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