[PATCH linux dev-4.10 v7 1/2] hwmon: (ucd9000) Add gpio chip interface
Andrew Jeffery
andrew at aj.id.au
Thu Sep 7 10:27:50 AEST 2017
On Wed, 2017-09-06 at 16:00 -0500, Christopher Bostic wrote:
> Add a struct gpio_chip and define some methods so that this device's
> I/O can be accessed via /sys/class/gpio.
>
> Present requirements only call for retrieving current state of pin
> values and their direction. No requirement at this time to switch
> modes between output and input within the device driver.
>
> > Signed-off-by: Christopher Bostic <cbostic at linux.vnet.ibm.com>
> ---
> v7 - Reorder this patch from #2 in series to #1
> v6 - Break out sysfs clear logged faults into separate patch
> - Fix logic bug that was bitwise inverting instead of !
> - Add further comments about assumptions related to pin mux.
> v5 - Clean up remaining branch return statements to !! non
> branching method.
> - Clean up white space issues.
> - Add return codes to error messages.
> - Add comments describing assumptions of ucd90160 type.
> - Define gpio direction set methods.
> - Add unique id for each ucd9000 in system for gpio chip.
> v4 - Change status check from branch to a !! non branching method
> - Remove usage comments on libgpiod for the struct gpio_chip
> methods.
> - Clean up some text formatting.
> v3 - Correct bug in gpio_chip get method. Wasn't retrieving
> gpio config information correctly.
> - Remove old debugfs flag from previous pmbus core changes.
> - Remove all sysfs files for mfr_status command.
> - Add comments on direct i2c_smbus calls to clarify that no page
> set is required.
> v2 - Remove clear_faults file - redundant since all other sysfs
> core accesses result in an automatic clear fault.
> - Removed local status_word and status_vout register dumps and
> use the new pmbus core status facilities instead.
> - Rename gpi<x>_fault to gpi<x>_alarm to better match core naming
> conventions.
> - Add full register dump for mfr_status.
> - Add gpio chip to device structure and use gpio interfaces.
> ---
> drivers/hwmon/pmbus/ucd9000.c | 206 ++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 206 insertions(+)
>
> diff --git a/drivers/hwmon/pmbus/ucd9000.c b/drivers/hwmon/pmbus/ucd9000.c
> index 3e3aa95..9a82e88 100644
> --- a/drivers/hwmon/pmbus/ucd9000.c
> +++ b/drivers/hwmon/pmbus/ucd9000.c
> @@ -26,6 +26,7 @@
> #include <linux/slab.h>
> #include <linux/i2c.h>
> #include <linux/i2c/pmbus.h>
> +#include <linux/gpio.h>
> #include "pmbus.h"
>
> enum chips { ucd9000, ucd90120, ucd90124, ucd90160, ucd9090, ucd90910 };
> @@ -34,8 +35,18 @@
> #define UCD9000_NUM_PAGES 0xd6
> #define UCD9000_FAN_CONFIG_INDEX 0xe7
> #define UCD9000_FAN_CONFIG 0xe8
> +#define UCD9000_GPIO_SELECT 0xfa
> +#define UCD9000_GPIO_CONFIG 0xfb
> #define UCD9000_DEVICE_ID 0xfd
>
> +/* GPIO CONFIG bits */
> +#define UCD9000_GPIO_CONFIG_ENABLE BIT(0)
> +#define UCD9000_GPIO_CONFIG_OUT_ENABLE BIT(1)
> +#define UCD9000_GPIO_CONFIG_OUT_VALUE BIT(2)
> +#define UCD9000_GPIO_CONFIG_STATUS BIT(3)
> +#define UCD9000_GPIO_INPUT 0
> +#define UCD9000_GPIO_OUTPUT 1
> +
> #define UCD9000_MON_TYPE(x) (((x) >> 5) & 0x07)
> #define UCD9000_MON_PAGE(x) ((x) & 0x0f)
>
> @@ -46,9 +57,13 @@
>
> #define UCD9000_NUM_FAN 4
>
> +#define UCD9000_GPIO_NAME_LEN 16
> +#define UCD90160_NUM_GPIOS 26
> +
> struct ucd9000_data {
> u8 fan_data[UCD9000_NUM_FAN][I2C_SMBUS_BLOCK_MAX];
> struct pmbus_driver_info info;
> + struct gpio_chip gpio;
> };
> #define to_ucd9000_data(_info) container_of(_info, struct ucd9000_data, info)
>
> @@ -119,6 +134,166 @@ static int ucd9000_read_byte_data(struct i2c_client *client, int page, int reg)
> };
> MODULE_DEVICE_TABLE(i2c, ucd9000_id);
>
> +static int ucd9000_gpio_read_config(struct i2c_client *client,
> + unsigned int offset)
> +{
> + int ret;
> +
> + /* No page set required */
> + ret = i2c_smbus_write_byte_data(client, UCD9000_GPIO_SELECT, offset);
> + if (ret < 0) {
> + dev_err(&client->dev, "Failed to select GPIO %d: %d\n", offset,
> + ret);
> +
> + return ret;
> + }
> +
> + return i2c_smbus_read_byte_data(client, UCD9000_GPIO_CONFIG);
> +}
> +
> +static int ucd9000_gpio_get(struct gpio_chip *gc, unsigned int offset)
> +{
> + struct i2c_client *client = gpiochip_get_data(gc);
> + int ret;
> +
> + ret = ucd9000_gpio_read_config(client, offset);
> + if (ret < 0) {
> + dev_err(&client->dev, "failed to read GPIO %d config: %d\n",
> + offset, ret);
> +
> + return ret;
> + }
> +
> + return !!(ret & UCD9000_GPIO_CONFIG_STATUS);
> +}
> +
> +static void ucd9000_gpio_set(struct gpio_chip *gc, unsigned int offset,
> + int value)
> +{
> + struct i2c_client *client = gpiochip_get_data(gc);
> + int ret;
> +
> + ret = ucd9000_gpio_read_config(client, offset);
> + if (ret < 0) {
> + dev_err(&client->dev, "failed to read GPIO %d config: %d\n",
> + offset, ret);
> +
> + return;
> + }
> +
> + if (value) {
> + if (ret & UCD9000_GPIO_CONFIG_STATUS)
> + return;
> +
> + ret |= UCD9000_GPIO_CONFIG_STATUS;
> + } else {
> + if (!(ret & UCD9000_GPIO_CONFIG_STATUS))
> + return;
> +
> + ret &= ~UCD9000_GPIO_CONFIG_STATUS;
> + }
> +
> + ret |= UCD9000_GPIO_CONFIG_ENABLE;
> +
> + /* Page set not required */
> + ret = i2c_smbus_write_byte_data(client, UCD9000_GPIO_CONFIG, ret);
> + if (ret < 0) {
> + dev_err(&client->dev, "Failed to write GPIO %d config: %d\n",
> + offset, ret);
> +
> + return;
> + }
> +
> + ret &= ~UCD9000_GPIO_CONFIG_ENABLE;
> +
> + ret = i2c_smbus_write_byte_data(client, UCD9000_GPIO_CONFIG, ret);
> + if (ret < 0)
> + dev_err(&client->dev, "Failed to write GPIO %d config: %d\n",
> + offset, ret);
> +}
> +
> +static int ucd9000_gpio_get_direction(struct gpio_chip *gc,
> + unsigned int offset)
> +{
> + struct i2c_client *client = gpiochip_get_data(gc);
> + int ret;
> +
> + ret = ucd9000_gpio_read_config(client, offset);
> + if (ret < 0) {
> + dev_err(&client->dev, "failed to read GPIO %d config: %d\n",
> + offset, ret);
> +
> + return ret;
> + }
> +
> + return !(!!(ret & UCD9000_GPIO_CONFIG_OUT_ENABLE));
Why are we triple negating? One is enough. This will work, but it's unnecessary
and excessive.
> +}
> +
> +static int ucd9000_gpio_set_direction(struct gpio_chip *gc, unsigned int offset,
> + bool direction_out, int requested_out)
> +{
> + struct i2c_client *client = gpiochip_get_data(gc);
> + int ret, config, out_val;
> +
> +
> + ret = ucd9000_gpio_read_config(client, offset);
> + if (ret < 0) {
> + dev_err(&client->dev, "failed to read GPIO %d config: %d\n",
> + offset, ret);
> +
> + return ret;
> + }
> +
> + if (direction_out) {
> + out_val = requested_out ? UCD9000_GPIO_CONFIG_OUT_VALUE : 0;
> +
> + if (ret & UCD9000_GPIO_CONFIG_OUT_ENABLE) {
> + if ((ret & UCD9000_GPIO_CONFIG_OUT_VALUE) == out_val)
> + return 0;
> + } else
> + ret |= UCD9000_GPIO_CONFIG_OUT_ENABLE;
> +
> + if (out_val)
> + ret |= UCD9000_GPIO_CONFIG_OUT_VALUE;
> + else
> + ret &= ~UCD9000_GPIO_CONFIG_OUT_VALUE;
> +
> + } else {
> + if (!(ret & UCD9000_GPIO_CONFIG_OUT_ENABLE))
> + return 0;
> +
> + ret &= ~UCD9000_GPIO_CONFIG_OUT_ENABLE;
> + }
> +
> + ret |= UCD9000_GPIO_CONFIG_ENABLE;
> + config = ret;
> +
> + /* Page set not required */
> + ret = i2c_smbus_write_byte_data(client, UCD9000_GPIO_CONFIG, config);
> + if (ret < 0) {
> + dev_err(&client->dev, "Failed to write GPIO %d config: %d\n",
> + offset, ret);
> +
> + return ret;
> + }
> +
> + config &= ~UCD9000_GPIO_CONFIG_ENABLE;
> +
> + return i2c_smbus_write_byte_data(client, UCD9000_GPIO_CONFIG, config);
> +}
> +
> +static int ucd9000_gpio_direction_input(struct gpio_chip *gc,
> + unsigned int offset)
> +{
> + return ucd9000_gpio_set_direction(gc, offset, UCD9000_GPIO_INPUT, 0);
> +}
> +
> +static int ucd9000_gpio_direction_output(struct gpio_chip *gc,
> + unsigned int offset, int val)
> +{
> + return ucd9000_gpio_set_direction(gc, offset, UCD9000_GPIO_OUTPUT, val);
> +}
> +
> static int ucd9000_probe(struct i2c_client *client,
> const struct i2c_device_id *id)
> {
> @@ -227,6 +402,37 @@ static int ucd9000_probe(struct i2c_client *client,
> | PMBUS_HAVE_FAN34 | PMBUS_HAVE_STATUS_FAN34;
> }
>
> + /*
> + * Note:
> + *
> + * Pinmux support has not been added to the new gpio_chip.
> + * This support should be added when possible given the mux
> + * behavior of these IO devices.
> + */
> + data->gpio.label = (const char *)&client->name;
> + data->gpio.get_direction = ucd9000_gpio_get_direction;
> + data->gpio.direction_input = ucd9000_gpio_direction_input;
> + data->gpio.direction_output = ucd9000_gpio_direction_output;
> + data->gpio.get = ucd9000_gpio_get;
> + data->gpio.set = ucd9000_gpio_set;
> + data->gpio.can_sleep = 1;
> + data->gpio.base = -1;
> +
> + /*
> + * TODO: set ngpio for ucd9000 devs that aren't 90160 type
> + */
> + if (mid->driver_data == ucd90160)
> + data->gpio.ngpio = UCD90160_NUM_GPIOS;
> + data->gpio.parent = &client->dev;
> + data->gpio.owner = THIS_MODULE;
> +
> + ret = devm_gpiochip_add_data(&client->dev, &data->gpio, client);
> + if (ret) {
> + data->gpio.parent = NULL;
> + dev_warn(&client->dev, "Could not add gpiochip: %d\n", ret);
> + return ret;
> + }
> +
> return pmbus_do_probe(client, mid, info);
> }
>
In the interest of expediting this:
Reviewed-by: Andrew Jeffery <andrew at aj.id.au>
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