[PATCH linux dev-4.10 v7 1/2] hwmon: (ucd9000) Add gpio chip interface
Christopher Bostic
cbostic at linux.vnet.ibm.com
Fri Sep 8 03:42:36 AEST 2017
On 9/6/17 7:27 PM, Andrew Jeffery wrote:
> 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.
>
Will remove the unnecessary negating since debugfs updates in patch 0002
of this series needs updating anyway.
Thanks
Chris
>> +}
>> +
>> +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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