Messages in this thread | | | Date | Fri, 22 Oct 2021 17:58:34 +0530 | From | skakit@codeauro ... | Subject | Re: [PATCH V2 3/4] regulator: Add a regulator driver for the PM8008 PMIC |
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On 2021-10-06 00:05, Stephen Boyd wrote: > Quoting Satya Priya (2021-09-30 21:00:58) >> diff --git a/drivers/regulator/qcom-pm8008-regulator.c >> b/drivers/regulator/qcom-pm8008-regulator.c >> new file mode 100644 >> index 0000000..5dacaa4 >> --- /dev/null >> +++ b/drivers/regulator/qcom-pm8008-regulator.c >> @@ -0,0 +1,320 @@ >> +// SPDX-License-Identifier: GPL-2.0-only >> +/* Copyright (c) 2021, The Linux Foundation. All rights reserved. */ >> + >> +#include <linux/delay.h> > > Is this include used? >
No will remove.
>> +#include <linux/device.h> >> +#include <linux/interrupt.h> >> +#include <linux/module.h> >> +#include <linux/mutex.h> > > Is this include used? >
No
>> +#include <linux/of.h> >> +#include <linux/of_device.h> >> +#include <linux/of_irq.h> > > Is this include used? >
No
>> +#include <linux/pm.h> > > Is this include used? >
No
>> +#include <linux/platform_device.h> >> +#include <linux/regmap.h> >> +#include <linux/string.h> > > Is this include used? Probably should just be kernel.h? >
string.h is not used , will change it as kernel.h
>> +#include <linux/regulator/driver.h> >> +#include <linux/regulator/machine.h> >> +#include <linux/regulator/of_regulator.h> > > Is this include used? >
Yes it is used. For of_get_regulator_init_data().
>> + >> +#define STARTUP_DELAY_USEC 20 >> +#define VSET_STEP_MV 8 >> +#define VSET_STEP_UV (VSET_STEP_MV * 1000) >> + >> +#define LDO_ENABLE_REG(base) (base + 0x46) >> +#define ENABLE_BIT BIT(7) >> + >> +#define LDO_STATUS1_REG(base) (base + 0x08) >> +#define VREG_READY_BIT BIT(7) >> + >> +#define LDO_VSET_LB_REG(base) (base + 0x40) >> + >> +#define LDO_STEPPER_CTL_REG(base) (base + 0x3b) >> +#define STEP_RATE_MASK GENMASK(1, 0) >> + >> +#define PM8008_MAX_LDO 7 > > Drop define. > ok.
>> + >> +struct regulator_data { >> + char *name; > > const? >
ok
>> + char *supply_name; > > const? >
ok
>> + int min_uv; >> + int max_uv; >> + int min_dropout_uv; >> +}; >> + >> +struct pm8008_regulator { >> + struct device *dev; >> + struct regmap *regmap; >> + struct regulator_desc rdesc; >> + struct regulator_dev *rdev; >> + struct device_node *of_node; >> + u16 base; >> + int step_rate; >> +}; >> + >> +static const struct regulator_data reg_data[PM8008_MAX_LDO] = { > > Use [] instead of PM8008_MAX_LDO. >
Ok.
>> + /* name parent min_uv max_uv headroom_uv */ >> + {"l1", "vdd_l1_l2", 528000, 1504000, 225000}, >> + {"l2", "vdd_l1_l2", 528000, 1504000, 225000}, >> + {"l3", "vdd_l3_l4", 1504000, 3400000, 200000}, >> + {"l4", "vdd_l3_l4", 1504000, 3400000, 200000}, >> + {"l5", "vdd_l5", 1504000, 3400000, 300000}, >> + {"l6", "vdd_l6", 1504000, 3400000, 300000}, >> + {"l7", "vdd_l7", 1504000, 3400000, 300000}, > > Nitpick: Put a space after { and before } to match kernel style. >
Okay.
>> +}; >> + >> +static int pm8008_read(struct regmap *regmap, u16 reg, u8 *val, int >> count) >> +{ >> + int rc; >> + >> + rc = regmap_bulk_read(regmap, reg, val, count); >> + if (rc < 0) >> + pr_err("failed to read %#x, rc=%d\n", reg, rc); >> + >> + return rc; >> +} >> + >> +static int pm8008_write(struct regmap *regmap, u16 reg, u8 *val, int >> count) >> +{ >> + int rc; >> + >> + pr_debug("Writing [%*ph] from address %#x\n", count, val, >> reg); > > Don't we already have regmap debugging facilities for this? Why > duplicate it in this driver? > >> + rc = regmap_bulk_write(regmap, reg, val, count); >> + if (rc < 0) >> + pr_err("failed to write %#x rc=%d\n", reg, rc); >> + >> + return rc; >> +} > > The above two functions should just be inlined. >
I am planning to remove these 2 APIs and use regmap_bulk_read/write directly.
>> + >> +static int pm8008_regulator_get_voltage(struct regulator_dev *rdev) >> +{ >> + struct pm8008_regulator *pm8008_reg = rdev_get_drvdata(rdev); >> + u8 vset_raw[2]; >> + int rc; >> + >> + rc = pm8008_read(pm8008_reg->regmap, >> + LDO_VSET_LB_REG(pm8008_reg->base), >> + vset_raw, 2); > > Can this be an __le16 mV? >
Below is the diff after changing as per your suggestion, Please correct me if wrong.
- u8 vset_raw[2]; + __le16 mV; int rc;
- rc = pm8008_read(pm8008_reg->regmap, - LDO_VSET_LB_REG(pm8008_reg->base), - vset_raw, 2); + rc = regmap_bulk_read(pm8008_reg->regmap, + LDO_VSET_LB_REG(pm8008_reg->base), &mV, 2); if (rc < 0) { dev_err(pm8008_reg->dev, "failed to read regulator voltage rc=%d\n", rc); return rc; }
- return (vset_raw[1] << 8 | vset_raw[0]) * 1000; + return le16_to_cpu(mV) * 1000;
>> + if (rc < 0) { >> + dev_err(pm8008_reg->dev, "failed to read regulator >> voltage rc=%d\n", rc); >> + return rc; >> + } >> + >> + return (vset_raw[1] << 8 | vset_raw[0]) * 1000; > > And then return le16_to_cpu(mV) * 1000; > > >> +} >> + >> +static inline int pm8008_write_voltage(struct pm8008_regulator >> *pm8008_reg, int min_uv, >> + int max_uv) >> +{ >> + int rc = 0, mv; >> + u8 vset_raw[2]; >> + >> + mv = DIV_ROUND_UP(min_uv, 1000); >> + >> + /* >> + * Each LSB of regulator is 1mV and the voltage setpoint >> + * should be multiple of 8mV(step). >> + */ >> + mv = DIV_ROUND_UP(mv, VSET_STEP_MV) * VSET_STEP_MV; >> + if (mv * 1000 > max_uv) { >> + dev_err(pm8008_reg->dev, >> + "requested voltage (%d uV) above maximum limit >> (%d uV)\n", >> + mv*1000, max_uv); >> + return -EINVAL; >> + } >> + >> + vset_raw[0] = mv & 0xff; >> + vset_raw[1] = (mv & 0xff00) >> 8; > > Make vset_raw a u16? > > vset = mv; > > And then use cpu_to_le16() below? >
Below is the diff:
- int rc = 0, mv; - u8 vset_raw[2]; + int rc, mv; + u16 vset_raw; [...] - vset_raw[0] = mv & 0xff; - vset_raw[1] = (mv & 0xff00) >> 8; - rc = pm8008_write(pm8008_reg->regmap, LDO_VSET_LB_REG(pm8008_reg->base), - vset_raw, 2); + vset_raw = cpu_to_le16(mv); + + rc = regmap_bulk_write(pm8008_reg->regmap, + LDO_VSET_LB_REG(pm8008_reg->base), &vset_raw, + sizeof(vset_raw));
>> + rc = pm8008_write(pm8008_reg->regmap, >> LDO_VSET_LB_REG(pm8008_reg->base), >> + vset_raw, 2); > > regmap_bulk_write(pm8008_reg->regmap, > LDO_VSET_LB_REG(pm8008_reg->base), > cpu_to_le16(vset), sizeof(vset)); > > does it work? >
It is working fine after modifying as above.
>> + if (rc < 0) { >> + dev_err(pm8008_reg->dev, "failed to write voltage >> rc=%d\n", rc); >> + return rc; >> + } >> + >> + return 0; >> +} >> + >> +static int pm8008_regulator_set_voltage_time(struct regulator_dev >> *rdev, >> + int old_uV, int new_uv) >> +{ >> + struct pm8008_regulator *pm8008_reg = rdev_get_drvdata(rdev); >> + >> + return DIV_ROUND_UP(abs(new_uv - old_uV), >> pm8008_reg->step_rate); >> +} >> + >> +static int pm8008_regulator_set_voltage(struct regulator_dev *rdev, >> + int min_uv, int max_uv, unsigned int >> *selector) >> +{ >> + struct pm8008_regulator *pm8008_reg = rdev_get_drvdata(rdev); >> + int rc; >> + >> + rc = pm8008_write_voltage(pm8008_reg, min_uv, max_uv); >> + if (rc < 0) >> + return rc; >> + >> + *selector = DIV_ROUND_UP(min_uv - pm8008_reg->rdesc.min_uV, >> + VSET_STEP_UV); >> + >> + dev_dbg(pm8008_reg->dev, "voltage set to %d\n", min_uv); >> + return 0; >> +} >> + >> +static const struct regulator_ops pm8008_regulator_ops = { >> + .enable = regulator_enable_regmap, > > Weird tabbing. >
Will correct it.
>> + .disable = regulator_disable_regmap, >> + .is_enabled = regulator_is_enabled_regmap, >> + .set_voltage = pm8008_regulator_set_voltage, >> + .get_voltage = pm8008_regulator_get_voltage, >> + .list_voltage = regulator_list_voltage_linear, >> + .set_voltage_time = pm8008_regulator_set_voltage_time, >> +}; >> + >> +static int pm8008_register_ldo(struct pm8008_regulator *pm8008_reg, >> + const char *name) >> +{ >> + struct regulator_config reg_config = {}; >> + struct regulator_init_data *init_data; >> + struct device *dev = pm8008_reg->dev; >> + struct device_node *reg_node = pm8008_reg->of_node; >> + int rc, i; >> + u32 base = 0; >> + u8 reg; >> + >> + /* get regulator data */ >> + for (i = 0; i < PM8008_MAX_LDO; i++) > > Use ARRAY_SIZE()
Ok.
> >> + if (strstr(name, reg_data[i].name)) >> + break; >> + >> + if (i == PM8008_MAX_LDO) { >> + dev_err(dev, "Invalid regulator name %s\n", name); >> + return -EINVAL; >> + } >> + >> + rc = of_property_read_u32(reg_node, "reg", &base); >> + if (rc < 0) { >> + dev_err(dev, "%s: failed to get regulator base >> rc=%d\n", name, rc); >> + return rc; >> + } >> + pm8008_reg->base = base; >> + >> + /* get slew rate */ >> + rc = pm8008_read(pm8008_reg->regmap, >> + LDO_STEPPER_CTL_REG(pm8008_reg->base), ®, >> 1); >> + if (rc < 0) { >> + dev_err(dev, "%s: failed to read step rate >> configuration rc=%d\n", >> + name, rc); >> + return rc; >> + } >> + pm8008_reg->step_rate = 38400 >> (reg & STEP_RATE_MASK); > > Where does 38400 come from? Is that a frequency? >
It is the default voltage step rate. I'll add a macro DEFAULT_VOLTAGE_STEP_RATE for this to be clear.
>> + >> + init_data = of_get_regulator_init_data(dev, reg_node, >> + &pm8008_reg->rdesc); >> + if (init_data == NULL) { > > if (!init_data) > > is more kernel style.
Okay.
> >> + dev_err(dev, "%s: failed to get regulator data\n", >> name); >> + return -ENODATA; >> + } >> + >> + init_data->constraints.input_uV = >> init_data->constraints.max_uV; >> + reg_config.dev = dev; >> + reg_config.init_data = init_data; >> + reg_config.driver_data = pm8008_reg; >> + reg_config.of_node = reg_node; >> + >> + pm8008_reg->rdesc.type = REGULATOR_VOLTAGE; >> + pm8008_reg->rdesc.ops = &pm8008_regulator_ops; >> + pm8008_reg->rdesc.name = init_data->constraints.name; >> + pm8008_reg->rdesc.supply_name = reg_data[i].supply_name; >> + pm8008_reg->rdesc.uV_step = VSET_STEP_UV; >> + pm8008_reg->rdesc.min_uV = reg_data[i].min_uv; >> + pm8008_reg->rdesc.n_voltages >> + = ((reg_data[i].max_uv - reg_data[i].min_uv) >> + / pm8008_reg->rdesc.uV_step) + 1; >> + >> + pm8008_reg->rdesc.enable_reg = LDO_ENABLE_REG(base); >> + pm8008_reg->rdesc.enable_mask = ENABLE_BIT; >> + pm8008_reg->rdesc.min_dropout_uV = reg_data[i].min_dropout_uv; >> + of_property_read_u32(reg_node, "qcom,min-dropout-voltage", >> + &pm8008_reg->rdesc.min_dropout_uV); > > Why do we allow DT to override this? Isn't it a property of the > hardware > that doesn't change? So the driver can hardcode the knowledge about the > dropout. >
The headroom values change with targets. We are adding some default headroom values in the driver and later overwriting them with the actual values specified in the DT.
>> + >> + pm8008_reg->rdev = devm_regulator_register(dev, >> &pm8008_reg->rdesc, > > Is this assignment ever used? Seems like it would be better to merely > > return PTR_ERR_OR_ZERO(devm_regulator_register(dev, ...)); >
Okay.
>> + ®_config); >> + if (IS_ERR(pm8008_reg->rdev)) { >> + rc = PTR_ERR(pm8008_reg->rdev); >> + dev_err(dev, "%s: failed to register regulator >> rc=%d\n", >> + pm8008_reg->rdesc.name, rc); >> + return rc; >> + } >> + >> + dev_dbg(dev, "%s regulator registered\n", name); >> + >> + return 0; >> +} >> + >> +static int pm8008_parse_regulator(struct regmap *regmap, struct >> device *dev) >> +{ >> + int rc = 0; > > Drop initialization. >
Okay.
>> + const char *name; >> + struct device_node *child; >> + struct pm8008_regulator *pm8008_reg; >> + >> + /* parse each subnode and register regulator for regulator >> child */ >> + for_each_available_child_of_node(dev->of_node, child) { >> + pm8008_reg = devm_kzalloc(dev, sizeof(*pm8008_reg), >> GFP_KERNEL); >> + >> + pm8008_reg->regmap = regmap; >> + pm8008_reg->of_node = child; >> + pm8008_reg->dev = dev; >> + >> + rc = of_property_read_string(child, "regulator-name", >> &name); >> + if (rc) >> + continue; >> + >> + rc = pm8008_register_ldo(pm8008_reg, name); > > Can we use the of_parse_cb similar to qcom_spmi-regulator.c? >
Are you suggesting to remove the pm8008_register_ldo API and add its contents in probe itself and then use of_parse_cb callback like in qcom_spmi-regulator.c?
Do we have any advantage using that here? Also I am not exactly sure what all contents to put in that. Seems like we can put the step rate and min-dropout-voltage configurations in there.
>> + if (rc < 0) { >> + dev_err(dev, "failed to register regulator %s >> rc=%d\n", >> + name, rc); >> + return rc; >> + } >> + } >> + >> + return 0; >> +} >> + >> +static int pm8008_regulator_probe(struct platform_device *pdev) >> +{ >> + int rc = 0; > > Please don't initialize locals and then overwrite them before testing > them. > >> + struct regmap *regmap; >> + >> + regmap = dev_get_regmap(pdev->dev.parent, NULL); >> + if (!regmap) { >> + dev_err(&pdev->dev, "parent regmap is missing\n"); >> + return -EINVAL; >> + } >> + >> + rc = pm8008_parse_regulator(regmap, &pdev->dev); > > Just inline this code. It's basically the entire probe function so > splitting it away to yet another function just makes it harder to read. >
Okay.
>> + if (rc < 0) { >> + dev_err(&pdev->dev, "failed to parse device tree >> rc=%d\n", rc); >> + return rc; >> + } >> + >> + return 0; >> +} >> + >> +static const struct of_device_id pm8008_regulator_match_table[] = { >> + { .compatible = "qcom,pm8008-regulator", }, >> + { }, > > Nitpick: Drop comma on sentinel so nothing can come after without > causing a compilation error. >
Okay
>> +}; > > Add a MODULE_DEVICE_TABLE please. Same comment applies to the mfd > driver. >
Okay
>> + >> +static struct platform_driver pm8008_regulator_driver = { >> + .driver = { >> + .name = "qcom,pm8008-regulator", >> + .of_match_table = pm8008_regulator_match_table, >> + }, >> + .probe = pm8008_regulator_probe, > > I have no idea what's going on with this tabbing. > >> +}; >> + >> +module_platform_driver(pm8008_regulator_driver); >> +
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