From 15609d1893020436e1e8ccfd9ded774a96dd17a2 Mon Sep 17 00:00:00 2001 From: Alexandru Tachici Date: Wed, 12 Aug 2020 17:20:54 +0300 Subject: [PATCH] hwmon: (pmbus/adm1266) read blackbox Use the nvmem kernel api to expose the black box chip functionality to userspace. Using this feature, the device is capable of recording to nonvolatile flash memory the vital data about the system status that caused the system to perform a black box write. A blackbox is 64 bytes of data containing all the status registers, last two states of the sequencer, timestamp and counters. The mapping of this data is described in the adm1266 datasheet. On power-up the driver sets the unix time to the adm1266 using the SET_RTC command. This value is incremented by an internal clock and it is used as timestamp for the black box feature. Signed-off-by: Alexandru Tachici Link: https://lore.kernel.org/r/20200812142055.9213-6-alexandru.tachici@analog.com Signed-off-by: Guenter Roeck --- drivers/hwmon/pmbus/adm1266.c | 127 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 127 insertions(+) diff --git a/drivers/hwmon/pmbus/adm1266.c b/drivers/hwmon/pmbus/adm1266.c index e129a88..c7b373b 100644 --- a/drivers/hwmon/pmbus/adm1266.c +++ b/drivers/hwmon/pmbus/adm1266.c @@ -15,12 +15,19 @@ #include #include #include +#include +#include #include "pmbus.h" #include +#include +#define ADM1266_BLACKBOX_CONFIG 0xD3 #define ADM1266_PDIO_CONFIG 0xD4 #define ADM1266_READ_STATE 0xD9 +#define ADM1266_READ_BLACKBOX 0xDE +#define ADM1266_SET_RTC 0xDF #define ADM1266_GPIO_CONFIG 0xE1 +#define ADM1266_BLACKBOX_INFO 0xE6 #define ADM1266_PDIO_STATUS 0xE9 #define ADM1266_GPIO_STATUS 0xEA @@ -37,6 +44,9 @@ #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_BLACKBOX_OFFSET 0 +#define ADM1266_BLACKBOX_SIZE 64 + #define ADM1266_PMBUS_BLOCK_MAX 255 struct adm1266_data { @@ -45,11 +55,22 @@ struct adm1266_data { const char *gpio_names[ADM1266_GPIO_NR + ADM1266_PDIO_NR]; struct i2c_client *client; struct dentry *debugfs_dir; + struct nvmem_config nvmem_config; + struct nvmem_device *nvmem; + u8 *dev_mem; struct mutex buf_mutex; u8 write_buf[ADM1266_PMBUS_BLOCK_MAX + 1] ____cacheline_aligned; u8 read_buf[ADM1266_PMBUS_BLOCK_MAX + 1] ____cacheline_aligned; }; +static const struct nvmem_cell_info adm1266_nvmem_cells[] = { + { + .name = "blackbox", + .offset = ADM1266_BLACKBOX_OFFSET, + .bytes = 2048, + }, +}; + DECLARE_CRC8_TABLE(pmbus_crc_table); /* @@ -325,6 +346,104 @@ static void adm1266_init_debugfs(struct adm1266_data *data) adm1266_state_read); } +static int adm1266_nvmem_read_blackbox(struct adm1266_data *data, u8 *read_buff) +{ + int record_count; + char index; + u8 buf[5]; + int ret; + + ret = i2c_smbus_read_block_data(data->client, ADM1266_BLACKBOX_INFO, buf); + if (ret < 0) + return ret; + + if (ret != 4) + return -EIO; + + record_count = buf[3]; + + for (index = 0; index < record_count; index++) { + ret = adm1266_pmbus_block_xfer(data, ADM1266_READ_BLACKBOX, 1, &index, read_buff); + if (ret < 0) + return ret; + + if (ret != ADM1266_BLACKBOX_SIZE) + return -EIO; + + read_buff += ADM1266_BLACKBOX_SIZE; + } + + return 0; +} + +static int adm1266_nvmem_read(void *priv, unsigned int offset, void *val, size_t bytes) +{ + struct adm1266_data *data = priv; + int ret; + + if (offset + bytes > data->nvmem_config.size) + return -EINVAL; + + if (offset == 0) { + memset(data->dev_mem, 0, data->nvmem_config.size); + + ret = adm1266_nvmem_read_blackbox(data, data->dev_mem); + if (ret) { + dev_err(&data->client->dev, "Could not read blackbox!"); + return ret; + } + } + + memcpy(val, data->dev_mem + offset, bytes); + + return 0; +} + +static int adm1266_config_nvmem(struct adm1266_data *data) +{ + data->nvmem_config.name = dev_name(&data->client->dev); + data->nvmem_config.dev = &data->client->dev; + data->nvmem_config.root_only = true; + data->nvmem_config.read_only = true; + data->nvmem_config.owner = THIS_MODULE; + data->nvmem_config.reg_read = adm1266_nvmem_read; + data->nvmem_config.cells = adm1266_nvmem_cells; + data->nvmem_config.ncells = ARRAY_SIZE(adm1266_nvmem_cells); + data->nvmem_config.priv = data; + data->nvmem_config.stride = 1; + data->nvmem_config.word_size = 1; + data->nvmem_config.size = adm1266_nvmem_cells[0].bytes; + + data->dev_mem = devm_kzalloc(&data->client->dev, data->nvmem_config.size, GFP_KERNEL); + if (!data->dev_mem) + return -ENOMEM; + + data->nvmem = devm_nvmem_register(&data->client->dev, &data->nvmem_config); + if (IS_ERR(data->nvmem)) { + dev_err(&data->client->dev, "Could not register nvmem!"); + return PTR_ERR(data->nvmem); + } + + return 0; +} + +static int adm1266_set_rtc(struct adm1266_data *data) +{ + time64_t kt; + char write_buf[6]; + int i; + + kt = ktime_get_seconds(); + + memset(write_buf, 0, sizeof(write_buf)); + + for (i = 0; i < 4; i++) + write_buf[2 + i] = (kt >> (i * 8)) & 0xFF; + + return i2c_smbus_write_block_data(data->client, ADM1266_SET_RTC, sizeof(write_buf), + write_buf); +} + static int adm1266_probe(struct i2c_client *client) { struct adm1266_data *data; @@ -348,6 +467,14 @@ static int adm1266_probe(struct i2c_client *client) if (ret < 0) return ret; + ret = adm1266_set_rtc(data); + if (ret < 0) + return ret; + + ret = adm1266_config_nvmem(data); + if (ret < 0) + return ret; + ret = pmbus_do_probe(client, &data->info); if (ret) return ret; -- 2.7.4