dst_id = dma_spec->slave_id,
  69                 .m_master = 0,
  70                 .p_master = 1,
  71         };
  72
  73         return dw_dma_filter(chan, &slave);
  74 }
  75
  76 static void dw_dma_acpi_controller_register(struct dw_dma *dw)
  77 {
  78         struct device *dev = dw->dma.dev;
  79         struct acpi_dma_filter_info *info;
  80         int ret;
  81
  82         info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
  83         if (!info)
  84                 return;
  85
  86         dma_cap_zero(info->dma_cap);
  87         dma_cap_set(DMA_SLAVE, info->dma_cap);
  88         info->filter_fn = dw_dma_acpi_filter;
  89
  90         ret = acpi_dma_controller_register(dev, acpi_dma_simple_xlate, info);
  91         if (ret)
  92                 dev_err(dev, "could not register acpi_dma_controller\n");
  93 }
  94
  95 static void dw_dma_acpi_controller_free(struct dw_dma *dw)
  96 {
  97         struct device *dev = dw->dma.dev;
  98
  99         acpi_dma_controller_free(dev);
 100 }
 101 #else /* !CONFIG_ACPI */
 102 static inline void dw_dma_acpi_controller_register(struct dw_dma *dw) {}
 103 static inline void dw_dma_acpi_controller_free(struct dw_dma *dw) {}
 104 #endif /* !CONFIG_ACPI */
 105
 106 #ifdef CONFIG_OF
 107 static struct dw_dma_platform_data *
 108 dw_dma_parse_dt(struct platform_device *pdev)
 109 {
 110         struct device_node *np = pdev->dev.of_node;
 111         struct dw_dma_platform_data *pdata;
 112         u32 tmp, arr[DW_DMA_MAX_NR_MASTERS];
 113         u32 nr_masters;
 114         u32 nr_channels;
 115
 116         if (!np) {
 117                 dev_err(&pdev->dev, "Missing DT data\n");
 118                 return NULL;
 119         }
 120
 121         if (of_property_read_u32(np, "dma-masters", &nr_masters))
 122                 return NULL;
 123         if (nr_masters < 1 || nr_masters > DW_DMA_MAX_NR_MASTERS)
 124                 return NULL;
 125
 126         if (of_property_read_u32(np, "dma-channels", &nr_channels))
 127                 return NULL;
 128
 129         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 130         if (!pdata)
 131                 return NULL;
 132
 133         pdata->nr_masters = nr_masters;
 134         pdata->nr_channels = nr_channels;
 135
 136         if (of_property_read_bool(np, "is_private"))
 137                 pdata->is_private = true;
 138
 139         if (!of_property_read_u32(np, "chan_allocation_order", &tmp))
 140                 pdata->chan_allocation_order = (unsigned char)tmp;
 141
 142         if (!of_property_read_u32(np, "chan_priority", &tmp))
 143                 pdata->chan_priority = tmp;
 144
 145         if (!of_property_read_u32(np, "block_size", &tmp))
 146                 pdata->block_size = tmp;
 147
 148         if (!of_property_read_u32_array(np, "data-width", arr, nr_masters)) {
 149                 for (tmp = 0; tmp < nr_masters; tmp++)
 150                         pdata->data_width[tmp] = arr[tmp];
 151         } else if (!of_property_read_u32_array(np, "data_width", arr, nr_masters)) {
 152                 for (tmp = 0; tmp < nr_masters; tmp++)
 153                         pdata->data_width[tmp] = BIT(arr[tmp] & 0x07);
 154         }
 155
 156         return pdata;
 157 }
 158 #else
 159 static inline struct dw_dma_platform_data *
 160 dw_dma_parse_dt(struct platform_device *pdev)
 161 {
 162         return NULL;
 163 }
 164 #endif
 165
 166 static int dw_probe(struct platform_device *pdev)
 167 {
 168         struct dw_dma_chip *chip;
 169         struct device *dev = &pdev->dev;
 170         struct resource *mem;
 171         const struct dw_dma_platform_data *pdata;
 172         int err;
 173
 174         chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
 175         if (!chip)
 176                 return -ENOMEM;
 177
 178         chip->irq = platform_get_irq(pdev, 0);
 179         if (chip->irq < 0)
 180                 return chip->irq;
 181
 182         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 183         chip->regs = devm_ioremap_resource(dev, mem);
 184         if (IS_ERR(chip->regs))
 185                 return PTR_ERR(chip->regs);
 186
 187         err = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
 188         if (err)
 189                 return err;
 190
 191         pdata = dev_get_platdata(dev);
 192         if (!pdata)
 193                 pdata = dw_dma_parse_dt(pdev);
 194
 195         chip->dev = dev;
 196         chip->pdata = pdata;
 197
 198         chip->clk = devm_clk_get(chip->dev, "hclk");
 199         if (IS_ERR(chip->clk))
 200                 return PTR_ERR(chip->clk);
 201         err = clk_prepare_enable(chip->clk);
 202         if (err)
 203                 return err;
 204
 205         pm_runtime_enable(&pdev->dev);
 206
 207         err = dw_dma_probe(chip);
 208         if (err)
 209                 goto err_dw_dma_probe;
 210
 211         platform_set_drvdata(pdev, chip);
 212
 213         if (pdev->dev.of_node) {
 214                 err = of_dma_controller_register(pdev->dev.of_node,
 215                                                  dw_dma_of_xlate, chip->dw);
 216                 if (err)
 217                         dev_err(&pdev->dev,
 218                                 "could not register of_dma_controller\n");
 219         }
 220
 221         if (ACPI_HANDLE(&pdev->dev))
 222                 dw_dma_acpi_controller_register(chip->dw);
 223
 224         return 0;
 225
 226 err_dw_dma_probe:
 227         pm_runtime_disable(&pdev->dev);
 228         clk_disable_unprepare(chip->clk);
 229         return err;
 230 }
 231
 232 static int dw_remove(struct platform_device *pdev)
 233 {
 234         struct dw_dma_chip *chip = platform_get_drvdata(pdev);
 235
 236         if (ACPI_HANDLE(&pdev->dev))
 237                 dw_dma_acpi_controller_free(chip->dw);
 238
 239         if (pdev->dev.of_node)
 240                 of_dma_controller_free(pdev->dev.of_node);
 241
 242         dw_dma_remove(chip);
 243         pm_runtime_disable(&pdev->dev);
 244         clk_disable_unprepare(chip->clk);
 245
 246         return 0;
 247 }
 248
 249 static void dw_shutdown(struct platform_device *pdev)
 250 {
 251         struct dw_dma_chip *chip = platform_get_drvdata(pdev);
 252
 253         /*
 254          * We have to call dw_dma_disable() to stop any ongoing transfer. On
 255          * some platforms we can't do that since DMA device is powered off.
 256          * Moreover we have no possibility to check if the platform is affected
 257          * or not. That's why we call pm_runtime_get_sync() / pm_runtime_put()
 258          * unconditionally. On the other hand we can't use
 259          * pm_runtime_suspended() because runtime PM framework is not fully
 260          * used by the driver.
 261          */
 262         pm_runtime_get_sync(chip->dev);
 263         dw_dma_disable(chip);
 264         pm_runtime_put_sync_suspend(chip->dev);
 265
 266         clk_disable_unprepare(chip->clk);
 267 }
 268
 269 #ifdef CONFIG_OF
 270 static const struct of_device_id dw_dma_of_id_table[] = {
 271         { .compatible = "snps,dma-spear1340" },
 272         {}
 273 };
 274 MODULE_DEVICE_TABLE(of, dw_dma_of_id_table);
 275 #endif
 276
 277 #ifdef CONFIG_ACPI
 278 static const struct acpi_device_id dw_dma_acpi_id_table[] = {
 279         { "INTL9C60", 0 },
 280         { }
 281 };
 282 MODULE_DEVICE_TABLE(acpi, dw_dma_acpi_id_table);
 283 #endif
 284
 285 #ifdef CONFIG_PM_SLEEP
 286
 287 static int dw_suspend_late(struct device *dev)
 288 {
 289         struct platform_device *pdev = to_platform_device(dev);
 290         struct dw_dma_chip *chip = platform_get_drvdata(pdev);
 291
 292         dw_dma_disable(chip);
 293         clk_disable_unprepare(chip->clk);
 294
 295         return 0;
 296 }
 297
 298 static int dw_resume_early(struct device *dev)
 299 {
 300         struct platform_device *pdev = to_platform_device(dev);
 301         struct dw_dma_chip *chip = platform_get_drvdata(pdev);
 302
 303         clk_prepare_enable(chip->clk);
 304         return dw_dma_enable(chip);
 305 }
 306
 307 #endif /* CONFIG_PM_SLEEP */
 308
 309 static const struct dev_pm_ops dw_dev_pm_ops = {
 310         SET_LATE_SYSTEM_SLEEP_PM_OPS(dw_suspend_late, dw_resume_early)
 311 };
 312
 313 static struct platform_driver dw_driver = {
 314         .probe          = dw_probe,
 315         .remove         = dw_remove,
 316         .shutdown       = dw_shutdown,
 317         .driver = {
 318                 .name   = DRV_NAME,
 319                 .pm     = &dw_dev_pm_ops,
 320                 .of_match_table = of_match_ptr(dw_dma_of_id_table),
 321                 .acpi_match_table = ACPI_PTR(dw_dma_acpi_id_table),
 322         },
 323 };
 324
 325 static int __init dw_init(void)
 326 {
 327         return platform_driver_register(&dw_driver);
 328 }
 329 subsys_initcall(dw_init);
 330
 331 static void __exit dw_exit(void)
 332 {
 333         platform_driver_unregister(&dw_driver);
 334 }
 335 module_exit(dw_exit);
 336
 337 MODULE_LICENSE("GPL v2");
 338 MODULE_DESCRIPTION("Synopsys DesignWare DMA Controller platform driver");
 339 MODULE_ALIAS("platform:" DRV_NAME);