From f9178dad67952673b653315f92620b7a981466e5 Mon Sep 17 00:00:00 2001 From: Lee Jones Date: Mon, 6 Jul 2015 09:58:29 +0100 Subject: regulator: pwm-regulator: Separate voltage-table initialisation Take this out of the main .probe() routine in order to facilitate the introduction of different ways to obtain 'duty cycle' information. Signed-off-by: Lee Jones Signed-off-by: Mark Brown --- drivers/regulator/pwm-regulator.c | 77 +++++++++++++++++++++++---------------- 1 file changed, 45 insertions(+), 32 deletions(-) (limited to 'drivers/regulator/pwm-regulator.c') diff --git a/drivers/regulator/pwm-regulator.c b/drivers/regulator/pwm-regulator.c index ffa96124a5e7..25560fc519b7 100644 --- a/drivers/regulator/pwm-regulator.c +++ b/drivers/regulator/pwm-regulator.c @@ -78,8 +78,7 @@ static int pwm_regulator_list_voltage(struct regulator_dev *rdev, return drvdata->duty_cycle_table[selector].uV; } - -static struct regulator_ops pwm_regulator_voltage_ops = { +static struct regulator_ops pwm_regulator_voltage_table_ops = { .set_voltage_sel = pwm_regulator_set_voltage_sel, .get_voltage_sel = pwm_regulator_get_voltage_sel, .list_voltage = pwm_regulator_list_voltage, @@ -88,20 +87,55 @@ static struct regulator_ops pwm_regulator_voltage_ops = { static struct regulator_desc pwm_regulator_desc = { .name = "pwm-regulator", - .ops = &pwm_regulator_voltage_ops, .type = REGULATOR_VOLTAGE, .owner = THIS_MODULE, .supply_name = "pwm", }; +static int pwm_regulator_init_table(struct platform_device *pdev, + struct pwm_regulator_data *drvdata) +{ + struct device_node *np = pdev->dev.of_node; + struct pwm_voltages *duty_cycle_table; + int length; + int ret; + + of_find_property(np, "voltage-table", &length); + + if ((length < sizeof(*duty_cycle_table)) || + (length % sizeof(*duty_cycle_table))) { + dev_err(&pdev->dev, + "voltage-table length(%d) is invalid\n", + length); + return -EINVAL; + } + + duty_cycle_table = devm_kzalloc(&pdev->dev, length, GFP_KERNEL); + if (!duty_cycle_table) + return -ENOMEM; + + ret = of_property_read_u32_array(np, "voltage-table", + (u32 *)duty_cycle_table, + length / sizeof(u32)); + if (ret) { + dev_err(&pdev->dev, "Failed to read voltage-table\n"); + return ret; + } + + drvdata->duty_cycle_table = duty_cycle_table; + pwm_regulator_desc.ops = &pwm_regulator_voltage_table_ops; + pwm_regulator_desc.n_voltages = length / sizeof(*duty_cycle_table); + + return 0; +} + static int pwm_regulator_probe(struct platform_device *pdev) { struct pwm_regulator_data *drvdata; - struct property *prop; struct regulator_dev *regulator; struct regulator_config config = { }; struct device_node *np = pdev->dev.of_node; - int length, ret; + int ret; if (!np) { dev_err(&pdev->dev, "Device Tree node missing\n"); @@ -112,36 +146,15 @@ static int pwm_regulator_probe(struct platform_device *pdev) if (!drvdata) return -ENOMEM; - /* determine the number of voltage-table */ - prop = of_find_property(np, "voltage-table", &length); - if (!prop) { - dev_err(&pdev->dev, "No voltage-table\n"); - return -EINVAL; - } - - if ((length < sizeof(*drvdata->duty_cycle_table)) || - (length % sizeof(*drvdata->duty_cycle_table))) { - dev_err(&pdev->dev, "voltage-table length(%d) is invalid\n", - length); + if (of_find_property(np, "voltage-table", NULL)) { + ret = pwm_regulator_init_table(pdev, drvdata); + if (ret) + return ret; + } else { + dev_err(&pdev->dev, "No \"voltage-table\" supplied\n"); return -EINVAL; } - pwm_regulator_desc.n_voltages = length / sizeof(*drvdata->duty_cycle_table); - - drvdata->duty_cycle_table = devm_kzalloc(&pdev->dev, - length, GFP_KERNEL); - if (!drvdata->duty_cycle_table) - return -ENOMEM; - - /* read voltage table from DT property */ - ret = of_property_read_u32_array(np, "voltage-table", - (u32 *)drvdata->duty_cycle_table, - length / sizeof(u32)); - if (ret < 0) { - dev_err(&pdev->dev, "read voltage-table failed\n"); - return ret; - } - config.init_data = of_get_regulator_init_data(&pdev->dev, np, &pwm_regulator_desc); if (!config.init_data) -- cgit v1.2.3-70-g09d2 From 4773be185a0f7c1c09d8966e100c76f4fa9a3227 Mon Sep 17 00:00:00 2001 From: Lee Jones Date: Tue, 7 Jul 2015 16:06:51 +0100 Subject: regulator: pwm-regulator: Add support for continuous-voltage The current version of PWM regulator only supports a static table approach, where pre-calculated values are supplied by the vendor and obtained via DT. The continuous-voltage method takes min_uV and max_uV, and divides the difference between them up into a number of slices. The number of slices depend on how large the duty cycle register is. This information is provided by a DT property. As the name alludes, this provides values for a continuous voltage range between min_uV and max_uV, which has obvious benefits over either limited voltage possibilities, or the requirement to provide a large voltage-table. Signed-off-by: Lee Jones Signed-off-by: Mark Brown --- drivers/regulator/pwm-regulator.c | 114 +++++++++++++++++++++++++++++++++++--- 1 file changed, 106 insertions(+), 8 deletions(-) (limited to 'drivers/regulator/pwm-regulator.c') diff --git a/drivers/regulator/pwm-regulator.c b/drivers/regulator/pwm-regulator.c index 25560fc519b7..dac145db305c 100644 --- a/drivers/regulator/pwm-regulator.c +++ b/drivers/regulator/pwm-regulator.c @@ -10,6 +10,7 @@ * published by the Free Software Foundation. */ +#include #include #include #include @@ -21,9 +22,16 @@ #include struct pwm_regulator_data { - struct pwm_voltages *duty_cycle_table; + /* Shared */ struct pwm_device *pwm; + + /* Voltage table */ + struct pwm_voltages *duty_cycle_table; int state; + + /* Continuous voltage */ + u32 max_duty_cycle; + int volt_uV; }; struct pwm_voltages { @@ -31,6 +39,9 @@ struct pwm_voltages { unsigned int dutycycle; }; +/** + * Voltage table call-backs + */ static int pwm_regulator_get_voltage_sel(struct regulator_dev *rdev) { struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); @@ -78,6 +89,71 @@ static int pwm_regulator_list_voltage(struct regulator_dev *rdev, return drvdata->duty_cycle_table[selector].uV; } + +/** + * Continuous voltage call-backs + */ +static int pwm_voltage_to_duty_cycle(struct regulator_dev *rdev, + int volt_mV) +{ + struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); + int min_mV = rdev->constraints->min_uV / 1000; + int max_mV = rdev->constraints->max_uV / 1000; + int max_duty_cycle = drvdata->max_duty_cycle; + int vdiff = min_mV - max_mV; + int pwm_code; + int tmp; + + tmp = ((max_duty_cycle - min_mV) * max_duty_cycle) / vdiff; + pwm_code = ((tmp + max_duty_cycle) * volt_mV) / vdiff; + + if (pwm_code < 0) + pwm_code = 0; + if (pwm_code > max_duty_cycle) + pwm_code = max_duty_cycle; + + return pwm_code * 100 / max_duty_cycle; +} + +static int pwm_regulator_get_voltage(struct regulator_dev *rdev) +{ + struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); + + return drvdata->volt_uV; +} + +static int pwm_regulator_set_voltage(struct regulator_dev *rdev, + int min_uV, int max_uV, + unsigned *selector) +{ + struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); + unsigned int ramp_delay = rdev->constraints->ramp_delay; + int duty_cycle; + int ret; + + duty_cycle = pwm_voltage_to_duty_cycle(rdev, min_uV / 1000); + + ret = pwm_config(drvdata->pwm, + (drvdata->pwm->period / 100) * duty_cycle, + drvdata->pwm->period); + if (ret) { + dev_err(&rdev->dev, "Failed to configure PWM\n"); + return ret; + } + + ret = pwm_enable(drvdata->pwm); + if (ret) { + dev_err(&rdev->dev, "Failed to enable PWM\n"); + return ret; + } + drvdata->volt_uV = min_uV; + + /* Delay required by PWM regulator to settle to the new voltage */ + usleep_range(ramp_delay, ramp_delay + 1000); + + return 0; +} + static struct regulator_ops pwm_regulator_voltage_table_ops = { .set_voltage_sel = pwm_regulator_set_voltage_sel, .get_voltage_sel = pwm_regulator_get_voltage_sel, @@ -85,6 +161,11 @@ static struct regulator_ops pwm_regulator_voltage_table_ops = { .map_voltage = regulator_map_voltage_iterate, }; +static struct regulator_ops pwm_regulator_voltage_continuous_ops = { + .get_voltage = pwm_regulator_get_voltage, + .set_voltage = pwm_regulator_set_voltage, +}; + static struct regulator_desc pwm_regulator_desc = { .name = "pwm-regulator", .type = REGULATOR_VOLTAGE, @@ -129,6 +210,25 @@ static int pwm_regulator_init_table(struct platform_device *pdev, return 0; } +static int pwm_regulator_init_continuous(struct platform_device *pdev, + struct pwm_regulator_data *drvdata) +{ + struct device_node *np = pdev->dev.of_node; + int ret; + + ret = of_property_read_u32(np, "max-duty-cycle", + &drvdata->max_duty_cycle); + if (ret) { + dev_err(&pdev->dev, "Failed to read \"pwm-max-value\"\n"); + return ret; + } + + pwm_regulator_desc.ops = &pwm_regulator_voltage_continuous_ops; + pwm_regulator_desc.continuous_voltage_range = true; + + return 0; +} + static int pwm_regulator_probe(struct platform_device *pdev) { struct pwm_regulator_data *drvdata; @@ -146,14 +246,12 @@ static int pwm_regulator_probe(struct platform_device *pdev) if (!drvdata) return -ENOMEM; - if (of_find_property(np, "voltage-table", NULL)) { + if (of_find_property(np, "voltage-table", NULL)) ret = pwm_regulator_init_table(pdev, drvdata); - if (ret) - return ret; - } else { - dev_err(&pdev->dev, "No \"voltage-table\" supplied\n"); - return -EINVAL; - } + else + ret = pwm_regulator_init_continuous(pdev, drvdata); + if (ret) + return ret; config.init_data = of_get_regulator_init_data(&pdev->dev, np, &pwm_regulator_desc); -- cgit v1.2.3-70-g09d2 From cae897dec26a9d81dcb5182b13b08450f38d6bde Mon Sep 17 00:00:00 2001 From: Lee Jones Date: Tue, 7 Jul 2015 16:06:52 +0100 Subject: regulator: pwm-regulator: Simplify voltage to duty-cycle call If we reverse some of the logic and change the formula used, we can simplify the function greatly. It is intentional that this function is supplied and then re-worked within the same patch-set. The submission in the previous patch is the tried and tested (i.e. in real releases) method written by ST. This patch contains a simplification provided later. It looks and performs better, but doesn't have the same time-under-test that the original method does. The idea is that we keep some history in order to provide an easy way back i.e. revert. Signed-off-by: Lee Jones Signed-off-by: Mark Brown --- drivers/regulator/pwm-regulator.c | 27 +++++++-------------------- 1 file changed, 7 insertions(+), 20 deletions(-) (limited to 'drivers/regulator/pwm-regulator.c') diff --git a/drivers/regulator/pwm-regulator.c b/drivers/regulator/pwm-regulator.c index dac145db305c..d5cb267fa192 100644 --- a/drivers/regulator/pwm-regulator.c +++ b/drivers/regulator/pwm-regulator.c @@ -93,26 +93,13 @@ static int pwm_regulator_list_voltage(struct regulator_dev *rdev, /** * Continuous voltage call-backs */ -static int pwm_voltage_to_duty_cycle(struct regulator_dev *rdev, - int volt_mV) +static int pwm_voltage_to_duty_cycle(struct regulator_dev *rdev, int req_uV) { - struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); - int min_mV = rdev->constraints->min_uV / 1000; - int max_mV = rdev->constraints->max_uV / 1000; - int max_duty_cycle = drvdata->max_duty_cycle; - int vdiff = min_mV - max_mV; - int pwm_code; - int tmp; - - tmp = ((max_duty_cycle - min_mV) * max_duty_cycle) / vdiff; - pwm_code = ((tmp + max_duty_cycle) * volt_mV) / vdiff; - - if (pwm_code < 0) - pwm_code = 0; - if (pwm_code > max_duty_cycle) - pwm_code = max_duty_cycle; - - return pwm_code * 100 / max_duty_cycle; + int min_uV = rdev->constraints->min_uV; + int max_uV = rdev->constraints->max_uV; + int diff = max_uV - min_uV; + + return 100 - ((((req_uV * 100) - (min_uV * 100)) / diff)); } static int pwm_regulator_get_voltage(struct regulator_dev *rdev) @@ -131,7 +118,7 @@ static int pwm_regulator_set_voltage(struct regulator_dev *rdev, int duty_cycle; int ret; - duty_cycle = pwm_voltage_to_duty_cycle(rdev, min_uV / 1000); + duty_cycle = pwm_voltage_to_duty_cycle(rdev, min_uV); ret = pwm_config(drvdata->pwm, (drvdata->pwm->period / 100) * duty_cycle, -- cgit v1.2.3-70-g09d2 From 5ad2cb14f5b8f3cb3d8688115037751b1ff45455 Mon Sep 17 00:00:00 2001 From: Lee Jones Date: Tue, 7 Jul 2015 16:06:53 +0100 Subject: regulator: pwm-regulator: Don't assign structure attributes right away Perhaps this is just personal preference, but ... This patch introduces a new local variable to receive and test regulator initialisation data. It simplifies and cleans up the code making it that little bit easier to read and maintain. The local value is assigned to the structure attribute when all the others are. This is the way we usually do things. Prevents this kind of nonsense: this->is->just.silly = fetch_silly_value(&pointer); if (!this->is->just.silly) { printk("Silly value failed: %d\n", this->is->just.silly); return this->is->just.silly; } Signed-off-by: Lee Jones Signed-off-by: Mark Brown --- drivers/regulator/pwm-regulator.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'drivers/regulator/pwm-regulator.c') diff --git a/drivers/regulator/pwm-regulator.c b/drivers/regulator/pwm-regulator.c index d5cb267fa192..cb482089050b 100644 --- a/drivers/regulator/pwm-regulator.c +++ b/drivers/regulator/pwm-regulator.c @@ -218,6 +218,7 @@ static int pwm_regulator_init_continuous(struct platform_device *pdev, static int pwm_regulator_probe(struct platform_device *pdev) { + const struct regulator_init_data *init_data; struct pwm_regulator_data *drvdata; struct regulator_dev *regulator; struct regulator_config config = { }; @@ -240,14 +241,15 @@ static int pwm_regulator_probe(struct platform_device *pdev) if (ret) return ret; - config.init_data = of_get_regulator_init_data(&pdev->dev, np, - &pwm_regulator_desc); - if (!config.init_data) + init_data = of_get_regulator_init_data(&pdev->dev, np, + &pwm_regulator_desc); + if (!init_data) return -ENOMEM; config.of_node = np; config.dev = &pdev->dev; config.driver_data = drvdata; + config.init_data = init_data; drvdata->pwm = devm_pwm_get(&pdev->dev, NULL); if (IS_ERR(drvdata->pwm)) { -- cgit v1.2.3-70-g09d2 From f747a1fe7848453957dbdf362a42d7a6735c6ff0 Mon Sep 17 00:00:00 2001 From: Lee Jones Date: Thu, 9 Jul 2015 16:35:27 +0100 Subject: regulator: pwm-regulator: Remove obsoleted property In "[3d7ef30] regulator: pwm-regulator: Simplify voltage to duty-cycle call" we stopped using max_duty_cycle, so we can retire it from device data and DT. There is no need to deprecate this property, as it hasn't hit Mainline yet. Signed-off-by: Lee Jones Signed-off-by: Mark Brown --- Documentation/devicetree/bindings/regulator/pwm-regulator.txt | 11 ++++------- drivers/regulator/pwm-regulator.c | 9 --------- 2 files changed, 4 insertions(+), 16 deletions(-) (limited to 'drivers/regulator/pwm-regulator.c') diff --git a/Documentation/devicetree/bindings/regulator/pwm-regulator.txt b/Documentation/devicetree/bindings/regulator/pwm-regulator.txt index 23b47720b2e4..ed936f0f34f2 100644 --- a/Documentation/devicetree/bindings/regulator/pwm-regulator.txt +++ b/Documentation/devicetree/bindings/regulator/pwm-regulator.txt @@ -29,15 +29,14 @@ Required properties: - pwms: PWM specification (See: ../pwm/pwm.txt) -One of these must be provided: +Only required for Voltage Table Mode: - voltage-table: Voltage and Duty-Cycle table consisting of 2 cells First cell is voltage in microvolts (uV) Second cell is duty-cycle in percent (%) -- max-duty-cycle: Maximum Duty-Cycle value -- this will normally be - 255 (0xff) for an 8 bit PWM device - -If both are provided, the current default is voltage-table mode. +NB: To be clear, if voltage-table is provided, then the device will be used +in Voltage Table Mode. If no voltage-table is provided, then the device will +be used in Continuous Voltage Mode. Any property defined as part of the core regulator binding can also be used. (See: ../regulator/regulator.txt) @@ -49,8 +48,6 @@ Continuous Voltage Example: regulator-min-microvolt = <1016000>; regulator-max-microvolt = <1114000>; regulator-name = "vdd_logic"; - - max-duty-cycle = <255>; /* 8bit PWM */ }; Voltage Table Example: diff --git a/drivers/regulator/pwm-regulator.c b/drivers/regulator/pwm-regulator.c index cb482089050b..d92e66772ec0 100644 --- a/drivers/regulator/pwm-regulator.c +++ b/drivers/regulator/pwm-regulator.c @@ -30,7 +30,6 @@ struct pwm_regulator_data { int state; /* Continuous voltage */ - u32 max_duty_cycle; int volt_uV; }; @@ -201,14 +200,6 @@ static int pwm_regulator_init_continuous(struct platform_device *pdev, struct pwm_regulator_data *drvdata) { struct device_node *np = pdev->dev.of_node; - int ret; - - ret = of_property_read_u32(np, "max-duty-cycle", - &drvdata->max_duty_cycle); - if (ret) { - dev_err(&pdev->dev, "Failed to read \"pwm-max-value\"\n"); - return ret; - } pwm_regulator_desc.ops = &pwm_regulator_voltage_continuous_ops; pwm_regulator_desc.continuous_voltage_range = true; -- cgit v1.2.3-70-g09d2 From f3f6439d8635d783f145b321db3049369e745799 Mon Sep 17 00:00:00 2001 From: Lee Jones Date: Thu, 9 Jul 2015 16:35:28 +0100 Subject: regulator: pwm-regulator: Small clean-ups Remove over-bracketing, use framework API to fetch PWM period and be more forthcoming that pwm_voltage_to_duty_cycle() actually returns duty cycle as a percentage, rather than a register value. Signed-off-by: Lee Jones Signed-off-by: Mark Brown --- drivers/regulator/pwm-regulator.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) (limited to 'drivers/regulator/pwm-regulator.c') diff --git a/drivers/regulator/pwm-regulator.c b/drivers/regulator/pwm-regulator.c index d92e66772ec0..936e387cc532 100644 --- a/drivers/regulator/pwm-regulator.c +++ b/drivers/regulator/pwm-regulator.c @@ -92,13 +92,13 @@ static int pwm_regulator_list_voltage(struct regulator_dev *rdev, /** * Continuous voltage call-backs */ -static int pwm_voltage_to_duty_cycle(struct regulator_dev *rdev, int req_uV) +static int pwm_voltage_to_duty_cycle_percentage(struct regulator_dev *rdev, int req_uV) { int min_uV = rdev->constraints->min_uV; int max_uV = rdev->constraints->max_uV; int diff = max_uV - min_uV; - return 100 - ((((req_uV * 100) - (min_uV * 100)) / diff)); + return 100 - (((req_uV * 100) - (min_uV * 100)) / diff); } static int pwm_regulator_get_voltage(struct regulator_dev *rdev) @@ -114,14 +114,13 @@ static int pwm_regulator_set_voltage(struct regulator_dev *rdev, { struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); unsigned int ramp_delay = rdev->constraints->ramp_delay; + unsigned int period = pwm_get_period(drvdata->pwm); int duty_cycle; int ret; - duty_cycle = pwm_voltage_to_duty_cycle(rdev, min_uV); + duty_cycle = pwm_voltage_to_duty_cycle_percentage(rdev, min_uV); - ret = pwm_config(drvdata->pwm, - (drvdata->pwm->period / 100) * duty_cycle, - drvdata->pwm->period); + ret = pwm_config(drvdata->pwm, (period / 100) * duty_cycle, period); if (ret) { dev_err(&rdev->dev, "Failed to configure PWM\n"); return ret; -- cgit v1.2.3-70-g09d2 From f293634b5a9e9acbcc1cac29fac7609bd999f868 Mon Sep 17 00:00:00 2001 From: Lee Jones Date: Fri, 10 Jul 2015 08:45:34 +0100 Subject: regulator: pwm-regulator: Fix 'unused-variable' warning drivers/regulator/pwm-regulator.c: In function 'pwm_regulator_init_continuous': drivers/regulator/pwm-regulator.c:202:22: warning: unused variable 'np' [-Wunused-variable] struct device_node *np = pdev->dev.of_node; ^ Reported-by: kbuild test robot Signed-off-by: Lee Jones Signed-off-by: Mark Brown --- drivers/regulator/pwm-regulator.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'drivers/regulator/pwm-regulator.c') diff --git a/drivers/regulator/pwm-regulator.c b/drivers/regulator/pwm-regulator.c index 936e387cc532..a4c2ce92d41f 100644 --- a/drivers/regulator/pwm-regulator.c +++ b/drivers/regulator/pwm-regulator.c @@ -198,8 +198,6 @@ static int pwm_regulator_init_table(struct platform_device *pdev, static int pwm_regulator_init_continuous(struct platform_device *pdev, struct pwm_regulator_data *drvdata) { - struct device_node *np = pdev->dev.of_node; - pwm_regulator_desc.ops = &pwm_regulator_voltage_continuous_ops; pwm_regulator_desc.continuous_voltage_range = true; -- cgit v1.2.3-70-g09d2 From b343e08f3c5623d12829ad4965dd4c4e50f86fa2 Mon Sep 17 00:00:00 2001 From: Lee Jones Date: Fri, 10 Jul 2015 08:45:35 +0100 Subject: regulator: pwm-regulator: Fix 'used uninitialized' warning drivers/regulator/pwm-regulator.c: In function 'pwm_regulator_init_table': drivers/regulator/pwm-regulator.c:172:14: warning: 'length' is used uninitialized in this function [-Wuninitialized] if ((length < sizeof(*duty_cycle_table)) || ^ Reported-by: kbuild test robot Signed-off-by: Lee Jones Signed-off-by: Mark Brown --- drivers/regulator/pwm-regulator.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/regulator/pwm-regulator.c') diff --git a/drivers/regulator/pwm-regulator.c b/drivers/regulator/pwm-regulator.c index a4c2ce92d41f..331b85148680 100644 --- a/drivers/regulator/pwm-regulator.c +++ b/drivers/regulator/pwm-regulator.c @@ -163,7 +163,7 @@ static int pwm_regulator_init_table(struct platform_device *pdev, { struct device_node *np = pdev->dev.of_node; struct pwm_voltages *duty_cycle_table; - int length; + int length = 0; int ret; of_find_property(np, "voltage-table", &length); -- cgit v1.2.3-70-g09d2 From 60cb65ebf49e6db114c3efeb3971064a6ddbea0e Mon Sep 17 00:00:00 2001 From: Lee Jones Date: Fri, 10 Jul 2015 08:45:36 +0100 Subject: regulator: pwm-regulator: Fix ' comparison between signed and unsigned integer' warning MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit drivers/regulator/pwm-regulator.c: In function ‘pwm_regulator_init_table’: drivers/regulator/pwm-regulator.c:171:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] Signed-off-by: Lee Jones Signed-off-by: Mark Brown --- drivers/regulator/pwm-regulator.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/regulator/pwm-regulator.c') diff --git a/drivers/regulator/pwm-regulator.c b/drivers/regulator/pwm-regulator.c index 331b85148680..fc3166dfcbfa 100644 --- a/drivers/regulator/pwm-regulator.c +++ b/drivers/regulator/pwm-regulator.c @@ -163,7 +163,7 @@ static int pwm_regulator_init_table(struct platform_device *pdev, { struct device_node *np = pdev->dev.of_node; struct pwm_voltages *duty_cycle_table; - int length = 0; + unsigned int length = 0; int ret; of_find_property(np, "voltage-table", &length); -- cgit v1.2.3-70-g09d2