Re: [PATCH 4/5] mmc: sdhci-omap: Add OMAP SDHCI driver

From: Kishon Vijay Abraham I
Date: Wed Aug 30 2017 - 09:55:31 EST


Hi,

On Monday 28 August 2017 02:36 PM, Adrian Hunter wrote:
> On 21/08/17 10:41, Kishon Vijay Abraham I wrote:
>> Create a new sdhci-omap driver to configure the eMMC/SD/SDIO controller
>> in TI's OMAP SoCs making use of the SDHCI core library. For OMAP specific
>> configurations, populate sdhci_ops with OMAP specific callbacks and use
>> SDHCI quirks.
>> Enable only high speed mode for both SD and eMMC here and add other
>> UHS mode support later.
>>
>> Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
>
> There are a few minor comments below.
>
>> ---
>> drivers/mmc/host/Kconfig | 12 +
>> drivers/mmc/host/Makefile | 1 +
>> drivers/mmc/host/sdhci-omap.c | 629 ++++++++++++++++++++++++++++++++++++++++++
>> 3 files changed, 642 insertions(+)
>> create mode 100644 drivers/mmc/host/sdhci-omap.c
>>
>> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
>> index 60f90d49e7a9..60d50843e165 100644
>> --- a/drivers/mmc/host/Kconfig
>> +++ b/drivers/mmc/host/Kconfig
>> @@ -899,3 +899,15 @@ config MMC_SDHCI_XENON
>> This selects Marvell Xenon eMMC/SD/SDIO SDHCI.
>> If you have a controller with this interface, say Y or M here.
>> If unsure, say N.
>> +
>> +config MMC_SDHCI_OMAP
>> + tristate "TI SDHCI Controller Support"
>> + depends on MMC_SDHCI_PLTFM
>> + help
>> + This selects the Secure Digital Host Controller Interface (SDHCI)
>> + support present in TI's DRA7 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.
>> diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
>> index 8c46766c000c..33181df88a10 100644
>> --- a/drivers/mmc/host/Makefile
>> +++ b/drivers/mmc/host/Makefile
>> @@ -88,6 +88,7 @@ obj-$(CONFIG_MMC_SDHCI_MSM) += sdhci-msm.o
>> obj-$(CONFIG_MMC_SDHCI_ST) += sdhci-st.o
>> obj-$(CONFIG_MMC_SDHCI_MICROCHIP_PIC32) += sdhci-pic32.o
>> obj-$(CONFIG_MMC_SDHCI_BRCMSTB) += sdhci-brcmstb.o
>> +obj-$(CONFIG_MMC_SDHCI_OMAP) += sdhci-omap.o
>>
>> ifeq ($(CONFIG_CB710_DEBUG),y)
>> CFLAGS-cb710-mmc += -DDEBUG
>> diff --git a/drivers/mmc/host/sdhci-omap.c b/drivers/mmc/host/sdhci-omap.c
>> new file mode 100644
>> index 000000000000..73ee3b4a400c
>> --- /dev/null
>> +++ b/drivers/mmc/host/sdhci-omap.c
>> @@ -0,0 +1,629 @@
>> +/**
>> + * SDHCI Controller driver for TI's OMAP SoCs
>> + *
>> + * Copyright (C) 2017 Texas Instruments
>> + * Author: Kishon Vijay Abraham I <kishon@xxxxxx>
>> + *
>> + * This program is free software: you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 of
>> + * the License 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.
>> + *
>> + * You should have received a copy of the GNU General Public License
>> + * along with this program. If not, see <http://www.gnu.org/licenses/>.
>> + */
>> +
>> +#include <linux/delay.h>
>> +#include <linux/mmc/slot-gpio.h>
>> +#include <linux/module.h>
>> +#include <linux/of.h>
>> +#include <linux/of_device.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/pm_runtime.h>
>> +#include <linux/regulator/consumer.h>
>> +
>> +#include "sdhci-pltfm.h"
>> +
>> +#define SDHCI_OMAP_CON 0x12c
>> +#define CON_DW8 BIT(5)
>> +#define CON_DMA_MASTER BIT(20)
>> +#define CON_INIT BIT(1)
>> +#define CON_OD BIT(0)
>> +
>> +#define SDHCI_OMAP_CMD 0x20c
>> +
>> +#define SDHCI_OMAP_HCTL 0x228
>> +#define HCTL_SDBP BIT(8)
>> +#define HCTL_SDVS_SHIFT 9
>> +#define HCTL_SDVS_MASK (0x7 << HCTL_SDVS_SHIFT)
>> +#define HCTL_SDVS_33 (0x7 << HCTL_SDVS_SHIFT)
>> +#define HCTL_SDVS_30 (0x6 << HCTL_SDVS_SHIFT)
>> +#define HCTL_SDVS_18 (0x5 << HCTL_SDVS_SHIFT)
>> +
>> +#define SDHCI_OMAP_SYSCTL 0x22c
>> +#define SYSCTL_CEN BIT(2)
>> +#define SYSCTL_CLKD_SHIFT 6
>> +#define SYSCTL_CLKD_MASK 0x3ff
>> +
>> +#define SDHCI_OMAP_STAT 0x230
>> +
>> +#define SDHCI_OMAP_IE 0x234
>> +#define INT_CC_EN BIT(0)
>> +
>> +#define SDHCI_OMAP_AC12 0x23c
>> +#define AC12_V1V8_SIGEN BIT(19)
>> +
>> +#define SDHCI_OMAP_CAPA 0x240
>> +#define CAPA_VS33 BIT(24)
>> +#define CAPA_VS30 BIT(25)
>> +#define CAPA_VS18 BIT(26)
>> +
>> +#define MMC_TIMEOUT 1 /* 1 msec */
>
> As before, SDHCI_OMAP_TIMEOUT is a better name

fixed it now.
>
>> +
>> +#define SYSCTL_CLKD_MAX 0x3FF
>> +
>> +#define IOV_1V8 1800000 /* 180000 uV */
>> +#define IOV_3V0 3000000 /* 300000 uV */
>> +#define IOV_3V3 3300000 /* 330000 uV */
>> +
>> +struct sdhci_omap_data {
>> + u32 offset;
>> +};
>> +
>> +struct sdhci_omap_host {
>> + void __iomem *base;
>> + struct device *dev;
>> + struct regulator *pbias;
>> + bool pbias_enabled;
>> + struct sdhci_host *host;
>> + unsigned int flags;
>> +
>> +#define SDHCI_OMAP_SUPPORTS_DUAL_VOLT BIT(0)
>> +#define SDHCI_OMAP_NO_1_8_V BIT(1)
>> +
>> + u8 bus_mode;
>> + u8 power_mode;
>> + bool io_3_3v_support;
>> +};
>> +
>> +static inline u32 sdhci_omap_readl(struct sdhci_omap_host *host,
>> + unsigned int offset)
>> +{
>> + return readl(host->base + offset);
>> +}
>> +
>> +static inline void sdhci_omap_writel(struct sdhci_omap_host *host,
>> + unsigned int offset, u32 data)
>> +{
>> + writel(data, host->base + offset);
>> +}
>> +
>> +static int sdhci_omap_set_pbias(struct sdhci_omap_host *omap_host,
>> + bool power_on, unsigned int iov)
>> +{
>> + int ret;
>> + struct device *dev = omap_host->dev;
>> +
>> + if (IS_ERR(omap_host->pbias))
>> + return 0;
>> +
>> + if (power_on) {
>> + ret = regulator_set_voltage(omap_host->pbias, iov, iov);
>> + if (ret) {
>> + dev_err(dev, "pbias set voltage failed\n");
>> + return ret;
>> + }
>> +
>> + if (omap_host->pbias_enabled)
>> + return 0;
>> +
>> + ret = regulator_enable(omap_host->pbias);
>> + if (ret) {
>> + dev_err(dev, "pbias reg enable fail\n");
>> + return ret;
>> + }
>> +
>> + omap_host->pbias_enabled = true;
>> + } else {
>> + if (!omap_host->pbias_enabled)
>> + return 0;
>> +
>> + ret = regulator_disable(omap_host->pbias);
>> + if (ret) {
>> + dev_err(dev, "pbias reg disable fail\n");
>> + return ret;
>> + }
>> + omap_host->pbias_enabled = false;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static int sdhci_omap_enable_iov(struct sdhci_omap_host *omap_host,
>> + unsigned int iov)
>> +{
>> + int ret;
>> + struct sdhci_host *host = omap_host->host;
>> + struct mmc_host *mmc = host->mmc;
>> +
>> + ret = sdhci_omap_set_pbias(omap_host, false, 0);
>> + if (ret)
>> + return ret;
>> +
>> + if (!IS_ERR(mmc->supply.vqmmc)) {
>> + ret = regulator_set_voltage(mmc->supply.vqmmc, iov, iov);
>> + if (ret) {
>> + dev_err(mmc_dev(mmc), "vqmmc set voltage failed\n");
>> + return ret;
>> + }
>> + }
>> +
>> + ret = sdhci_omap_set_pbias(omap_host, true, iov);
>> + if (ret)
>> + return ret;
>> +
>> + return 0;
>> +}
>> +
>> +static void sdhci_omap_conf_bus_power(struct sdhci_omap_host *omap_host,
>> + unsigned char signal_voltage)
>> +{
>> + u32 reg;
>> + ktime_t timeout;
>> +
>> + reg = sdhci_omap_readl(omap_host, SDHCI_OMAP_HCTL);
>> + reg &= ~HCTL_SDVS_MASK;
>> +
>> + if (signal_voltage == MMC_SIGNAL_VOLTAGE_180)
>> + reg |= HCTL_SDVS_18;
>> + else if (omap_host->io_3_3v_support)
>> + reg |= HCTL_SDVS_33;
>> + else
>> + reg |= HCTL_SDVS_30;
>> +
>> + sdhci_omap_writel(omap_host, SDHCI_OMAP_HCTL, reg);
>> +
>> + reg |= HCTL_SDBP;
>> + sdhci_omap_writel(omap_host, SDHCI_OMAP_HCTL, reg);
>> +
>> + /* wait 1ms */
>> + timeout = ktime_add_ms(ktime_get(), MMC_TIMEOUT);
>> + while (!(sdhci_omap_readl(omap_host, SDHCI_OMAP_HCTL) & HCTL_SDBP)) {
>> + if (WARN_ON(ktime_after(ktime_get(), timeout)))
>> + return;
>> + usleep_range(5, 10);
>> + }
>> +}
>> +
>> +static int sdhci_omap_start_signal_voltage_switch(struct mmc_host *mmc,
>> + struct mmc_ios *ios)
>> +{
>> + u32 reg;
>> + int ret;
>> + unsigned int iov;
>> + struct sdhci_host *host = mmc_priv(mmc);
>> + struct sdhci_pltfm_host *pltfm_host;
>> + struct sdhci_omap_host *omap_host;
>> + struct device *dev;
>> +
>> + pltfm_host = sdhci_priv(host);
>> + omap_host = sdhci_pltfm_priv(pltfm_host);
>> + dev = omap_host->dev;
>> +
>> + if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330) {
>> + reg = sdhci_omap_readl(omap_host, SDHCI_OMAP_CAPA);
>> + if (!(reg & (CAPA_VS33 | CAPA_VS30)))
>> + return -EOPNOTSUPP;
>> +
>> + sdhci_omap_conf_bus_power(omap_host, ios->signal_voltage);
>> +
>> + reg = sdhci_omap_readl(omap_host, SDHCI_OMAP_AC12);
>> + reg &= ~AC12_V1V8_SIGEN;
>> + sdhci_omap_writel(omap_host, SDHCI_OMAP_AC12, reg);
>> +
>> + if (omap_host->io_3_3v_support)
>> + iov = IOV_3V3;
>> + else
>> + iov = IOV_3V0;
>> + } else if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_180) {
>> + reg = sdhci_omap_readl(omap_host, SDHCI_OMAP_CAPA);
>> + if (!(reg & CAPA_VS18))
>> + return -EOPNOTSUPP;
>> +
>> + sdhci_omap_conf_bus_power(omap_host, ios->signal_voltage);
>> +
>> + reg = sdhci_omap_readl(omap_host, SDHCI_OMAP_AC12);
>> + reg |= AC12_V1V8_SIGEN;
>> + sdhci_omap_writel(omap_host, SDHCI_OMAP_AC12, reg);
>> +
>> + iov = IOV_1V8;
>> + } else {
>> + return -EOPNOTSUPP;
>> + }
>> +
>> + ret = sdhci_omap_enable_iov(omap_host, iov);
>> + if (ret) {
>> + dev_err(dev, "failed to switch IO voltage to %dmV\n", iov);
>> + return ret;
>> + }
>> +
>> + dev_dbg(dev, "IO voltage switched to %dmV\n", iov);
>> + return 0;
>> +}
>> +
>> +static void sdhci_omap_set_bus_mode(struct sdhci_omap_host *omap_host,
>> + unsigned int mode)
>> +{
>> + u32 reg;
>> +
>> + if (omap_host->bus_mode == mode)
>> + return;
>> +
>> + reg = sdhci_omap_readl(omap_host, SDHCI_OMAP_CON);
>> + if (mode == MMC_BUSMODE_OPENDRAIN)
>> + reg |= CON_OD;
>> + else
>> + reg &= ~CON_OD;
>> + sdhci_omap_writel(omap_host, SDHCI_OMAP_CON, reg);
>> +
>> + omap_host->bus_mode = mode;
>> +}
>> +
>> +void sdhci_omap_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>> +{
>> + struct sdhci_host *host = mmc_priv(mmc);
>> + struct sdhci_pltfm_host *pltfm_host;
>> + struct sdhci_omap_host *omap_host;
>> +
>> + pltfm_host = sdhci_priv(host);
>> + omap_host = sdhci_pltfm_priv(pltfm_host);
>> +
>> + sdhci_omap_set_bus_mode(omap_host, ios->bus_mode);
>> + sdhci_set_ios(mmc, ios);
>> +}
>> +
>> +static void sdhci_omap_set_capabilities(struct sdhci_omap_host *omap_host)
>> +{
>> + u32 reg;
>> +
>> + /* voltage capabilities might be set by boot loader, clear it */
>> + reg = sdhci_omap_readl(omap_host, SDHCI_OMAP_CAPA);
>> + reg &= ~(CAPA_VS18 | CAPA_VS30 | CAPA_VS33);
>> +
>> + if (omap_host->flags & SDHCI_OMAP_SUPPORTS_DUAL_VOLT) {
>> + if (omap_host->io_3_3v_support)
>> + reg |= (CAPA_VS33 | CAPA_VS18);
>> + else
>> + reg |= (CAPA_VS30 | CAPA_VS18);
>> + } else if (omap_host->flags & SDHCI_OMAP_NO_1_8_V) {
>> + if (omap_host->io_3_3v_support)
>> + reg |= CAPA_VS33;
>> + else
>> + reg |= CAPA_VS30;
>> + } else {
>> + reg |= CAPA_VS18;
>> + }
>> +
>> + sdhci_omap_writel(omap_host, SDHCI_OMAP_CAPA, reg);
>> +}
>> +
>> +static u16 sdhci_omap_calc_divisor(struct sdhci_pltfm_host *host,
>> + unsigned int clock)
>> +{
>> + u16 dsor;
>> +
>> + dsor = DIV_ROUND_UP(clk_get_rate(host->clk), clock);
>> + if (dsor > SYSCTL_CLKD_MAX)
>> + dsor = SYSCTL_CLKD_MAX;
>> +
>> + return dsor;
>> +}
>> +
>> +static void sdhci_omap_start_clock(struct sdhci_omap_host *omap_host)
>> +{
>> + u32 reg;
>> +
>> + reg = sdhci_omap_readl(omap_host, SDHCI_OMAP_SYSCTL);
>> + reg |= SYSCTL_CEN;
>> + sdhci_omap_writel(omap_host, SDHCI_OMAP_SYSCTL, reg);
>> +}
>> +
>> +static void sdhci_omap_stop_clock(struct sdhci_omap_host *omap_host)
>> +{
>> + u32 reg;
>> +
>> + reg = sdhci_omap_readl(omap_host, SDHCI_OMAP_SYSCTL);
>> + reg &= ~SYSCTL_CEN;
>> + sdhci_omap_writel(omap_host, SDHCI_OMAP_SYSCTL, reg);
>> +}
>> +
>> +static void sdhci_omap_set_clock(struct sdhci_host *host, unsigned int clock)
>> +{
>> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>> + struct sdhci_omap_host *omap_host = sdhci_pltfm_priv(pltfm_host);
>> + unsigned long clkdiv;
>> +
>> + if (!clock)
>> + return;
>
> Are you sure you don't want to stop the clock.

There is never a case where the MMC core sends a request to stop the clock.
Maybe this check is not required at all.
>
>> +
>> + sdhci_omap_stop_clock(omap_host);
>> +
>> + clkdiv = sdhci_omap_calc_divisor(pltfm_host, clock);
>> + clkdiv = (clkdiv & SYSCTL_CLKD_MASK) << SYSCTL_CLKD_SHIFT;
>> + sdhci_enable_clk(host, clkdiv);
>> +
>> + sdhci_omap_start_clock(omap_host);
>> +}
>> +
>> +void sdhci_omap_set_power(struct sdhci_host *host, unsigned char mode,
>> + unsigned short vdd)
>> +{
>> + struct mmc_host *mmc = host->mmc;
>> +
>> + mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, vdd);
>> +}
>> +
>> +static int sdhci_omap_enable_dma(struct sdhci_host *host)
>> +{
>> + u32 reg;
>> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>> + struct sdhci_omap_host *omap_host = sdhci_pltfm_priv(pltfm_host);
>> +
>> + reg = sdhci_omap_readl(omap_host, SDHCI_OMAP_CON);
>> + reg |= CON_DMA_MASTER;
>> + sdhci_omap_writel(omap_host, SDHCI_OMAP_CON, reg);
>> +
>> + return 0;
>> +}
>> +
>> +unsigned int sdhci_omap_get_min_clock(struct sdhci_host *host)
>> +{
>> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>> +
>> + return clk_get_rate(pltfm_host->clk) / SYSCTL_CLKD_MAX;
>> +}
>> +
>> +static void sdhci_omap_set_bus_width(struct sdhci_host *host, int width)
>> +{
>> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>> + struct sdhci_omap_host *omap_host = sdhci_pltfm_priv(pltfm_host);
>> + u32 reg;
>> +
>> + reg = sdhci_omap_readl(omap_host, SDHCI_OMAP_CON);
>> + if (width == MMC_BUS_WIDTH_8)
>> + reg |= CON_DW8;
>> + else
>> + reg &= ~CON_DW8;
>> + sdhci_omap_writel(omap_host, SDHCI_OMAP_CON, reg);
>> +
>> + sdhci_set_bus_width(host, width);
>> +}
>> +
>> +static void sdhci_omap_init_74_clocks(struct sdhci_host *host, u8 power_mode)
>> +{
>> + u32 reg;
>> + ktime_t timeout;
>> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>> + struct sdhci_omap_host *omap_host = sdhci_pltfm_priv(pltfm_host);
>> +
>> + if (omap_host->power_mode == power_mode)
>> + return;
>> +
>> + if (power_mode != MMC_POWER_ON)
>> + return;
>> +
>> + disable_irq(host->irq);
>> +
>> + reg = sdhci_omap_readl(omap_host, SDHCI_OMAP_CON);
>> + reg |= CON_INIT;
>> + sdhci_omap_writel(omap_host, SDHCI_OMAP_CON, reg);
>> + sdhci_omap_writel(omap_host, SDHCI_OMAP_CMD, 0x0);
>> +
>> + /* wait 1ms */
>> + timeout = ktime_add_ms(ktime_get(), MMC_TIMEOUT);
>> + while (!(sdhci_omap_readl(omap_host, SDHCI_OMAP_STAT) & INT_CC_EN)) {
>> + if (WARN_ON(ktime_after(ktime_get(), timeout)))
>> + return;
>> + usleep_range(5, 10);
>> + }
>> +
>> + reg = sdhci_omap_readl(omap_host, SDHCI_OMAP_CON);
>> + reg &= ~CON_INIT;
>> + sdhci_omap_writel(omap_host, SDHCI_OMAP_CON, reg);
>> + sdhci_omap_writel(omap_host, SDHCI_OMAP_STAT, INT_CC_EN);
>> +
>> + enable_irq(host->irq);
>> +
>> + omap_host->power_mode = power_mode;
>> +}
>> +
>> +static struct sdhci_ops sdhci_omap_ops = {
>> + .set_clock = sdhci_omap_set_clock,
>> + .set_power = sdhci_omap_set_power,
>> + .enable_dma = sdhci_omap_enable_dma,
>> + .get_max_clock = sdhci_pltfm_clk_get_max_clock,
>> + .get_min_clock = sdhci_omap_get_min_clock,
>> + .set_bus_width = sdhci_omap_set_bus_width,
>> + .platform_send_init_74_clocks = sdhci_omap_init_74_clocks,
>> + .reset = sdhci_reset,
>> + .set_uhs_signaling = sdhci_set_uhs_signaling,
>> +};
>> +
>> +void sdhci_omap_get_of_property(struct sdhci_omap_host *omap_host)
>> +{
>> + struct device *dev = omap_host->dev;
>> + struct sdhci_host *host = omap_host->host;
>> + struct mmc_host *mmc = host->mmc;
>> +
>> + if (device_property_read_bool(dev, "ti,dual-volt"))
>> + omap_host->flags |= SDHCI_OMAP_SUPPORTS_DUAL_VOLT;
>> +
>> + if (device_property_read_bool(dev, "no-1-8-v"))
>> + omap_host->flags |= SDHCI_OMAP_NO_1_8_V;
>> +
>> + if (device_property_read_bool(dev, "ti,non-removable"))
>> + mmc->caps |= MMC_CAP_NONREMOVABLE;
>> +}
>> +
>> +static const struct sdhci_pltfm_data sdhci_omap_pdata = {
>> + .quirks = SDHCI_QUIRK_BROKEN_CARD_DETECTION |
>> + SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK |
>> + SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN |
>> + SDHCI_QUIRK_NO_HISPD_BIT |
>> + SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC,
>> + .quirks2 = SDHCI_QUIRK2_NO_1_8_V |
>> + SDHCI_QUIRK2_ACMD23_BROKEN |
>> + SDHCI_QUIRK2_RSP_136_HAS_CRC,
>> + .ops = &sdhci_omap_ops,
>> +};
>> +
>> +static const struct sdhci_omap_data dra7_data = {
>> + .offset = 0x200,
>> +};
>> +
>> +static const struct of_device_id omap_sdhci_match[] = {
>> + { .compatible = "ti,dra7-sdhci", .data = &dra7_data },
>> + {},
>> +};
>> +MODULE_DEVICE_TABLE(of, omap_sdhci_match);
>> +
>> +static int sdhci_omap_probe(struct platform_device *pdev)
>> +{
>> + int ret;
>> + u32 offset;
>> + struct device *dev = &pdev->dev;
>> + struct sdhci_host *host;
>> + struct sdhci_pltfm_host *pltfm_host;
>> + struct sdhci_omap_host *omap_host;
>> + struct mmc_host *mmc;
>> + const struct of_device_id *match;
>> + struct sdhci_omap_data *data;
>> +
>> + match = of_match_device(omap_sdhci_match, dev);
>> + if (!match)
>> + return -EINVAL;
>> +
>> + data = (struct sdhci_omap_data *)match->data;
>> + if (!data) {
>> + dev_err(dev, "no sdhci omap data\n");
>> + return -EINVAL;
>> + }
>> +
>> + offset = data->offset;
>> +
>> + host = sdhci_pltfm_init(pdev, &sdhci_omap_pdata,
>> + sizeof(*omap_host));
>> + if (IS_ERR(host)) {
>> + dev_err(dev, "Failed sdhci_pltfm_init\n");
>> + return PTR_ERR(host);
>> + }
>> +
>> + pltfm_host = sdhci_priv(host);
>> + omap_host = sdhci_pltfm_priv(pltfm_host);
>> + omap_host->host = host;
>> + omap_host->base = host->ioaddr;
>> + omap_host->dev = dev;
>> + sdhci_omap_get_of_property(omap_host);
>> +
>> + host->ioaddr += offset;
>> +
>> + mmc = host->mmc;
>> + ret = mmc_of_parse(mmc);
>> + if (ret)
>> + goto err_of_parse;
>> +
>> + pltfm_host->clk = devm_clk_get(dev, "fck");
>> + if (IS_ERR(pltfm_host->clk)) {
>> + ret = PTR_ERR(pltfm_host->clk);
>> + goto err_of_parse;
>> + }
>> +
>> + ret = clk_set_rate(pltfm_host->clk, mmc->f_max);
>> + if (ret) {
>> + dev_err(dev, "failed to set clock to %d\n", mmc->f_max);
>> + goto err_of_parse;
>> + }
>> +
>> + omap_host->pbias = devm_regulator_get_optional(dev, "pbias");
>> + if (IS_ERR(omap_host->pbias)) {
>> + ret = PTR_ERR(omap_host->pbias);
>> + if (ret != -ENODEV) {
>> + dev_err(dev, "CONFIG_REGULATOR_PBIAS not enabled??\n");
>> + return ret;
>> + }
>> + dev_dbg(dev, "unable to get pbias regulator %ld\n",
>> + PTR_ERR(omap_host->pbias));
>> + } else {
>> + if (regulator_is_supported_voltage(omap_host->pbias, IOV_3V3,
>> + IOV_3V3))
>> + omap_host->io_3_3v_support = true;
>> + dev_vdbg(dev, "Max PBIAS support Voltage: %dmv\n",
>> + omap_host->io_3_3v_support ? IOV_3V3 : IOV_3V0);
>> + }
>> + omap_host->pbias_enabled = false;
>> +
>> + /* Enable main Func clock, interface clock and program SYSCONFIG */
>
> Maybe also mention that the PM domain does those things. Out of curiousity,
> what happens if CONFIG_PM is not set?

I think then most of the peripherals will depend on bootloader to enable the
clocks if CONFIG_PM is not set.
>
>> + pm_runtime_enable(dev);
>> + ret = pm_runtime_get_sync(dev);
>> + if (ret < 0) {
>> + dev_err(dev, "pm_runtime_get_sync failed\n");
>> + goto err_get_sync;
>
> The correct "undo" function for pm_runtime_get_sync() failing is
> pm_runtime_put_noidle() not pm_runtime_put_sync(). So:

yeah right! Missed that.
>
> pm_runtime_put_noidle(dev);
> goto err_rpm_disable;
>
>> + }
>> +
>> + sdhci_omap_set_capabilities(omap_host);
>> +
>> + host->mmc_host_ops.get_ro = mmc_gpio_get_ro;
>> + host->mmc_host_ops.start_signal_voltage_switch =
>> + sdhci_omap_start_signal_voltage_switch;
>> + host->mmc_host_ops.set_ios = sdhci_omap_set_ios;
>> +
>> + sdhci_read_caps(host);
>> + host->caps |= SDHCI_CAN_DO_ADMA2;
>> +
>> + ret = sdhci_add_host(host);
>> + if (ret)
>> + goto err_get_sync;
>> +
>> + return 0;
>> +
>> +err_get_sync:
>
> It is more usual for error labels to describe what they will do rather than
> what failed. i.e. this would be err_put_sync:
>
>> + pm_runtime_put_sync(dev);
>
> err_rpm_disable:
>
>> + pm_runtime_disable(dev);
>> +
>> +err_of_parse:
>
> err_pltfm_free:
>
>> + sdhci_pltfm_free(pdev);
>> + return ret;
>> +}
>> +
>> +static int sdhci_omap_remove(struct platform_device *pdev)
>> +{
>> + struct device *dev = &pdev->dev;
>> + struct sdhci_host *host = platform_get_drvdata(pdev);
>> +
>> + sdhci_remove_host(host, true);
>> + pm_runtime_put_sync(dev);
>> + pm_runtime_disable(dev);
>> + sdhci_pltfm_free(pdev);
>> +
>> + return 0;
>> +}
>> +
>> +static struct platform_driver sdhci_omap_driver = {
>> + .probe = sdhci_omap_probe,
>> + .remove = sdhci_omap_remove,
>> + .driver = {
>> + .name = "sdhci-omap",
>> + .of_match_table = of_match_ptr(omap_sdhci_match),
>
> Don't you need #ifdef CONFIG_OF around the table if you use of_match_ptr()?

yeah. I think I'll remove of_match_ptr here and make the driver depend on OF.
>
>> + },
>> +};
>> +
>> +module_platform_driver(sdhci_omap_driver);
>> +
>> +MODULE_DESCRIPTION("SDHCI driver for OMAP SoCs");
>> +MODULE_AUTHOR("Texas Instruments Inc.");
>> +MODULE_LICENSE("GPL v2");
>> +MODULE_ALIAS("OMAP SDHCI Driver");
>
> A module alias with spaces in it looks strange. Is that the intention?

No. Will fix it.

Thanks
Kishon