This commit adds on-chip I2C driver used on some old Panasonic UniPhier SoCs.
Signed-off-by: Masahiro Yamada yamada.m@jp.panasonic.com ---
drivers/i2c/Kconfig | 14 +++ drivers/i2c/Makefile | 1 + drivers/i2c/i2c-uniphier.c | 225 +++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 240 insertions(+) create mode 100644 drivers/i2c/i2c-uniphier.c
diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig index e69de29..6a479ef 100644 --- a/drivers/i2c/Kconfig +++ b/drivers/i2c/Kconfig @@ -0,0 +1,14 @@ +config DM_I2C + bool "Enable Driver Model for I2C drivers" + depends on DM + help + If you want to use driver model for I2C drivers, say Y. + To use legacy I2C drivers, say N. + +config SYS_I2C_UNIPHIER + bool "UniPhier I2C driver" + depends on ARCH_UNIPHIER && DM_I2C + default y + help + Support for Panasonic UniPhier I2C controller driver. This I2C + controller is used on PH1-LD4, PH1-sLD8 or older UniPhier SoCs. diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile index 6f3c86c..e2fcd24 100644 --- a/drivers/i2c/Makefile +++ b/drivers/i2c/Makefile @@ -31,4 +31,5 @@ obj-$(CONFIG_SYS_I2C_SANDBOX) += sandbox_i2c.o i2c-emul-uclass.o obj-$(CONFIG_SYS_I2C_SH) += sh_i2c.o obj-$(CONFIG_SYS_I2C_SOFT) += soft_i2c.o obj-$(CONFIG_SYS_I2C_TEGRA) += tegra_i2c.o +obj-$(CONFIG_SYS_I2C_UNIPHIER) += i2c-uniphier.o obj-$(CONFIG_SYS_I2C_ZYNQ) += zynq_i2c.o diff --git a/drivers/i2c/i2c-uniphier.c b/drivers/i2c/i2c-uniphier.c new file mode 100644 index 0000000..05035ac --- /dev/null +++ b/drivers/i2c/i2c-uniphier.c @@ -0,0 +1,225 @@ +/* + * Copyright (C) 2014 Panasonic Corporation + * Author: Masahiro Yamada yamada.m@jp.panasonic.com + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> +#include <linux/types.h> +#include <asm/io.h> +#include <asm/errno.h> +#include <dm/device.h> +#include <dm/root.h> +#include <i2c.h> +#include <fdtdec.h> + +DECLARE_GLOBAL_DATA_PTR; + +#define I2C_DTRM 0x00 /* data transmission */ +#define I2C_DTRM_STA (1 << 10) +#define I2C_DTRM_STO (1 << 9) +#define I2C_DTRM_NACK (1 << 8) +#define I2C_DTRM_RD (1 << 0) +#define I2C_DREC 0x04 /* data reception */ +#define I2C_DREC_STS (1 << 12) +#define I2C_DREC_LRB (1 << 11) +#define I2C_DREC_LAB (1 << 9) +#define I2C_MYAD 0x08 +#define I2C_CLK 0x0c +#define I2C_BRST 0x10 /* bus reset */ +#define I2C_BRST_FOEN (1 << 1) +#define I2C_BRST_BRST (1 << 0) +#define I2C_HOLD 0x14 +#define I2C_BSTS 0x18 +#define I2C_NOISE 0x1c +#define I2C_SETUP 0x20 + +#define IOBUS_FREQ 100000000 + +struct uniphier_i2c_dev { + void __iomem *base; /* register base */ + unsigned long input_clk; /* master clock (Hz) */ + unsigned long wait_us; /* wait for every byte transfer (us) */ +}; + +static int uniphier_i2c_probe(struct udevice *dev) +{ + fdt_addr_t addr; + fdt_size_t size; + struct uniphier_i2c_dev *priv = dev_get_priv(dev); + + addr = fdtdec_get_addr_size(gd->fdt_blob, dev->of_offset, "reg", &size); + + priv->base = map_sysmem(addr, size); + + if (!priv->base) + return -ENOMEM; + + priv->input_clk = IOBUS_FREQ; + + /* deassert reset */ + writel(0x3, priv->base + I2C_BRST); + + return 0; +} + +static int uniphier_i2c_remove(struct udevice *dev) +{ + struct uniphier_i2c_dev *priv = dev_get_priv(dev); + + unmap_sysmem(priv->base); + + return 0; +} + +static int uniphier_i2c_child_pre_probe(struct udevice *dev) +{ + struct dm_i2c_chip *i2c_chip = dev_get_parentdata(dev); + + if (dev->of_offset == -1) + return 0; + return i2c_chip_ofdata_to_platdata(gd->fdt_blob, dev->of_offset, + i2c_chip); +} + +static int send_and_recv_byte(struct uniphier_i2c_dev *dev, u32 dtrm) +{ + writel(dtrm, dev->base + I2C_DTRM); + + /* + * U-Boot does not have a good support of interrupt. + * Wait for a while. + */ + udelay(dev->wait_us); + + return readl(dev->base + I2C_DREC); +} + +static int send_byte(struct uniphier_i2c_dev *dev, u32 dtrm, bool *stop) +{ + int ret = 0; + u32 drec; + + drec = send_and_recv_byte(dev, dtrm); + + if (drec & I2C_DREC_LAB) { + debug("uniphier_i2c: bus arbitration failed\n"); + *stop = false; + ret = -EREMOTEIO; + } + if (drec & I2C_DREC_LRB) { + debug("uniphier_i2c: slave did not return ACK\n"); + ret = -EREMOTEIO; + } + return ret; +} + +static int uniphier_i2c_transmit(struct uniphier_i2c_dev *dev, + uint addr, uint len, const u8 *buf) +{ + int ret; + bool stop = true; + + ret = send_byte(dev, I2C_DTRM_STA | I2C_DTRM_NACK | addr << 1, &stop); + if (ret < 0) + goto fail; + + while (len--) { + ret = send_byte(dev, I2C_DTRM_NACK | *buf++, &stop); + if (ret < 0) + goto fail; + } + +fail: + if (stop) + writel(I2C_DTRM_STO | I2C_DTRM_NACK, dev->base + I2C_DTRM); + + return ret; +} + +static int uniphier_i2c_receive(struct uniphier_i2c_dev *dev, + uint addr, uint len, u8 *buf) +{ + int ret; + bool stop = true; + + ret = send_byte(dev, I2C_DTRM_STA | I2C_DTRM_NACK | + I2C_DTRM_RD | addr << 1, &stop); + if (ret < 0) + goto fail; + + while (len--) + *buf++ = send_and_recv_byte(dev, len ? 0 : I2C_DTRM_NACK); + +fail: + if (stop) + writel(I2C_DTRM_STO | I2C_DTRM_NACK, dev->base + I2C_DTRM); + + return ret; +} + +static int uniphier_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, + int nmsgs) +{ + int ret = 0; + struct uniphier_i2c_dev *dev = dev_get_priv(bus); + + for (; nmsgs > 0; nmsgs--, msg++) { + if (msg->flags & I2C_M_RD) + ret = uniphier_i2c_receive(dev, msg->addr, + msg->len, msg->buf); + else + ret = uniphier_i2c_transmit(dev, msg->addr, + msg->len, msg->buf); + + if (ret < 0) + break; + } + + return ret; +} + +static int uniphier_i2c_set_bus_speed(struct udevice *bus, unsigned int speed) +{ + struct uniphier_i2c_dev *priv = dev_get_priv(bus); + + /* max supported frequency is 400 kHz */ + if (speed > 400000) + return -EINVAL; + + /* bus reset: make sure the bus is idle when change the freqency */ + writel(0x1, priv->base + I2C_BRST); + + writel((priv->input_clk / speed / 2 << 16) | (priv->input_clk / speed), + priv->base + I2C_CLK); + + writel(0x3, priv->base + I2C_BRST); + + priv->wait_us = 20000000 / speed; + + return 0; +} + + +static const struct dm_i2c_ops uniphier_i2c_ops = { + .xfer = uniphier_i2c_xfer, + .set_bus_speed = uniphier_i2c_set_bus_speed, +}; + +static const struct udevice_id uniphier_i2c_of_match[] = { + { .compatible = "panasonic,uniphier-i2c" }, + {}, +}; + +U_BOOT_DRIVER(uniphier_i2c) = { + .name = "uniphier-i2c", + .id = UCLASS_I2C, + .of_match = uniphier_i2c_of_match, + .probe = uniphier_i2c_probe, + .remove = uniphier_i2c_remove, + .per_child_auto_alloc_size = sizeof(struct dm_i2c_chip), + .child_pre_probe = uniphier_i2c_child_pre_probe, + .priv_auto_alloc_size = sizeof(struct uniphier_i2c_dev), + .ops = &uniphier_i2c_ops, +};