[PATCH v7 3/9] hwmon: pmbus: adm1266: Add support for GPIOs

alexandru.tachici
2020-07-27T16:18:25Z

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>
---
drivers/hwmon/pmbus/adm1266.c | 204 ++++++++++++++++++++++++++++++++++
1 file changed, 204 insertions(+)

diff --git a/drivers/hwmon/pmbus/adm1266.c b/drivers/hwmon/pmbus/adm1266.c
index 63975eba34ad..be911de02cf6 100644
--- 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;
@@ -88,9 +112,185 @@ 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, const struct i2c_device_id *id)
{
struct adm1266_data *data;
+ int ret;
int i;

data = devm_kzalloc(&client->dev, sizeof(struct adm1266_data), GFP_KERNEL);
@@ -106,6 +306,10 @@ static int adm1266_probe(struct i2c_client *client, const struct i2c_device_id *
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, id, &data->info);
}

--
2.20.1