On 5/29/20 6:05 AM, alexandru.tach...@analog.com wrote:
> From: Alexandru Tachici <alexandru.tach...@analog.com>
> 
> 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.tach...@analog.com>
> ---
>  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;
> 

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