Merge branch 'i2c/for-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

Pull i2c updates from Wolfram Sang:

 - the first series of making i2c_device_id optional instead of
   mandatory (in favor of alternatives like of_device_id).

   This involves adding a new probe callback (probe_new) which removes
   some peculiarities I2C had for a long time now. The new probe is
   matching the other subsystems now and the old one will be removed
   once all users are converted. It is expected to take a while but
   there is ongoing interest in that.

 - SMBus Host Notify introduced 4.9 got refactored. They are now using
   interrupts instead of the alert callback which solves multiple
   issues.

 - new drivers for iMX LowPower I2C, Mellanox CPLD and its I2C mux

 - significant refactoring for bcm2835 driver

 - the usual set of driver updates and improvements

* 'i2c/for-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (46 commits)
  i2c: fsl-lpi2c: read lpi2c fifo size in probe()
  i2c: octeon: thunderx: Remove double-check after interrupt
  i2c: octeon: thunderx: TWSI software reset in recovery
  i2c: cadence: Allow Cadence I2C to be selected for Cadence Xtensa CPUs
  i2c: sh_mobile: Add per-Generation fallback bindings
  i2c: rcar: Add per-Generation fallback bindings
  i2c: imx-lpi2c: add low power i2c bus driver
  dt-bindings: i2c: imx-lpi2c: add devicetree bindings
  i2c: designware-pcidrv: Add 10bit address feature to medfield/merrifield
  i2c: pxa: Add support for the I2C units found in Armada 3700
  i2c: pxa: Add definition of fast and high speed modes via the regs layout
  dt-bindings: i2c: pxa: Update the documentation for the Armada 3700
  i2c: qup: support SMBus block read
  i2c: qup: add ACPI support
  i2c: designware: Consolidate default functionality bits
  i2c: i2c-mux-gpio: update mux with gpiod_set_array_value_cansleep
  i2c: mux: pca954x: Add ACPI support for pca954x
  i2c: use an IRQ to report Host Notify events, not alert
  i2c: i801: remove SMBNTFDDAT reads as they always seem to return 0
  i2c: i801: use the BIT() macro for FEATURES_* also
  ...

1 files changed, 43 insertions, 3 deletions

diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c
index b403fa5ecf49..6d81c56184d3 100644
--- a/drivers/i2c/busses/i2c-designware-core.c
+++ b/drivers/i2c/busses/i2c-designware-core.c
@@ -536,6 +536,8 @@ i2c_dw_xfer_msg(struct dw_i2c_dev *dev)
 	intr_mask = DW_IC_INTR_DEFAULT_MASK;
 
 	for (; dev->msg_write_idx < dev->msgs_num; dev->msg_write_idx++) {
+		u32 flags = msgs[dev->msg_write_idx].flags;
+
 		/*
 		 * if target address has changed, we need to
 		 * reprogram the target address in the i2c
@@ -581,8 +583,15 @@ i2c_dw_xfer_msg(struct dw_i2c_dev *dev)
 			 * detected from the registers so we set it always
 			 * when writing/reading the last byte.
 			 */
+
+			/*
+			 * i2c-core.c always sets the buffer length of
+			 * I2C_FUNC_SMBUS_BLOCK_DATA to 1. The length will
+			 * be adjusted when receiving the first byte.
+			 * Thus we can't stop the transaction here.
+			 */
 			if (dev->msg_write_idx == dev->msgs_num - 1 &&
-			    buf_len == 1)
+			    buf_len == 1 && !(flags & I2C_M_RECV_LEN))
 				cmd |= BIT(9);
 
 			if (need_restart) {
@@ -607,7 +616,12 @@ i2c_dw_xfer_msg(struct dw_i2c_dev *dev)
 		dev->tx_buf = buf;
 		dev->tx_buf_len = buf_len;
 
-		if (buf_len > 0) {
+		/*
+		 * Because we don't know the buffer length in the
+		 * I2C_FUNC_SMBUS_BLOCK_DATA case, we can't stop
+		 * the transaction here.
+		 */
+		if (buf_len > 0 || flags & I2C_M_RECV_LEN) {
 			/* more bytes to be written */
 			dev->status |= STATUS_WRITE_IN_PROGRESS;
 			break;
@@ -628,6 +642,24 @@ i2c_dw_xfer_msg(struct dw_i2c_dev *dev)
 	dw_writel(dev, intr_mask,  DW_IC_INTR_MASK);
 }
 
+static u8
+i2c_dw_recv_len(struct dw_i2c_dev *dev, u8 len)
+{
+	struct i2c_msg *msgs = dev->msgs;
+	u32 flags = msgs[dev->msg_read_idx].flags;
+
+	/*
+	 * Adjust the buffer length and mask the flag
+	 * after receiving the first byte.
+	 */
+	len += (flags & I2C_CLIENT_PEC) ? 2 : 1;
+	dev->tx_buf_len = len - min_t(u8, len, dev->rx_outstanding);
+	msgs[dev->msg_read_idx].len = len;
+	msgs[dev->msg_read_idx].flags &= ~I2C_M_RECV_LEN;
+
+	return len;
+}
+
 static void
 i2c_dw_read(struct dw_i2c_dev *dev)
 {
@@ -652,7 +684,15 @@ i2c_dw_read(struct dw_i2c_dev *dev)
 		rx_valid = dw_readl(dev, DW_IC_RXFLR);
 
 		for (; len > 0 && rx_valid > 0; len--, rx_valid--) {
-			*buf++ = dw_readl(dev, DW_IC_DATA_CMD);
+			u32 flags = msgs[dev->msg_read_idx].flags;
+
+			*buf = dw_readl(dev, DW_IC_DATA_CMD);
+			/* Ensure length byte is a valid value */
+			if (flags & I2C_M_RECV_LEN &&
+				*buf <= I2C_SMBUS_BLOCK_MAX && *buf > 0) {
+				len = i2c_dw_recv_len(dev, *buf);
+			}
+			buf++;
 			dev->rx_outstanding--;
 		}