[PATCH v2 3/7] i2c: rzg2l: Add I2C driver for RZ/G2L family
Biju Das
biju.das.jz at bp.renesas.com
Mon Feb 26 18:43:13 CET 2024
> -----Original Message-----
> From: U-Boot <u-boot-bounces at lists.denx.de> On Behalf Of Paul Barker
> Sent: Monday, February 26, 2024 3:06 PM
> To: Marek Vasut <marek.vasut+renesas at mailbox.org>; Nobuhiro Iwamatsu
> <iwamatsu at nigauri.org>
> Cc: Paul Barker <paul.barker.ct at bp.renesas.com>; u-boot at lists.denx.de
> Subject: [PATCH v2 3/7] i2c: rzg2l: Add I2C driver for RZ/G2L family
>
> 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 v6.7 driver (commit
> 0dd3ee311255).
>
> 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]:
>
> Signed-off-by: Paul Barker <paul.barker.ct at bp.renesas.com>
> eviewed-by: Marek Vasut <marek.vasut+renesas at mailbox.org>
Typo. R is missing in the Rb tag.
Also change log is missing.
> ---
> 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 | 624 ++++++++++++++++++++++++++
> 5 files changed, 635 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 e45579ae6b98..ad46297c6619 100644
> --- a/configs/renesas_rzg2l_smarc_defconfig
> +++ b/configs/renesas_rzg2l_smarc_defconfig
> @@ -24,6 +24,7 @@ CONFIG_HUSH_PARSER=y
> CONFIG_SYS_MAXARGS=64
> 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..5f3f8d1b24b7
> --- /dev/null
> +++ b/drivers/i2c/rz_riic.c
> @@ -0,0 +1,624 @@
> +// 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 ?: 1);
> +
> + 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");
> + return ret;
> + }
> +
> + 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);
> + 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,
> +};
> --
> 2.43.2
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