diff options
Diffstat (limited to 'drivers/regulator/pwm-regulator.c')
| -rw-r--r-- | drivers/regulator/pwm-regulator.c | 78 |
1 files changed, 47 insertions, 31 deletions
diff --git a/drivers/regulator/pwm-regulator.c b/drivers/regulator/pwm-regulator.c index 4689d62f4841..fafa3488e960 100644 --- a/drivers/regulator/pwm-regulator.c +++ b/drivers/regulator/pwm-regulator.c @@ -59,18 +59,18 @@ static int pwm_regulator_set_voltage_sel(struct regulator_dev *rdev, unsigned selector) { struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); - unsigned int pwm_reg_period; + struct pwm_args pargs; int dutycycle; int ret; - pwm_reg_period = pwm_get_period(drvdata->pwm); + pwm_get_args(drvdata->pwm, &pargs); - dutycycle = (pwm_reg_period * + dutycycle = (pargs.period * drvdata->duty_cycle_table[selector].dutycycle) / 100; - ret = pwm_config(drvdata->pwm, dutycycle, pwm_reg_period); + ret = pwm_config(drvdata->pwm, dutycycle, pargs.period); if (ret) { - dev_err(&rdev->dev, "Failed to configure PWM\n"); + dev_err(&rdev->dev, "Failed to configure PWM: %d\n", ret); return ret; } @@ -113,18 +113,6 @@ static int pwm_regulator_is_enabled(struct regulator_dev *dev) return pwm_is_enabled(drvdata->pwm); } -/** - * Continuous voltage call-backs - */ -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 ((req_uV * 100) - (min_uV * 100)) / diff; -} - static int pwm_regulator_get_voltage(struct regulator_dev *rdev) { struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); @@ -138,21 +126,42 @@ 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; + struct pwm_args pargs; + unsigned int req_diff = min_uV - rdev->constraints->min_uV; + unsigned int diff; + unsigned int duty_pulse; + u64 req_period; + u32 rem; int ret; - duty_cycle = pwm_voltage_to_duty_cycle_percentage(rdev, min_uV); + pwm_get_args(drvdata->pwm, &pargs); + diff = rdev->constraints->max_uV - rdev->constraints->min_uV; - ret = pwm_config(drvdata->pwm, (period / 100) * duty_cycle, period); + /* First try to find out if we get the iduty cycle time which is + * factor of PWM period time. If (request_diff_to_min * pwm_period) + * is perfect divided by voltage_range_diff then it is possible to + * get duty cycle time which is factor of PWM period. This will help + * to get output voltage nearer to requested value as there is no + * calculation loss. + */ + req_period = req_diff * pargs.period; + div_u64_rem(req_period, diff, &rem); + if (!rem) { + do_div(req_period, diff); + duty_pulse = (unsigned int)req_period; + } else { + duty_pulse = (pargs.period / 100) * ((req_diff * 100) / diff); + } + + ret = pwm_config(drvdata->pwm, duty_pulse, pargs.period); if (ret) { - dev_err(&rdev->dev, "Failed to configure PWM\n"); + dev_err(&rdev->dev, "Failed to configure PWM: %d\n", ret); return ret; } ret = pwm_enable(drvdata->pwm); if (ret) { - dev_err(&rdev->dev, "Failed to enable PWM\n"); + dev_err(&rdev->dev, "Failed to enable PWM: %d\n", ret); return ret; } drvdata->volt_uV = min_uV; @@ -200,8 +209,7 @@ static int pwm_regulator_init_table(struct platform_device *pdev, if ((length < sizeof(*duty_cycle_table)) || (length % sizeof(*duty_cycle_table))) { - dev_err(&pdev->dev, - "voltage-table length(%d) is invalid\n", + dev_err(&pdev->dev, "voltage-table length(%d) is invalid\n", length); return -EINVAL; } @@ -214,7 +222,7 @@ static int pwm_regulator_init_table(struct platform_device *pdev, (u32 *)duty_cycle_table, length / sizeof(u32)); if (ret) { - dev_err(&pdev->dev, "Failed to read voltage-table\n"); + dev_err(&pdev->dev, "Failed to read voltage-table: %d\n", ret); return ret; } @@ -277,16 +285,24 @@ static int pwm_regulator_probe(struct platform_device *pdev) drvdata->pwm = devm_pwm_get(&pdev->dev, NULL); if (IS_ERR(drvdata->pwm)) { - dev_err(&pdev->dev, "Failed to get PWM\n"); - return PTR_ERR(drvdata->pwm); + ret = PTR_ERR(drvdata->pwm); + dev_err(&pdev->dev, "Failed to get PWM: %d\n", ret); + return ret; } + /* + * FIXME: pwm_apply_args() should be removed when switching to the + * atomic PWM API. + */ + pwm_apply_args(drvdata->pwm); + regulator = devm_regulator_register(&pdev->dev, &drvdata->desc, &config); if (IS_ERR(regulator)) { - dev_err(&pdev->dev, "Failed to register regulator %s\n", - drvdata->desc.name); - return PTR_ERR(regulator); + ret = PTR_ERR(regulator); + dev_err(&pdev->dev, "Failed to register regulator %s: %d\n", + drvdata->desc.name, ret); + return ret; } return 0; |