Re: [PATCH v4 3/4] power: supply: max17040: Config alert SOC low level threshold from FDT

Krzysztof Kozlowski
2019-11-01T15:28:03Z

On Thu, Oct 31, 2019 at 03:41:33PM -0300, Matheus Castello wrote:
> For configuration of fuel gauge alert for a low level state of charge
> interrupt we add a function to config level threshold and a device tree
> binding property to set it in flatned device tree node.
>
> Now we can use "maxim,alert-low-soc-level" property with the values from
> 1% up to 32% to configure alert interrupt threshold.
>
> Signed-off-by: Matheus Castello <matheus@castello.eng.br>
> ---
> drivers/power/supply/max17040_battery.c | 88 +++++++++++++++++++++----
> 1 file changed, 74 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/power/supply/max17040_battery.c b/drivers/power/supply/max17040_battery.c
> index 75459f76d02c..802575342c72 100644
> --- a/drivers/power/supply/max17040_battery.c
> +++ b/drivers/power/supply/max17040_battery.c
> @@ -29,6 +29,9 @@
> #define MAX17040_DELAY 1000
> #define MAX17040_BATTERY_FULL 95
>
> +#define MAX17040_ATHD_MASK 0xFFC0
> +#define MAX17040_ATHD_DEFAULT_POWER_UP 4
> +
> struct max17040_chip {
> struct i2c_client *client;
> struct delayed_work work;
> @@ -43,6 +46,8 @@ struct max17040_chip {
> int soc;
> /* State Of Charge */
> int status;
> + /* Low alert threshold from 32% to 1% of the State of Charge */
> + u32 low_soc_alert_threshold;
> };
>
> static int max17040_get_property(struct power_supply *psy,
> @@ -99,6 +104,22 @@ static void max17040_reset(struct i2c_client *client)
> max17040_write_reg(client, MAX17040_CMD, 0x0054);
> }
>
> +static int max17040_set_low_soc_threshold_alert(struct i2c_client *client,
> + u32 level)
> +{
> + int ret;
> + u16 data;
> +
> + level = 32 - level;
> + data = max17040_read_reg(client, MAX17040_RCOMP);
> + /* clear the alrt bit and set LSb 5 bits */
> + data &= MAX17040_ATHD_MASK;
> + data |= level;
> + ret = max17040_write_reg(client, MAX17040_RCOMP, data);
> +
> + return ret;
> +}
> +
> static void max17040_get_vcell(struct i2c_client *client)
> {
> struct max17040_chip *chip = i2c_get_clientdata(client);
> @@ -115,7 +136,6 @@ static void max17040_get_soc(struct i2c_client *client)
> u16 soc;
>
> soc = max17040_read_reg(client, MAX17040_SOC);
> -
> chip->soc = (soc >> 8);
> }
>
> @@ -161,6 +181,24 @@ static void max17040_get_status(struct i2c_client *client)
> chip->status = POWER_SUPPLY_STATUS_FULL;
> }
>
> +static int max17040_get_of_data(struct max17040_chip *chip)
> +{
> + struct device *dev = &chip->client->dev;
> + struct device_node *np = dev->of_node;
> + int ret = 0;
> +
> + if (of_property_read_u32(np, "maxim,alert-low-soc-level",
> + &chip->low_soc_alert_threshold)) {

Please align the line break with line above. checkpatch --strict might
give you hints about this.

> + chip->low_soc_alert_threshold = MAX17040_ATHD_DEFAULT_POWER_UP;
> + /* check if low_soc_alert_threshold is between 1% and 32% */

The comment looks misleading here, like it belongs to previous block.
Maybe put it inside else if {} block?

> + } else if (chip->low_soc_alert_threshold <= 0 ||
> + chip->low_soc_alert_threshold >= 33){

Missing space before {.

> + ret = -EINVAL;
> + }
> +
> + return ret;
> +}
> +
> static void max17040_check_changes(struct i2c_client *client)
> {
> max17040_get_vcell(client);
> @@ -192,6 +230,10 @@ static irqreturn_t max17040_thread_handler(int id, void *dev)
> /* send uevent */
> power_supply_changed(chip->battery);
>
> + /* reset alert bit */
> + max17040_set_low_soc_threshold_alert(client,
> + chip->low_soc_alert_threshold);

Unless the continuation exceeds 80 character limit, please align it with
previous line.

> +
> return IRQ_HANDLED;
> }
>
> @@ -216,6 +258,7 @@ static int max17040_probe(struct i2c_client *client,
> struct i2c_adapter *adapter = client->adapter;
> struct power_supply_config psy_cfg = {};
> struct max17040_chip *chip;
> + int ret;
>
> if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
> return -EIO;
> @@ -226,6 +269,12 @@ static int max17040_probe(struct i2c_client *client,
>
> chip->client = client;
> chip->pdata = client->dev.platform_data;
> + ret = max17040_get_of_data(chip);
> + if (ret) {
> + dev_err(&client->dev,
> + "failed: low SOC alert OF data out of bounds\n");
> + return ret;
> + }
>
> i2c_set_clientdata(client, chip);
> psy_cfg.drv_data = chip;
> @@ -242,20 +291,31 @@ static int max17040_probe(struct i2c_client *client,
>
> /* check interrupt */
> if (client->irq) {
> - int ret;
> - unsigned int flags;
> -
> - dev_info(&client->dev, "IRQ: enabled\n");
> - flags = IRQF_TRIGGER_FALLING | IRQF_ONESHOT;
> - ret = devm_request_threaded_irq(&client->dev, client->irq, NULL,
> - max17040_thread_handler, flags,
> - chip->battery->desc->name,
> - chip);
> -
> - if (ret) {
> - client->irq = 0;
> + if (of_device_is_compatible(client->dev.of_node,
> + "maxim,max77836-battery")) {

Alignment.

> + ret = max17040_set_low_soc_threshold_alert(client,
> + chip->low_soc_alert_threshold);

Ditto.

> + if (ret) {
> + dev_err(&client->dev,
> + "Failed to set low SOC alert: err %d\n",
> + ret);
> + return ret;
> + }
> +
> + dev_info(&client->dev, "IRQ: enabled\n");
> + ret = devm_request_threaded_irq(&client->dev,
> + client->irq, NULL, max17040_thread_handler,
> + (client->flags | IRQF_ONESHOT),

This looks unrelated. Befor ethis were IRQF_TRIGGER_FALLING |
IRQF_ONESHOT, now you use client->flags. There is no reason why this
commit should change it.

> + chip->battery->desc->name, chip);

This breaks alignment which was here before.

Best regards,
Krzysztof

> +
> + if (ret) {
> + client->irq = 0;
> + dev_warn(&client->dev,
> + "Failed to get IRQ err %d\n", ret);
> + }
> + } else {
> dev_warn(&client->dev,
> - "Failed to get IRQ err %d\n", ret);
> + "Device not compatible for IRQ");
> }
> }
>
> --
> 2.24.0.rc2
>