WORKAROUND: avoid the i2c controller no response

When the LAB flag is set in i2c controller status register, we should
reset the controller to avoid i2c controller no response.

We also need to change the ttansaction_state to stopped when i2c read
is completed.

Signed-off-by: Josh Tsai <josh_tsai@compal.com>

Author: Josh Tsai

board/hx20/ps2mouse.c

@@ -305,7 +305,7 @@ void setup_touchpad(void)
 	/* These are touchpad firmware dependent
 	 * They set the touchpad into the mouse device mode, instead of PTP mode
 	 * And are based on the HID descriptor for our unique device */
-	const static uint16_t cmd[5] = {0x0336, 0x0023, 0x0004, 0x0006};
+	const static uint16_t cmd[4] = {0x0336, 0x0023, 0x0004, 0x0006};
 
 	rv = i2c_write_offset16_block(I2C_PORT_TOUCHPAD,
 									TOUCHPAD_I2C_HID_EP | I2C_FLAG_ADDR16_LITTLE_ENDIAN,

chip/mchp/i2c.c

@@ -80,6 +80,10 @@
 #define CFG_ENABLE	BIT(10) /* enable controller */
 #define CFG_GC_DIS	BIT(14) /* disable general call address */
 #define CFG_PROM_EN BIT(15) /* enable Promiscuous mode */
+#define CFG_FLUSH_SXBUF (16) /* clear slave Tx buffer */
+#define CFG_FLUSH_SRBUF (17) /* clear slave Rx buffer */
+#define CFG_FLUSH_MXBUF (18) /* clear master Tx buffer */
+#define CFG_FLUSH_MRBUF (19) /* clear master Rx buffer */
 #define CFG_ENIDI	BIT(29) /* Enable I2C idle interrupt */
 /* Enable network layer master done interrupt */
 #define CFG_ENMI	BIT(30)
@@ -617,6 +621,21 @@ static int i2c_mtx(int ctrl)
 		cdata[ctrl].transaction_state = I2C_TRANSACTION_OPEN;
 	}
 
+	/* Workaround to revocer the LAB flag error */
+	while (MCHP_I2C_STATUS(ctrl) & STS_LAB) {
+		CPRINTS("I2C%d wSTS LAB error, doing reset!", ctrl);
+		MCHP_I2C_CONFIG(ctrl) |= CFG_FLUSH_MRBUF | CFG_FLUSH_MXBUF |
+					CFG_FLUSH_SRBUF | CFG_FLUSH_SXBUF;
+		reset_controller(ctrl);
+		usleep(1000);
+
+		MCHP_I2C_DATA(ctrl) = cdata[ctrl].slv_addr_8bit;
+		/* Clock out the slave address, sending START bit */
+		MCHP_I2C_CTRL(ctrl) = CTRL_PIN | CTRL_ESO | CTRL_ENI |
+			CTRL_ACK | CTRL_STA;
+		cdata[ctrl].transaction_state = I2C_TRANSACTION_OPEN;
+	}
+
 	for (i = 0; i < cdata[ctrl].out_size; ++i) {
 		rv = wait_byte_done(ctrl, 0xff, 0x00);
 		if (rv) {
@@ -700,6 +719,29 @@ static int i2c_mrx_start(int ctrl)
 		/* address then START */
 		MCHP_I2C_CTRL(ctrl) = u8 | CTRL_PIN;
 	}
+
+	/* Workaround to revocer the LAB flag error */
+	while (MCHP_I2C_STATUS(ctrl) & STS_LAB) {
+		CPRINTS("I2C%d rSTS LAB error, doing reset!", ctrl);
+		MCHP_I2C_CONFIG(ctrl) |= CFG_FLUSH_MRBUF | CFG_FLUSH_MXBUF |
+					CFG_FLUSH_SRBUF | CFG_FLUSH_SXBUF;
+		reset_controller(ctrl);
+		usleep(1000);
+
+		if (cdata[ctrl].transaction_state == I2C_TRANSACTION_OPEN) {
+			cdata[ctrl].flags |= (1ul << 5);
+			/* Repeated-START then address */
+			MCHP_I2C_CTRL(ctrl) = u8;
+		}
+
+		MCHP_I2C_DATA(ctrl) = cdata[ctrl].slv_addr_8bit | 0x01;
+		if (cdata[ctrl].transaction_state == I2C_TRANSACTION_STOPPED) {
+			cdata[ctrl].flags |= (1ul << 6);
+			/* address then START */
+			MCHP_I2C_CTRL(ctrl) = u8 | CTRL_PIN;
+		}
+	}
+
 	cdata[ctrl].transaction_state = I2C_TRANSACTION_OPEN;
 	/* Controller generates START, transmits data(address) capturing
 	 * 9-bits from SDA (8-bit address + (N)Ack bit).
@@ -841,8 +883,10 @@ int chip_i2c_xfer(int port, uint16_t slave_addr_flags,
 
 	cdata[ctrl].flags |= (1ul << 15);
 	/* MCHP wait for STOP to complete */
-	if (cdata[ctrl].xflags & I2C_XFER_STOP)
+	if (cdata[ctrl].xflags & I2C_XFER_STOP) {
+		cdata[ctrl].transaction_state = I2C_TRANSACTION_STOPPED;
 		wait_idle(ctrl);
+	}
 
 	/* Check for error conditions */
 	if (MCHP_I2C_STATUS(ctrl) & (STS_LAB | STS_BER)) {