From a06a0ac36d5986ebcb189a92475ccacc37348cd3 Mon Sep 17 00:00:00 2001 From: Marek Vasut Date: Sat, 21 Apr 2018 18:57:28 +0200 Subject: [PATCH] i2c: rcar_i2c: Add DM and DT capable I2C driver Add derivative of the rcar_i2c driver which is capable of probing itself from DM and uses DT. Signed-off-by: Marek Vasut Cc: Heiko Schocher Cc: Nobuhiro Iwamatsu --- drivers/i2c/Kconfig | 6 + drivers/i2c/Makefile | 1 + drivers/i2c/rcar_i2c.c | 353 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 360 insertions(+) create mode 100644 drivers/i2c/rcar_i2c.c diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig index 7fb201d8e6..5eceab9ea8 100644 --- a/drivers/i2c/Kconfig +++ b/drivers/i2c/Kconfig @@ -339,6 +339,12 @@ config SYS_OMAP24_I2C_SPEED OMAP24xx Slave speed channel 0 endif +config SYS_I2C_RCAR_I2C + bool "Renesas RCar I2C driver" + depends on (RCAR_GEN3 || RCAR_GEN2) && DM_I2C + help + Support for Renesas RCar I2C controller. + config SYS_I2C_RCAR_IIC bool "Renesas RCar Gen3 IIC driver" depends on (RCAR_GEN3 || RCAR_GEN2) && DM_I2C diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile index c48a71ac6f..8bb3c18b57 100644 --- a/drivers/i2c/Makefile +++ b/drivers/i2c/Makefile @@ -28,6 +28,7 @@ obj-$(CONFIG_SYS_I2C_MVTWSI) += mvtwsi.o obj-$(CONFIG_SYS_I2C_MXC) += mxc_i2c.o obj-$(CONFIG_SYS_I2C_MXS) += mxs_i2c.o obj-$(CONFIG_SYS_I2C_OMAP24XX) += omap24xx_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_S3C24X0) += s3c24x0_i2c.o exynos_hs_i2c.o diff --git a/drivers/i2c/rcar_i2c.c b/drivers/i2c/rcar_i2c.c new file mode 100644 index 0000000000..8d87c73713 --- /dev/null +++ b/drivers/i2c/rcar_i2c.c @@ -0,0 +1,353 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * drivers/i2c/rcar_i2c.c + * + * Copyright (C) 2018 Marek Vasut + * + * Clock configuration based on Linux i2c-rcar.c: + * Copyright (C) 2014-15 Wolfram Sang + * Copyright (C) 2011-2015 Renesas Electronics Corporation + * Copyright (C) 2012-14 Renesas Solutions Corp. + * Kuninori Morimoto + */ + +#include +#include +#include +#include +#include +#include + +#define RCAR_I2C_ICSCR 0x00 +#define RCAR_I2C_ICMCR 0x04 +#define RCAR_I2C_ICMCR_MDBS BIT(7) +#define RCAR_I2C_ICMCR_FSCL BIT(6) +#define RCAR_I2C_ICMCR_FSDA BIT(5) +#define RCAR_I2C_ICMCR_OBPC BIT(4) +#define RCAR_I2C_ICMCR_MIE BIT(3) +#define RCAR_I2C_ICMCR_TSBE BIT(2) +#define RCAR_I2C_ICMCR_FSB BIT(1) +#define RCAR_I2C_ICMCR_ESG BIT(0) +#define RCAR_I2C_ICSSR 0x08 +#define RCAR_I2C_ICMSR 0x0c +#define RCAR_I2C_ICMSR_MASK 0x7f +#define RCAR_I2C_ICMSR_MNR BIT(6) +#define RCAR_I2C_ICMSR_MAL BIT(5) +#define RCAR_I2C_ICMSR_MST BIT(4) +#define RCAR_I2C_ICMSR_MDE BIT(3) +#define RCAR_I2C_ICMSR_MDT BIT(2) +#define RCAR_I2C_ICMSR_MDR BIT(1) +#define RCAR_I2C_ICMSR_MAT BIT(0) +#define RCAR_I2C_ICSIER 0x10 +#define RCAR_I2C_ICMIER 0x14 +#define RCAR_I2C_ICCCR 0x18 +#define RCAR_I2C_ICCCR_SCGD_OFF 3 +#define RCAR_I2C_ICSAR 0x1c +#define RCAR_I2C_ICMAR 0x20 +#define RCAR_I2C_ICRXD_ICTXD 0x24 + +struct rcar_i2c_priv { + void __iomem *base; + struct clk clk; + u32 intdelay; + u32 icccr; +}; + +static int rcar_i2c_finish(struct udevice *dev) +{ + struct rcar_i2c_priv *priv = dev_get_priv(dev); + int ret; + + ret = wait_for_bit_le32(priv->base + RCAR_I2C_ICMSR, RCAR_I2C_ICMSR_MST, + true, 10, true); + + writel(0, priv->base + RCAR_I2C_ICSSR); + writel(0, priv->base + RCAR_I2C_ICMSR); + writel(0, priv->base + RCAR_I2C_ICMCR); + + return ret; +} + +static void rcar_i2c_recover(struct udevice *dev) +{ + struct rcar_i2c_priv *priv = dev_get_priv(dev); + u32 mcr = RCAR_I2C_ICMCR_MDBS | RCAR_I2C_ICMCR_OBPC; + u32 mcra = mcr | RCAR_I2C_ICMCR_FSDA; + int i; + + /* Send 9 SCL pulses */ + for (i = 0; i < 9; i++) { + writel(mcra | RCAR_I2C_ICMCR_FSCL, priv->base + RCAR_I2C_ICMCR); + udelay(5); + writel(mcra, priv->base + RCAR_I2C_ICMCR); + udelay(5); + } + + /* Send stop condition */ + udelay(5); + writel(mcra, priv->base + RCAR_I2C_ICMCR); + udelay(5); + writel(mcr, priv->base + RCAR_I2C_ICMCR); + udelay(5); + writel(mcr | RCAR_I2C_ICMCR_FSCL, priv->base + RCAR_I2C_ICMCR); + udelay(5); + writel(mcra | RCAR_I2C_ICMCR_FSCL, priv->base + RCAR_I2C_ICMCR); + udelay(5); +} + +static int rcar_i2c_set_addr(struct udevice *dev, u8 chip, u8 read) +{ + struct rcar_i2c_priv *priv = dev_get_priv(dev); + u32 mask = RCAR_I2C_ICMSR_MAT | + (read ? RCAR_I2C_ICMSR_MDR : RCAR_I2C_ICMSR_MDE); + u32 val; + int ret; + + writel(0, priv->base + RCAR_I2C_ICMIER); + writel(RCAR_I2C_ICMCR_MDBS, priv->base + RCAR_I2C_ICMCR); + writel(0, priv->base + RCAR_I2C_ICMSR); + writel(priv->icccr, priv->base + RCAR_I2C_ICCCR); + + ret = wait_for_bit_le32(priv->base + RCAR_I2C_ICMCR, + RCAR_I2C_ICMCR_FSDA, false, 2, true); + if (ret) { + rcar_i2c_recover(dev); + val = readl(priv->base + RCAR_I2C_ICMSR); + if (val & RCAR_I2C_ICMCR_FSDA) { + dev_err(dev, "Bus busy, aborting\n"); + return ret; + } + } + + writel((chip << 1) | read, priv->base + RCAR_I2C_ICMAR); + writel(0, priv->base + RCAR_I2C_ICMSR); + writel(RCAR_I2C_ICMCR_MDBS | RCAR_I2C_ICMCR_MIE | RCAR_I2C_ICMCR_ESG, + priv->base + RCAR_I2C_ICMCR); + + ret = wait_for_bit_le32(priv->base + RCAR_I2C_ICMSR, mask, + true, 100, true); + if (ret) + return ret; + + /* Check NAK */ + if (readl(priv->base + RCAR_I2C_ICMSR) & RCAR_I2C_ICMSR_MNR) + return -EREMOTEIO; + + return 0; +} + +static int rcar_i2c_read_common(struct udevice *dev, struct i2c_msg *msg) +{ + struct rcar_i2c_priv *priv = dev_get_priv(dev); + u32 icmcr = RCAR_I2C_ICMCR_MDBS | RCAR_I2C_ICMCR_MIE; + int i, ret = -EREMOTEIO; + + ret = rcar_i2c_set_addr(dev, msg->addr, 1); + if (ret) + return ret; + + for (i = 0; i < msg->len; i++) { + if (msg->len - 1 == i) + icmcr |= RCAR_I2C_ICMCR_FSB; + + writel(icmcr, priv->base + RCAR_I2C_ICMCR); + writel(~RCAR_I2C_ICMSR_MDR, priv->base + RCAR_I2C_ICMSR); + + ret = wait_for_bit_le32(priv->base + RCAR_I2C_ICMSR, + RCAR_I2C_ICMSR_MDR, true, 100, true); + if (ret) + return ret; + + msg->buf[i] = readl(priv->base + RCAR_I2C_ICRXD_ICTXD) & 0xff; + } + + writel(~RCAR_I2C_ICMSR_MDR, priv->base + RCAR_I2C_ICMSR); + + return rcar_i2c_finish(dev); +} + +static int rcar_i2c_write_common(struct udevice *dev, struct i2c_msg *msg) +{ + struct rcar_i2c_priv *priv = dev_get_priv(dev); + u32 icmcr = RCAR_I2C_ICMCR_MDBS | RCAR_I2C_ICMCR_MIE; + int i, ret = -EREMOTEIO; + + ret = rcar_i2c_set_addr(dev, msg->addr, 0); + if (ret) + return ret; + + for (i = 0; i < msg->len; i++) { + writel(msg->buf[i], priv->base + RCAR_I2C_ICRXD_ICTXD); + writel(icmcr, priv->base + RCAR_I2C_ICMCR); + writel(~RCAR_I2C_ICMSR_MDE, priv->base + RCAR_I2C_ICMSR); + + ret = wait_for_bit_le32(priv->base + RCAR_I2C_ICMSR, + RCAR_I2C_ICMSR_MDE, true, 100, true); + if (ret) + return ret; + } + + writel(~RCAR_I2C_ICMSR_MDE, priv->base + RCAR_I2C_ICMSR); + icmcr |= RCAR_I2C_ICMCR_FSB; + writel(icmcr, priv->base + RCAR_I2C_ICMCR); + + return rcar_i2c_finish(dev); +} + +static int rcar_i2c_xfer(struct udevice *dev, struct i2c_msg *msg, int nmsgs) +{ + int ret; + + for (; nmsgs > 0; nmsgs--, msg++) { + if (msg->flags & I2C_M_RD) + ret = rcar_i2c_read_common(dev, msg); + else + ret = rcar_i2c_write_common(dev, msg); + + if (ret) + return -EREMOTEIO; + } + + return ret; +} + +static int rcar_i2c_probe_chip(struct udevice *dev, uint addr, uint flags) +{ + struct rcar_i2c_priv *priv = dev_get_priv(dev); + int ret; + + /* Ignore address 0, slave address */ + if (addr == 0) + return -EINVAL; + + ret = rcar_i2c_set_addr(dev, addr, 1); + writel(0, priv->base + RCAR_I2C_ICMSR); + return ret; +} + +static int rcar_i2c_set_speed(struct udevice *dev, uint bus_freq_hz) +{ + struct rcar_i2c_priv *priv = dev_get_priv(dev); + u32 scgd, cdf, round, ick, sum, scl; + unsigned long rate; + + /* + * calculate SCL clock + * see + * ICCCR + * + * ick = clkp / (1 + CDF) + * SCL = ick / (20 + SCGD * 8 + F[(ticf + tr + intd) * ick]) + * + * ick : I2C internal clock < 20 MHz + * ticf : I2C SCL falling time + * tr : I2C SCL rising time + * intd : LSI internal delay + * clkp : peripheral_clk + * F[] : integer up-valuation + */ + rate = clk_get_rate(&priv->clk); + cdf = rate / 20000000; + if (cdf >= 8) { + dev_err(dev, "Input clock %lu too high\n", rate); + return -EIO; + } + ick = rate / (cdf + 1); + + /* + * it is impossible to calculate large scale + * number on u32. separate it + * + * F[(ticf + tr + intd) * ick] with sum = (ticf + tr + intd) + * = F[sum * ick / 1000000000] + * = F[(ick / 1000000) * sum / 1000] + */ + sum = 35 + 200 + priv->intdelay; + round = (ick + 500000) / 1000000 * sum; + round = (round + 500) / 1000; + + /* + * SCL = ick / (20 + SCGD * 8 + F[(ticf + tr + intd) * ick]) + * + * Calculation result (= SCL) should be less than + * bus_speed for hardware safety + * + * We could use something along the lines of + * div = ick / (bus_speed + 1) + 1; + * scgd = (div - 20 - round + 7) / 8; + * scl = ick / (20 + (scgd * 8) + round); + * (not fully verified) but that would get pretty involved + */ + for (scgd = 0; scgd < 0x40; scgd++) { + scl = ick / (20 + (scgd * 8) + round); + if (scl <= bus_freq_hz) + goto scgd_find; + } + dev_err(dev, "it is impossible to calculate best SCL\n"); + return -EIO; + +scgd_find: + dev_dbg(dev, "clk %d/%d(%lu), round %u, CDF:0x%x, SCGD: 0x%x\n", + scl, bus_freq_hz, clk_get_rate(&priv->clk), round, cdf, scgd); + + priv->icccr = (scgd << RCAR_I2C_ICCCR_SCGD_OFF) | cdf; + writel(priv->icccr, priv->base + RCAR_I2C_ICCCR); + + return 0; +} + +static int rcar_i2c_probe(struct udevice *dev) +{ + struct rcar_i2c_priv *priv = dev_get_priv(dev); + int ret; + + priv->base = dev_read_addr_ptr(dev); + priv->intdelay = dev_read_u32_default(dev, + "i2c-scl-internal-delay-ns", 5); + + ret = clk_get_by_index(dev, 0, &priv->clk); + if (ret) + return ret; + + ret = clk_enable(&priv->clk); + if (ret) + return ret; + + /* reset slave mode */ + writel(0, priv->base + RCAR_I2C_ICSIER); + writel(0, priv->base + RCAR_I2C_ICSAR); + writel(0, priv->base + RCAR_I2C_ICSCR); + writel(0, priv->base + RCAR_I2C_ICSSR); + + /* reset master mode */ + writel(0, priv->base + RCAR_I2C_ICMIER); + writel(0, priv->base + RCAR_I2C_ICMCR); + writel(0, priv->base + RCAR_I2C_ICMSR); + writel(0, priv->base + RCAR_I2C_ICMAR); + + ret = rcar_i2c_set_speed(dev, 100000); + if (ret) + clk_disable(&priv->clk); + + return ret; +} + +static const struct dm_i2c_ops rcar_i2c_ops = { + .xfer = rcar_i2c_xfer, + .probe_chip = rcar_i2c_probe_chip, + .set_bus_speed = rcar_i2c_set_speed, +}; + +static const struct udevice_id rcar_i2c_ids[] = { + { .compatible = "renesas,rcar-gen2-i2c" }, + { } +}; + +U_BOOT_DRIVER(i2c_rcar) = { + .name = "i2c_rcar", + .id = UCLASS_I2C, + .of_match = rcar_i2c_ids, + .probe = rcar_i2c_probe, + .priv_auto_alloc_size = sizeof(struct rcar_i2c_priv), + .ops = &rcar_i2c_ops, +};