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