Re: [PATCH v3 5/6] hwmon: pmbus: adm1266: read blackbox

From: Guenter Roeck
Date: Fri May 29 2020 - 14:45:13 EST

On 5/29/20 6:05 AM, alexandru.tachici@xxxxxxxxxx wrote:
> From: Alexandru Tachici <alexandru.tachici@xxxxxxxxxx>
>
> Use the nvmem kernel api to expose the black box
> chip functionality to userspace.
>

This needs to be split into two functions: Add nvmem support, add
debugfs file.

Guenter

> Signed-off-by: Alexandru Tachici <alexandru.tachici@xxxxxxxxxx>
> ---
> drivers/hwmon/pmbus/adm1266.c | 160 ++++++++++++++++++++++++++++++++++
> 1 file changed, 160 insertions(+)
>
> diff --git a/drivers/hwmon/pmbus/adm1266.c b/drivers/hwmon/pmbus/adm1266.c
> index 85d6795b79d3..831156004087 100644
> --- a/drivers/hwmon/pmbus/adm1266.c
> +++ b/drivers/hwmon/pmbus/adm1266.c
> @@ -14,14 +14,19 @@
> #include <linux/init.h>
> #include <linux/kernel.h>
> #include <linux/module.h>
> +#include <linux/nvmem-consumer.h>
> +#include <linux/nvmem-provider.h>
> #include <linux/slab.h>
>
> #include "pmbus.h"
>
> +#define ADM1266_BLACKBOX_CONFIG 0xD3
> #define ADM1266_PDIO_CONFIG 0xD4
> #define ADM1266_GO_COMMAND 0xD8
> #define ADM1266_READ_STATE 0xD9
> +#define ADM1266_READ_BLACKBOX 0xDE
> #define ADM1266_GPIO_CONFIG 0xE1
> +#define ADM1266_BLACKBOX_INFO 0xE6
> #define ADM1266_PDIO_STATUS 0xE9
> #define ADM1266_GPIO_STATUS 0xEA
>
> @@ -38,12 +43,26 @@
> #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 0x7F700
> +#define ADM1266_BLACKBOX_SIZE 64
> +
> 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 dentry *debugfs_dir;
> + struct nvmem_config nvmem_config;
> + struct nvmem_device *nvmem;
> + u8 *dev_mem;
> +};
> +
> +static const struct nvmem_cell_info adm1266_nvmem_cells[] = {
> + {
> + .name = "blackbox",
> + .offset = ADM1266_BLACKBOX_OFFSET,
> + .bytes = 2048,
> + },
> };
>
> #if IS_ENABLED(CONFIG_GPIOLIB)
> @@ -261,6 +280,28 @@ static int adm1266_set_go_command_op(void *pdata, u64 val)
> return i2c_smbus_write_word_data(data->client, ADM1266_GO_COMMAND, reg);
> }
>
> +static int adm1266_blackbox_information_read(struct seq_file *s, void *pdata)
> +{
> + struct device *dev = s->private;
> + struct i2c_client *client = to_i2c_client(dev);
> + u8 read_buf[PMBUS_BLOCK_MAX + 1];
> + unsigned int latest_id;
> + int ret;
> +
> + ret = i2c_smbus_read_block_data(client, ADM1266_BLACKBOX_INFO,
> + read_buf);
> + if (ret < 0)
> + return ret;
> +
> + seq_puts(s, "BLACKBOX_INFORMATION:\n");
> + latest_id = read_buf[0] + (read_buf[1] << 8);
> + seq_printf(s, "Black box ID: %x\n", latest_id);
> + seq_printf(s, "Logic index: %x\n", read_buf[2]);
> + seq_printf(s, "Record count: %x\n", read_buf[3]);
> +
> + return 0;
> +}
> +
> DEFINE_DEBUGFS_ATTRIBUTE(go_command_fops, NULL, adm1266_set_go_command_op,
> "%llu\n");
> DEFINE_DEBUGFS_ATTRIBUTE(read_state_fops, adm1266_get_state_op, NULL, "%llu\n");
> @@ -277,6 +318,121 @@ static void adm1266_debug_init(struct adm1266_data *data)
> &go_command_fops);
> debugfs_create_file_unsafe("read_state", 0400, root, data,
> &read_state_fops);
> + debugfs_create_devm_seqfile(&data->client->dev, "blackbox_information",
> + root, adm1266_blackbox_information_read);
> +}
> +
> +static int adm1266_nvmem_read_blackbox(struct adm1266_data *data, u8 *buf)
> +{
> + u8 write_buf[PMBUS_BLOCK_MAX + 1];
> + u8 read_buf[PMBUS_BLOCK_MAX + 1];
> + int record_count;
> + int ret;
> + int i;
> +
> + ret = i2c_smbus_read_block_data(data->client, ADM1266_BLACKBOX_INFO,
> + read_buf);
> + if (ret < 0)
> + return ret;
> +
> + record_count = read_buf[3];
> +
> + for (i = 0; i < record_count; i++) {
> + write_buf[0] = i;
> + ret = pmbus_block_wr(data->client, ADM1266_READ_BLACKBOX, 1,
> + write_buf, buf);
> + if (ret < 0)
> + return ret;
> +
> + buf += ADM1266_BLACKBOX_SIZE;
> + }
> +
> + return 0;
> +}
> +
> +static bool adm1266_cell_is_accessed(const struct nvmem_cell_info *mem_cell,
> + unsigned int offset, size_t bytes)
> +{
> + unsigned int start_addr = offset;
> + unsigned int end_addr = offset + bytes;
> + unsigned int cell_start = mem_cell->offset;
> + unsigned int cell_end = mem_cell->offset + mem_cell->bytes;
> +
> + if (start_addr <= cell_end && cell_start <= end_addr)
> + return true;
> +
> + return false;
> +}
> +
> +static int adm1266_read_mem_cell(struct adm1266_data *data,
> + const struct nvmem_cell_info *mem_cell)
> +{
> + u8 *mem_offset;
> + int ret;
> +
> + switch (mem_cell->offset) {
> + case ADM1266_BLACKBOX_OFFSET:
> + mem_offset = data->dev_mem + mem_cell->offset;
> + ret = adm1266_nvmem_read_blackbox(data, mem_offset);
> + if (ret)
> + dev_err(&data->client->dev, "Could not read blackbox!");
> + return ret;
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static int adm1266_nvmem_read(void *priv, unsigned int offset, void *val,
> + size_t bytes)
> +{
> + const struct nvmem_cell_info *mem_cell;
> + struct adm1266_data *data = priv;
> + int ret;
> + int i;
> +
> + for (i = 0; i < data->nvmem_config.ncells; i++) {
> + mem_cell = &adm1266_nvmem_cells[i];
> + if (!adm1266_cell_is_accessed(mem_cell, offset, bytes))
> + continue;
> +
> + ret = adm1266_read_mem_cell(data, mem_cell);
> + if (ret < 0)
> + 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 = 0x80000;
> +
> + data->nvmem = nvmem_register(&data->nvmem_config);
> + if (IS_ERR(data->nvmem)) {
> + dev_err(&data->client->dev, "Could not register nvmem!");
> + return PTR_ERR(data->nvmem);
> + }
> +
> + data->dev_mem = devm_kzalloc(&data->client->dev,
> + data->nvmem_config.size,
> + GFP_KERNEL);
> + if (!data->dev_mem)
> + return -ENOMEM;
> +
> + return 0;
> }
>
> static int adm1266_probe(struct i2c_client *client,
> @@ -299,6 +455,10 @@ static int adm1266_probe(struct i2c_client *client,
> if (ret < 0)
> return ret;
>
> + ret = adm1266_config_nvmem(data);
> + if (ret < 0)
> + return ret;
> +
> adm1266_debug_init(data);
>
> info = &data->info;
>