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

   1 From patchwork Wed Jan 16 13:13:59 2013
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   5 Subject: [4/5] mmc: mvsdio: implement a Device Tree binding
   6 Date: Wed, 16 Jan 2013 13:13:59 -0000
   7 From: Andrew Lunn <andrew@lunn.ch>
   8 X-Patchwork-Id: 1987921
   9 Message-Id: <1358342040-7130-5-git-send-email-andrew@lunn.ch>
  10 To: Jason Cooper <jason@lakedaemon.net>
  11 Cc: linux ARM <linux-arm-kernel@lists.infradead.org>,
  12  linux-mmc@vger.kernel.org, linux@arm.linux.org.uk,
  13  Thomas Petazzoni <thomas.petazzoni@free-electrons.com>,
  14  Andrew Lunn <andrew@lunn.ch>
  15
  16 From: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
  17
  18 This patch adds a simple Device Tree binding for the mvsdio driver, as
  19 well as the necessary documentation for it. Compatibility with non-DT
  20 platforms is preserved, by keeping the platform_data based
  21 initialization.
  22
  23 We introduce a small difference between non-DT and DT platforms: DT
  24 platforms are required to provide a clocks = <...> property, which the
  25 driver uses to get the frequency of the clock that goes to the SDIO
  26 IP. The behaviour on non-DT platforms is kept unchanged: a clock
  27 reference is not mandatory, but the clock frequency must be passed in
  28 the "clock" field of the mvsdio_platform_data structure.
  29
  30 Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
  31 Signed-off-by: Andrew Lunn <andrew@lunn.ch>
  32 Tested-by: Stefan Peter <s.peter@mpl.ch>
  33 Tested-by: Florian Fainelli <florian@openwrt.org>
  34 Signed-off-by: Jason Cooper <jason@lakedaemon.net>
  35
  36 ---
  37 .../devicetree/bindings/mmc/orion-sdio.txt         |   17 ++++++
  38  drivers/mmc/host/mvsdio.c                          |   62 +++++++++++++++-----
  39  2 files changed, 64 insertions(+), 15 deletions(-)
  40  create mode 100644 Documentation/devicetree/bindings/mmc/orion-sdio.txt
  41
  42 --- /dev/null
  43 +++ b/Documentation/devicetree/bindings/mmc/orion-sdio.txt
  44 @@ -0,0 +1,17 @@
  45 +* Marvell orion-sdio controller
  46 +
  47 +This file documents differences between the core properties in mmc.txt
  48 +and the properties used by the orion-sdio driver.
  49 +
  50 +- compatible: Should be "marvell,orion-sdio"
  51 +- clocks: reference to the clock of the SDIO interface
  52 +
  53 +Example:
  54 +
  55 +       mvsdio@d00d4000 {
  56 +               compatible = "marvell,orion-sdio";
  57 +               reg = <0xd00d4000 0x200>;
  58 +               interrupts = <54>;
  59 +               clocks = <&gateclk 17>;
  60 +               status = "disabled";
  61 +       };
  62 --- a/drivers/mmc/host/mvsdio.c
  63 +++ b/drivers/mmc/host/mvsdio.c
  64 @@ -21,6 +21,8 @@
  65  #include <linux/irq.h>
  66  #include <linux/clk.h>
  67  #include <linux/gpio.h>
  68 +#include <linux/of_gpio.h>
  69 +#include <linux/of_irq.h>
  70  #include <linux/mmc/host.h>
  71  #include <linux/mmc/slot-gpio.h>
  72
  73 @@ -681,17 +683,17 @@ mv_conf_mbus_windows(struct mvsd_host *h
  74
  75  static int __init mvsd_probe(struct platform_device *pdev)
  76  {
  77 +       struct device_node *np = pdev->dev.of_node;
  78         struct mmc_host *mmc = NULL;
  79         struct mvsd_host *host = NULL;
  80 -       const struct mvsdio_platform_data *mvsd_data;
  81         const struct mbus_dram_target_info *dram;
  82         struct resource *r;
  83         int ret, irq;
  84 +       int gpio_card_detect, gpio_write_protect;
  85
  86         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  87         irq = platform_get_irq(pdev, 0);
  88 -       mvsd_data = pdev->dev.platform_data;
  89 -       if (!r || irq < 0 || !mvsd_data)
  90 +       if (!r || irq < 0)
  91                 return -ENXIO;
  92
  93         mmc = mmc_alloc_host(sizeof(struct mvsd_host), &pdev->dev);
  94 @@ -703,8 +705,37 @@ static int __init mvsd_probe(struct plat
  95         host = mmc_priv(mmc);
  96         host->mmc = mmc;
  97         host->dev = &pdev->dev;
  98 -       host->base_clock = mvsd_data->clock / 2;
  99 -       host->clk = ERR_PTR(-EINVAL);
 100 +
 101 +       /* Some non-DT platforms do not pass a clock, and the clock
 102 +          frequency is passed through platform_data. On DT platforms,
 103 +          a clock must always be passed, even if there is no gatable
 104 +          clock associated to the SDIO interface (it can simply be a
 105 +          fixed rate clock). */
 106 +       host->clk = devm_clk_get(&pdev->dev, NULL);
 107 +       if (!IS_ERR(host->clk))
 108 +               clk_prepare_enable(host->clk);
 109 +
 110 +       if (np) {
 111 +               if (IS_ERR(host->clk)) {
 112 +                       dev_err(&pdev->dev, "DT platforms must have a clock associated\n");
 113 +                       ret = -EINVAL;
 114 +                       goto out;
 115 +               }
 116 +
 117 +               host->base_clock = clk_get_rate(host->clk) / 2;
 118 +               gpio_card_detect = of_get_named_gpio(np, "cd-gpios", 0);
 119 +               gpio_write_protect = of_get_named_gpio(np, "wp-gpios", 0);
 120 +       } else {
 121 +               const struct mvsdio_platform_data *mvsd_data;
 122 +               mvsd_data = pdev->dev.platform_data;
 123 +               if (!mvsd_data) {
 124 +                       ret = -ENXIO;
 125 +                       goto out;
 126 +               }
 127 +               host->base_clock = mvsd_data->clock / 2;
 128 +               gpio_card_detect = mvsd_data->gpio_card_detect;
 129 +               gpio_write_protect = mvsd_data->gpio_write_protect;
 130 +       }
 131
 132         mmc->ops = &mvsd_ops;
 133
 134 @@ -743,20 +774,14 @@ static int __init mvsd_probe(struct plat
 135                 goto out;
 136         }
 137
 138 -       /* Not all platforms can gate the clock, so it is not
 139 -          an error if the clock does not exists. */
 140 -       host->clk = devm_clk_get(&pdev->dev, NULL);
 141 -       if (!IS_ERR(host->clk))
 142 -               clk_prepare_enable(host->clk);
 143 -
 144 -       if (gpio_is_valid(mvsd_data->gpio_card_detect)) {
 145 -               ret = mmc_gpio_request_cd(mmc, mvsd_data->gpio_card_detect);
 146 +       if (gpio_is_valid(gpio_card_detect)) {
 147 +               ret = mmc_gpio_request_cd(mmc, gpio_card_detect);
 148                 if (ret)
 149                         goto out;
 150         } else
 151                 mmc->caps |= MMC_CAP_NEEDS_POLL;
 152
 153 -       mmc_gpio_request_ro(mmc, mvsd_data->gpio_write_protect);
 154 +       mmc_gpio_request_ro(mmc, gpio_write_protect);
 155
 156         setup_timer(&host->timer, mvsd_timeout_timer, (unsigned long)host);
 157         platform_set_drvdata(pdev, mmc);
 158 @@ -768,7 +793,7 @@ static int __init mvsd_probe(struct plat
 159                            mmc_hostname(mmc), DRIVER_NAME);
 160         if (!(mmc->caps & MMC_CAP_NEEDS_POLL))
 161                 printk("using GPIO %d for card detection\n",
 162 -                      mvsd_data->gpio_card_detect);
 163 +                      gpio_card_detect);
 164         else
 165                 printk("lacking card detect (fall back to polling)\n");
 166         return 0;
 167 @@ -832,12 +857,19 @@ static int mvsd_resume(struct platform_d
 168  #define mvsd_resume    NULL
 169  #endif
 170
 171 +static const struct of_device_id mvsdio_dt_ids[] = {
 172 +       { .compatible = "marvell,orion-sdio" },
 173 +       { /* sentinel */ }
 174 +};
 175 +MODULE_DEVICE_TABLE(of, mvsdio_dt_ids);
 176 +
 177  static struct platform_driver mvsd_driver = {
 178         .remove         = __exit_p(mvsd_remove),
 179         .suspend        = mvsd_suspend,
 180         .resume         = mvsd_resume,
 181         .driver         = {
 182                 .name   = DRIVER_NAME,
 183 +               .of_match_table = mvsdio_dt_ids,
 184         },
 185  };
 186