[PATCH 3/5] i2c: rzg2l: Add I2C driver for RZ/G2L family
Paul Barker
paul.barker.ct at bp.renesas.com
Wed Nov 15 18:40:23 CET 2023
This driver supports the I2C module on the Renesas RZ/G2L (R9A07G044)
SoC, also known as the RIIC module.
This patch is based on both the u-boot driver in the Renesas RZ BSP
3.0.5 release [1] (commit 7fcc1fdc2534), and the Linux v6.6 driver
(commit ffc253263a13).
Support for deblocking the I2C bus is included as this may be needed
after triggering a reset via the Power Management IC (PMIC) over I2C
(the PMIC asserts the reset line before the SoC completes the I2C write
transaction with obvious bus locking effects). If the SDA line is
observed to be low during initialisation, we automatically attempt to
deblock.
[1]: https://github.com/renesas-rz/renesas-u-boot-cip
Signed-off-by: Paul Barker <paul.barker.ct at bp.renesas.com>
---
arch/arm/mach-rmobile/Kconfig | 1 +
configs/renesas_rzg2l_smarc_defconfig | 2 +
drivers/i2c/Kconfig | 7 +
drivers/i2c/Makefile | 1 +
drivers/i2c/rz_riic.c | 626 ++++++++++++++++++++++++++
5 files changed, 637 insertions(+)
create mode 100644 drivers/i2c/rz_riic.c
diff --git a/arch/arm/mach-rmobile/Kconfig b/arch/arm/mach-rmobile/Kconfig
index 2bb96749fc0d..38ede6e0b5b5 100644
--- a/arch/arm/mach-rmobile/Kconfig
+++ b/arch/arm/mach-rmobile/Kconfig
@@ -78,6 +78,7 @@ config RZG2L
imply RENESAS_SDHI
imply RZG2L_GPIO
imply SCIF_CONSOLE
+ imply SYS_I2C_RZ_RIIC
imply SYS_MALLOC_F
help
Enable support for the Renesas RZ/G2L family of SoCs. Currently
diff --git a/configs/renesas_rzg2l_smarc_defconfig b/configs/renesas_rzg2l_smarc_defconfig
index e17d22695787..acf9e6a9f4f5 100644
--- a/configs/renesas_rzg2l_smarc_defconfig
+++ b/configs/renesas_rzg2l_smarc_defconfig
@@ -24,6 +24,7 @@ CONFIG_SYS_MAXARGS=64
CONFIG_SYS_PBSIZE=2068
CONFIG_CMD_CLK=y
CONFIG_CMD_GPIO=y
+CONFIG_CMD_I2C=y
CONFIG_CMD_MMC=y
CONFIG_CMD_PART=y
CONFIG_CMD_EXT2=y
@@ -44,6 +45,7 @@ CONFIG_CLK=y
CONFIG_CLK_RENESAS=y
# CONFIG_CLK_RCAR_GEN3 is not set
CONFIG_GPIO_HOG=y
+CONFIG_DM_I2C=y
CONFIG_MMC_IO_VOLTAGE=y
CONFIG_MMC_UHS_SUPPORT=y
CONFIG_MMC_HS400_SUPPORT=y
diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig
index 4f42200f3923..d2a3a13493aa 100644
--- a/drivers/i2c/Kconfig
+++ b/drivers/i2c/Kconfig
@@ -524,6 +524,13 @@ config SYS_I2C_ROCKCHIP
have several I2C ports and all are provided, controlled by the
device tree.
+config SYS_I2C_RZ_RIIC
+ bool "Renesas RZ/G2L RIIC driver"
+ depends on RZG2L && DM_I2C
+ help
+ Support for the I2C controller (RIIC) on the Renesas RZ/G2L SoC
+ family.
+
config SYS_I2C_SANDBOX
bool "Sandbox I2C driver"
depends on SANDBOX && DM_I2C
diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile
index a96a8c7e955e..692f63bafd02 100644
--- a/drivers/i2c/Makefile
+++ b/drivers/i2c/Makefile
@@ -40,6 +40,7 @@ obj-$(CONFIG_SYS_I2C_QUP) += qup_i2c.o
obj-$(CONFIG_SYS_I2C_RCAR_I2C) += rcar_i2c.o
obj-$(CONFIG_SYS_I2C_RCAR_IIC) += rcar_iic.o
obj-$(CONFIG_SYS_I2C_ROCKCHIP) += rk_i2c.o
+obj-$(CONFIG_SYS_I2C_RZ_RIIC) += rz_riic.o
obj-$(CONFIG_SYS_I2C_S3C24X0) += s3c24x0_i2c.o exynos_hs_i2c.o
obj-$(CONFIG_SYS_I2C_SANDBOX) += sandbox_i2c.o i2c-emul-uclass.o
obj-$(CONFIG_SYS_I2C_SH) += sh_i2c.o
diff --git a/drivers/i2c/rz_riic.c b/drivers/i2c/rz_riic.c
new file mode 100644
index 000000000000..734ed084f666
--- /dev/null
+++ b/drivers/i2c/rz_riic.c
@@ -0,0 +1,626 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * RZ/G2L I2C (RIIC) driver
+ *
+ * Copyright (C) 2021-2023 Renesas Electronics Corp.
+ */
+
+#include <asm/io.h>
+#include <clk.h>
+#include <dm.h>
+#include <dm/device_compat.h>
+#include <errno.h>
+#include <i2c.h>
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <reset.h>
+#include <wait_bit.h>
+
+#define RIIC_ICCR1 0x00
+#define RIIC_ICCR2 0x04
+#define RIIC_ICMR1 0x08
+#define RIIC_ICMR2 0x0c
+#define RIIC_ICMR3 0x10
+#define RIIC_ICFER 0x14
+#define RIIC_ICSER 0x18
+#define RIIC_ICIER 0x1c
+#define RIIC_ICSR1 0x20
+#define RIIC_ICSR2 0x24
+#define RIIC_ICSAR0 0x28
+#define RIIC_ICBRL 0x34
+#define RIIC_ICBRH 0x38
+#define RIIC_ICDRT 0x3c
+#define RIIC_ICDRR 0x40
+
+/* ICCR1 */
+#define ICCR1_ICE BIT(7)
+#define ICCR1_IICRST BIT(6)
+#define ICCR1_CLO BIT(5)
+#define ICCR1_SOWP BIT(4)
+#define ICCR1_SCLO BIT(3)
+#define ICCR1_SDAO BIT(2)
+#define ICCR1_SCLI BIT(1)
+#define ICCR1_SDAI BIT(0)
+
+/* ICCR2 */
+#define ICCR2_BBSY BIT(7)
+#define ICCR2_MST BIT(6)
+#define ICCR2_TRS BIT(5)
+#define ICCR2_SP BIT(3)
+#define ICCR2_RS BIT(2)
+#define ICCR2_ST BIT(1)
+
+/* ICMR1 */
+#define ICMR1_MTWP BIT(7)
+#define ICMR1_CKS_MASK GENMASK(6, 4)
+#define ICMR1_BCWP BIT(3)
+#define ICMR1_BC_MASK GENMASK(2, 0)
+
+#define ICMR1_CKS(x) (((x) << 4) & ICMR1_CKS_MASK)
+#define ICMR1_BC(x) ((x) & ICMR1_BC_MASK)
+
+/* ICMR2 */
+#define ICMR2_DLCS BIT(7)
+#define ICMR2_SDDL_MASK GENMASK(6, 4)
+#define ICMR2_TMOH BIT(2)
+#define ICMR2_TMOL BIT(1)
+#define ICMR2_TMOS BIT(0)
+
+/* ICMR3 */
+#define ICMR3_SMBS BIT(7)
+#define ICMR3_WAIT BIT(6)
+#define ICMR3_RDRFS BIT(5)
+#define ICMR3_ACKWP BIT(4)
+#define ICMR3_ACKBT BIT(3)
+#define ICMR3_ACKBR BIT(2)
+#define ICMR3_NF_MASK GENMASK(1, 0)
+
+/* ICFER */
+#define ICFER_FMPE BIT(7)
+#define ICFER_SCLE BIT(6)
+#define ICFER_NFE BIT(5)
+#define ICFER_NACKE BIT(4)
+#define ICFER_SALE BIT(3)
+#define ICFER_NALE BIT(2)
+#define ICFER_MALE BIT(1)
+#define ICFER_TMOE BIT(0)
+
+/* ICSER */
+#define ICSER_HOAE BIT(7)
+#define ICSER_DIDE BIT(5)
+#define ICSER_GCAE BIT(3)
+#define ICSER_SAR2E BIT(2)
+#define ICSER_SAR1E BIT(1)
+#define ICSER_SAR0E BIT(0)
+
+/* ICIER */
+#define ICIER_TIE BIT(7)
+#define ICIER_TEIE BIT(6)
+#define ICIER_RIE BIT(5)
+#define ICIER_NAKIE BIT(4)
+#define ICIER_SPIE BIT(3)
+#define ICIER_STIE BIT(2)
+#define ICIER_ALIE BIT(1)
+#define ICIER_TMOIE BIT(0)
+
+/* ICSR1 */
+#define ICSR1_HOA BIT(7)
+#define ICSR1_DID BIT(5)
+#define ICSR1_GCA BIT(3)
+#define ICSR1_AAS2 BIT(2)
+#define ICSR1_AAS1 BIT(1)
+#define ICSR1_AAS0 BIT(0)
+
+/* ICSR2 */
+#define ICSR2_TDRE BIT(7)
+#define ICSR2_TEND BIT(6)
+#define ICSR2_RDRF BIT(5)
+#define ICSR2_NACKF BIT(4)
+#define ICSR2_STOP BIT(3)
+#define ICSR2_START BIT(2)
+#define ICSR2_AL BIT(1)
+#define ICSR2_TMOF BIT(0)
+
+/* ICBRH */
+#define ICBRH_RESERVED GENMASK(7, 5) /* The write value should always be 1 */
+#define ICBRH_BRH_MASK GENMASK(4, 0)
+
+/* ICBRL */
+#define ICBRL_RESERVED GENMASK(7, 5) /* The write value should always be 1 */
+#define ICBRL_BRL_MASK GENMASK(4, 0)
+
+#define RIIC_TIMEOUT_MSEC 100
+
+#define RIIC_FLAG_DEFAULT_SCL_RISE_TIME BIT(0)
+#define RIIC_FLAG_DEFAULT_SCL_FALL_TIME BIT(1)
+
+/*
+ * If SDA is stuck in a low state, the I2C spec says up to 9 clock cycles on SCL
+ * may be needed to unblock whichever other device on the bus is holding SDA low.
+ */
+#define I2C_DEBLOCK_MAX_CYCLES 9
+
+struct riic_priv {
+ void __iomem *base;
+ struct clk clk;
+ uint bus_speed;
+ u32 scl_rise_ns;
+ u32 scl_fall_ns;
+ u32 flags;
+};
+
+static int riic_check_busy(struct udevice *dev)
+{
+ struct riic_priv *priv = dev_get_priv(dev);
+ int ret;
+
+ ret = wait_for_bit_8(priv->base + RIIC_ICCR2, ICCR2_BBSY, 0,
+ RIIC_TIMEOUT_MSEC, 0);
+ if (ret == -ETIMEDOUT) {
+ dev_dbg(dev, "bus is busy!\n");
+ return -EBUSY;
+ }
+
+ return ret;
+}
+
+static int riic_wait_for_icsr2(struct udevice *dev, u8 bit)
+{
+ struct riic_priv *priv = dev_get_priv(dev);
+ ulong start = get_timer(0);
+ u8 icsr2;
+
+ /* We can't use wait_for_bit_8() here as we need to check for NACK. */
+ while (!((icsr2 = readb(priv->base + RIIC_ICSR2)) & bit)) {
+ if (icsr2 & ICSR2_NACKF)
+ return -EIO;
+ if (get_timer(start) > RIIC_TIMEOUT_MSEC) {
+ dev_dbg(dev, "timeout! (bit=%x, icsr2=%x, iccr2=%x)\n",
+ bit, icsr2, readb(priv->base + RIIC_ICCR2));
+ return -ETIMEDOUT;
+ }
+ udelay(1);
+ schedule();
+ }
+
+ return 0;
+}
+
+static int riic_check_nack_receive(struct udevice *dev)
+{
+ struct riic_priv *priv = dev_get_priv(dev);
+
+ if (readb(priv->base + RIIC_ICSR2) & ICSR2_NACKF) {
+ dev_dbg(dev, "received nack!\n");
+ /* received NACK */
+ clrbits_8(priv->base + RIIC_ICSR2, ICSR2_NACKF);
+ setbits_8(priv->base + RIIC_ICCR2, ICCR2_SP);
+ readb(priv->base + RIIC_ICDRR); /* dummy read */
+ return -EIO;
+ }
+ return 0;
+}
+
+static int riic_i2c_raw_write(struct udevice *dev, u8 *buf, size_t len)
+{
+ struct riic_priv *priv = dev_get_priv(dev);
+ size_t i;
+ int ret;
+
+ for (i = 0; i < len; i++) {
+ ret = riic_check_nack_receive(dev);
+ if (ret < 0)
+ return ret;
+
+ ret = riic_wait_for_icsr2(dev, ICSR2_TDRE);
+ if (ret < 0)
+ return ret;
+
+ writeb(buf[i], priv->base + RIIC_ICDRT);
+ }
+
+ return riic_check_nack_receive(dev);
+}
+
+static int riic_send_start_cond(struct udevice *dev, int restart)
+{
+ struct riic_priv *priv = dev_get_priv(dev);
+ int ret;
+
+ if (restart)
+ setbits_8(priv->base + RIIC_ICCR2, ICCR2_RS);
+ else
+ setbits_8(priv->base + RIIC_ICCR2, ICCR2_ST);
+
+ ret = riic_wait_for_icsr2(dev, ICSR2_START);
+ if (ret < 0)
+ return ret;
+ clrbits_8(priv->base + RIIC_ICSR2, ICSR2_START);
+
+ return ret;
+}
+
+static int riic_receive_data(struct udevice *dev, struct i2c_msg *msg)
+{
+ struct riic_priv *priv = dev_get_priv(dev);
+ int ret, stop_ret, i;
+
+ ret = riic_wait_for_icsr2(dev, ICSR2_RDRF);
+ if (ret < 0)
+ goto send_stop;
+
+ ret = riic_check_nack_receive(dev);
+ if (ret < 0)
+ goto send_stop;
+
+ setbits_8(priv->base + RIIC_ICMR3, ICMR3_WAIT | ICMR3_ACKWP | ICMR3_RDRFS);
+
+ /* A dummy read must be performed to trigger data reception */
+ readb(priv->base + RIIC_ICDRR);
+
+ for (i = 0; i < msg->len; i++) {
+ ret = riic_wait_for_icsr2(dev, ICSR2_RDRF);
+ if (ret < 0)
+ goto send_stop;
+
+ if (i == (msg->len - 1)) {
+ clrbits_8(priv->base + RIIC_ICSR2, ICSR2_STOP);
+ setbits_8(priv->base + RIIC_ICCR2, ICCR2_SP);
+ setbits_8(priv->base + RIIC_ICMR3, ICMR3_ACKBT);
+ } else {
+ clrbits_8(priv->base + RIIC_ICMR3, ICMR3_ACKBT);
+ }
+
+ msg->buf[i] = readb(priv->base + RIIC_ICDRR);
+ };
+
+send_stop:
+ if (ret) {
+ /*
+ * We got here due to an error condition, so we need to perform
+ * a dummy read to issue the stop bit.
+ */
+ clrbits_8(priv->base + RIIC_ICSR2, ICSR2_STOP);
+ setbits_8(priv->base + RIIC_ICCR2, ICCR2_SP);
+ readb(priv->base + RIIC_ICDRR);
+ }
+ stop_ret = riic_wait_for_icsr2(dev, ICSR2_STOP);
+ clrbits_8(priv->base + RIIC_ICSR2, ICSR2_STOP | ICSR2_NACKF);
+ clrbits_8(priv->base + RIIC_ICMR3, ICMR3_WAIT | ICMR3_ACKWP | ICMR3_RDRFS);
+ return ret ? ret : stop_ret;
+}
+
+static int riic_transmit_stop(struct udevice *dev)
+{
+ struct riic_priv *priv = dev_get_priv(dev);
+ int ret;
+
+ clrbits_8(priv->base + RIIC_ICSR2, ICSR2_STOP);
+ setbits_8(priv->base + RIIC_ICCR2, ICCR2_SP);
+
+ ret = riic_wait_for_icsr2(dev, ICSR2_STOP);
+ clrbits_8(priv->base + RIIC_ICSR2, ICSR2_STOP | ICSR2_NACKF);
+ return ret;
+}
+
+static int riic_transmit_data(struct udevice *dev, struct i2c_msg *msg)
+{
+ int ret, stop_ret;
+
+ ret = riic_i2c_raw_write(dev, msg->buf, msg->len);
+ if (ret < 0)
+ goto send_stop;
+
+ ret = riic_wait_for_icsr2(dev, ICSR2_TEND);
+ if (ret < 0)
+ goto send_stop;
+
+ if (!ret && !(msg->flags & I2C_M_STOP))
+ return 0;
+
+send_stop:
+ stop_ret = riic_transmit_stop(dev);
+ return ret ? ret : stop_ret;
+}
+
+static int riic_xfer_one(struct udevice *dev, struct i2c_msg *msg, int first_msg)
+{
+ u8 addr_byte = ((msg->addr << 1) | (msg->flags & I2C_M_RD));
+ int ret;
+
+ if (!(msg->flags & I2C_M_NOSTART)) {
+ /*
+ * Send a start for the first message and a restart for
+ * subsequent messages.
+ */
+ ret = riic_send_start_cond(dev, !first_msg);
+ if (ret < 0)
+ return ret;
+ }
+
+ ret = riic_i2c_raw_write(dev, &addr_byte, 1);
+ if (ret < 0) {
+ /*
+ * We're aborting the transfer while still in master transmit
+ * mode.
+ */
+ riic_transmit_stop(dev);
+ return ret;
+ }
+
+ if (msg->flags & I2C_M_RD)
+ return riic_receive_data(dev, msg);
+
+ return riic_transmit_data(dev, msg);
+}
+
+static int riic_xfer(struct udevice *dev, struct i2c_msg *msg, int nmsgs)
+{
+ int ret, i;
+
+ ret = riic_check_busy(dev);
+ if (ret < 0)
+ return ret;
+
+ /* Ensure that the last message is terminated with a stop bit. */
+ msg[nmsgs - 1].flags |= I2C_M_STOP;
+
+ for (i = 0; i < nmsgs; i++) {
+ ret = riic_xfer_one(dev, &msg[i], !i);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static int riic_deblock(struct udevice *dev)
+{
+ struct riic_priv *priv = dev_get_priv(dev);
+ int i = 0;
+
+ /*
+ * Issue clock cycles on SCL to hopefully unblock whatever is holding
+ * SDA low. These clock cycles may trigger error conditions such as
+ * Arbitration Lost, so we clear the status bits in ICSR2 after each
+ * cycle.
+ */
+ while (!(readb(priv->base + RIIC_ICCR1) & ICCR1_SDAI)) {
+ if (i++ == I2C_DEBLOCK_MAX_CYCLES)
+ return -EIO;
+
+ setbits_8(priv->base + RIIC_ICCR1, ICCR1_CLO);
+ if (wait_for_bit_8(priv->base + RIIC_ICCR1, ICCR1_CLO, 0,
+ RIIC_TIMEOUT_MSEC, false))
+ return -ETIMEDOUT;
+ writeb(0, priv->base + RIIC_ICSR2);
+ }
+
+ /*
+ * We have released SDA, but the I2C module is now out of sync
+ * with the bus state, so we need to reset its state machine.
+ */
+ setbits_8(priv->base + RIIC_ICCR1, ICCR1_IICRST);
+ clrbits_8(priv->base + RIIC_ICCR1, ICCR1_IICRST);
+
+ return 0;
+}
+
+static int riic_set_bus_speed(struct udevice *dev, uint bus_speed)
+{
+ struct riic_priv *priv = dev_get_priv(dev);
+ ulong refclk;
+ uint total_ticks, cks, brl, brh;
+
+ if (bus_speed > I2C_SPEED_FAST_PLUS_RATE) {
+ dev_err(dev, "unsupported bus speed (%dHz). %d max\n", bus_speed,
+ I2C_SPEED_FAST_PLUS_RATE);
+ return -EINVAL;
+ }
+
+ /*
+ * Assume the default register settings:
+ * FER.SCLE = 1 (SCL sync circuit enabled, adds 2 or 3 cycles)
+ * FER.NFE = 1 (noise circuit enabled)
+ * MR3.NF = 0 (1 cycle of noise filtered out)
+ *
+ * Freq (CKS=000) = (I2CCLK + tr + tf)/ (BRH + 3 + 1) + (BRL + 3 + 1)
+ * Freq (CKS!=000) = (I2CCLK + tr + tf)/ (BRH + 2 + 1) + (BRL + 2 + 1)
+ */
+
+ /*
+ * Determine reference clock rate. We must be able to get the desired
+ * frequency with only 62 clock ticks max (31 high, 31 low).
+ * Aim for a duty of 60% LOW, 40% HIGH.
+ */
+ refclk = clk_get_rate(&priv->clk);
+ total_ticks = DIV_ROUND_UP(refclk, bus_speed);
+
+ for (cks = 0; cks < 7; cks++) {
+ /*
+ * 60% low time must be less than BRL + 2 + 1
+ * BRL max register value is 0x1F.
+ */
+ brl = ((total_ticks * 6) / 10);
+ if (brl <= (0x1f + 3))
+ break;
+
+ total_ticks /= 2;
+ refclk /= 2;
+ }
+
+ if (brl > (0x1f + 3)) {
+ dev_err(dev, "invalid speed (%u). Too slow.\n", bus_speed);
+ return -EINVAL;
+ }
+
+ brh = total_ticks - brl;
+
+ /* Remove automatic clock ticks for sync circuit and NF */
+ if (cks == 0) {
+ brl -= 4;
+ brh -= 4;
+ } else {
+ brl -= 3;
+ brh -= 3;
+ }
+
+ /*
+ * If SCL rise and fall times weren't set in the device tree, set them
+ * based on the desired bus speed and the maximum timings given in the
+ * I2C specification.
+ */
+ if (priv->flags & RIIC_FLAG_DEFAULT_SCL_RISE_TIME)
+ priv->scl_rise_ns = bus_speed <= I2C_SPEED_STANDARD_RATE ? 1000 :
+ bus_speed <= I2C_SPEED_FAST_RATE ? 300 : 120;
+ if (priv->flags & RIIC_FLAG_DEFAULT_SCL_FALL_TIME)
+ priv->scl_fall_ns = bus_speed <= I2C_SPEED_FAST_RATE ? 300 : 120;
+
+ /*
+ * Remove clock ticks for rise and fall times. Convert ns to clock
+ * ticks.
+ */
+ brl -= priv->scl_fall_ns / (1000000000 / refclk);
+ brh -= priv->scl_rise_ns / (1000000000 / refclk);
+
+ /* Adjust for min register values for when SCLE=1 and NFE=1 */
+ if (brl < 1)
+ brl = 1;
+ if (brh < 1)
+ brh = 1;
+
+ priv->bus_speed = refclk / total_ticks;
+ dev_dbg(dev, "freq=%u, duty=%d, fall=%lu, rise=%lu, cks=%d, brl=%d, brh=%d\n",
+ priv->bus_speed, ((brl + 3) * 100) / (brl + brh + 6),
+ priv->scl_fall_ns / (1000000000 / refclk),
+ priv->scl_rise_ns / (1000000000 / refclk), cks, brl, brh);
+
+ setbits_8(priv->base + RIIC_ICCR1, ICCR1_IICRST);
+ writeb(ICMR1_CKS(cks), priv->base + RIIC_ICMR1);
+ writeb(brh | ICBRH_RESERVED, priv->base + RIIC_ICBRH);
+ writeb(brl | ICBRL_RESERVED, priv->base + RIIC_ICBRL);
+ clrbits_8(priv->base + RIIC_ICCR1, ICCR1_IICRST);
+
+ return 0;
+}
+
+static int riic_get_bus_speed(struct udevice *dev)
+{
+ struct riic_priv *priv = dev_get_priv(dev);
+
+ return priv->bus_speed;
+}
+
+static const struct dm_i2c_ops riic_ops = {
+ .xfer = riic_xfer,
+ .deblock = riic_deblock,
+ .set_bus_speed = riic_set_bus_speed,
+ .get_bus_speed = riic_get_bus_speed,
+};
+
+static int riic_init_setting(struct udevice *dev)
+{
+ struct riic_priv *priv = dev_get_priv(dev);
+ int ret;
+
+ clrbits_8(priv->base + RIIC_ICCR1, ICCR1_ICE);
+ setbits_8(priv->base + RIIC_ICCR1, ICCR1_IICRST);
+ setbits_8(priv->base + RIIC_ICCR1, ICCR1_ICE);
+
+ /*
+ * Set a default bitrate. The rate may be overridden based on the device
+ * tree as part of i2c_post_probe().
+ */
+ ret = riic_set_bus_speed(dev, I2C_SPEED_STANDARD_RATE);
+ if (ret < 0)
+ goto err;
+
+ clrbits_8(priv->base + RIIC_ICCR1, ICCR1_IICRST);
+
+ /* Make sure the bus is not stuck. */
+ if (!(readb(priv->base + RIIC_ICCR1) & ICCR1_SDAI)) {
+ dev_dbg(dev, "clearing SDA low state\n");
+ ret = riic_deblock(dev);
+ if (ret) {
+ dev_err(dev, "failed to clear SDA low state!\n");
+ goto err;
+ }
+ }
+ return 0;
+
+err:
+ clrbits_8(priv->base + RIIC_ICCR1, ICCR1_ICE | ICCR1_IICRST);
+ return ret;
+}
+
+static int riic_probe(struct udevice *dev)
+{
+ struct riic_priv *priv = dev_get_priv(dev);
+ struct reset_ctl rst;
+ int ret;
+
+ priv->base = dev_read_addr_ptr(dev);
+
+ ret = dev_read_u32(dev, "i2c-scl-rising-time-ns", &priv->scl_rise_ns);
+ if (ret)
+ priv->flags |= RIIC_FLAG_DEFAULT_SCL_RISE_TIME;
+ ret = dev_read_u32(dev, "i2c-scl-falling-time-ns", &priv->scl_fall_ns);
+ if (ret)
+ priv->flags |= RIIC_FLAG_DEFAULT_SCL_FALL_TIME;
+
+ ret = clk_get_by_index(dev, 0, &priv->clk);
+ if (ret) {
+ dev_err(dev, "failed to get clock\n");
+ return ret;
+ }
+
+ ret = clk_enable(&priv->clk);
+ if (ret) {
+ dev_err(dev, "failed to enable clock\n");
+ goto err_clk;
+ }
+
+ ret = reset_get_by_index(dev, 0, &rst);
+ if (ret < 0) {
+ dev_err(dev, "failed to get reset line\n");
+ goto err_get_reset;
+ }
+
+ ret = reset_deassert(&rst);
+ if (ret < 0) {
+ dev_err(dev, "failed to de-assert reset line\n");
+ goto err_reset;
+ }
+
+ ret = riic_init_setting(dev);
+ if (ret < 0) {
+ dev_err(dev, "failed to init i2c bus interface\n");
+ goto err_init;
+ }
+
+ return 0;
+
+err_init:
+ reset_assert(&rst);
+err_reset:
+ reset_free(&rst);
+err_get_reset:
+ clk_disable(&priv->clk);
+err_clk:
+ clk_free(&priv->clk);
+ return ret;
+}
+
+static const struct udevice_id riic_ids[] = {
+ { .compatible = "renesas,riic-rz", },
+ { /* sentinel */ }
+};
+
+U_BOOT_DRIVER(riic_i2c) = {
+ .name = "riic-i2c",
+ .id = UCLASS_I2C,
+ .of_match = riic_ids,
+ .probe = riic_probe,
+ .priv_auto = sizeof(struct riic_priv),
+ .ops = &riic_ops,
+};
--
2.39.2
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