hwmon: (pmbus/adm1266) Add support for GPIOs

Adm1266 exposes 9 GPIOs and 16 PDIOs which are currently read-only. They
are controlled by the internal sequencing engine.

This patch makes adm1266 driver expose GPIOs and PDIOs to user-space
using GPIO provider kernel api.

Signed-off-by: Alexandru Tachici <alexandru.tachici@analog.com>
Link: https://lore.kernel.org/r/20200812142055.9213-4-alexandru.tachici@analog.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
index 7902a9a..db90e00 100644 (file)
--- a/drivers/hwmon/pmbus/Kconfig
+++ b/drivers/hwmon/pmbus/Kconfig
@@ -29,6 +29,7 @@ config SENSORS_PMBUS
 config SENSORS_ADM1266
        tristate "Analog Devices ADM1266 Sequencer"
        select CRC8
+       depends on GPIOLIB
        help
          If you say yes here you get hardware monitoring support for Analog
          Devices ADM1266 Cascadable Super Sequencer.

diff --git a/drivers/hwmon/pmbus/adm1266.c b/drivers/hwmon/pmbus/adm1266.c
index d858350..bcc8a78 100644 (file)
--- a/drivers/hwmon/pmbus/adm1266.c
+++ b/drivers/hwmon/pmbus/adm1266.c
@@ -6,18 +6,42 @@
  * Copyright 2020 Analog Devices Inc.
  */
 
+#include <linux/bitfield.h>
 #include <linux/crc8.h>
+#include <linux/debugfs.h>
+#include <linux/gpio/driver.h>
 #include <linux/i2c.h>
+#include <linux/i2c-smbus.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include "pmbus.h"
 #include <linux/slab.h>
 
+#define ADM1266_PDIO_CONFIG    0xD4
+#define ADM1266_GPIO_CONFIG    0xE1
+#define ADM1266_PDIO_STATUS    0xE9
+#define ADM1266_GPIO_STATUS    0xEA
+
+/* ADM1266 GPIO defines */
+#define ADM1266_GPIO_NR                        9
+#define ADM1266_GPIO_FUNCTIONS(x)      FIELD_GET(BIT(0), x)
+#define ADM1266_GPIO_INPUT_EN(x)       FIELD_GET(BIT(2), x)
+#define ADM1266_GPIO_OUTPUT_EN(x)      FIELD_GET(BIT(3), x)
+#define ADM1266_GPIO_OPEN_DRAIN(x)     FIELD_GET(BIT(4), x)
+
+/* ADM1266 PDIO defines */
+#define ADM1266_PDIO_NR                        16
+#define ADM1266_PDIO_PIN_CFG(x)                FIELD_GET(GENMASK(15, 13), x)
+#define ADM1266_PDIO_GLITCH_FILT(x)    FIELD_GET(GENMASK(12, 9), x)
+#define ADM1266_PDIO_OUT_CFG(x)                FIELD_GET(GENMASK(2, 0), x)
+
 #define ADM1266_PMBUS_BLOCK_MAX                255
 
 struct adm1266_data {
        struct pmbus_driver_info info;
+       struct gpio_chip gc;
+       const char *gpio_names[ADM1266_GPIO_NR + ADM1266_PDIO_NR];
        struct i2c_client *client;
        struct mutex buf_mutex;
        u8 write_buf[ADM1266_PMBUS_BLOCK_MAX + 1] ____cacheline_aligned;
@@ -93,9 +117,185 @@ static int adm1266_pmbus_block_xfer(struct adm1266_data *data, u8 cmd, u8 w_len,
        return ret;
 }
 
+static const unsigned int adm1266_gpio_mapping[ADM1266_GPIO_NR][2] = {
+       {1, 0},
+       {2, 1},
+       {3, 2},
+       {4, 8},
+       {5, 9},
+       {6, 10},
+       {7, 11},
+       {8, 6},
+       {9, 7},
+};
+
+static const char *adm1266_names[ADM1266_GPIO_NR + ADM1266_PDIO_NR] = {
+       "GPIO1", "GPIO2", "GPIO3", "GPIO4", "GPIO5", "GPIO6", "GPIO7", "GPIO8",
+       "GPIO9", "PDIO1", "PDIO2", "PDIO3", "PDIO4", "PDIO5", "PDIO6",
+       "PDIO7", "PDIO8", "PDIO9", "PDIO10", "PDIO11", "PDIO12", "PDIO13",
+       "PDIO14", "PDIO15", "PDIO16",
+};
+
+static int adm1266_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+       struct adm1266_data *data = gpiochip_get_data(chip);
+       u8 read_buf[I2C_SMBUS_BLOCK_MAX + 1];
+       unsigned long pins_status;
+       unsigned int pmbus_cmd;
+       int ret;
+
+       if (offset < ADM1266_GPIO_NR)
+               pmbus_cmd = ADM1266_GPIO_STATUS;
+       else
+               pmbus_cmd = ADM1266_PDIO_STATUS;
+
+       ret = i2c_smbus_read_block_data(data->client, pmbus_cmd, read_buf);
+       if (ret < 0)
+               return ret;
+
+       pins_status = read_buf[0] + (read_buf[1] << 8);
+       if (offset < ADM1266_GPIO_NR)
+               return test_bit(adm1266_gpio_mapping[offset][1], &pins_status);
+
+       return test_bit(offset - ADM1266_GPIO_NR, &pins_status);
+}
+
+static int adm1266_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask,
+                                    unsigned long *bits)
+{
+       struct adm1266_data *data = gpiochip_get_data(chip);
+       u8 read_buf[ADM1266_PMBUS_BLOCK_MAX + 1];
+       unsigned long status;
+       unsigned int gpio_nr;
+       int ret;
+
+       ret = i2c_smbus_read_block_data(data->client, ADM1266_GPIO_STATUS, read_buf);
+       if (ret < 0)
+               return ret;
+
+       status = read_buf[0] + (read_buf[1] << 8);
+
+       *bits = 0;
+       for_each_set_bit(gpio_nr, mask, ADM1266_GPIO_NR) {
+               if (test_bit(adm1266_gpio_mapping[gpio_nr][1], &status))
+                       set_bit(gpio_nr, bits);
+       }
+
+       ret = i2c_smbus_read_block_data(data->client, ADM1266_PDIO_STATUS, read_buf);
+       if (ret < 0)
+               return ret;
+
+       status = read_buf[0] + (read_buf[1] << 8);
+
+       *bits = 0;
+       for_each_set_bit_from(gpio_nr, mask, ADM1266_GPIO_NR + ADM1266_PDIO_STATUS) {
+               if (test_bit(gpio_nr - ADM1266_GPIO_NR, &status))
+                       set_bit(gpio_nr, bits);
+       }
+
+       return 0;
+}
+
+static void adm1266_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
+{
+       struct adm1266_data *data = gpiochip_get_data(chip);
+       u8 read_buf[ADM1266_PMBUS_BLOCK_MAX + 1];
+       unsigned long gpio_config;
+       unsigned long pdio_config;
+       unsigned long pin_cfg;
+       u8 write_cmd;
+       int ret;
+       int i;
+
+       for (i = 0; i < ADM1266_GPIO_NR; i++) {
+               write_cmd = adm1266_gpio_mapping[i][1];
+               ret = adm1266_pmbus_block_xfer(data, ADM1266_GPIO_CONFIG, 1, &write_cmd, read_buf);
+               if (ret != 2)
+                       return;
+
+               gpio_config = read_buf[0];
+               seq_puts(s, adm1266_names[i]);
+
+               seq_puts(s, " ( ");
+               if (!ADM1266_GPIO_FUNCTIONS(gpio_config)) {
+                       seq_puts(s, "high-Z )\n");
+                       continue;
+               }
+               if (ADM1266_GPIO_INPUT_EN(gpio_config))
+                       seq_puts(s, "input ");
+               if (ADM1266_GPIO_OUTPUT_EN(gpio_config))
+                       seq_puts(s, "output ");
+               if (ADM1266_GPIO_OPEN_DRAIN(gpio_config))
+                       seq_puts(s, "open-drain )\n");
+               else
+                       seq_puts(s, "push-pull )\n");
+       }
+
+       write_cmd = 0xFF;
+       ret = adm1266_pmbus_block_xfer(data, ADM1266_PDIO_CONFIG, 1, &write_cmd, read_buf);
+       if (ret != 32)
+               return;
+
+       for (i = 0; i < ADM1266_PDIO_NR; i++) {
+               seq_puts(s, adm1266_names[ADM1266_GPIO_NR + i]);
+
+               pdio_config = read_buf[2 * i];
+               pdio_config += (read_buf[2 * i + 1] << 8);
+               pin_cfg = ADM1266_PDIO_PIN_CFG(pdio_config);
+
+               seq_puts(s, " ( ");
+               if (!pin_cfg || pin_cfg > 5) {
+                       seq_puts(s, "high-Z )\n");
+                       continue;
+               }
+
+               if (pin_cfg & BIT(0))
+                       seq_puts(s, "output ");
+
+               if (pin_cfg & BIT(1))
+                       seq_puts(s, "input ");
+
+               seq_puts(s, ")\n");
+       }
+}
+
+static int adm1266_config_gpio(struct adm1266_data *data)
+{
+       const char *name = dev_name(&data->client->dev);
+       char *gpio_name;
+       int ret;
+       int i;
+
+       for (i = 0; i < ARRAY_SIZE(data->gpio_names); i++) {
+               gpio_name = devm_kasprintf(&data->client->dev, GFP_KERNEL, "adm1266-%x-%s",
+                                          data->client->addr, adm1266_names[i]);
+               if (!gpio_name)
+                       return -ENOMEM;
+
+               data->gpio_names[i] = gpio_name;
+       }
+
+       data->gc.label = name;
+       data->gc.parent = &data->client->dev;
+       data->gc.owner = THIS_MODULE;
+       data->gc.base = -1;
+       data->gc.names = data->gpio_names;
+       data->gc.ngpio = ARRAY_SIZE(data->gpio_names);
+       data->gc.get = adm1266_gpio_get;
+       data->gc.get_multiple = adm1266_gpio_get_multiple;
+       data->gc.dbg_show = adm1266_gpio_dbg_show;
+
+       ret = devm_gpiochip_add_data(&data->client->dev, &data->gc, data);
+       if (ret)
+               dev_err(&data->client->dev, "GPIO registering failed (%d)\n", ret);
+
+       return ret;
+}
+
 static int adm1266_probe(struct i2c_client *client)
 {
        struct adm1266_data *data;
+       int ret;
        int i;
 
        data = devm_kzalloc(&client->dev, sizeof(struct adm1266_data), GFP_KERNEL);
@@ -111,6 +311,10 @@ static int adm1266_probe(struct i2c_client *client)
        crc8_populate_msb(pmbus_crc_table, 0x7);
        mutex_init(&data->buf_mutex);
 
+       ret = adm1266_config_gpio(data);
+       if (ret < 0)
+               return ret;
+
        return pmbus_do_probe(client, &data->info);
 }