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Date:	Wed, 18 Sep 2013 18:42:01 +0300
From:	Georgi Djakov <gdjakov@...sol.com>
To:	Stanimir Varbanov <svarbanov@...sol.com>
CC:	linux-mmc@...r.kernel.org, cjb@...top.org, grant.likely@...aro.org,
	rob.herring@...xeda.com, linux-kernel@...r.kernel.org,
	devicetree@...r.kernel.org, linux-arm-msm@...r.kernel.org,
	Asutosh Das <asutoshd@...eaurora.org>,
	Venkat Gopalakrishnan <venkatg@...eaurora.org>,
	Sahitya Tummala <stummala@...eaurora.org>,
	Subhash Jadavani <subhashj@...eaurora.org>
Subject: Re: [PATCH v5] mmc: sdhci-msm: Add support for MSM chipsets

Hi Stan,

Thank you for the detailed review on this patch.

On 09/17/2013 05:55 PM, Stanimir Varbanov wrote:
> Hi Georgi,
>
> Thanks for the patch.
>
> I have some commnets below.
>
> On 09/16/2013 05:23 PM, Georgi Djakov wrote:
>> This platform driver adds the support of Secure Digital Host Controller
>> Interface compliant controller found in Qualcomm MSM chipsets.
>>
>> CC: Asutosh Das <asutoshd@...eaurora.org>
>> CC: Venkat Gopalakrishnan <venkatg@...eaurora.org>
>> CC: Sahitya Tummala <stummala@...eaurora.org>
>> CC: Subhash Jadavani <subhashj@...eaurora.org>
>> Signed-off-by: Georgi Djakov <gdjakov@...sol.com>
>> ---
>> Changes from v4:
>> - Simplified sdhci_msm_vreg_disable() and sdhci_msm_set_vdd_io_vol()
>> - Use devm_ioremap_resource() instead of devm_ioremap()
>> - Converted IS_ERR_OR_NULL to IS_ERR
>> - Disable regulators in sdhci_msm_remove()
>> - Check for DT node at the beginning in sdhci_msm_probe()
>> - Removed more redundant code
>> - Changes in some error messages
>> - Minor fixes
>>
>> Changes from v3:
>> - Allocate memory for all required structs at once
>> - Added termination entry in sdhci_msm_dt_match[]
>> - Fixed a missing sdhci_pltfm_free() in probe()
>> - Removed redundant of_match_ptr
>> - Removed the unneeded function sdhci_msm_vreg_reset()
>>
>> Changes from v2:
>> - Added DT bindings for clocks
>> - Moved voltage regulators data to platform data
>> - Removed unneeded includes
>> - Removed obsolete and wrapper functions
>> - Removed error checking where unnecessary
>> - Removed redundant _clk suffix from clock names
>> - Just return instead of goto where possible
>> - Minor fixes
>>
>> Changes from v1:
>> - GPIO references are replaced by pinctrl
>> - DT parsing is done mostly by mmc_of_parse()
>> - Use of_match_device() for DT matching
>> - A few minor changes
>>
>>   .../devicetree/bindings/mmc/sdhci-msm.txt          |   71 +++
>>   drivers/mmc/host/Kconfig                           |   13 +
>>   drivers/mmc/host/Makefile                          |    1 +
>>   drivers/mmc/host/sdhci-msm.c                       |  627 ++++++++++++++++++++
>>   4 files changed, 712 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/mmc/sdhci-msm.txt
>>   create mode 100644 drivers/mmc/host/sdhci-msm.c
>>
>> diff --git a/Documentation/devicetree/bindings/mmc/sdhci-msm.txt b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
>> new file mode 100644
>> index 0000000..ee112da
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
>> @@ -0,0 +1,71 @@
>> +* Qualcomm SDHCI controller (sdhci-msm)
>> +
>> +This file documents differences between the core properties in mmc.txt
>> +and the properties used by the sdhci-msm driver.
>> +
>> +Required properties:
>> +- compatible: should be "qcom,sdhci-msm"
>> +- reg: should contain SDHC, SD Core register map
>> +- reg-names: indicates various resources passed to driver (via reg proptery) by name
>> +	"reg-names" examples are "hc_mem" and "core_mem"
>> +- interrupts: should contain SDHC interrupts
>> +- interrupt-names: indicates interrupts passed to driver (via interrupts property) by name
>> +	"interrupt-names" examples are "hc_irq" and "pwr_irq"
>> +- <supply-name>-supply: phandle to the regulator device tree node
>> +	"supply-name" examples are "vdd" and "vdd-io"
>> +- pinctrl-names: Should contain only one value - "default".
>> +- pinctrl-0: Should specify pin control groups used for this controller.
>> +- clocks: phandles to clock instances of the device tree nodes
>> +- clock-names:
>> +	iface: Main peripheral bus clock (PCLK/HCLK - AHB Bus clock) (required)
>> +	core: SDC MMC clock (MCLK) (required)
>> +	bus: SDCC bus voter clock (optional)
>> +
>> +Optional properties:
>> +- qcom,bus-speed-mode - specifies supported bus speed modes by host
>> +	The supported bus speed modes are :
>> +	"HS200_1p8v" - indicates that host can support HS200 at 1.8v
>> +	"HS200_1p2v" - indicates that host can support HS200 at 1.2v
>> +	"DDR_1p8v" - indicates that host can support DDR mode at 1.8v
>> +	"DDR_1p2v" - indicates that host can support DDR mode at 1.2v
>> +
>> +In the following, <supply> can be vdd (flash core voltage) or vdd-io (I/O voltage).
>> +- qcom,<supply>-always-on - specifies whether supply should be kept "on" always.
>> +- qcom,<supply>-lpm-sup - specifies whether supply can be kept in low power mode (lpm).
>> +- qcom,<supply>-voltage-level - specifies voltage levels for supply. Should be
>> +specified in pairs (min, max), units uV.
>> +- qcom,<supply>-current-level - specifies load levels for supply in lpm or high power mode
>> +	(hpm). Should be specified in pairs (lpm, hpm), units uA.
>> +
>> +Example:
>> +
>> +	aliases {
>> +		sdhc1 = &sdhc_1;
>> +	};
>> +
>> +	sdhc_1: qcom,sdhc@...24900 {
>> +		compatible = "qcom,sdhci-msm";
>> +		reg = <0xf9824900 0x11c>, <0xf9824000 0x800>;
>> +		reg-names = "hc_mem", "core_mem";
>> +		interrupts = <0 123 0>, <0 138 0>;
>> +		interrupt-names = "hc_irq", "pwr_irq";
>> +		bus-width = <4>;
>> +		non-removable;
>> +
>> +		vdd-supply = <&pm8941_l21>;
>> +		vdd-io-supply = <&pm8941_l13>;
>> +		qcom,vdd-voltage-level = <2950000 2950000>;
>> +		qcom,vdd-current-level = <9000 800000>;
>> +		qcom,vdd-io-always-on;
>> +		qcom,vdd-io-lpm-sup;
>> +		qcom,vdd-io-voltage-level = <1800000 2950000>;
>> +		qcom,vdd-io-current-level = <6 22000>;
>> +		qcom,bus-speed-mode = "HS200_1p8v", "DDR_1p8v";
>> +
>> +		pinctrl-names = "default";
>> +		pinctrl-0 = <&sdc1_clk &sdc1_cmd &sdc1_data>;
>> +
>> +		clocks = <&iface>, <&core>, <&bus>;
>> +		clock-names = "iface", "core", "bus";
>> +
>> +	};
>> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
>> index 7fc5099..e8da488 100644
>> --- a/drivers/mmc/host/Kconfig
>> +++ b/drivers/mmc/host/Kconfig
>> @@ -322,6 +322,19 @@ config MMC_ATMELMCI
>>
>>   	  If unsure, say N.
>>
>> +config MMC_SDHCI_MSM
>> +	tristate "Qualcomm SDHCI Controller Support"
>> +	depends on ARCH_MSM
>> +	depends on MMC_SDHCI_PLTFM
>> +	help
>> +	  This selects the Secure Digital Host Controller Interface (SDHCI)
>> +	  support present in MSM SOCs from Qualcomm. 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_MSM
>> diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
>> index c41d0c3..5faed14 100644
>> --- a/drivers/mmc/host/Makefile
>> +++ b/drivers/mmc/host/Makefile
>> @@ -61,6 +61,7 @@ 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..c746a9b
>> --- /dev/null
>> +++ b/drivers/mmc/host/sdhci-msm.c
>> @@ -0,0 +1,627 @@
>> +/*
>> + * drivers/mmc/host/sdhci-msm.c - Qualcomm MSM SDHCI Platform
>> + * driver source file
>> + *
>> + * Copyright (c) 2013, 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/pinctrl/consumer.h>
>> +#include <linux/regulator/consumer.h>
>> +
>> +#include "sdhci-pltfm.h"
>> +
>> +#define CORE_HC_MODE		0x78
>> +#define HC_MODE_EN		0x1
>> +
>> +#define CORE_POWER		0x0
>> +#define CORE_SW_RST		(1 << 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	0x01
>> +#define CORE_PWRCTL_BUS_ON	(1 << 1)
>> +#define CORE_PWRCTL_IO_LOW	(1 << 2)
>> +#define CORE_PWRCTL_IO_HIGH	(1 << 3)
>> +
>> +#define CORE_PWRCTL_BUS_SUCCESS	0x01
>> +#define CORE_PWRCTL_BUS_FAIL	(1 << 1)
>> +#define CORE_PWRCTL_IO_SUCCESS	(1 << 2)
>> +#define CORE_PWRCTL_IO_FAIL	(1 << 3)
>> +
>> +#define INT_MASK		0xf
>> +
>> +/* This structure keeps information per regulator */
>> +struct sdhci_msm_reg_data {
>> +	/* voltage regulator handle */
>
> useless comment, please remove it.

Ok.

>
>> +	struct regulator *reg;
>> +	/* regulator name */
>
> useless comment

Ok.

>
>> +	const char *name;
>> +	/* voltage level to be set */
>> +	u32 low_vol_level;
>> +	u32 high_vol_level;
>> +	/* Load values for low power and high power mode */
>> +	u32 lpm_uA;
>> +	u32 hpm_uA;
>> +
>> +	/* is this regulator needs to be always on? */
>> +	bool is_always_on;
>> +	/* is low power mode setting required for this regulator? */
>> +	bool lpm_sup;
>> +};
>> +
>> +struct sdhci_msm_pltfm_data {
>> +	u32 caps;				/* Supported UHS-I Modes */
>> +	u32 caps2;				/* More capabilities */
>> +	struct sdhci_msm_reg_data vdd_data;	/* VDD/VCC regulator info */
>> +	struct sdhci_msm_reg_data vdd_io_data;	/* VDD IO regulator info */
>> +};
>> +
>> +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;
>> +};
>> +
>> +enum vdd_io_level {
>> +	/* set vdd_io_data->low_vol_level */
>> +	VDD_IO_LOW,
>> +	/* set vdd_io_data->high_vol_level */
>> +	VDD_IO_HIGH,
>> +	/*
>> +	 * set whatever there in voltage_level (third argument) of
>> +	 * sdhci_msm_set_vdd_io_vol() function.
>> +	 */
>> +	VDD_IO_SET_LEVEL,
>> +};
>> +
>> +#define MAX_PROP_SIZE 32
>> +static int sdhci_msm_dt_parse_vreg_info(struct device *dev,
>> +					struct sdhci_msm_reg_data *vreg,
>> +					const char *vreg_name)
>> +{
>> +	int len, ret = 0;
>
> ret is not used you can remove it and return 0 at the function end.

Ok.

>
>> +	const __be32 *prop;
>> +	char prop_name[MAX_PROP_SIZE];
>> +	struct device_node *np = dev->of_node;
>> +
>> +	snprintf(prop_name, MAX_PROP_SIZE, "%s-supply", vreg_name);
>> +	if (!of_parse_phandle(np, prop_name, 0)) {
>> +		dev_info(dev, "No vreg data found for %s\n", vreg_name);
>> +		return -EINVAL;
>> +	}
>> +
>> +	vreg->name = vreg_name;
>> +
>> +	snprintf(prop_name, MAX_PROP_SIZE, "qcom,%s-always-on", vreg_name);
>> +	if (of_get_property(np, prop_name, NULL))
>> +		vreg->is_always_on = true;
>> +
>> +	snprintf(prop_name, MAX_PROP_SIZE, "qcom,%s-lpm-sup", vreg_name);
>> +	if (of_get_property(np, prop_name, NULL))
>> +		vreg->lpm_sup = true;
>> +
>> +	snprintf(prop_name, MAX_PROP_SIZE, "qcom,%s-voltage-level", vreg_name);
>> +	prop = of_get_property(np, prop_name, &len);
>> +	if (!prop || (len != (2 * sizeof(__be32)))) {
>> +		dev_warn(dev, "%s %s property\n",
>> +			 prop ? "invalid format" : "no", prop_name);
>> +	} else {
>> +		vreg->low_vol_level = be32_to_cpup(&prop[0]);
>> +		vreg->high_vol_level = be32_to_cpup(&prop[1]);
>> +	}
>> +
>> +	snprintf(prop_name, MAX_PROP_SIZE, "qcom,%s-current-level", vreg_name);
>> +	prop = of_get_property(np, prop_name, &len);
>> +	if (!prop || (len != (2 * sizeof(__be32)))) {
>> +		dev_warn(dev, "%s %s property\n",
>> +			 prop ? "invalid format" : "no", prop_name);
>> +	} else {
>> +		vreg->lpm_uA = be32_to_cpup(&prop[0]);
>> +		vreg->hpm_uA = be32_to_cpup(&prop[1]);
>> +	}
>> +
>> +	dev_dbg(dev, "%s: %s%svol=[%d %d]uV, curr=[%d %d]uA\n",
>> +		vreg->name, vreg->is_always_on ? "always_on, " : "",
>> +		vreg->lpm_sup ? "lpm_sup, " : "", vreg->low_vol_level,
>> +		vreg->high_vol_level, vreg->lpm_uA, vreg->hpm_uA);
>> +
>> +	return ret;
>> +}
>> +
>> +/* Parse platform data */
>
> parse devicetree data ?

Yes, devicetree.

>
>> +static int sdhci_msm_populate_pdata(struct device *dev,
>> +					struct sdhci_msm_pltfm_data *pdata)
>> +{
>> +	struct device_node *np = dev->of_node;
>> +	int len, i;
>> +
>> +	if (sdhci_msm_dt_parse_vreg_info(dev, &pdata->vdd_data, "vdd")) {
>> +		dev_err(dev, "failed parsing vdd data\n");
>> +		return -EINVAL;
>> +	}
>> +	if (sdhci_msm_dt_parse_vreg_info(dev, &pdata->vdd_io_data, "vdd-io")) {
>> +		dev_err(dev, "failed parsing vdd-io data\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	len = of_property_count_strings(np, "qcom,bus-speed-mode");
>> +
>> +	for (i = 0; i < len; i++) {
>> +		const char *name = NULL;
>> +
>> +		of_property_read_string_index(np,
>> +					"qcom,bus-speed-mode", i, &name);
>> +		if (!name)
>> +			continue;
>> +
>> +		if (!strncmp(name, "HS200_1p8v", sizeof("HS200_1p8v")))
>> +			pdata->caps2 |= MMC_CAP2_HS200_1_8V_SDR;
>> +		else if (!strncmp(name, "HS200_1p2v", sizeof("HS200_1p2v")))
>> +			pdata->caps2 |= MMC_CAP2_HS200_1_2V_SDR;
>> +		else if (!strncmp(name, "DDR_1p8v", sizeof("DDR_1p8v")))
>> +			pdata->caps |= MMC_CAP_1_8V_DDR | MMC_CAP_UHS_DDR50;
>> +		else if (!strncmp(name, "DDR_1p2v", sizeof("DDR_1p2v")))
>> +			pdata->caps |= MMC_CAP_1_2V_DDR | MMC_CAP_UHS_DDR50;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +/* Regulator utility functions */
>> +static int sdhci_msm_vreg_init_reg(struct device *dev,
>> +				   struct sdhci_msm_reg_data *vreg)
>> +{
>> +	int ret = 0;
>
> could you remove ret variable, please.

Ok.

>
>> +	/* Get the regulator handle */
>
> useless comment

Ok.

>
>> +	vreg->reg = devm_regulator_get(dev, vreg->name);
>> +	if (IS_ERR(vreg->reg)) {
>> +		ret = PTR_ERR(vreg->reg);
>> +		dev_err(dev, "devm_regulator_get(%s) failed. ret=%d\n",
>> +			vreg->name, ret);
>> +		return ret;
>
> just return PTR_ERR(vreg->reg)

Ok.

>
>> +	}
>> +
>> +	/* sanity check */
>> +	if (!vreg->high_vol_level || !vreg->hpm_uA) {
>
> if this is sanity check shouldn't you check low_vol_level and lpm_uA as
> well?

Yes, I'll improve it. Thanks!

>
>> +		dev_err(dev, "%s invalid constraints specified\n", vreg->name);
>> +		return -EINVAL;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int sdhci_msm_vreg_enable(struct sdhci_msm_reg_data *vreg)
>> +{
>> +	int ret = 0;
>> +
>> +	/* Put regulator in HPM (high power mode) */
>> +	ret = regulator_set_optimum_mode(vreg->reg, vreg->hpm_uA);
>> +	if (ret < 0) {
>> +		pr_err("regulator_set_optimum_mode(%s,uA_load=%d) fail (%d)\n",
>> +			vreg->name, vreg->hpm_uA, ret);
>
> use dev_err() instead.

Ok.

>
>> +		return ret;
>> +	}
>> +
>> +	if (!regulator_is_enabled(vreg->reg)) {
>> +		/* Set voltage level */
>> +		ret = regulator_set_voltage(vreg->reg, vreg->high_vol_level,
>> +						vreg->high_vol_level);
>> +		if (ret)
>> +			return ret;
>> +	}
>> +
>> +	ret = regulator_enable(vreg->reg);
>> +	if (ret) {
>> +		pr_err("regulator_enable(%s) fail (%d)\n", vreg->name, ret);
>
> use dev_err().

Ok.

>
>> +		return ret;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int sdhci_msm_vreg_disable(struct sdhci_msm_reg_data *vreg)
>> +{
>> +	int ret = 0;
>
> IMO no need to initialize ret variable?

Agree.

>
>> +
>> +	if (!regulator_is_enabled(vreg->reg))
>> +		return 0;
>> +
>> +	/* Never disable regulator marked as always_on */
>> +	if (vreg->is_always_on) {
>> +		if (vreg->lpm_sup) {
>> +			/* Put always_on regulator in LPM (low power mode) */
>> +			ret = regulator_set_optimum_mode(vreg->reg,
>> +				vreg->lpm_uA);
>> +			if (ret < 0)
>> +				return ret;
>> +		}
>> +	} else {
>> +		ret = regulator_disable(vreg->reg);
>> +		if (ret) {
>> +			pr_err("regulator_disable(%s) fail (%d)\n",
>> +				vreg->name, ret);
>
> dev_err(), please.

Ok.

>
>> +			return ret;
>> +		}
>> +
>> +		ret = regulator_set_optimum_mode(vreg->reg, 0);
>> +		if (ret < 0)
>> +			return ret;
>> +
>> +		/* Set min. voltage level to 0 */
>> +		ret = regulator_set_voltage(vreg->reg, 0, vreg->high_vol_level);
>> +		if (ret)
>> +			return ret;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int sdhci_msm_setup_vreg(struct sdhci_msm_pltfm_data *pdata,
>> +				bool enable, bool is_init)
>> +{
>> +	int ret = 0, i;
>
> no need to initialize ret variable?

Agree.

>
>> +	struct sdhci_msm_reg_data *vreg_table[2];
>> +
>> +	vreg_table[0] = &pdata->vdd_data;
>> +	vreg_table[1] = &pdata->vdd_io_data;
>> +
>> +	for (i = 0; i < ARRAY_SIZE(vreg_table); i++) {
>> +		if (vreg_table[i]) {
>
> could you invert the logic here:
>
> 		if (!vreg_table[i])
> 			continue;
>
> by that way you will save one tab below.

Yes, thanks!

>
>> +			if (enable)
>> +				ret = sdhci_msm_vreg_enable(vreg_table[i]);
>> +			else
>> +				ret = sdhci_msm_vreg_disable(vreg_table[i]);
>> +			if (ret)
>> +				return ret;
>> +		}
>> +	}
>
> blank line ?

Ok.

>
>> +	return 0;
>> +}
>> +
>> +/* This init function should be called only once for each SDHC slot */
>> +static int sdhci_msm_vreg_init(struct device *dev,
>> +				struct sdhci_msm_pltfm_data *pdata)
>> +{
>> +	struct sdhci_msm_reg_data *curr_vdd_reg = &pdata->vdd_data;
>> +	struct sdhci_msm_reg_data *curr_vdd_io_reg = &pdata->vdd_io_data;
>> +	int ret = 0;
>
> no need to initialize ret variable.

Agree.

>
>> +
>> +	ret = sdhci_msm_vreg_init_reg(dev, curr_vdd_reg);
>> +	if (ret)
>> +		return ret;
>> +
>> +	ret = sdhci_msm_vreg_init_reg(dev, curr_vdd_io_reg);
>> +	if (ret)
>> +		return ret;
>> +
>> +	return 0;
>> +}
>> +
>> +static int sdhci_msm_set_vdd_io_vol(struct sdhci_msm_pltfm_data *pdata,
>> +				    enum vdd_io_level level,
>> +				    unsigned int voltage_level)
>> +{
>> +	int set_level;
>> +	struct sdhci_msm_reg_data *vdd_io_reg = &pdata->vdd_io_data;
>> +
>> +	if (!regulator_is_enabled(vdd_io_reg->reg))
>> +		return 0;
>> +
>> +	switch (level) {
>> +	case VDD_IO_LOW:
>> +		set_level = vdd_io_reg->low_vol_level;
>> +		break;
>> +	case VDD_IO_HIGH:
>> +		set_level = vdd_io_reg->high_vol_level;
>> +		break;
>> +	case VDD_IO_SET_LEVEL:
>> +		set_level = voltage_level;
>> +		break;
>> +	default:
>> +		pr_err("invalid vdd_io level = %d", level);
>> +		return -EINVAL;
>> +	}
>
> add blank line here, please.

Ok.

>
>> +	return regulator_set_voltage(vdd_io_reg->reg, set_level, set_level);
>> +}
>> +
>> +static irqreturn_t sdhci_msm_pwr_irq(int irq, void *data)
>> +{
>> +	struct sdhci_msm_host *msm_host = (struct sdhci_msm_host *)data;
>> +	u8 irq_status = 0;
>> +	u8 irq_ack = 0;
>> +	int ret = 0;
>
> no need to initialize irq_status and ret, right?

Agree.

>
>> +
>> +	irq_status = readb_relaxed(msm_host->core_mem + CORE_PWRCTL_STATUS);
>> +	pr_debug("%s: Received IRQ(%d), status=0x%x\n",
>> +		 mmc_hostname(msm_host->mmc), irq, irq_status);
>
> dev_dbg() ?

Ok.

>
>> +
>> +	/* Clear the interrupt */
>> +	writeb_relaxed(irq_status, (msm_host->core_mem + CORE_PWRCTL_CLEAR));
>
> why you use writeb here, but in .probe you use writel?

 From the limited documentation I have, it seems that only 4 bits from 
these registers are defined and used, so I prefer to keep it this way.

>
>> +	/*
>> +	 * SDHC has core_mem and hc_mem device memory and these memory
>> +	 * addresses do not fall within 1KB region. Hence, any update to
>> +	 * core_mem address space would require an mb() to ensure this gets
>> +	 * completed before its next update to registers within hc_mem.
>> +	 */
>> +	mb();
>> +
>> +	/* Handle BUS ON/OFF */
>> +	if (irq_status & (CORE_PWRCTL_BUS_ON | CORE_PWRCTL_BUS_OFF)) {
>> +		bool flag = (irq_status & CORE_PWRCTL_BUS_ON) ? 1 : 0;
>> +		ret = sdhci_msm_setup_vreg(&msm_host->pdata, flag, false);
>> +		if (ret)
>> +			irq_ack |= CORE_PWRCTL_BUS_FAIL;
>> +		else
>> +			irq_ack |= CORE_PWRCTL_BUS_SUCCESS;
>> +	}
>> +	/* Handle IO LOW/HIGH */
>> +	if (irq_status & (CORE_PWRCTL_IO_LOW | CORE_PWRCTL_IO_HIGH)) {
>> +		/* Switch voltage */
>> +		int io_status = (irq_status & CORE_PWRCTL_IO_LOW) ?
>> +		    VDD_IO_LOW : VDD_IO_HIGH;
>> +		ret = sdhci_msm_set_vdd_io_vol(&msm_host->pdata, io_status, 0);
>> +		if (ret)
>> +			irq_ack |= CORE_PWRCTL_IO_FAIL;
>> +		else
>> +			irq_ack |= CORE_PWRCTL_IO_SUCCESS;
>> +	}
>> +
>> +	/* ACK status to the core */
>> +	writeb_relaxed(irq_ack, (msm_host->core_mem + CORE_PWRCTL_CTL));
>> +	/*
>> +	 * SDHC has core_mem and hc_mem device memory and these memory
>> +	 * addresses do not fall within 1KB region. Hence, any update to
>> +	 * core_mem address space would require an mb() to ensure this gets
>> +	 * completed before its next update to registers within hc_mem.
>> +	 */
>> +	mb();
>> +
>> +	pr_debug("%s: Handled IRQ(%d), ret=%d, ack=0x%x\n",
>> +		 mmc_hostname(msm_host->mmc), irq, ret, irq_ack);
>
> dev_dbg() ?

Ok.

>
>> +	return IRQ_HANDLED;
>> +}
>> +
>> +/* This function returns the max. current supported by VDD rail in mA */
>> +static u32 sdhci_msm_get_vdd_max_current(struct sdhci_msm_host *host)
>> +{
>> +	return host->pdata.vdd_data.hpm_uA / 1000;
>> +}
>> +
>> +static const struct of_device_id sdhci_msm_dt_match[] = {
>> +	{.compatible = "qcom,sdhci-msm"},
>> +	{},
>> +};
>> +
>> +MODULE_DEVICE_TABLE(of, sdhci_msm_dt_match);
>> +
>> +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 = NULL;
>> +	int ret = 0, dead = 0;
>
> no need to initialize ret and dead variables.

Agree.

>
>> +	struct pinctrl *pinctrl;
>> +
>> +	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;
>> +
>> +	host = sdhci_pltfm_init(pdev, &msm_host->sdhci_msm_pdata, 0);
>> +	if (IS_ERR(host)) {
>> +		dev_err(mmc_dev(host->mmc), "sdhci_pltfm_init error\n");
>> +		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;
>> +	}
>> +
>> +	/* Extract platform data */
>
> needless comment, again.
>

Ok.

>> +	ret = sdhci_msm_populate_pdata(&pdev->dev, &msm_host->pdata);
>> +	if (ret) {
>> +		dev_err(&pdev->dev, "DT parsing error\n");
>> +		goto pltfm_free;
>> +	}
>> +
>> +	/* Setup pins */
>> +	pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
>> +	if (IS_ERR(pinctrl))
>> +		dev_warn(&pdev->dev, "pins are not configured by the driver\n");
>> +
>> +	/* 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 = clk_prepare_enable(msm_host->pclk);
>> +		if (ret) {
>> +			dev_err(&pdev->dev,
>> +				"Main peripheral clock setup failed (%d)\n",
>> +				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 clock 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) {
>> +		dev_err(&pdev->dev, "Regulator setup failed (%d)\n", ret);
>> +		goto clk_disable;
>> +	}
>> +
>> +	/* Reset the core and Enable SDHC mode */
>
> this comment should go few lines below.
>

Ok.

>> +	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 vreg_disable;
>> +	}
>> +
>> +	/* Set SW_RST bit in POWER register (Offset 0x0) */
>
> those comments are stupid, please remove them.
>

Ok.

>> +	writel_relaxed(CORE_SW_RST, msm_host->core_mem + CORE_POWER);
>> +	/* Set HC_MODE_EN bit in HC_MODE register */
>> +	writel_relaxed(HC_MODE_EN, (msm_host->core_mem + CORE_HC_MODE));
>> +
>
> are all interrupts disabled at this point?
>

Yes, they are enabled later.

>> +	/*
>> +	 * 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;
>> +
>> +	/* 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 vreg_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 vreg_disable;
>> +	}
>> +
>> +	/* Enable pwr irq interrupts */
>> +	writel_relaxed(INT_MASK, (msm_host->core_mem + CORE_PWRCTL_MASK));
>> +
>> +	/* Set host capabilities */
>
> useless comment
>

Ok. I'll remove it.

>> +	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;
>> +	}
>> +
>> +	/* Set core clk rate */
>
> useless comment
>

Ok.

>> +	ret = clk_set_rate(msm_host->clk, host->max_clk);
>> +	if (ret) {
>> +		dev_err(&pdev->dev, "MClk rate set failed (%d)\n", ret);
>> +		goto remove_host;
>> +	}
>> +
>> +	host->mmc->max_current_180 = host->mmc->max_current_300 =
>> +	host->mmc->max_current_330 = sdhci_msm_get_vdd_max_current(msm_host);
>> +
>> +	/* Successful initialization */
>
> useless comment
>

Ok.

>> +	return 0;
>> +
>> +remove_host:
>> +	dead = (readl_relaxed(host->ioaddr + SDHCI_INT_STATUS) == 0xffffffff);
>> +	sdhci_remove_host(host, dead);
>> +vreg_disable:
>> +	if (!IS_ERR(msm_host->pdata.vdd_data.reg))
>> +		sdhci_msm_vreg_disable(&msm_host->pdata.vdd_data);
>> +	if (!IS_ERR(msm_host->pdata.vdd_io_data.reg))
>> +		sdhci_msm_vreg_disable(&msm_host->pdata.vdd_io_data);
>> +clk_disable:
>> +	if (!IS_ERR(msm_host->clk))
>> +		clk_disable_unprepare(msm_host->clk);
>> +pclk_disable:
>> +	if (!IS_ERR(msm_host->pclk))
>> +		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 = (readl_relaxed(host->ioaddr + SDHCI_INT_STATUS) ==
>> +		    0xffffffff);
>> +
>> +	sdhci_remove_host(host, dead);
>> +	sdhci_pltfm_free(pdev);
>> +	sdhci_msm_vreg_disable(&msm_host->pdata.vdd_data);
>> +	sdhci_msm_vreg_disable(&msm_host->pdata.vdd_io_data);
>> +	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,
>> +		   },
>
> this bracket should be under ".driver".

Ok. Thanks!

BR,
Georgi

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