Merge tag 'i2cfixes-for-2025.07-rc1' of https://source.denx.de/u-boot/custodians/u-boot-i2c

i2c updates for v2025.07-rc1

- omap24xx_i2c: Enable Repeated Start functionality
  add Repeated Start functionality for the DM_I2C xfer
  API (omap_i2c_xfer()

  from Aniket Limaye

- mediatek i2c driver
  fixes from Martin
  - add end marker for struct udevice_id mtk_i2c_ids
  - remove duplicate entry in mt_i2c_regs_v1

3 files changed, 145 insertions, 32 deletions

diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig
index 46e76385961..146bc621c7e 100644
--- a/drivers/i2c/Kconfig
+++ b/drivers/i2c/Kconfig
@@ -510,6 +510,15 @@ config SYS_I2C_OMAP24XX
 	help
 	  Add support for the OMAP2+ I2C driver.
 
+config SYS_I2C_OMAP24XX_REPEATED_START
+	bool "Enable I2C repeated start"
+	depends on SYS_I2C_OMAP24XX
+	default y if ARCH_K3
+	help
+	  Enable support for repeated start. Updates driver defaults to not
+	  send a Stop condition and issue Repeated Start (Sr) for subsequent
+	  i2c msgs.
+
 config SYS_I2C_RCAR_I2C
 	bool "Renesas R-Car I2C driver"
 	depends on (RCAR_GEN2 || RCAR_64) && DM_I2C
diff --git a/drivers/i2c/mtk_i2c.c b/drivers/i2c/mtk_i2c.c
index 3450177741a..55381dbeced 100644
--- a/drivers/i2c/mtk_i2c.c
+++ b/drivers/i2c/mtk_i2c.c
@@ -143,7 +143,6 @@ static const uint mt_i2c_regs_v1[] = {
 	[REG_RSV_DEBUG] = 0x44,
 	[REG_HS] = 0x48,
 	[REG_SOFTRESET] = 0x50,
-	[REG_SOFTRESET] = 0x50,
 	[REG_DCM_EN] = 0x54,
 	[REG_DEBUGSTAT] = 0x64,
 	[REG_DEBUGCTRL] = 0x68,
@@ -879,7 +878,7 @@ static const struct udevice_id mtk_i2c_ids[] = {
 	}, {
 		.compatible = "mediatek,mt8518-i2c",
 		.data = (ulong)&mt8518_soc_data,
-	}
+	}, {}
 };
 
 U_BOOT_DRIVER(mtk_i2c) = {
diff --git a/drivers/i2c/omap24xx_i2c.c b/drivers/i2c/omap24xx_i2c.c
index ebe472e20cd..a6361d3d17d 100644
--- a/drivers/i2c/omap24xx_i2c.c
+++ b/drivers/i2c/omap24xx_i2c.c
@@ -535,12 +535,16 @@ pr_exit:
 	return res;
 }
 
+#if !CONFIG_IS_ENABLED(DM_I2C)
+/*
+ * The legacy I2C functions. These need to get removed once
+ * all users of this driver are converted to DM.
+ */
+
 /*
  * i2c_read: Function now uses a single I2C read transaction with bulk transfer
  *           of the requested number of bytes (note that the 'i2c md' command
- *           limits this to 16 bytes anyway). If CONFIG_I2C_REPEATED_START is
- *           defined in the board config header, this transaction shall be with
- *           Repeated Start (Sr) between the address and data phases; otherwise
+ *           limits this to 16 bytes anyway).
  *           Stop-Start (P-S) shall be used (some I2C chips do require a P-S).
  *           The address (reg offset) may be 0, 1 or 2 bytes long.
  *           Function now reads correctly from chips that return more than one
@@ -608,16 +612,10 @@ static int __omap24_i2c_read(void __iomem *i2c_base, int ip_rev, int waitdelay,
 
 	if (alen) {
 		/* Must write reg offset first */
-#ifdef CONFIG_I2C_REPEATED_START
-		/* No stop bit, use Repeated Start (Sr) */
-		omap_i2c_write_reg(i2c_base, ip_rev, I2C_CON_EN | I2C_CON_MST |
-				   I2C_CON_STT | I2C_CON_TRX, OMAP_I2C_CON_REG);
-#else
 		/* Stop - Start (P-S) */
 		omap_i2c_write_reg(i2c_base, ip_rev, I2C_CON_EN | I2C_CON_MST |
 				   I2C_CON_STT | I2C_CON_STP | I2C_CON_TRX,
 				   OMAP_I2C_CON_REG);
-#endif
 		/* Send register offset */
 		while (1) {
 			status = wait_for_event(i2c_base, ip_rev, waitdelay);
@@ -836,11 +834,6 @@ wr_exit:
 	return i2c_error;
 }
 
-#if !CONFIG_IS_ENABLED(DM_I2C)
-/*
- * The legacy I2C functions. These need to get removed once
- * all users of this driver are converted to DM.
- */
 static void __iomem *omap24_get_base(struct i2c_adapter *adap)
 {
 	switch (adap->hwadapnr) {
@@ -971,28 +964,140 @@ U_BOOT_I2C_ADAP_COMPLETE(omap24_4, omap24_i2c_init, omap24_i2c_probe,
 
 #else /* CONFIG_DM_I2C */
 
+static int __omap24_i2c_xfer_msg(void __iomem *i2c_base, int ip_rev, int waitdelay,
+				 uchar chip, uchar *buffer, int len, u16 i2c_con_reg)
+{
+	int i;
+	u16 status;
+	int i2c_error = 0;
+	int timeout = I2C_TIMEOUT;
+
+	if (len < 0) {
+		printf("%s: data len < 0\n", __func__);
+		return -EINVAL;
+	}
+
+	if (!buffer) {
+		printf("%s: NULL pointer passed\n", __func__);
+		return -EINVAL;
+	}
+
+	if (!(i2c_con_reg & I2C_CON_EN)) {
+		printf("%s: I2C_CON_EN not set\n", __func__);
+		return -EINVAL;
+	}
+
+	/* Set slave address */
+	omap_i2c_write_reg(i2c_base, ip_rev, chip, OMAP_I2C_SA_REG);
+	/* Read/Write len bytes data */
+	omap_i2c_write_reg(i2c_base, ip_rev, len, OMAP_I2C_CNT_REG);
+	/* Configure the I2C_CON register */
+	omap_i2c_write_reg(i2c_base, ip_rev, i2c_con_reg, OMAP_I2C_CON_REG);
+
+	/* read/write data bytewise */
+	for (i = 0; i < len; i++) {
+		status = wait_for_event(i2c_base, ip_rev, waitdelay);
+		/* Ignore I2C_STAT_RRDY in transmitter mode */
+		if (i2c_con_reg & I2C_CON_TRX)
+			status &= ~I2C_STAT_RRDY;
+		else
+			status &= ~I2C_STAT_XRDY;
+
+		/* Try to identify bus that is not padconf'd for I2C */
+		if (status == I2C_STAT_XRDY) {
+			i2c_error = -EREMOTEIO;
+			printf("%s: pads on bus probably not configured (status=0x%x)\n",
+			       __func__, status);
+			goto xfer_exit;
+		}
+		if (status == 0 || (status & I2C_STAT_NACK)) {
+			i2c_error = -EREMOTEIO;
+			printf("%s: error waiting for ACK (status=0x%x)\n",
+			       __func__, status);
+			goto xfer_exit;
+		}
+		if (status & I2C_STAT_XRDY) {
+			/* Transmit data */
+			omap_i2c_write_reg(i2c_base, ip_rev,
+					   buffer[i], OMAP_I2C_DATA_REG);
+			omap_i2c_write_reg(i2c_base, ip_rev,
+					   I2C_STAT_XRDY, OMAP_I2C_STAT_REG);
+		}
+		if (status & I2C_STAT_RRDY) {
+			/* Receive data */
+			*buffer++ = omap_i2c_read_reg(i2c_base, ip_rev,
+							OMAP_I2C_DATA_REG);
+			omap_i2c_write_reg(i2c_base, ip_rev,
+					   I2C_STAT_RRDY, OMAP_I2C_STAT_REG);
+		}
+	}
+
+	/*
+	 * poll ARDY bit for making sure that last byte really has been
+	 * transferred on the bus.
+	 */
+	do {
+		status = wait_for_event(i2c_base, ip_rev, waitdelay);
+	} while (!(status & I2C_STAT_ARDY) && timeout--);
+	if (timeout <= 0) {
+		printf("%s: timed out on last byte!\n", __func__);
+		i2c_error = -EREMOTEIO;
+		goto xfer_exit;
+	} else {
+		omap_i2c_write_reg(i2c_base, ip_rev, I2C_STAT_ARDY, OMAP_I2C_STAT_REG);
+	}
+
+	/* If Stop bit set, flush FIFO. */
+	if (i2c_con_reg & I2C_CON_STP)
+		goto xfer_exit;
+
+	return 0;
+
+xfer_exit:
+	flush_fifo(i2c_base, ip_rev);
+	omap_i2c_write_reg(i2c_base, ip_rev, 0xFFFF, OMAP_I2C_STAT_REG);
+	return i2c_error;
+}
+
 static int omap_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs)
 {
 	struct omap_i2c *priv = dev_get_priv(bus);
 	int ret;
+	u16 i2c_con_reg = 0;
 
-	debug("i2c_xfer: %d messages\n", nmsgs);
-	for (; nmsgs > 0; nmsgs--, msg++) {
-		debug("i2c_xfer: chip=0x%x, len=0x%x\n", msg->addr, msg->len);
-		if (msg->flags & I2C_M_RD) {
-			ret = __omap24_i2c_read(priv->regs, priv->ip_rev,
-						priv->waitdelay,
-						msg->addr, 0, 0, msg->buf,
-						msg->len);
-		} else {
-			ret = __omap24_i2c_write(priv->regs, priv->ip_rev,
-						 priv->waitdelay,
-						 msg->addr, 0, 0, msg->buf,
-						 msg->len);
-		}
+	debug("%s: %d messages\n", __func__, nmsgs);
+	for (int i = 0; i < nmsgs; i++, msg++) {
+		/*
+		 * If previous msg sent a Stop or if this is the first msg
+		 * Wait until bus not busy
+		 */
+		if ((i2c_con_reg & I2C_CON_STP) || (i == 0))
+			if (wait_for_bb(priv->regs, priv->ip_rev, priv->waitdelay))
+				return -EREMOTEIO;
+
+		/* Set Controller mode with Start bit */
+		i2c_con_reg = I2C_CON_EN | I2C_CON_MST | I2C_CON_STT;
+		/* Set Transmitter/Receiver mode if it is a write/read msg */
+		if (msg->flags & I2C_M_RD)
+			i2c_con_reg &= ~I2C_CON_TRX;
+		else
+			i2c_con_reg |= I2C_CON_TRX;
+		/* Send Stop condition (P) by default */
+		if (!IS_ENABLED(CONFIG_SYS_I2C_OMAP24XX_REPEATED_START))
+			i2c_con_reg |= I2C_CON_STP;
+		/* Send Stop if explicitly requested or if this is the last msg */
+		if ((msg->flags & I2C_M_STOP) || (i == nmsgs - 1))
+			i2c_con_reg |= I2C_CON_STP;
+
+		debug("%s: chip=0x%x, len=0x%x, i2c_con_reg=0x%x\n",
+		      __func__, msg->addr, msg->len, i2c_con_reg);
+
+		ret = __omap24_i2c_xfer_msg(priv->regs, priv->ip_rev, priv->waitdelay,
+					    msg->addr, msg->buf, msg->len,
+					    i2c_con_reg);
 		if (ret) {
-			debug("i2c_write: error sending\n");
-			return -EREMOTEIO;
+			printf("%s: errored out at msg %d: %d\n", __func__, i, ret);
+			return ret;
 		}
 	}