Merge branch 'i2c/for-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

Pull i2c updates from Wolfram Sang:

 - the core has now a lockless variant of i2c_smbus_xfer. Some open
   coded versions of this got removed in drivers. This also enables
   proper SCCB support in regmap.

 - locking got a more precise naming. i2c_{un}lock_adapter() had to go,
   and we know use i2c_lock_bus() consistently with flags like
   I2C_LOCK_ROOT_ADAPTER and I2C_LOCK_SEGMENT to avoid ambiguity.

 - the gpio fault injector got a new delicate testcase

 - the bus recovery procedure got fixed to handle the new testcase
   correctly

 - a new quirk flag for controllers not able to handle zero length
   messages together with driver updates to use it

 - new drivers: FSI bus attached I2C masters, GENI I2C controller, Owl
   family S900

 - and a good set of driver improvements and bugfixes

* 'i2c/for-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (77 commits)
  i2c: rcar: implement STOP and REP_START according to docs
  i2c: rcar: refactor private flags
  i2c: core: ACPI: Make acpi_gsb_i2c_read_bytes() check i2c_transfer return value
  i2c: core: ACPI: Properly set status byte to 0 for multi-byte writes
  dt-bindings: i2c: rcar: Add r8a774a1 support
  dt-bindings: i2c: sh_mobile: Add r8a774a1 support
  i2c: imx: Simplify stopped state tracking
  i2c: imx: Fix race condition in dma read
  i2c: pasemi: remove hardcoded bus numbers on smbus
  i2c: designware: Add SPDX license tag
  i2c: designware: Convert to use struct i2c_timings
  i2c: core: Parse SDA hold time from firmware
  i2c: designware-pcidrv: Mark expected switch fall-through
  i2c: amd8111: Mark expected switch fall-through
  i2c: sh_mobile: use core to detect 'no zero length read' quirk
  i2c: xlr: use core to detect 'no zero length' quirk
  i2c: rcar: use core to detect 'no zero length' quirk
  i2c: stu300: use core to detect 'no zero length' quirk
  i2c: pmcmsp: use core to detect 'no zero length' quirk
  i2c: mxs: use core to detect 'no zero length' quirk
  ...

1 files changed, 1 insertions, 16 deletions

diff --git a/drivers/i2c/busses/i2c-pmcmsp.c b/drivers/i2c/busses/i2c-pmcmsp.c
index dae8ac618a52..0829cb696d9d 100644
--- a/drivers/i2c/busses/i2c-pmcmsp.c
+++ b/drivers/i2c/busses/i2c-pmcmsp.c
@@ -444,16 +444,6 @@ static enum pmcmsptwi_xfer_result pmcmsptwi_xfer_cmd(
 {
 	enum pmcmsptwi_xfer_result retval;
 
-	if ((cmd->type == MSP_TWI_CMD_WRITE && cmd->write_len == 0) ||
-	    (cmd->type == MSP_TWI_CMD_READ && cmd->read_len == 0) ||
-	    (cmd->type == MSP_TWI_CMD_WRITE_READ &&
-	    (cmd->read_len == 0 || cmd->write_len == 0))) {
-		dev_err(&pmcmsptwi_adapter.dev,
-			"%s: Cannot transfer less than 1 byte\n",
-			__func__);
-		return -EINVAL;
-	}
-
 	mutex_lock(&data->lock);
 	dev_dbg(&pmcmsptwi_adapter.dev,
 		"Setting address to 0x%04x\n", cmd->addr);
@@ -532,11 +522,6 @@ static int pmcmsptwi_master_xfer(struct i2c_adapter *adap,
 		cmd.write_data = msg->buf;
 	}
 
-	if (msg->len == 0) {
-		dev_err(&adap->dev, "Zero-byte messages unsupported\n");
-		return -EINVAL;
-	}
-
 	cmd.addr = msg->addr;
 
 	if (msg->flags & I2C_M_TEN) {
@@ -578,7 +563,7 @@ static u32 pmcmsptwi_i2c_func(struct i2c_adapter *adapter)
 }
 
 static const struct i2c_adapter_quirks pmcmsptwi_i2c_quirks = {
-	.flags = I2C_AQ_COMB_WRITE_THEN_READ,
+	.flags = I2C_AQ_COMB_WRITE_THEN_READ | I2C_AQ_NO_ZERO_LEN,
 	.max_write_len = MSP_MAX_BYTES_PER_RW,
 	.max_read_len = MSP_MAX_BYTES_PER_RW,
 	.max_comb_1st_msg_len = MSP_MAX_BYTES_PER_RW,