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Message-ID: <20130621151523.GA27646@sirena.org.uk>
Date: Fri, 21 Jun 2013 16:15:23 +0100
From: Mark Brown <broonie@...nel.org>
To: Steve Twiss <stwiss.opensource@...semi.com>
Cc: Liam Girdwood <lgirdwood@...il.com>,
David Dajun Chen <david.chen@...semi.com>,
Guennadi Liakhovetski <g.liakhovetski@....de>,
LKML <linux-kernel@...r.kernel.org>
Subject: Re: [RFC V1] COMMIT 1: DA9210 driver files
On Thu, Jun 20, 2013 at 02:42:03PM +0100, Steve Twiss wrote:
> @@ -293,6 +293,13 @@ config REGULATOR_LP8788
> help
> This driver supports LP8788 voltage regulator chip.
>
> +config REGULATOR_DA9210
> + bool "Dialog Semiconductor DA9210 Regulator"
> + depends on I2C=y
> + select REGMAP_I2C
> + help
> + Support for the Dialog Semiconductor DA9210 chip.
> +
> config REGULATOR_PCF50633
This file ought to be kept sorted though it seems that's not been
happening, and I'm not seeing any reason why this can't be a tristate.
> +#define DRIVER_NAME "da9210"
Why?
> +struct da9210 {
> + struct i2c_client *i2c;
> + struct device *dev;
> + struct mutex io_mutex;
Why do you need an I/O lock?
> +static int da9210_enable(struct regulator_dev *rdev);
> +static int da9210_set_voltage(struct regulator_dev *rdev, int min_uV,
> + int max_uV, unsigned *selector);
> +static int da9210_get_voltage(struct regulator_dev *rdev);
> +static int da9210_set_current_limit(struct regulator_dev *rdev, int min_uA,
> + int max_uA);
> +static int da9210_get_current_limit(struct regulator_dev *rdev);
> +
> +static struct regulator_ops da9210_buck_ops = {
> + .enable = da9210_enable,
> + .disable = regulator_disable_regmap,
> + .is_enabled = regulator_is_enabled_regmap,
> + .set_voltage = da9210_set_voltage,
> + .get_voltage = da9210_get_voltage,
> + .list_voltage = regulator_list_voltage_linear,
> + .set_current_limit = da9210_set_current_limit,
> + .get_current_limit = da9210_get_current_limit,
> +};
Drivers are normally written to avoid forward declarations like this.
> +static struct regulator_consumer_supply __initdata def_da9210_consumers[] = {
> + REGULATOR_SUPPLY("DA9210", NULL),
> +};
> +
> +static struct regulator_init_data __initdata default_da9210_constraints = {
> + .constraints = {
This is not at all sensible, there's a good solid reason why regulator
drivers don't generally do this... please review the machine interface
and its purpose.
> +static int da9210_set_voltage(struct regulator_dev *rdev, int min_uV,
> + int max_uV, unsigned *selector)
> +{
> + struct da9210 *chip = rdev_get_drvdata(rdev);
> + int val;
> + int ret;
> +
> + val = regulator_map_voltage_linear(rdev, min_uV, max_uV);
> + if (val < 0)
> + return -EINVAL;
> +
> + ret = regmap_update_bits(chip->regmap, DA9210_REG_VBUCK_A,
> + DA9210_VBUCK_MASK, val);
> + return ret;
> +}
Why not just use set_voltage_sel()?
> +static int da9210_get_voltage_sel(struct regulator_dev *rdev)
> +{
> + struct da9210 *chip = rdev_get_drvdata(rdev);
> + unsigned int data;
> + int sel;
> + int ret;
> +
> + ret = regmap_read(chip->regmap, DA9210_REG_VBUCK_A, &data);
> + if (ret < 0)
> + return ret;
> +
> + sel = (data & DA9210_VBUCK_MASK) >> DA9210_VBUCK_SHIFT;
> + sel -= DA9210_VBUCK_BIAS;
> + if (sel < 0)
> + sel = 0;
> + if (sel >= chip->info->n_steps)
> + sel = chip->info->n_steps - 1;
This looks like poor error handling, if the value is out of range isn't
there an error state?
> +static int da9210_get_voltage(struct regulator_dev *rdev)
> +{
> + struct da9210 *chip = rdev_get_drvdata(rdev);
> + int sel = da9210_get_voltage_sel(rdev);
> +
> + if (sel < 0)
> + return sel;
> +
> + return (chip->info->step_uV * sel) + chip->info->min_uV;
> +}
Why are you open coding core functionalit?
> +static int da9210_enable(struct regulator_dev *rdev)
> +{
> + return regulator_enable_regmap(rdev);
> +}
This is pointless, just use the generic function directly.
> +
> + dev_info(chip->dev, "Device DA9210 detected.\n");
This is just noise.
> +static const struct i2c_device_id da9210_i2c_id[] = {
> + {DRIVER_NAME, 0},
> + {},
Just use the string.
> +static struct i2c_driver da9210_regulator_driver = {
> + .driver = {
> + .name = DRIVER_NAME,
Similarly here.
> + .owner = THIS_MODULE,
> + },
Indentation.
> +static int __init da9210_regulator_init(void)
> +{
> + int ret;
> +
> + ret = i2c_add_driver(&da9210_regulator_driver);
> + if (0 != ret)
> + pr_err("Failed to register da9210 I2C driver\n");
> +
> + return ret;
> +}
> +
> +subsys_initcall(da9210_regulator_init);
Just use module_platform_driver() now we have probe deferral.
> +/*
> + * Registers bits
> + */
> +/* DA9210_REG_PAGE_CON (addr=0x00) */
> +#define DA9210_PEG_PAGE_SHIFT 0
> +#define DA9210_REG_PAGE_MASK 0x0F
> +/* On I2C registers 0x00 - 0xFF */
> +#define DA9210_REG_PAGE0 0
> +/* On I2C registers 0x100 - 0x1FF */
> +#define DA9210_REG_PAGE2 2
> +#define DA9210_PAGE_WRITE_MODE 0x00
> +#define DA9210_REPEAT_WRITE_MODE 0x40
> +#define DA9210_PAGE_REVERT 0x80
This looks liike you should be using a regmap range.
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