@@ -5,7 +5,7 @@
menuconfig PMBUS
tristate "PMBus support"
- depends on I2C
+ depends on I2C && CRC8
help
Say yes here if you want to enable PMBus support.
@@ -392,6 +392,8 @@ enum pmbus_sensor_classes {
#define PMBUS_PHASE_VIRTUAL BIT(30) /* Phases on this page are virtual */
#define PMBUS_PAGE_VIRTUAL BIT(31) /* Page is virtual */
+#define PMBUS_BLOCK_MAX 255
+
enum pmbus_data_format { linear = 0, direct, vid };
enum vrm_version { vr11 = 0, vr12, vr13, imvp9, amd625mv };
@@ -467,6 +469,8 @@ int pmbus_read_word_data(struct i2c_client *client, int page, int phase,
u8 reg);
int pmbus_write_word_data(struct i2c_client *client, int page, u8 reg,
u16 word);
+int pmbus_block_wr(struct i2c_client *client, u8 cmd, u8 w_len, u8 *data_w,
+ u8 *data_r);
int pmbus_read_byte_data(struct i2c_client *client, int page, u8 reg);
int pmbus_write_byte(struct i2c_client *client, int page, u8 value);
int pmbus_write_byte_data(struct i2c_client *client, int page, u8 reg,
@@ -6,6 +6,7 @@
* Copyright (c) 2012 Guenter Roeck
*/
+#include <linux/crc8.h>
#include <linux/debugfs.h>
#include <linux/kernel.h>
#include <linux/math64.h>
@@ -44,6 +45,8 @@
#define PMBUS_NAME_SIZE 24
+DECLARE_CRC8_TABLE(pmbus_crc_table);
+
struct pmbus_sensor {
struct pmbus_sensor *next;
char name[PMBUS_NAME_SIZE]; /* sysfs sensor name */
@@ -184,6 +187,89 @@ int pmbus_set_page(struct i2c_client *client, int page, int phase)
}
EXPORT_SYMBOL_GPL(pmbus_set_page);
+/* Block Write/Read command.
+ * @client: Handle to slave device
+ * @cmd: Byte interpreted by slave
+ * @w_len: Size of write data block; PMBus allows at most 255 bytes
+ * @data_w: byte array which will be written.
+ * @data_r: Byte array into which data will be read; big enough to hold
+ * the data returned by the slave. PMBus allows at most 255 bytes.
+ *
+ * Different from Block Read as it sends data and waits for the slave to
+ * return a value dependent on that data. The protocol is simply a Write Block
+ * followed by a Read Block without the Read-Block command field and the
+ * Write-Block STOP bit.
+ *
+ * Returns number of bytes read or negative errno.
+ */
+int pmbus_block_wr(struct i2c_client *client, u8 cmd, u8 w_len,
+ u8 *data_w, u8 *data_r)
+{
+ u8 write_buf[PMBUS_BLOCK_MAX + 1];
+ struct i2c_msg msgs[2] = {
+ {
+ .addr = client->addr,
+ .flags = 0,
+ .buf = write_buf,
+ .len = w_len + 2,
+ },
+ {
+ .addr = client->addr,
+ .flags = I2C_M_RD,
+ .len = PMBUS_BLOCK_MAX,
+ }
+ };
+ u8 addr = 0;
+ u8 crc = 0;
+ int ret;
+
+ msgs[0].buf[0] = cmd;
+ msgs[0].buf[1] = w_len;
+ memcpy(&msgs[0].buf[2], data_w, w_len);
+
+ msgs[0].buf = i2c_get_dma_safe_msg_buf(&msgs[0], 1);
+ if (!msgs[0].buf)
+ return -ENOMEM;
+
+ msgs[1].buf = i2c_get_dma_safe_msg_buf(&msgs[1], 1);
+ if (!msgs[1].buf) {
+ i2c_put_dma_safe_msg_buf(msgs[0].buf, &msgs[0], false);
+ return -ENOMEM;
+ }
+
+ ret = i2c_transfer(client->adapter, msgs, 2);
+ if (ret != 2) {
+ dev_err(&client->dev, "I2C transfer error.");
+ goto cleanup;
+ }
+
+ if (client->flags & I2C_CLIENT_PEC) {
+ addr = i2c_8bit_addr_from_msg(&msgs[0]);
+ crc = crc8(pmbus_crc_table, &addr, 1, crc);
+ crc = crc8(pmbus_crc_table, msgs[0].buf, msgs[0].len, crc);
+
+ addr = i2c_8bit_addr_from_msg(&msgs[1]);
+ crc = crc8(pmbus_crc_table, &addr, 1, crc);
+ crc = crc8(pmbus_crc_table, msgs[1].buf, msgs[1].buf[0] + 1,
+ crc);
+
+ if (crc != msgs[1].buf[msgs[1].buf[0] + 1]) {
+ ret = -EBADMSG;
+ goto cleanup;
+ }
+ }
+
+ memcpy(data_r, &msgs[1].buf[1], msgs[1].buf[0]);
+ ret = msgs[1].buf[0];
+
+cleanup:
+ i2c_put_dma_safe_msg_buf(msgs[0].buf, &msgs[0], true);
+ i2c_put_dma_safe_msg_buf(msgs[1].buf, &msgs[1], true);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(pmbus_block_wr);
+
int pmbus_write_byte(struct i2c_client *client, int page, u8 value)
{
int rv;
@@ -2522,6 +2608,8 @@ int pmbus_do_probe(struct i2c_client *client, const struct i2c_device_id *id,
if (!data->groups)
return -ENOMEM;
+ crc8_populate_msb(pmbus_crc_table, 0x7);
+
i2c_set_clientdata(client, data);
mutex_init(&data->update_lock);
data->dev = dev;