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.hutchi...@codethink.co.uk>
---
drivers/mmc/host/sh_mobile_sdhi.c | 60 +++++++++++++++++++++++++++++++++++++++
1 file changed, 60 insertions(+)
diff --git a/drivers/mmc/host/sh_mobile_sdhi.c
b/drivers/mmc/host/sh_mobile_sdhi.c
index 354f4f335ed5..2e65b855a7f7 100644
--- a/drivers/mmc/host/sh_mobile_sdhi.c
+++ b/drivers/mmc/host/sh_mobile_sdhi.c
@@ -30,6 +30,9 @@
#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"
@@ -86,6 +89,8 @@ 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 *pinctrl_3v3, *pinctrl_1v8;
};
static void sh_mobile_sdhi_sdbuf_width(struct tmio_mmc_host *host, int width)
@@ -136,6 +141,49 @@ static void sh_mobile_sdhi_clk_disable(struct
platform_device *pdev)
clk_disable_unprepare(priv->clk);
}
+static int sh_mobile_sdhi_start_signal_voltage_switch(
+ struct tmio_mmc_host *host, unsigned char signal_voltage)
+{
+ struct sh_mobile_sdhi *priv = host_to_priv(host);
+ struct pinctrl_state *state;
+ int min_uV, max_uV;
+ int ret;
+
+ switch (signal_voltage) {
+ case MMC_SIGNAL_VOLTAGE_330:
+ min_uV = 2700000;
+ max_uV = 3600000;
+ state = priv->pinctrl_3v3;
+ break;
+ case MMC_SIGNAL_VOLTAGE_180:
+ min_uV = 1700000;
+ max_uV = 1950000;
+ state = priv->pinctrl_1v8;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ /*
+ * If anything is missing, assume signal voltage is fixed at
+ * 3.3V and succeed/fail accordingly.
+ */
+ if (IS_ERR(host->mmc->supply.vqmmc) ||
+ IS_ERR(priv->pinctrl) || IS_ERR(state))
+ return signal_voltage == MMC_SIGNAL_VOLTAGE_330 ? 0 : -EINVAL;
+
+ ret = regulator_set_voltage(host->mmc->supply.vqmmc, min_uV, max_uV);
+ if (ret)
+ return ret;
+
+ ret = pinctrl_select_state(priv->pinctrl, state);
+ if (ret)
+ return ret;
+
+ usleep_range(5000, 5500);
+ return 0;
+}
+
static int sh_mobile_sdhi_wait_idle(struct tmio_mmc_host *host)
{
int timeout = 1000;
@@ -228,6 +276,14 @@ 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->pinctrl_3v3 = pinctrl_lookup_state(priv->pinctrl,
+ PINCTRL_STATE_DEFAULT);
+ priv->pinctrl_1v8 = pinctrl_lookup_state(priv->pinctrl,
+ "1v8");
+ }
+
host = tmio_mmc_host_alloc(pdev);
if (!host) {
ret = -ENOMEM;
@@ -239,6 +295,10 @@ static int sh_mobile_sdhi_probe(struct platform_device
*pdev)
host->clk_enable = sh_mobile_sdhi_clk_enable;
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;
+
/* SD control register space size is 0x100, 0x200 for bus_shift=1 */
if (resource_size(res) > 0x100)
host->bus_shift = 1;
--
2.1.4
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