mmc: sh_mobile_sdhi: Add UHS-I mode support

Implement voltage switch, supporting modes up to SDR-50.

Based on work by Shinobu Uehara, Rob Taylor, William Towle and Ian Molton.

Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/Documentation/devicetree/bindings/mmc/tmio_mmc.txt b/Documentation/devicetree/bindings/mmc/tmio_mmc.txt
index 7fb746d..0f610d4 100644 (file)
--- a/Documentation/devicetree/bindings/mmc/tmio_mmc.txt
+++ b/Documentation/devicetree/bindings/mmc/tmio_mmc.txt
@@ -26,3 +26,6 @@ Required properties:
 
 Optional properties:
 - toshiba,mmc-wrprotect-disable: write-protect detection is unavailable
+- pinctrl-names: should be "default", "state_uhs"
+- pinctrl-0: should contain default/high speed pin ctrl
+- pinctrl-1: should contain uhs mode pin ctrl

diff --git a/drivers/mmc/host/sh_mobile_sdhi.c b/drivers/mmc/host/sh_mobile_sdhi.c
index 8fd1d6b..3c23027 100644 (file)
--- a/drivers/mmc/host/sh_mobile_sdhi.c
+++ b/drivers/mmc/host/sh_mobile_sdhi.c
@@ -32,6 +32,9 @@
 #include <linux/mfd/tmio.h>
 #include <linux/sh_dma.h>
 #include <linux/delay.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/pinctrl/pinctrl-state.h>
+#include <linux/regulator/consumer.h>
 
 #include "tmio_mmc.h"
 
@@ -97,6 +100,8 @@ struct sh_mobile_sdhi {
        struct clk *clk;
        struct tmio_mmc_data mmc_data;
        struct tmio_mmc_dma dma_priv;
+       struct pinctrl *pinctrl;
+       struct pinctrl_state *pins_default, *pins_uhs;
 };
 
 static void sh_mobile_sdhi_sdbuf_width(struct tmio_mmc_host *host, int width)
@@ -205,6 +210,44 @@ static void sh_mobile_sdhi_clk_disable(struct tmio_mmc_host *host)
        clk_disable_unprepare(priv->clk);
 }
 
+static int sh_mobile_sdhi_start_signal_voltage_switch(struct mmc_host *mmc,
+                                                     struct mmc_ios *ios)
+{
+       struct tmio_mmc_host *host = mmc_priv(mmc);
+       struct sh_mobile_sdhi *priv = host_to_priv(host);
+       struct pinctrl_state *pin_state;
+       int ret;
+
+       switch (ios->signal_voltage) {
+       case MMC_SIGNAL_VOLTAGE_330:
+               pin_state = priv->pins_default;
+               break;
+       case MMC_SIGNAL_VOLTAGE_180:
+               pin_state = priv->pins_uhs;
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       /*
+        * If anything is missing, assume signal voltage is fixed at
+        * 3.3V and succeed/fail accordingly.
+        */
+       if (IS_ERR(priv->pinctrl) || IS_ERR(pin_state))
+               return ios->signal_voltage ==
+                       MMC_SIGNAL_VOLTAGE_330 ? 0 : -EINVAL;
+
+       ret = mmc_regulator_set_vqmmc(host->mmc, ios);
+       if (ret)
+               return ret;
+
+       ret = pinctrl_select_state(priv->pinctrl, pin_state);
+       if (ret)
+               return ret;
+
+       return 0;
+}
+
 static int sh_mobile_sdhi_wait_idle(struct tmio_mmc_host *host)
 {
        int timeout = 1000;
@@ -296,6 +339,14 @@ static int sh_mobile_sdhi_probe(struct platform_device *pdev)
                goto eprobe;
        }
 
+       priv->pinctrl = devm_pinctrl_get(&pdev->dev);
+       if (!IS_ERR(priv->pinctrl)) {
+               priv->pins_default = pinctrl_lookup_state(priv->pinctrl,
+                                               PINCTRL_STATE_DEFAULT);
+               priv->pins_uhs = pinctrl_lookup_state(priv->pinctrl,
+                                               "state_uhs");
+       }
+
        host = tmio_mmc_host_alloc(pdev);
        if (!host) {
                ret = -ENOMEM;
@@ -319,6 +370,7 @@ static int sh_mobile_sdhi_probe(struct platform_device *pdev)
        host->clk_update        = sh_mobile_sdhi_clk_update;
        host->clk_disable       = sh_mobile_sdhi_clk_disable;
        host->multi_io_quirk    = sh_mobile_sdhi_multi_io_quirk;
+       host->start_signal_voltage_switch = sh_mobile_sdhi_start_signal_voltage_switch;
 
        /* Orginally registers were 16 bit apart, could be 32 or 64 nowadays */
        if (!host->bus_shift && resource_size(res) > 0x100) /* old way to determine the shift */