target/linux/mvebu/patches-3.8/008-mmc_mvsdio_implement_a_device_tree_binding.patch

   1 This patch adds a simple Device Tree binding for the mvsdio driver, as
   2 well as the necessary documentation for it. Compatibility with non-DT
   3 platforms is preserved, by keeping the platform_data based
   4 initialization.
   5
   6 We introduce a small difference between non-DT and DT platforms: DT
   7 platforms are required to provide a clocks = <...> property, which the
   8 driver uses to get the frequency of the clock that goes to the SDIO
   9 IP. The behaviour on non-DT platforms is kept unchanged: a clock
  10 reference is not mandatory, but the clock frequency must be passed in
  11 the "clock" field of the mvsdio_platform_data structure.
  12
  13 Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
  14 ---
  15  .../devicetree/bindings/mmc/orion-sdio.txt         |   17 ++++++
  16  drivers/mmc/host/mvsdio.c                          |   60 +++++++++++++++-----
  17  2 files changed, 62 insertions(+), 15 deletions(-)
  18  create mode 100644 Documentation/devicetree/bindings/mmc/orion-sdio.txt
  19
  20 diff --git a/Documentation/devicetree/bindings/mmc/orion-sdio.txt b/Documentation/devicetree/bindings/mmc/orion-sdio.txt
  21 new file mode 100644
  22 index 0000000..84f0ebd
  23 --- /dev/null
  24 +++ b/Documentation/devicetree/bindings/mmc/orion-sdio.txt
  25 @@ -0,0 +1,17 @@
  26 +* Marvell orion-sdio controller
  27 +
  28 +This file documents differences between the core properties in mmc.txt
  29 +and the properties used by the orion-sdio driver.
  30 +
  31 +- compatible: Should be "marvell,orion-sdio"
  32 +- clocks: reference to the clock of the SDIO interface
  33 +
  34 +Example:
  35 +
  36 +       mvsdio@d00d4000 {
  37 +               compatible = "marvell,orion-sdio";
  38 +               reg = <0xd00d4000 0x200>;
  39 +               interrupts = <54>;
  40 +               clocks = <&gateclk 17>;
  41 +               status = "disabled";
  42 +       };
  43 diff --git a/drivers/mmc/host/mvsdio.c b/drivers/mmc/host/mvsdio.c
  44 index baf19fc..56954bc 100644
  45 --- a/drivers/mmc/host/mvsdio.c
  46 +++ b/drivers/mmc/host/mvsdio.c
  47 @@ -21,6 +21,8 @@
  48  #include <linux/irq.h>
  49  #include <linux/clk.h>
  50  #include <linux/gpio.h>
  51 +#include <linux/of_gpio.h>
  52 +#include <linux/of_irq.h>
  53  #include <linux/mmc/host.h>
  54  #include <linux/mmc/slot-gpio.h>
  55
  56 @@ -683,17 +685,17 @@ mv_conf_mbus_windows(struct mvsd_host *host,
  57
  58  static int __init mvsd_probe(struct platform_device *pdev)
  59  {
  60 +       struct device_node *np = pdev->dev.of_node;
  61         struct mmc_host *mmc = NULL;
  62         struct mvsd_host *host = NULL;
  63 -       const struct mvsdio_platform_data *mvsd_data;
  64         const struct mbus_dram_target_info *dram;
  65         struct resource *r;
  66         int ret, irq;
  67 +       int gpio_card_detect, gpio_write_protect;
  68
  69         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  70         irq = platform_get_irq(pdev, 0);
  71 -       mvsd_data = pdev->dev.platform_data;
  72 -       if (!r || irq < 0 || !mvsd_data)
  73 +       if (!r || irq < 0)
  74                 return -ENXIO;
  75
  76         r = request_mem_region(r->start, SZ_1K, DRIVER_NAME);
  77 @@ -710,7 +712,35 @@ static int __init mvsd_probe(struct platform_device *pdev)
  78         host->mmc = mmc;
  79         host->dev = &pdev->dev;
  80         host->res = r;
  81 -       host->base_clock = mvsd_data->clock / 2;
  82 +
  83 +       /* Some non-DT platforms do not pass a clock, and the clock
  84 +          frequency is passed through platform_data. On DT platforms,
  85 +          a clock must always be passed, even if there is no gatable
  86 +          clock associated to the SDIO interface (it can simply be a
  87 +          fixed rate clock). */
  88 +       host->clk = clk_get(&pdev->dev, NULL);
  89 +       if (!IS_ERR(host->clk))
  90 +               clk_prepare_enable(host->clk);
  91 +
  92 +       if (np) {
  93 +               if (IS_ERR(host->clk)) {
  94 +                       dev_err(&pdev->dev, "DT platforms must have a clock associated\n");
  95 +                       ret = -EINVAL;
  96 +                       goto out;
  97 +               }
  98 +
  99 +               host->base_clock = clk_get_rate(host->clk) / 2;
 100 +               gpio_card_detect = of_get_named_gpio(np, "cd-gpios", 0);
 101 +               gpio_write_protect = of_get_named_gpio(np, "wp-gpios", 0);
 102 +       } else {
 103 +               const struct mvsdio_platform_data *mvsd_data;
 104 +               mvsd_data = pdev->dev.platform_data;
 105 +               if (!mvsd_data)
 106 +                       return -ENXIO;
 107 +               host->base_clock = mvsd_data->clock / 2;
 108 +               gpio_card_detect = mvsd_data->gpio_card_detect;
 109 +               gpio_write_protect = mvsd_data->gpio_write_protect;
 110 +       }
 111
 112         mmc->ops = &mvsd_ops;
 113
 114 @@ -750,21 +780,14 @@ static int __init mvsd_probe(struct platform_device *pdev)
 115         } else
 116                 host->irq = irq;
 117
 118 -       /* Not all platforms can gate the clock, so it is not
 119 -          an error if the clock does not exists. */
 120 -       host->clk = clk_get(&pdev->dev, NULL);
 121 -       if (!IS_ERR(host->clk)) {
 122 -               clk_prepare_enable(host->clk);
 123 -       }
 124 -
 125 -       if (gpio_is_valid(mvsd_data->gpio_card_detect)) {
 126 -               ret = mmc_gpio_request_cd(mmc, mvsd_data->gpio_card_detect);
 127 +       if (gpio_is_valid(gpio_card_detect)) {
 128 +               ret = mmc_gpio_request_cd(mmc, gpio_card_detect);
 129                 if (ret)
 130                         goto out;
 131         } else
 132                 mmc->caps |= MMC_CAP_NEEDS_POLL;
 133
 134 -       mmc_gpio_request_ro(mmc, mvsd_data->gpio_write_protect);
 135 +       mmc_gpio_request_ro(mmc, gpio_write_protect);
 136
 137         setup_timer(&host->timer, mvsd_timeout_timer, (unsigned long)host);
 138         platform_set_drvdata(pdev, mmc);
 139 @@ -776,7 +799,7 @@ static int __init mvsd_probe(struct platform_device *pdev)
 140                            mmc_hostname(mmc), DRIVER_NAME);
 141         if (!(mmc->caps & MMC_CAP_NEEDS_POLL))
 142                 printk("using GPIO %d for card detection\n",
 143 -                      mvsd_data->gpio_card_detect);
 144 +                      gpio_card_detect);
 145         else
 146                 printk("lacking card detect (fall back to polling)\n");
 147         return 0;
 148 @@ -855,12 +878,19 @@ static int mvsd_resume(struct platform_device *dev)
 149  #define mvsd_resume    NULL
 150  #endif
 151
 152 +static const struct of_device_id mvsdio_dt_ids[] = {
 153 +       { .compatible = "marvell,orion-sdio" },
 154 +       { /* sentinel */ }
 155 +};
 156 +MODULE_DEVICE_TABLE(of, mvsdio_dt_ids);
 157 +
 158  static struct platform_driver mvsd_driver = {
 159         .remove         = __exit_p(mvsd_remove),
 160         .suspend        = mvsd_suspend,
 161         .resume         = mvsd_resume,
 162         .driver         = {
 163                 .name   = DRIVER_NAME,
 164 +               .of_match_table = mvsdio_dt_ids,
 165         },
 166  };
 167
 168 --
 169 1.7.9.5