[PATCH v6 9/9] mmc: dw_mmc: add support for exynos specific implementation of dw-mshc
Thomas Abraham
thomas.abraham at linaro.org
Tue Sep 18 04:16:43 EST 2012
From: Thomas Abraham <thomas.ab at samsung.com>
Samsung Exynos SoC's extend the dw-mshc controller for additional clock and bus
control. Add support for these extensions and include provide device tree based
discovery suppory as well.
Signed-off-by: Thomas Abraham <thomas.abraham at linaro.org>
Acked-by: Will Newton <will.newton at imgtec.com>
---
.../devicetree/bindings/mmc/exynos-dw-mshc.txt | 87 +++++++
drivers/mmc/host/Kconfig | 9 +
drivers/mmc/host/Makefile | 1 +
drivers/mmc/host/dw_mmc-exynos.c | 253 ++++++++++++++++++++
include/linux/mmc/dw_mmc.h | 2 +-
5 files changed, 351 insertions(+), 1 deletions(-)
create mode 100644 Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt
create mode 100644 drivers/mmc/host/dw_mmc-exynos.c
diff --git a/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt b/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt
new file mode 100644
index 0000000..7927689
--- /dev/null
+++ b/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt
@@ -0,0 +1,87 @@
+* Samsung Exynos specific extensions to the Synopsis Designware Mobile
+ Storage Host Controller
+
+The Synopsis designware mobile storage host controller is used to interface
+a SoC with storage medium such as eMMC or SD/MMC cards. This file documents
+differences between the core Synopsis dw mshc controller properties described
+by synposis-dw-mshc.txt and the properties used by the Samsung Exynos specific
+extensions to the Synopsis Designware Mobile Storage Host Controller.
+
+Required Properties:
+
+* compatible: should be
+ - "samsung,exynos4210-dw-mshc": for controllers with Samsung Exynos4210
+ specific extentions.
+ - "samsung,exynos4412-dw-mshc": for controllers with Samsung Exynos4412
+ specific extentions.
+ - "samsung,exynos5250-dw-mshc": for controllers with Samsung Exynos5250
+ specific extentions.
+
+* samsung,dw-mshc-ciu-div: Specifies the divider value for the card interface
+ unit (ciu) clock. This property is applicable only for Exynos5 SoC's and
+ ignored for Exynos4 SoC's. The valid range of divider value is 0 to 7.
+
+* samsung,dw-mshc-sdr-timing: Specifies the value of CIU clock phase shift value
+ in transmit mode and CIU clock phase shift value in receive mode for single
+ data rate mode operation. Refer notes below for the order of the cells and the
+ valid values.
+
+* samsung,dw-mshc-ddr-timing: Specifies the value of CUI clock phase shift value
+ in transmit mode and CIU clock phase shift value in receive mode for double
+ data rate mode operation. Refer notes below for the order of the cells and the
+ valid values.
+
+ Notes for the sdr-timing and ddr-timing values:
+
+ The order of the cells should be
+ - First Cell: CIU clock phase shift value for tx mode.
+ - Second Cell: CIU clock phase shift value for rx mode.
+
+ Valid values for SDR and DDR CIU clock timing for Exynos5250:
+ - valid value for tx phase shift and rx phase shift is 0 to 7.
+ - when CIU clock divider value is set to 3, all possible 8 phase shift
+ values can be used.
+ - if CIU clock divider value is 0 (that is divide by 1), both tx and rx
+ phase shift clocks should be 0.
+
+Required properties for a slot:
+
+* gpios: specifies a list of gpios used for command, clock and data bus. The
+ first gpio is the command line and the second gpio is the clock line. The
+ rest of the gpios (depending on the bus-width property) are the data lines in
+ no particular order. The format of the gpio specifier depends on the gpio
+ controller.
+
+Example:
+
+ The MSHC controller node can be split into two portions, SoC specific and
+ board specific portions as listed below.
+
+ dwmmc0 at 12200000 {
+ compatible = "samsung,exynos5250-dw-mshc";
+ reg = <0x12200000 0x1000>;
+ interrupts = <0 75 0>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+ };
+
+ dwmmc0 at 12200000 {
+ num-slots = <1>;
+ supports-highspeed;
+ broken-cd;
+ fifo-depth = <0x80>;
+ card-detect-delay = <200>;
+ samsung,dw-mshc-ciu-div = <3>;
+ samsung,dw-mshc-sdr-timing = <2 3>;
+ samsung,dw-mshc-ddr-timing = <1 2>;
+
+ slot at 0 {
+ reg = <0>;
+ bus-width = <8>;
+ gpios = <&gpc0 0 2 0 3>, <&gpc0 1 2 0 3>,
+ <&gpc1 0 2 3 3>, <&gpc1 1 2 3 3>,
+ <&gpc1 2 2 3 3>, <&gpc1 3 2 3 3>,
+ <&gpc0 3 2 3 3>, <&gpc0 4 2 3 3>,
+ <&gpc0 5 2 3 3>, <&gpc0 6 2 3 3>;
+ };
+ };
diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index d588a27..dee73c0 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -540,6 +540,15 @@ config MMC_DW_PLTFM
If unsure, say Y.
+config MMC_DW_EXYNOS
+ tristate "Exynos specific extentions for Synopsys DW Memory Card Interface"
+ depends on MMC_DW
+ select MMC_DW_PLTFM
+ help
+ This selects support for Samsung Exynos SoC specific extensions to the
+ Synopsys DesignWare Memory Card Interface driver. Select this option
+ for platforms based on Exynos4 and Exynos5 SoC's.
+
config MMC_DW_PCI
tristate "Synopsys Designware MCI support on PCI bus"
depends on MMC_DW && PCI
diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
index 44c94ed..0f804d1 100644
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -39,6 +39,7 @@ obj-$(CONFIG_MMC_VIA_SDMMC) += via-sdmmc.o
obj-$(CONFIG_SDH_BFIN) += bfin_sdh.o
obj-$(CONFIG_MMC_DW) += dw_mmc.o
obj-$(CONFIG_MMC_DW_PLTFM) += dw_mmc-pltfm.o
+obj-$(CONFIG_MMC_DW_EXYNOS) += dw_mmc-exynos.o
obj-$(CONFIG_MMC_DW_PCI) += dw_mmc-pci.o
obj-$(CONFIG_MMC_SH_MMCIF) += sh_mmcif.o
obj-$(CONFIG_MMC_JZ4740) += jz4740_mmc.o
diff --git a/drivers/mmc/host/dw_mmc-exynos.c b/drivers/mmc/host/dw_mmc-exynos.c
new file mode 100644
index 0000000..660bbc5
--- /dev/null
+++ b/drivers/mmc/host/dw_mmc-exynos.c
@@ -0,0 +1,253 @@
+/*
+ * Exynos Specific Extensions for Synopsys DW Multimedia Card Interface driver
+ *
+ * Copyright (C) 2012, Samsung Electronics Co., Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/mmc/host.h>
+#include <linux/mmc/dw_mmc.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+
+#include "dw_mmc.h"
+#include "dw_mmc-pltfm.h"
+
+#define NUM_PINS(x) (x + 2)
+
+#define SDMMC_CLKSEL 0x09C
+#define SDMMC_CLKSEL_CCLK_SAMPLE(x) (((x) & 7) << 0)
+#define SDMMC_CLKSEL_CCLK_DRIVE(x) (((x) & 7) << 16)
+#define SDMMC_CLKSEL_CCLK_DIVIDER(x) (((x) & 7) << 24)
+#define SDMMC_CLKSEL_GET_DRV_WD3(x) (((x) >> 16) & 0x7)
+#define SDMMC_CLKSEL_TIMING(x, y, z) (SDMMC_CLKSEL_CCLK_SAMPLE(x) | \
+ SDMMC_CLKSEL_CCLK_DRIVE(y) | \
+ SDMMC_CLKSEL_CCLK_DIVIDER(z))
+
+#define SDMMC_CMD_USE_HOLD_REG BIT(29)
+
+#define EXYNOS4210_FIXED_CIU_CLK_DIV 2
+#define EXYNOS4412_FIXED_CIU_CLK_DIV 4
+
+/* Variations in Exynos specific dw-mshc controller */
+enum dw_mci_exynos_type {
+ DW_MCI_TYPE_EXYNOS4210,
+ DW_MCI_TYPE_EXYNOS4412,
+ DW_MCI_TYPE_EXYNOS5250,
+};
+
+/* Exynos implementation specific driver private data */
+struct dw_mci_exynos_priv_data {
+ enum dw_mci_exynos_type ctrl_type;
+ u8 ciu_div;
+ u32 sdr_timing;
+ u32 ddr_timing;
+};
+
+static struct dw_mci_exynos_compatible {
+ char *compatible;
+ enum dw_mci_exynos_type ctrl_type;
+} exynos_compat[] = {
+ {
+ .compatible = "samsung,exynos4210-dw-mshc",
+ .ctrl_type = DW_MCI_TYPE_EXYNOS4210,
+ }, {
+ .compatible = "samsung,exynos4412-dw-mshc",
+ .ctrl_type = DW_MCI_TYPE_EXYNOS4412,
+ }, {
+ .compatible = "samsung,exynos5250-dw-mshc",
+ .ctrl_type = DW_MCI_TYPE_EXYNOS5250,
+ },
+};
+
+static int dw_mci_exynos_priv_init(struct dw_mci *host)
+{
+ struct dw_mci_exynos_priv_data *priv;
+ int idx;
+
+ priv = devm_kzalloc(host->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv) {
+ dev_err(host->dev, "mem alloc failed for private data\n");
+ return -ENOMEM;
+ }
+
+ for (idx = 0; idx < ARRAY_SIZE(exynos_compat); idx++) {
+ if (of_device_is_compatible(host->dev->of_node,
+ exynos_compat[idx].compatible))
+ priv->ctrl_type = exynos_compat[idx].ctrl_type;
+ }
+
+ host->priv = priv;
+ return 0;
+}
+
+static int dw_mci_exynos_setup_clock(struct dw_mci *host)
+{
+ struct dw_mci_exynos_priv_data *priv = host->priv;
+
+ if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS5250)
+ host->bus_hz /= (priv->ciu_div + 1);
+ else if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS4412)
+ host->bus_hz /= EXYNOS4412_FIXED_CIU_CLK_DIV;
+ else if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS4210)
+ host->bus_hz /= EXYNOS4210_FIXED_CIU_CLK_DIV;
+
+ return 0;
+}
+
+static void dw_mci_exynos_prepare_command(struct dw_mci *host, u32 *cmdr)
+{
+ /*
+ * Exynos4412 and Exynos5250 extends the use of CMD register with the
+ * use of bit 29 (which is reserved on standard MSHC controllers) for
+ * optionally bypassing the HOLD register for command and data. The
+ * HOLD register should be bypassed in case there is no phase shift
+ * applied on CMD/DATA that is sent to the card.
+ */
+ if (SDMMC_CLKSEL_GET_DRV_WD3(mci_readl(host, CLKSEL)))
+ *cmdr |= SDMMC_CMD_USE_HOLD_REG;
+}
+
+static void dw_mci_exynos_set_ios(struct dw_mci *host, struct mmc_ios *ios)
+{
+ struct dw_mci_exynos_priv_data *priv = host->priv;
+
+ if (ios->timing == MMC_TIMING_UHS_DDR50)
+ mci_writel(host, CLKSEL, priv->ddr_timing);
+ else
+ mci_writel(host, CLKSEL, priv->sdr_timing);
+}
+
+static int dw_mci_exynos_parse_dt(struct dw_mci *host)
+{
+ struct dw_mci_exynos_priv_data *priv = host->priv;
+ struct device_node *np = host->dev->of_node;
+ u32 timing[2];
+ u32 div = 0;
+ int ret;
+
+ of_property_read_u32(np, "samsung,dw-mshc-ciu-div", &div);
+ priv->ciu_div = div;
+
+ ret = of_property_read_u32_array(np,
+ "samsung,dw-mshc-sdr-timing", timing, 2);
+ if (ret)
+ return ret;
+
+ priv->sdr_timing = SDMMC_CLKSEL_TIMING(timing[0], timing[1], div);
+
+ ret = of_property_read_u32_array(np,
+ "samsung,dw-mshc-ddr-timing", timing, 2);
+ if (ret)
+ return ret;
+
+ priv->ddr_timing = SDMMC_CLKSEL_TIMING(timing[0], timing[1], div);
+ return 0;
+}
+
+static int dw_mci_exynos_setup_bus(struct dw_mci *host,
+ struct device_node *slot_np, u8 bus_width)
+{
+ int idx, gpio, ret;
+
+ if (!slot_np)
+ return -EINVAL;
+
+ /* cmd + clock + bus-width pins */
+ for (idx = 0; idx < NUM_PINS(bus_width); idx++) {
+ gpio = of_get_gpio(slot_np, idx);
+ if (!gpio_is_valid(gpio)) {
+ dev_err(host->dev, "invalid gpio: %d\n", gpio);
+ return -EINVAL;
+ }
+
+ ret = devm_gpio_request(host->dev, gpio, "dw-mci-bus");
+ if (ret) {
+ dev_err(host->dev, "gpio [%d] request failed\n", gpio);
+ return -EBUSY;
+ }
+ }
+
+ gpio = of_get_named_gpio(slot_np, "wp-gpios", 0);
+ if (gpio_is_valid(gpio)) {
+ if (devm_gpio_request(host->dev, gpio, "dw-mci-wp"))
+ dev_info(host->dev, "gpio [%d] request failed\n",
+ gpio);
+ } else {
+ dev_info(host->dev, "wp gpio not available");
+ host->pdata->quirks |= DW_MCI_QUIRK_NO_WRITE_PROTECT;
+ }
+
+ if (host->pdata->quirks & DW_MCI_QUIRK_BROKEN_CARD_DETECTION)
+ return 0;
+
+ gpio = of_get_named_gpio(slot_np, "samsung,cd-pinmux-gpio", 0);
+ if (gpio_is_valid(gpio)) {
+ if (devm_gpio_request(host->dev, gpio, "dw-mci-cd"))
+ dev_err(host->dev, "gpio [%d] request failed\n", gpio);
+ } else {
+ dev_info(host->dev, "cd gpio not available");
+ }
+
+ return 0;
+}
+
+/* Exynos5250 controller specific capabilities */
+static unsigned long exynos5250_dwmmc_caps[4] = {
+ MMC_CAP_UHS_DDR50 | MMC_CAP_1_8V_DDR |
+ MMC_CAP_8_BIT_DATA | MMC_CAP_CMD23,
+ MMC_CAP_CMD23,
+ MMC_CAP_CMD23,
+ MMC_CAP_CMD23,
+};
+
+static struct dw_mci_drv_data exynos5250_drv_data = {
+ .caps = exynos5250_dwmmc_caps,
+ .init = dw_mci_exynos_priv_init,
+ .setup_clock = dw_mci_exynos_setup_clock,
+ .prepare_command = dw_mci_exynos_prepare_command,
+ .set_ios = dw_mci_exynos_set_ios,
+ .parse_dt = dw_mci_exynos_parse_dt,
+ .setup_bus = dw_mci_exynos_setup_bus,
+};
+
+static const struct of_device_id dw_mci_exynos_match[] = {
+ { .compatible = "samsung,exynos5250-dw-mshc",
+ .data = (void *)&exynos5250_drv_data, },
+ {},
+};
+MODULE_DEVICE_TABLE(of, dw_mci_pltfm_match);
+
+int dw_mci_exynos_probe(struct platform_device *pdev)
+{
+ struct dw_mci_drv_data *drv_data;
+ const struct of_device_id *match;
+
+ match = of_match_node(dw_mci_exynos_match, pdev->dev.of_node);
+ drv_data = match->data;
+ return dw_mci_pltfm_register(pdev, drv_data);
+}
+
+static struct platform_driver dw_mci_exynos_pltfm_driver = {
+ .probe = dw_mci_exynos_probe,
+ .remove = __exit_p(dw_mci_pltfm_remove),
+ .driver = {
+ .name = "dwmmc_exynos",
+ .of_match_table = of_match_ptr(dw_mci_exynos_match),
+ .pm = &dw_mci_pltfm_pmops,
+ },
+};
+
+module_platform_driver(dw_mci_exynos_pltfm_driver);
+
+MODULE_DESCRIPTION("Samsung Specific DW-MSHC Driver Extension");
+MODULE_AUTHOR("Thomas Abraham <thomas.ab at samsung.com");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:dwmmc-exynos");
diff --git a/include/linux/mmc/dw_mmc.h b/include/linux/mmc/dw_mmc.h
index 6cb043e..7c6a113 100644
--- a/include/linux/mmc/dw_mmc.h
+++ b/include/linux/mmc/dw_mmc.h
@@ -227,7 +227,7 @@ struct dw_mci_board {
u32 num_slots;
u32 quirks; /* Workaround / Quirk flags */
- unsigned int bus_hz; /* Bus speed */
+ unsigned int bus_hz; /* Clock speed at the cclk_in pad */
unsigned int caps; /* Capabilities */
unsigned int caps2; /* More capabilities */
--
1.6.6.rc2
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