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drm/amdgpu: EEPROM respects I2C quirks

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Consult the i2c_adapter.quirks table for
the maximum read/write data length per bus
transaction. Do not exceed this transaction
limit.

Cc: Jean Delvare <jdelvare@suse.de>
Cc: Alexander Deucher <Alexander.Deucher@amd.com>
Cc: Andrey Grodzovsky <Andrey.Grodzovsky@amd.com>
Cc: Lijo Lazar <Lijo.Lazar@amd.com>
Cc: Stanley Yang <Stanley.Yang@amd.com>
Cc: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Luben Tuikov <luben.tuikov@amd.com>
Acked-by: Alexander Deucher <Alexander.Deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
Luben Tuikov 2021-01-28 14:24:09 -05:00 committed by Alex Deucher
parent 746b584762
commit 93ade343bb
1 changed files with 64 additions and 16 deletions
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80
drivers/gpu/drm/amd/amdgpu/amdgpu_eeprom.c
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@ -32,20 +32,9 @@
#define EEPROM_OFFSET_SIZE 2
/**
* amdgpu_eeprom_xfer -- Read/write from/to an I2C EEPROM device
* @i2c_adap: pointer to the I2C adapter to use
* @slave_addr: I2C address of the slave device
* @eeprom_addr: EEPROM address from which to read/write
* @eeprom_buf: pointer to data buffer to read into/write from
* @buf_size: the size of @eeprom_buf
* @read: True if reading from the EEPROM, false if writing
*
* Returns the number of bytes read/written; -errno on error.
*/
int amdgpu_eeprom_xfer(struct i2c_adapter *i2c_adap,
u16 slave_addr, u16 eeprom_addr,
u8 *eeprom_buf, u16 buf_size, bool read)
static int __amdgpu_eeprom_xfer(struct i2c_adapter *i2c_adap,
u16 slave_addr, u16 eeprom_addr,
u8 *eeprom_buf, u16 buf_size, bool read)
{
u8 eeprom_offset_buf[EEPROM_OFFSET_SIZE];
struct i2c_msg msgs[] = {
@ -65,8 +54,8 @@ int amdgpu_eeprom_xfer(struct i2c_adapter *i2c_adap,
u16 len;
r = 0;
for (len = 0; buf_size > 0;
buf_size -= len, eeprom_addr += len, eeprom_buf += len) {
for ( ; buf_size > 0;
buf_size -= len, eeprom_addr += len, eeprom_buf += len) {
/* Set the EEPROM address we want to write to/read from.
*/
msgs[0].buf[0] = (eeprom_addr >> 8) & 0xff;
@ -120,3 +109,62 @@ int amdgpu_eeprom_xfer(struct i2c_adapter *i2c_adap,
return r < 0 ? r : eeprom_buf - p;
}
/**
* amdgpu_eeprom_xfer -- Read/write from/to an I2C EEPROM device
* @i2c_adap: pointer to the I2C adapter to use
* @slave_addr: I2C address of the slave device
* @eeprom_addr: EEPROM address from which to read/write
* @eeprom_buf: pointer to data buffer to read into/write from
* @buf_size: the size of @eeprom_buf
* @read: True if reading from the EEPROM, false if writing
*
* Returns the number of bytes read/written; -errno on error.
*/
int amdgpu_eeprom_xfer(struct i2c_adapter *i2c_adap,
u16 slave_addr, u16 eeprom_addr,
u8 *eeprom_buf, u16 buf_size, bool read)
{
const struct i2c_adapter_quirks *quirks = i2c_adap->quirks;
u16 limit;
if (!quirks)
limit = 0;
else if (read)
limit = quirks->max_read_len;
else
limit = quirks->max_write_len;
if (limit == 0) {
return __amdgpu_eeprom_xfer(i2c_adap, slave_addr, eeprom_addr,
eeprom_buf, buf_size, read);
} else if (limit <= EEPROM_OFFSET_SIZE) {
dev_err_ratelimited(&i2c_adap->dev,
"maddr:0x%04X size:0x%02X:quirk max_%s_len must be > %d",
eeprom_addr, buf_size,
read ? "read" : "write", EEPROM_OFFSET_SIZE);
return -EINVAL;
} else {
u16 ps; /* Partial size */
int res = 0, r;
/* The "limit" includes all data bytes sent/received,
* which would include the EEPROM_OFFSET_SIZE bytes.
* Account for them here.
*/
limit -= EEPROM_OFFSET_SIZE;
for ( ; buf_size > 0;
buf_size -= ps, eeprom_addr += ps, eeprom_buf += ps) {
ps = min(limit, buf_size);
r = __amdgpu_eeprom_xfer(i2c_adap,
slave_addr, eeprom_addr,
eeprom_buf, ps, read);
if (r < 0)
return r;
res += r;
}
return res;
}
}