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 = devm_acpi_dma_controller_register(dev, acpi_dma_simple_xlate,
  91                                                 info);
  92         if (ret)
  93                 dev_err(dev, "could not register acpi_dma_controller\n");
  94 }
  95 #else /* !CONFIG_ACPI */
  96 static inline void dw_dma_acpi_controller_register(struct dw_dma *dw) {}
  97 #endif /* !CONFIG_ACPI */
  98
  99 #ifdef CONFIG_OF
 100 static struct dw_dma_platform_data *
 101 dw_dma_parse_dt(struct platform_device *pdev)
 102 {
 103         struct device_node *np = pdev->dev.of_node;
 104         struct dw_dma_platform_data *pdata;
 105         u32 tmp, arr[DW_DMA_MAX_NR_MASTERS], mb[DW_DMA_MAX_NR_CHANNELS];
 106         u32 nr_masters;
 107         u32 nr_channels;
 108
 109         if (!np) {
 110                 dev_err(&pdev->dev, "Missing DT data\n");
 111                 return NULL;
 112         }
 113
 114         if (of_property_read_u32(np, "dma-masters", &nr_masters))
 115                 return NULL;
 116         if (nr_masters < 1 || nr_masters > DW_DMA_MAX_NR_MASTERS)
 117                 return NULL;
 118
 119         if (of_property_read_u32(np, "dma-channels", &nr_channels))
 120                 return NULL;
 121         if (nr_channels > DW_DMA_MAX_NR_CHANNELS)
 122                 return NULL;
 123
 124         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 125         if (!pdata)
 126                 return NULL;
 127
 128         pdata->nr_masters = nr_masters;
 129         pdata->nr_channels = nr_channels;
 130
 131         if (of_property_read_bool(np, "is_private"))
 132                 pdata->is_private = true;
 133
 134         /*
 135          * All known devices, which use DT for configuration, support
 136          * memory-to-memory transfers. So enable it by default.
 137          */
 138         pdata->is_memcpy = true;
 139
 140         if (!of_property_read_u32(np, "chan_allocation_order", &tmp))
 141                 pdata->chan_allocation_order = (unsigned char)tmp;
 142
 143         if (!of_property_read_u32(np, "chan_priority", &tmp))
 144                 pdata->chan_priority = tmp;
 145
 146         if (!of_property_read_u32(np, "block_size", &tmp))
 147                 pdata->block_size = tmp;
 148
 149         if (!of_property_read_u32_array(np, "data-width", arr, nr_masters)) {
 150                 for (tmp = 0; tmp < nr_masters; tmp++)
 151                         pdata->data_width[tmp] = arr[tmp];
 152         } else if (!of_property_read_u32_array(np, "data_width", arr, nr_masters)) {
 153                 for (tmp = 0; tmp < nr_masters; tmp++)
 154                         pdata->data_width[tmp] = BIT(arr[tmp] & 0x07);
 155         }
 156
 157         if (!of_property_read_u32_array(np, "multi-block", mb, nr_channels)) {
 158                 for (tmp = 0; tmp < nr_channels; tmp++)
 159                         pdata->multi_block[tmp] = mb[tmp];
 160         } else {
 161                 for (tmp = 0; tmp < nr_channels; tmp++)
 162                         pdata->multi_block[tmp] = 1;
 163         }
 164
 165         return pdata;
 166 }
 167 #else
 168 static inline struct dw_dma_platform_data *
 169 dw_dma_parse_dt(struct platform_device *pdev)
 170 {
 171         return NULL;
 172 }
 173 #endif
 174
 175 static int dw_probe(struct platform_device *pdev)
 176 {
 177         struct dw_dma_chip *chip;
 178         struct device *dev = &pdev->dev;
 179         struct resource *mem;
 180         const struct dw_dma_platform_data *pdata;
 181         int err;
 182
 183         chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
 184         if (!chip)
 185                 return -ENOMEM;
 186
 187         chip->irq = platform_get_irq(pdev, 0);
 188         if (chip->irq < 0)
 189                 return chip->irq;
 190
 191         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 192         chip->regs = devm_ioremap_resource(dev, mem);
 193         if (IS_ERR(chip->regs))
 194                 return PTR_ERR(chip->regs);
 195
 196         err = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
 197         if (err)
 198                 return err;
 199
 200         pdata = dev_get_platdata(dev);
 201         if (!pdata)
 202                 pdata = dw_dma_parse_dt(pdev);
 203
 204         chip->dev = dev;
 205         chip->id = pdev->id;
 206         chip->pdata = pdata;
 207
 208         chip->clk = devm_clk_get(chip->dev, "hclk");
 209         if (IS_ERR(chip->clk))
 210                 return PTR_ERR(chip->clk);
 211         err = clk_prepare_enable(chip->clk);
 212         if (err)
 213                 return err;
 214
 215         pm_runtime_enable(&pdev->dev);
 216
 217         err = dw_dma_probe(chip);
 218         if (err)
 219                 goto err_dw_dma_probe;
 220
 221         platform_set_drvdata(pdev, chip);
 222
 223         if (pdev->dev.of_node) {
 224                 err = of_dma_controller_register(pdev->dev.of_node,
 225                                                  dw_dma_of_xlate, chip->dw);
 226                 if (err)
 227                         dev_err(&pdev->dev,
 228                                 "could not register of_dma_controller\n");
 229         }
 230
 231         if (ACPI_HANDLE(&pdev->dev))
 232                 dw_dma_acpi_controller_register(chip->dw);
 233
 234         return 0;
 235
 236 err_dw_dma_probe:
 237         pm_runtime_disable(&pdev->dev);
 238         clk_disable_unprepare(chip->clk);
 239         return err;
 240 }
 241
 242 static int dw_remove(struct platform_device *pdev)
 243 {
 244         struct dw_dma_chip *chip = platform_get_drvdata(pdev);
 245
 246         if (pdev->dev.of_node)
 247                 of_dma_controller_free(pdev->dev.of_node);
 248
 249         dw_dma_remove(chip);
 250         pm_runtime_disable(&pdev->dev);
 251         clk_disable_unprepare(chip->clk);
 252
 253         return 0;
 254 }
 255
 256 static void dw_shutdown(struct platform_device *pdev)
 257 {
 258         struct dw_dma_chip *chip = platform_get_drvdata(pdev);
 259
 260         /*
 261          * We have to call dw_dma_disable() to stop any ongoing transfer. On
 262          * some platforms we can't do that since DMA device is powered off.
 263          * Moreover we have no possibility to check if the platform is affected
 264          * or not. That's why we call pm_runtime_get_sync() / pm_runtime_put()
 265          * unconditionally. On the other hand we can't use
 266          * pm_runtime_suspended() because runtime PM framework is not fully
 267          * used by the driver.
 268          */
 269         pm_runtime_get_sync(chip->dev);
 270         dw_dma_disable(chip);
 271         pm_runtime_put_sync_suspend(chip->dev);
 272
 273         clk_disable_unprepare(chip->clk);
 274 }
 275
 276 #ifdef CONFIG_OF
 277 static const struct of_device_id dw_dma_of_id_table[] = {
 278         { .compatible = "snps,dma-spear1340" },
 279         {}
 280 };
 281 MODULE_DEVICE_TABLE(of, dw_dma_of_id_table);
 282 #endif
 283
 284 #ifdef CONFIG_ACPI
 285 static const struct acpi_device_id dw_dma_acpi_id_table[] = {
 286         { "INTL9C60", 0 },
 287         { }
 288 };
 289 MODULE_DEVICE_TABLE(acpi, dw_dma_acpi_id_table);
 290 #endif
 291
 292 #ifdef CONFIG_PM_SLEEP
 293
 294 static int dw_suspend_late(struct device *dev)
 295 {
 296         struct platform_device *pdev = to_platform_device(dev);
 297         struct dw_dma_chip *chip = platform_get_drvdata(pdev);
 298
 299         dw_dma_disable(chip);
 300         clk_disable_unprepare(chip->clk);
 301
 302         return 0;
 303 }
 304
 305 static int dw_resume_early(struct device *dev)
 306 {
 307         struct platform_device *pdev = to_platform_device(dev);
 308         struct dw_dma_chip *chip = platform_get_drvdata(pdev);
 309         int ret;
 310
 311         ret = clk_prepare_enable(chip->clk);
 312         if (ret)
 313                 return ret;
 314
 315         return dw_dma_enable(chip);
 316 }
 317
 318 #endif /* CONFIG_PM_SLEEP */
 319
 320 static const struct dev_pm_ops dw_dev_pm_ops = {
 321         SET_LATE_SYSTEM_SLEEP_PM_OPS(dw_suspend_late, dw_resume_early)
 322 };
 323
 324 static struct platform_driver dw_driver = {
 325         .probe          = dw_probe,
 326         .remove         = dw_remove,
 327         .shutdown       = dw_shutdown,
 328         .driver = {
 329                 .name   = DRV_NAME,
 330                 .pm     = &dw_dev_pm_ops,
 331                 .of_match_table = of_match_ptr(dw_dma_of_id_table),
 332                 .acpi_match_table = ACPI_PTR(dw_dma_acpi_id_table),
 333         },
 334 };
 335
 336 static int __init dw_init(void)
 337 {
 338         return platform_driver_register(&dw_driver);
 339 }
 340 subsys_initcall(dw_init);
 341
 342 static void __exit dw_exit(void)
 343 {
 344         platform_driver_unregister(&dw_driver);
 345 }
 346 module_exit(dw_exit);
 347
 348 MODULE_LICENSE("GPL v2");
 349 MODULE_DESCRIPTION("Synopsys DesignWare DMA Controller platform driver");
 350 MODULE_ALIAS("platform:" DRV_NAME);