2020-06-24 15:16:52

by Alexandru Tachici

[permalink] [raw]
Subject: [PATCH v5 5/7] hwmon: pmbus: adm1266: read blackbox

From: Alexandru Tachici <[email protected]>

Use the nvmem kernel api to expose the black box
chip functionality to userspace.

Signed-off-by: Alexandru Tachici <[email protected]>
---
drivers/hwmon/pmbus/adm1266.c | 134 ++++++++++++++++++++++++++++++++++
1 file changed, 134 insertions(+)

diff --git a/drivers/hwmon/pmbus/adm1266.c b/drivers/hwmon/pmbus/adm1266.c
index 0960ead8d96a..b9e92ab1e39a 100644
--- a/drivers/hwmon/pmbus/adm1266.c
+++ b/drivers/hwmon/pmbus/adm1266.c
@@ -15,6 +15,8 @@
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
+#include <linux/nvmem-consumer.h>
+#include <linux/nvmem-provider.h>
#include <linux/proc_fs.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
@@ -22,10 +24,13 @@
#include <linux/adm1266.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

@@ -42,6 +47,9 @@
#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 0x7F700
+#define ADM1266_BLACKBOX_SIZE 64
+
#define ADM1266_PMBUS_BLOCK_MAX 255

DECLARE_CRC8_TABLE(pmbus_crc_table);
@@ -52,6 +60,17 @@ struct adm1266_data {
const char *gpio_names[ADM1266_GPIO_NR + ADM1266_PDIO_NR];
struct i2c_client *client;
struct mutex ioctl_mutex; /* lock ioctl access */
+ 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,
+ },
};

/* Different from Block Read as it sends data and waits for the slave to
@@ -404,6 +423,117 @@ static int adm1266_init_procfs(struct adm1266_data *data)
return 0;
}

+static int adm1266_nvmem_read_blackbox(struct adm1266_data *data, u8 *buf)
+{
+ u8 read_buf[5];
+ char index;
+ int record_count;
+ int ret;
+
+ ret = i2c_smbus_read_block_data(data->client, ADM1266_BLACKBOX_INFO,
+ read_buf);
+ if (ret < 0)
+ return ret;
+
+ record_count = read_buf[3];
+
+ for (index = 0; index < record_count; index++) {
+ ret = pmbus_block_xfer(data->client, ADM1266_READ_BLACKBOX, 1,
+ &index, 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,
const struct i2c_device_id *id)
{
@@ -430,6 +560,10 @@ static int adm1266_probe(struct i2c_client *client,
if (ret < 0)
return ret;

+ ret = adm1266_config_nvmem(data);
+ if (ret < 0)
+ return ret;
+
info = &data->info;
info->pages = 17;
info->format[PSC_VOLTAGE_OUT] = linear;
--
2.20.1