Re: [PATCH v10 2/3] mmc: sdhci-msm: Initial support for Qualcomm chipsets

From: Ulf Hansson
Date: Tue Mar 04 2014 - 23:41:27 EST


On 4 March 2014 20:27, Georgi Djakov <gdjakov@xxxxxxxxxx> wrote:
> This platform driver adds the initial support of Secure
> Digital Host Controller Interface compliant controller
> found in Qualcomm chipsets.
>
> Signed-off-by: Asutosh Das <asutoshd@xxxxxxxxxxxxxx>
> Signed-off-by: Venkat Gopalakrishnan <venkatg@xxxxxxxxxxxxxx>
> Tested-by: Ivan T. Ivanov <iivanov@xxxxxxxxxx>
> Signed-off-by: Georgi Djakov <gdjakov@xxxxxxxxxx>
> ---
> drivers/mmc/host/Kconfig | 13 ++
> drivers/mmc/host/Makefile | 1 +
> drivers/mmc/host/sdhci-msm.c | 427 ++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 441 insertions(+)
> create mode 100644 drivers/mmc/host/sdhci-msm.c
>
> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
> index 82cc34d..66ef8b9 100644
> --- a/drivers/mmc/host/Kconfig
> +++ b/drivers/mmc/host/Kconfig
> @@ -334,6 +334,19 @@ config MMC_ATMELMCI
>
> If unsure, say N.
>
> +config MMC_SDHCI_MSM
> + tristate "Qualcomm SDHCI Controller Support"
> + depends on ARCH_QCOM
> + depends on MMC_SDHCI_PLTFM
> + help
> + This selects the Secure Digital Host Controller Interface (SDHCI)
> + support present in Qualcomm SOCs. The controller supports
> + SD/MMC/SDIO devices.
> +
> + If you have a controller with this interface, say Y or M here.
> +
> + If unsure, say N.
> +
> config MMC_MSM
> tristate "Qualcomm SDCC Controller Support"
> depends on MMC && (ARCH_MSM7X00A || ARCH_MSM7X30 || ARCH_QSD8X50)
> diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
> index f162f87a0..0c8aa5e 100644
> --- a/drivers/mmc/host/Makefile
> +++ b/drivers/mmc/host/Makefile
> @@ -63,6 +63,7 @@ obj-$(CONFIG_MMC_SDHCI_OF_ESDHC) += sdhci-of-esdhc.o
> obj-$(CONFIG_MMC_SDHCI_OF_HLWD) += sdhci-of-hlwd.o
> obj-$(CONFIG_MMC_SDHCI_BCM_KONA) += sdhci-bcm-kona.o
> obj-$(CONFIG_MMC_SDHCI_BCM2835) += sdhci-bcm2835.o
> +obj-$(CONFIG_MMC_SDHCI_MSM) += sdhci-msm.o
>
> ifeq ($(CONFIG_CB710_DEBUG),y)
> CFLAGS-cb710-mmc += -DDEBUG
> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
> new file mode 100644
> index 0000000..46e4e0b
> --- /dev/null
> +++ b/drivers/mmc/host/sdhci-msm.c
> @@ -0,0 +1,427 @@
> +/*
> + * drivers/mmc/host/sdhci-msm.c - Qualcomm SDHCI Platform driver
> + *
> + * Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 and
> + * only version 2 as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + */
> +
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/delay.h>
> +
> +#include "sdhci-pltfm.h"
> +
> +#define CORE_HC_MODE 0x78
> +#define HC_MODE_EN 0x1
> +
> +#define CORE_POWER 0x0
> +#define CORE_SW_RST BIT(7)
> +
> +#define CORE_PWRCTL_STATUS 0xdc
> +#define CORE_PWRCTL_MASK 0xe0
> +#define CORE_PWRCTL_CLEAR 0xe4
> +#define CORE_PWRCTL_CTL 0xe8
> +
> +#define CORE_PWRCTL_BUS_OFF BIT(0)
> +#define CORE_PWRCTL_BUS_ON BIT(1)
> +#define CORE_PWRCTL_IO_LOW BIT(2)
> +#define CORE_PWRCTL_IO_HIGH BIT(3)
> +
> +#define CORE_PWRCTL_BUS_SUCCESS BIT(0)
> +#define CORE_PWRCTL_BUS_FAIL BIT(1)
> +#define CORE_PWRCTL_IO_SUCCESS BIT(2)
> +#define CORE_PWRCTL_IO_FAIL BIT(3)
> +
> +#define INT_MASK 0xf
> +
> +#define QCOM_SDHCI_VOLTAGE_LOW 1800000
> +#define QCOM_SDHCI_VOLTAGE_HIGH 2950000
> +
> +
> +struct sdhci_msm_pltfm_data {
> + u32 caps; /* Supported UHS-I Modes */
> + u32 caps2; /* More capabilities */

Why do you need these caps, there are already a part of the mmc host.

> + struct regulator *vdd; /* VDD/VCC regulator */
> + struct regulator *vdd_io; /* VDD IO regulator */

Why do you need to duplicate the regulators for sdhci_msm? sdhci core
is already taking care of regulators, I suppose you should adopt to
that!?

> +};
> +
> +struct sdhci_msm_host {
> + struct platform_device *pdev;
> + void __iomem *core_mem; /* MSM SDCC mapped address */
> + int pwr_irq; /* power irq */
> + struct clk *clk; /* main SD/MMC bus clock */
> + struct clk *pclk; /* SDHC peripheral bus clock */
> + struct clk *bus_clk; /* SDHC bus voter clock */
> + struct sdhci_msm_pltfm_data pdata;
> + struct mmc_host *mmc;
> + struct sdhci_pltfm_data sdhci_msm_pdata;
> +};
> +
> +/* MSM platform specific tuning */
> +int sdhci_msm_execute_tuning(struct sdhci_host *host, u32 opcode)
> +{
> + /*
> + * Tuning is required for SDR104, HS200 and HS400 cards and if the clock
> + * frequency greater than 100MHz in those modes. The standard tuning
> + * procedure should not be executed, but a custom implementation will be
> + * added here instead.
> + */
> + return 0;
> +}
> +
> +static int sdhci_msm_vreg_enable(struct device *dev, struct regulator *vreg)
> +{
> + int ret = 0;
> +
> + if (!regulator_is_enabled(vreg)) {
> + /* Set voltage level */
> + ret = regulator_set_voltage(vreg, QCOM_SDHCI_VOLTAGE_HIGH,
> + QCOM_SDHCI_VOLTAGE_HIGH);
> + if (ret)
> + return ret;
> + }
> +
> + ret = regulator_enable(vreg);
> + if (ret)
> + dev_err(dev, "Failed to enable regulator (%d)\n", ret);
> +
> + return ret;
> +}
> +
> +static int sdhci_msm_vreg_disable(struct device *dev, struct regulator *vreg)
> +{
> + int ret = 0;
> +
> + if (!regulator_is_enabled(vreg))
> + return ret;
> +
> + /* Set min. voltage to 0 */
> + ret = regulator_set_voltage(vreg, 0, QCOM_SDHCI_VOLTAGE_HIGH);
> + if (ret)
> + return ret;
> +
> + ret = regulator_disable(vreg);
> + if (ret)
> + dev_err(dev, "Failed to disable regulator (%d)\n", ret);
> +
> + return ret;
> +}
> +
> +static int sdhci_msm_setup_vreg(struct sdhci_msm_host *msm_host, bool enable)
> +{
> + int ret;
> +
> + if (enable) {
> + ret = sdhci_msm_vreg_enable(&msm_host->pdev->dev,
> + msm_host->pdata.vdd);
> + ret |= sdhci_msm_vreg_enable(&msm_host->pdev->dev,
> + msm_host->pdata.vdd_io);
> + } else {
> + ret = sdhci_msm_vreg_disable(&msm_host->pdev->dev,
> + msm_host->pdata.vdd);
> + ret |= sdhci_msm_vreg_disable(&msm_host->pdev->dev,
> + msm_host->pdata.vdd_io);
> + }
> +
> + return ret;
> +}
> +
> +static int sdhci_msm_vreg_init(struct device *dev,
> + struct sdhci_msm_pltfm_data *pdata)
> +{
> + pdata->vdd = devm_regulator_get(dev, "vdd-supply");
> + if (IS_ERR(pdata->vdd))
> + return PTR_ERR(pdata->vdd);
> +
> + pdata->vdd_io = devm_regulator_get(dev, "vdd-io-supply");
> + if (IS_ERR(pdata->vdd_io))
> + return PTR_ERR(pdata->vdd_io);
> +
> + return 0;
> +}
> +

The hole regulator handling seems like it's being duplicated from the
sdhci core. If the regulator handling from the sdhci core don't suite
your need I guess you should extend that instead - to prevent the
duplication of code and structs.

Moreover I think it's time for sdhci core to move on to use the
mmc_regulator_get_supply() API. Additionally it should be able to use
mmc_regulator_set_ocr() API to change voltage. I guess that's not
related to this patch though, but just wanted to provide you my view
on it.


> +static irqreturn_t sdhci_msm_pwr_irq(int irq, void *data)
> +{
> + struct sdhci_host *host = (struct sdhci_host *)data;
> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> + struct sdhci_msm_host *msm_host = pltfm_host->priv;
> + u8 irq_status;
> + u8 irq_ack = 0;
> + int ret = 0;
> +
> + irq_status = readb_relaxed(msm_host->core_mem + CORE_PWRCTL_STATUS);
> + dev_dbg(mmc_dev(msm_host->mmc), "%s: Received IRQ(%d), status=0x%x\n",
> + mmc_hostname(msm_host->mmc), irq, irq_status);
> +
> + /* Clear the interrupt */
> + writeb_relaxed(irq_status, (msm_host->core_mem + CORE_PWRCTL_CLEAR));
> +
> + /* Ensure that the write has reached the device */
> + mb();
> +
> + if (irq_status & (CORE_PWRCTL_BUS_ON | CORE_PWRCTL_BUS_OFF)) {
> + /* Handle BUS ON/OFF */
> + bool bus_on = (irq_status & CORE_PWRCTL_BUS_ON) ? 1 : 0;
> +
> + ret = sdhci_msm_setup_vreg(msm_host, bus_on);
> + } else if (irq_status & (CORE_PWRCTL_IO_LOW | CORE_PWRCTL_IO_HIGH)) {
> + /* Handle IO LOW/HIGH */
> + int io_high = (irq_status & CORE_PWRCTL_IO_HIGH) ? 1 : 0;
> +
> + if (io_high) {
> + ret = regulator_set_voltage(msm_host->pdata.vdd_io,
> + QCOM_SDHCI_VOLTAGE_HIGH,
> + QCOM_SDHCI_VOLTAGE_HIGH);
> + } else {
> + ret = regulator_set_voltage(msm_host->pdata.vdd_io,
> + QCOM_SDHCI_VOLTAGE_LOW,
> + QCOM_SDHCI_VOLTAGE_LOW);
> + }
> + }
> +
> + if (ret)
> + irq_ack = CORE_PWRCTL_BUS_FAIL;
> + else
> + irq_ack = CORE_PWRCTL_BUS_SUCCESS;
> +
> + /* ACK status to the core */
> + writeb_relaxed(irq_ack, (msm_host->core_mem + CORE_PWRCTL_CTL));
> +
> + /* Commit the write to the device */
> + mb();
> +
> + dev_dbg(mmc_dev(msm_host->mmc), "%s: Handled IRQ(%d), ret=%d, ack=0x%x\n",
> + mmc_hostname(msm_host->mmc), irq, ret, irq_ack);
> + return IRQ_HANDLED;
> +}
> +
> +static const struct of_device_id sdhci_msm_dt_match[] = {
> + { .compatible = "qcom,sdhci-msm-v4" },
> + {},
> +};
> +
> +MODULE_DEVICE_TABLE(of, sdhci_msm_dt_match);
> +
> +static struct sdhci_ops sdhci_msm_ops = {
> + .platform_execute_tuning = sdhci_msm_execute_tuning,
> +};
> +
> +static int sdhci_msm_probe(struct platform_device *pdev)
> +{
> + struct sdhci_host *host;
> + struct sdhci_pltfm_host *pltfm_host;
> + struct sdhci_msm_host *msm_host;
> + struct resource *core_memres;
> + int ret, dead;
> + u16 host_version;
> +
> + if (!pdev->dev.of_node) {
> + dev_err(&pdev->dev, "No device tree data\n");
> + return -ENOENT;
> + }
> +
> + msm_host = devm_kzalloc(&pdev->dev, sizeof(*msm_host), GFP_KERNEL);
> + if (!msm_host)
> + return -ENOMEM;
> +
> + msm_host->sdhci_msm_pdata.ops = &sdhci_msm_ops;
> + host = sdhci_pltfm_init(pdev, &msm_host->sdhci_msm_pdata, 0);
> + if (IS_ERR(host))
> + return PTR_ERR(host);
> +
> + pltfm_host = sdhci_priv(host);
> + pltfm_host->priv = msm_host;
> + msm_host->mmc = host->mmc;
> + msm_host->pdev = pdev;
> +
> + ret = mmc_of_parse(host->mmc);
> + if (ret) {
> + dev_err(&pdev->dev, "Failed parsing mmc device tree\n");
> + goto pltfm_free;
> + }
> +
> + sdhci_get_of_property(pdev);
> +
> + /* Setup SDCC bus voter clock. */
> + msm_host->bus_clk = devm_clk_get(&pdev->dev, "bus");
> + if (!IS_ERR(msm_host->bus_clk)) {
> + /* Vote for max. clk rate for max. performance */
> + ret = clk_set_rate(msm_host->bus_clk, INT_MAX);
> + if (ret)
> + goto pltfm_free;
> + ret = clk_prepare_enable(msm_host->bus_clk);
> + if (ret)
> + goto pltfm_free;
> + }
> +
> + /* Setup main peripheral bus clock */
> + msm_host->pclk = devm_clk_get(&pdev->dev, "iface");
> + if (IS_ERR(msm_host->pclk)) {
> + ret = PTR_ERR(msm_host->pclk);
> + dev_err(&pdev->dev, "Perpheral clk setup failed (%d)\n", ret);
> + goto bus_clk_disable;
> + }
> +
> + ret = clk_prepare_enable(msm_host->pclk);
> + if (ret)
> + goto bus_clk_disable;
> +
> + /* Setup SDC MMC clock */
> + msm_host->clk = devm_clk_get(&pdev->dev, "core");
> + if (IS_ERR(msm_host->clk)) {
> + ret = PTR_ERR(msm_host->clk);
> + dev_err(&pdev->dev, "SDC MMC clk setup failed (%d)\n", ret);
> + goto pclk_disable;
> + }
> +
> + ret = clk_prepare_enable(msm_host->clk);
> + if (ret)
> + goto pclk_disable;
> +
> + /* Setup regulators */
> + ret = sdhci_msm_vreg_init(&pdev->dev, &msm_host->pdata);
> + if (ret) {
> + if (ret != -EPROBE_DEFER)
> + dev_err(&pdev->dev,
> + "Regulator setup failed (%d)\n", ret);
> + goto clk_disable;
> + }
> +
> + core_memres = platform_get_resource_byname(pdev,
> + IORESOURCE_MEM, "core_mem");
> + msm_host->core_mem = devm_ioremap_resource(&pdev->dev, core_memres);
> +
> + if (IS_ERR(msm_host->core_mem)) {
> + dev_err(&pdev->dev, "Failed to remap registers\n");
> + ret = PTR_ERR(msm_host->core_mem);
> + goto clk_disable;
> + }
> +
> + /* Reset the core and Enable SDHC mode */
> + writel_relaxed(readl_relaxed(msm_host->core_mem + CORE_POWER) |
> + CORE_SW_RST, msm_host->core_mem + CORE_POWER);
> +
> + /* SW reset can take upto 10HCLK + 15MCLK cycles. (min 40us) */
> + usleep_range(1000, 5000);
> + if (readl(msm_host->core_mem + CORE_POWER) & CORE_SW_RST) {
> + dev_err(&pdev->dev, "Stuck in reset\n");
> + ret = -ETIMEDOUT;
> + goto clk_disable;
> + }
> +
> + /* Set HC_MODE_EN bit in HC_MODE register */
> + writel_relaxed(HC_MODE_EN, (msm_host->core_mem + CORE_HC_MODE));
> +
> + /*
> + * Following are the deviations from SDHC spec v3.0 -
> + * 1. Card detection is handled using separate GPIO.
> + * 2. Bus power control is handled by interacting with PMIC.
> + */
> + host->quirks |= SDHCI_QUIRK_BROKEN_CARD_DETECTION;
> + host->quirks |= SDHCI_QUIRK_SINGLE_POWER_WRITE;
> +
> + host_version = readw_relaxed((host->ioaddr + SDHCI_HOST_VERSION));
> + dev_dbg(&pdev->dev, "Host Version: 0x%x Vendor Version 0x%x\n",
> + host_version, ((host_version & SDHCI_VENDOR_VER_MASK) >>
> + SDHCI_VENDOR_VER_SHIFT));
> +
> + /* Setup PWRCTL irq */
> + msm_host->pwr_irq = platform_get_irq_byname(pdev, "pwr_irq");
> + if (msm_host->pwr_irq < 0) {
> + dev_err(&pdev->dev, "Failed to get pwr_irq by name (%d)\n",
> + msm_host->pwr_irq);
> + goto clk_disable;
> + }
> + ret = devm_request_threaded_irq(&pdev->dev, msm_host->pwr_irq, NULL,
> + sdhci_msm_pwr_irq, IRQF_ONESHOT,
> + dev_name(&pdev->dev), host);
> + if (ret) {
> + dev_err(&pdev->dev, "Request threaded irq(%d) failed (%d)\n",
> + msm_host->pwr_irq, ret);
> + goto clk_disable;
> + }
> +
> + /* Enable power irq */
> + writel_relaxed(INT_MASK, (msm_host->core_mem + CORE_PWRCTL_MASK));
> +
> + msm_host->mmc->caps |= msm_host->pdata.caps;
> + msm_host->mmc->caps2 |= msm_host->pdata.caps2;
> +
> + ret = sdhci_add_host(host);
> + if (ret) {
> + dev_err(&pdev->dev, "Add host failed (%d)\n", ret);
> + goto vreg_disable;
> + }
> +
> + ret = clk_set_rate(msm_host->clk, host->max_clk);

Don't you need to set the rate before adding the host?

> + if (ret) {
> + dev_err(&pdev->dev, "MClk rate set failed (%d)\n", ret);
> + goto remove_host;
> + }
> +
> + return 0;
> +
> +remove_host:
> + dead = (readl_relaxed(host->ioaddr + SDHCI_INT_STATUS) == 0xffffffff);
> + sdhci_remove_host(host, dead);
> +vreg_disable:
> + sdhci_msm_vreg_disable(&pdev->dev, msm_host->pdata.vdd);
> + sdhci_msm_vreg_disable(&pdev->dev, msm_host->pdata.vdd_io);
> +clk_disable:
> + clk_disable_unprepare(msm_host->clk);
> +pclk_disable:
> + clk_disable_unprepare(msm_host->pclk);
> +bus_clk_disable:
> + if (!IS_ERR(msm_host->bus_clk))
> + clk_disable_unprepare(msm_host->bus_clk);
> +pltfm_free:
> + sdhci_pltfm_free(pdev);
> + return ret;
> +}
> +
> +static int sdhci_msm_remove(struct platform_device *pdev)
> +{
> + struct sdhci_host *host = platform_get_drvdata(pdev);
> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> + struct sdhci_msm_host *msm_host = pltfm_host->priv;
> + int dead;
> +
> + /* Disable power irq */
> + writel_relaxed(~INT_MASK, (msm_host->core_mem + CORE_PWRCTL_MASK));
> +
> + dead = (readl_relaxed(host->ioaddr + SDHCI_INT_STATUS) == 0xffffffff);
> + sdhci_remove_host(host, dead);
> + sdhci_pltfm_free(pdev);
> + sdhci_msm_vreg_disable(&pdev->dev, msm_host->pdata.vdd);
> + sdhci_msm_vreg_disable(&pdev->dev, msm_host->pdata.vdd_io);
> + clk_disable_unprepare(msm_host->clk);
> + clk_disable_unprepare(msm_host->pclk);
> + if (!IS_ERR(msm_host->bus_clk))
> + clk_disable_unprepare(msm_host->bus_clk);
> + return 0;
> +}
> +
> +static struct platform_driver sdhci_msm_driver = {
> + .probe = sdhci_msm_probe,
> + .remove = sdhci_msm_remove,
> + .driver = {
> + .name = "sdhci_msm",
> + .owner = THIS_MODULE,
> + .of_match_table = sdhci_msm_dt_match,
> + },
> +};
> +
> +module_platform_driver(sdhci_msm_driver);
> +
> +MODULE_DESCRIPTION("Qualcomm Secure Digital Host Controller Interface driver");
> +MODULE_LICENSE("GPL v2");
> --
> 1.7.9.5
>

Kind regards
Ulf Hansson
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