[U-Boot] [PATCH v1 03/16] mmc: Add support for Qualcomm SDHCI controller

Mateusz Kulikowski
2016-01-06T18:21:15Z

Add support for SD/eMMC controller present on some Qualcomm Snapdragon
devices. This controller implements SDHCI 2.0 interface but requires
vendor-specific initialization.
Driver works in PIO mode as ADMA is not supported by U-Boot (yet).

Signed-off-by: Mateusz Kulikowski <mateusz.kulikowski@gmail.com>
---

Changes in v1:
- Added commit message
- Added DT binding documentation
- Added Kconfig help
- Reordered includes
- Dropped redundant fields from msm_sdhc
- Cleaned up clock init code (+ added error handling)
- Dropped mdelay - use wait_for_bit instead in reset code
- Added missing newline after declarations
- Added error handling if "reg" is missing
- Converted base address to pointer

doc/device-tree-bindings/mmc/msm_sdhci.txt | 25 ++++
drivers/mmc/Kconfig | 9 ++
drivers/mmc/Makefile | 1 +
drivers/mmc/msm_sdhci.c | 180 +++++++++++++++++++++++++++++
4 files changed, 215 insertions(+)
create mode 100644 doc/device-tree-bindings/mmc/msm_sdhci.txt
create mode 100644 drivers/mmc/msm_sdhci.c

diff --git a/doc/device-tree-bindings/mmc/msm_sdhci.txt b/doc/device-tree-bindings/mmc/msm_sdhci.txt
new file mode 100644
index 0000000..08a290c
--- /dev/null
+++ b/doc/device-tree-bindings/mmc/msm_sdhci.txt
@@ -0,0 +1,25 @@
+Qualcomm Snapdragon SDHCI controller
+
+Required properties:
+- compatible : "qcom,sdhci-msm-v4"
+- reg: Base address and length of registers:
+ - Host controller registers (SDHCI)
+ - SD Core registers
+- clock: interface clock (must accept SD bus clock as a frequency)
+
+Optional properties:
+- index: If there is more than one controller - controller index (required
+ by generic SDHCI code).
+- bus_width: Width of SD/eMMC bus (default 4)
+- clock-frequency: Frequency of SD/eMMC bus (default 400 kHz)
+
+Example:
+
+sdhci at 07864000 {
+ compatible = "qcom,sdhci-msm-v4";
+ reg = <0x7864900 0x11c 0x7864000 0x800>;
+ index = <0x1>;
+ bus-width = <0x4>;
+ clock = <&clkc 1>;
+ clock-frequency = <200000000>;
+};
diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
index ceae7bc..280f015 100644
--- a/drivers/mmc/Kconfig
+++ b/drivers/mmc/Kconfig
@@ -16,6 +16,15 @@ config DM_MMC
appear as block devices in U-Boot and can support filesystems such
as EXT4 and FAT.

+config MSM_SDHCI
+ bool "Qualcomm SDHCI controller"
+ depends on DM_MMC
+ help
+ Enables support for SDHCI 2.0 controller present on some Qualcomm
+ Snapdragon devices. This device is compatible with eMMC v4.5 and
+ SD 3.0 specifications. Both SD and eMMC devices are supported.
+ Card-detect gpios are not supported.
+
config ROCKCHIP_DWMMC
bool "Rockchip SD/MMC controller support"
depends on DM_MMC && OF_CONTROL
diff --git a/drivers/mmc/Makefile b/drivers/mmc/Makefile
index 5d35705..f4fdfca 100644
--- a/drivers/mmc/Makefile
+++ b/drivers/mmc/Makefile
@@ -49,3 +49,4 @@ else
obj-$(CONFIG_GENERIC_MMC) += mmc_write.o
endif

+obj-$(CONFIG_MSM_SDHCI) += msm_sdhci.o
diff --git a/drivers/mmc/msm_sdhci.c b/drivers/mmc/msm_sdhci.c
new file mode 100644
index 0000000..1e2a29b
--- /dev/null
+++ b/drivers/mmc/msm_sdhci.c
@@ -0,0 +1,180 @@
+/*
+ * Qualcomm SDHCI driver - SD/eMMC controller
+ *
+ * (C) Copyright 2015 Mateusz Kulikowski <mateusz.kulikowski@gmail.com>
+ *
+ * Based on Linux driver
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <clk.h>
+#include <dm.h>
+#include <sdhci.h>
+#include <wait_bit.h>
+#include <asm/io.h>
+#include <linux/bitops.h>
+
+/* Non-standard registers needed for SDHCI startup */
+#define SDCC_MCI_POWER 0x0
+#define SDCC_MCI_POWER_SW_RST BIT(7)
+
+/* This is undocumented register */
+#define SDCC_MCI_VERSION 0x50
+#define SDCC_MCI_VERSION_MAJOR_SHIFT 28
+#define SDCC_MCI_VERSION_MAJOR_MASK (0xf << SDCC_MCI_VERSION_MAJOR_SHIFT)
+#define SDCC_MCI_VERSION_MINOR_MASK 0xff
+
+#define SDCC_MCI_STATUS2 0x6C
+#define SDCC_MCI_STATUS2_MCI_ACT 0x1
+#define SDCC_MCI_HC_MODE 0x78
+
+/* Offset to SDHCI registers */
+#define SDCC_SDHCI_OFFSET 0x900
+
+/* Non standard (?) SDHCI register */
+#define SDHCI_VENDOR_SPEC_CAPABILITIES0 0x11c
+
+struct msm_sdhc {
+ struct sdhci_host host;
+ void *base;
+};
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static int msm_sdc_clk_init(struct udevice *dev)
+{
+ uint clk_rate = fdtdec_get_uint(gd->fdt_blob, dev->of_offset,
+ "clock-frequency", 400000);
+ uint clkd[2]; /* clk_id and clk_no */
+ int clk_offset;
+ struct udevice *clk;
+ int ret;
+
+ ret = fdtdec_get_int_array(gd->fdt_blob, dev->of_offset, "clock", clkd,
+ 2);
+ if (ret)
+ return ret;
+
+ clk_offset = fdt_node_offset_by_phandle(gd->fdt_blob, clkd[0]);
+ if (clk_offset < 0)
+ return clk_offset;
+
+ ret = uclass_get_device_by_of_offset(UCLASS_CLK, clk_offset, &clk);
+ if (ret)
+ return ret;
+
+ ret = clk_set_periph_rate(clk, clkd[1], clk_rate);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+static int msm_sdc_probe(struct udevice *dev)
+{
+ struct msm_sdhc *prv = dev_get_priv(dev);
+ struct sdhci_host *host = &prv->host;
+ u32 core_version, core_minor, core_major;
+ int ret;
+
+ host->quirks = SDHCI_QUIRK_WAIT_SEND_CMD | SDHCI_QUIRK_BROKEN_R1B;
+
+ /* Init clocks */
+ ret = msm_sdc_clk_init(dev);
+ if (ret)
+ return ret;
+
+ /* Reset the core and Enable SDHC mode */
+ writel(readl(prv->base + SDCC_MCI_POWER) | SDCC_MCI_POWER_SW_RST,
+ prv->base + SDCC_MCI_POWER);
+
+
+ /* Wait for reset to be written to register */
+ if (wait_for_bit(__func__, prv->base + SDCC_MCI_STATUS2,
+ SDCC_MCI_STATUS2_MCI_ACT, false, 10, false)) {
+ printf("msm_sdhci: reset request failed\n");
+ return -EIO;
+ }
+
+ /* SW reset can take upto 10HCLK + 15MCLK cycles. (min 40us) */
+ if (wait_for_bit(__func__, prv->base + SDCC_MCI_POWER,
+ SDCC_MCI_POWER_SW_RST, false, 2, false)) {
+ printf("msm_sdhci: stuck in reset\n");
+ return -ETIMEDOUT;
+ }
+
+ /* Enable host-controller mode */
+ writel(1, prv->base + SDCC_MCI_HC_MODE);
+
+ core_version = readl(prv->base + SDCC_MCI_VERSION);
+
+ core_major = (core_version & SDCC_MCI_VERSION_MAJOR_MASK);
+ core_major >>= SDCC_MCI_VERSION_MAJOR_SHIFT;
+
+ core_minor = core_version & SDCC_MCI_VERSION_MINOR_MASK;
+
+ /*
+ * Support for some capabilities is not advertised by newer
+ * controller versions and must be explicitly enabled.
+ */
+ if (core_major >= 1 && core_minor != 0x11 && core_minor != 0x12) {
+ u32 caps = readl(host->ioaddr + SDHCI_CAPABILITIES);
+ caps |= SDHCI_CAN_VDD_300 | SDHCI_CAN_DO_8BIT;
+ writel(caps, host->ioaddr + SDHCI_VENDOR_SPEC_CAPABILITIES0);
+ }
+
+ /* Set host controller version */
+ host->version = sdhci_readw(host, SDHCI_HOST_VERSION);
+
+ /* automatically detect max and min speed */
+ return add_sdhci(host, 0, 0);
+}
+
+static int msm_sdc_remove(struct udevice *dev)
+{
+ struct msm_sdhc *priv = dev_get_priv(dev);
+
+ /* Disable host-controller mode */
+ writel(0, priv->base + SDCC_MCI_HC_MODE);
+
+ return 0;
+}
+
+static int msm_ofdata_to_platdata(struct udevice *dev)
+{
+ struct udevice *parent = dev->parent;
+ struct msm_sdhc *priv = dev_get_priv(dev);
+ struct sdhci_host *host = &priv->host;
+
+ host->name = strdup(dev->name);
+ host->ioaddr = (void *)dev_get_addr(dev);
+ host->bus_width = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
+ "bus-width", 4);
+ host->index = fdtdec_get_uint(gd->fdt_blob, dev->of_offset, "index", 0);
+ priv->base = (void *)fdtdec_get_addr_size_auto_parent(gd->fdt_blob,
+ parent->of_offset,
+ dev->of_offset,
+ "reg", 1, NULL);
+ if (priv->base == (void *)FDT_ADDR_T_NONE ||
+ host->ioaddr == (void *)FDT_ADDR_T_NONE)
+ return -EINVAL;
+
+ return 0;
+}
+
+static const struct udevice_id msm_mmc_ids[] = {
+ { .compatible = "qcom,sdhci-msm-v4" },
+ { }
+};
+
+U_BOOT_DRIVER(msm_sdc_drv) = {
+ .name = "msm_sdc",
+ .id = UCLASS_MMC,
+ .of_match = msm_mmc_ids,
+ .ofdata_to_platdata = msm_ofdata_to_platdata,
+ .probe = msm_sdc_probe,
+ .remove = msm_sdc_remove,
+ .priv_auto_alloc_size = sizeof(struct msm_sdhc),
+};
--
2.5.0