Add I2C driver code for the Microchip PolarFire SoC. This driver supports I2C data transfer and probe for I2C slave addresses.
Signed-off-by: Padmarao Begari padmarao.begari@microchip.com Reviewed-by: Leo Yu-Chi Liang ycliang@andestech.com --- drivers/i2c/Kconfig | 6 + drivers/i2c/Makefile | 1 + drivers/i2c/i2c-microchip.c | 482 ++++++++++++++++++++++++++++++++++++ 3 files changed, 489 insertions(+) create mode 100644 drivers/i2c/i2c-microchip.c
diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig index 7c447a8aa0..5482a4a470 100644 --- a/drivers/i2c/Kconfig +++ b/drivers/i2c/Kconfig @@ -250,6 +250,12 @@ config SYS_I2C_MESON internal buffer holding up to 8 bytes for transfers and supports both 7-bit and 10-bit addresses.
+config SYS_I2C_MICROCHIP + bool "Microchip I2C driver" + help + Add support for the Microchip I2C driver. This is operating on + standard mode up to 100 kbits/s and fast mode up to 400 kbits/s. + config SYS_I2C_MXC bool "NXP MXC I2C driver" help diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile index fca6b157f8..9d41f379bb 100644 --- a/drivers/i2c/Makefile +++ b/drivers/i2c/Makefile @@ -28,6 +28,7 @@ obj-$(CONFIG_SYS_I2C_IPROC) += iproc_i2c.o obj-$(CONFIG_SYS_I2C_KONA) += kona_i2c.o obj-$(CONFIG_SYS_I2C_LPC32XX) += lpc32xx_i2c.o obj-$(CONFIG_SYS_I2C_MESON) += meson_i2c.o +obj-$(CONFIG_SYS_I2C_MICROCHIP) += i2c-microchip.o obj-$(CONFIG_SYS_I2C_MV) += mv_i2c.o obj-$(CONFIG_SYS_I2C_MVTWSI) += mvtwsi.o obj-$(CONFIG_SYS_I2C_MXC) += mxc_i2c.o diff --git a/drivers/i2c/i2c-microchip.c b/drivers/i2c/i2c-microchip.c new file mode 100644 index 0000000000..12f65d0af7 --- /dev/null +++ b/drivers/i2c/i2c-microchip.c @@ -0,0 +1,482 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Microchip I2C controller driver + * + * Copyright (C) 2021 Microchip Technology Inc. + * Padmarao Begari padmarao.begari@microchip.com + */ +#include <common.h> +#include <clk.h> +#include <dm.h> +#include <i2c.h> +#include <asm/io.h> +#include <dm/device_compat.h> +#include <linux/bitops.h> +#include <linux/delay.h> +#include <linux/err.h> + +#define MICROCHIP_I2C_TIMEOUT (1000 * 60) + +#define MPFS_I2C_CTRL (0x00) +#define CTRL_CR0 (0x00) +#define CTRL_CR1 (0x01) +#define CTRL_AA BIT(2) +#define CTRL_SI BIT(3) +#define CTRL_STO BIT(4) +#define CTRL_STA BIT(5) +#define CTRL_ENS1 BIT(6) +#define CTRL_CR2 (0x07) +#define MPFS_I2C_STATUS (0x04) +#define STATUS_BUS_ERROR (0x00) +#define STATUS_M_START_SENT (0x08) +#define STATUS_M_REPEATED_START_SENT (0x10) +#define STATUS_M_SLAW_ACK (0x18) +#define STATUS_M_SLAW_NACK (0x20) +#define STATUS_M_TX_DATA_ACK (0x28) +#define STATUS_M_TX_DATA_NACK (0x30) +#define STATUS_M_ARB_LOST (0x38) +#define STATUS_M_SLAR_ACK (0x40) +#define STATUS_M_SLAR_NACK (0x48) +#define STATUS_M_RX_DATA_ACKED (0x50) +#define STATUS_M_RX_DATA_NACKED (0x58) +#define STATUS_S_SLAW_ACKED (0x60) +#define STATUS_S_ARB_LOST_SLAW_ACKED (0x68) +#define STATUS_S_GENERAL_CALL_ACKED (0x70) +#define STATUS_S_ARB_LOST_GENERAL_CALL_ACKED (0x78) +#define STATUS_S_RX_DATA_ACKED (0x80) +#define STATUS_S_RX_DATA_NACKED (0x88) +#define STATUS_S_GENERAL_CALL_RX_DATA_ACKED (0x90) +#define STATUS_S_GENERAL_CALL_RX_DATA_NACKED (0x98) +#define STATUS_S_RX_STOP (0xA0) +#define STATUS_S_SLAR_ACKED (0xA8) +#define STATUS_S_ARB_LOST_SLAR_ACKED (0xB0) +#define STATUS_S_TX_DATA_ACK (0xb8) +#define STATUS_S_TX_DATA_NACK (0xC0) +#define STATUS_LAST_DATA_ACK (0xC8) +#define STATUS_M_SMB_MASTER_RESET (0xD0) +#define STATUS_S_SCL_LOW_TIMEOUT (0xD8) +#define STATUS_NO_STATE_INFO (0xF8) +#define MPFS_I2C_DATA (0x08) +#define MPFS_I2C_SLAVE0_ADDR (0x0c) +#define MPFS_I2C_SMBUS (0x10) +#define MPFS_I2C_FREQ (0x14) +#define MPFS_I2C_GLITCHREG (0x18) +#define MPFS_I2C_SLAVE1_ADDR (0x1c) + +#define PCLK_DIV_256 ((0 << CTRL_CR0) | (0 << CTRL_CR1) | (0 << CTRL_CR2)) +#define PCLK_DIV_224 ((1 << CTRL_CR0) | (0 << CTRL_CR1) | (0 << CTRL_CR2)) +#define PCLK_DIV_192 ((0 << CTRL_CR0) | (1 << CTRL_CR1) | (0 << CTRL_CR2)) +#define PCLK_DIV_160 ((1 << CTRL_CR0) | (1 << CTRL_CR1) | (0 << CTRL_CR2)) +#define PCLK_DIV_960 ((0 << CTRL_CR0) | (0 << CTRL_CR1) | (1 << CTRL_CR2)) +#define PCLK_DIV_120 ((1 << CTRL_CR0) | (0 << CTRL_CR1) | (1 << CTRL_CR2)) +#define PCLK_DIV_60 ((0 << CTRL_CR0) | (1 << CTRL_CR1) | (1 << CTRL_CR2)) +#define BCLK_DIV_8 ((1 << CTRL_CR0) | (1 << CTRL_CR1) | (1 << CTRL_CR2)) +#define CLK_MASK ((1 << CTRL_CR0) | (1 << CTRL_CR1) | (1 << CTRL_CR2)) + +/* + * mpfs_i2c_bus - I2C bus context + * @base: pointer to register struct + * @msg_len: number of bytes transferred in msg + * @msg_err: error code for completed message + * @i2c_clk: clock reference for i2c input clock + * @clk_rate: current i2c bus clock rate + * @buf: ptr to msg buffer for easier use. + * @addr: i2c address. + * @isr_status: cached copy of local ISR status. + */ +struct mpfs_i2c_bus { + void __iomem *base; + size_t msg_len; + int msg_err; + struct clk i2c_clk; + u32 clk_rate; + u8 *buf; + u8 addr; + u32 isr_status; +}; + +static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg) +{ + return (msg->addr << 1) | (msg->flags & I2C_M_RD ? 1 : 0); +} + +static void mpfs_i2c_int_clear(struct mpfs_i2c_bus *bus) +{ + u8 ctrl = readl(bus->base + MPFS_I2C_CTRL); + + ctrl &= ~CTRL_SI; + writel(ctrl, bus->base + MPFS_I2C_CTRL); +} + +static void mpfs_i2c_core_disable(struct mpfs_i2c_bus *bus) +{ + u8 ctrl = readl(bus->base + MPFS_I2C_CTRL); + + ctrl &= ~CTRL_ENS1; + writel(ctrl, bus->base + MPFS_I2C_CTRL); +} + +static void mpfs_i2c_core_enable(struct mpfs_i2c_bus *bus) +{ + u8 ctrl = readl(bus->base + MPFS_I2C_CTRL); + + ctrl |= CTRL_ENS1; + writel(ctrl, bus->base + MPFS_I2C_CTRL); +} + +static void mpfs_i2c_reset(struct mpfs_i2c_bus *bus) +{ + mpfs_i2c_core_disable(bus); + mpfs_i2c_core_enable(bus); +} + +static inline void mpfs_i2c_stop(struct mpfs_i2c_bus *bus) +{ + u8 ctrl = readl(bus->base + MPFS_I2C_CTRL); + + ctrl |= CTRL_STO; + writel(ctrl, bus->base + MPFS_I2C_CTRL); +} + +static inline int mpfs_generate_divisor(u32 rate, u8 *code) +{ + int ret = 0; + + if (rate >= 960) + *code = PCLK_DIV_960; + else if (rate >= 256) + *code = PCLK_DIV_256; + else if (rate >= 224) + *code = PCLK_DIV_224; + else if (rate >= 192) + *code = PCLK_DIV_192; + else if (rate >= 160) + *code = PCLK_DIV_160; + else if (rate >= 120) + *code = PCLK_DIV_120; + else if (rate >= 60) + *code = PCLK_DIV_60; + else if (rate >= 8) + *code = BCLK_DIV_8; + else + ret = -EINVAL; + + return ret; +} + +static int mpfs_i2c_init(struct mpfs_i2c_bus *bus, struct udevice *dev) +{ + u32 clk_rate, divisor; + u8 clkval, ctrl; + int ret; + + ret = clk_get_by_index(dev, 0, &bus->i2c_clk); + if (ret) + return -EINVAL; + + ret = clk_enable(&bus->i2c_clk); + if (ret) + return ret; + + clk_rate = clk_get_rate(&bus->i2c_clk); + if (!clk_rate) + return -EINVAL; + + clk_free(&bus->i2c_clk); + + divisor = clk_rate / bus->clk_rate; + + ctrl = readl(bus->base + MPFS_I2C_CTRL); + + ctrl &= ~CLK_MASK; + + ret = mpfs_generate_divisor(divisor, &clkval); + if (ret) + return -EINVAL; + + ctrl |= clkval; + + writel(ctrl, bus->base + MPFS_I2C_CTRL); + + ctrl = readl(bus->base + MPFS_I2C_CTRL); + + /* Reset I2C core */ + mpfs_i2c_reset(bus); + + return 0; +} + +static void mpfs_i2c_transfer(struct mpfs_i2c_bus *bus, u32 data) +{ + if (bus->msg_len > 0) + writel(data, bus->base + MPFS_I2C_DATA); +} + +static void mpfs_i2c_empty_rx(struct mpfs_i2c_bus *bus) +{ + u8 ctrl; + u8 data_read; + + if (bus->msg_len > 0) { + data_read = readl(bus->base + MPFS_I2C_DATA); + *bus->buf++ = data_read; + bus->msg_len--; + } + + if (bus->msg_len == 0) { + ctrl = readl(bus->base + MPFS_I2C_CTRL); + ctrl &= ~CTRL_AA; + writel(ctrl, bus->base + MPFS_I2C_CTRL); + } +} + +static int mpfs_i2c_fill_tx(struct mpfs_i2c_bus *bus) +{ + mpfs_i2c_transfer(bus, *bus->buf++); + bus->msg_len--; + + return 0; +} + +static int mpfs_i2c_service_handler(struct mpfs_i2c_bus *bus) +{ + bool finish = false; + u32 status; + u8 ctrl; + + status = bus->isr_status; + + switch (status) { + case STATUS_M_START_SENT: + case STATUS_M_REPEATED_START_SENT: + ctrl = readl(bus->base + MPFS_I2C_CTRL); + ctrl &= ~CTRL_STA; + writel(bus->addr, bus->base + MPFS_I2C_DATA); + writel(ctrl, bus->base + MPFS_I2C_CTRL); + break; + case STATUS_M_SLAW_ACK: + case STATUS_M_TX_DATA_ACK: + if (bus->msg_len > 0) { + mpfs_i2c_fill_tx(bus); + } else { + /* On the last byte to be transmitted, send STOP */ + mpfs_i2c_stop(bus); + finish = true; + } + break; + case STATUS_M_SLAR_ACK: + ctrl = readl(bus->base + MPFS_I2C_CTRL); + ctrl |= CTRL_AA; + writel(ctrl, bus->base + MPFS_I2C_CTRL); + if (bus->msg_len == 0) { + /* On the last byte to be transmitted, send STOP */ + mpfs_i2c_stop(bus); + finish = true; + } + break; + case STATUS_M_RX_DATA_ACKED: + mpfs_i2c_empty_rx(bus); + if (bus->msg_len == 0) { + /* On the last byte to be transmitted, send STOP */ + mpfs_i2c_stop(bus); + finish = true; + } + break; + case STATUS_M_TX_DATA_NACK: + case STATUS_M_RX_DATA_NACKED: + case STATUS_M_SLAR_NACK: + case STATUS_M_SLAW_NACK: + bus->msg_err = -ENXIO; + mpfs_i2c_stop(bus); + finish = true; + break; + + case STATUS_M_ARB_LOST: + /* Handle Lost Arbitration */ + bus->msg_err = -EAGAIN; + finish = true; + break; + default: + break; + } + + if (finish) { + ctrl = readl(bus->base + MPFS_I2C_CTRL); + ctrl &= ~CTRL_AA; + writel(ctrl, bus->base + MPFS_I2C_CTRL); + return 0; + } + + return 1; +} + +static int mpfs_i2c_service(struct mpfs_i2c_bus *bus) +{ + int ret = 0; + int si_bit; + + si_bit = readl(bus->base + MPFS_I2C_CTRL); + if (si_bit & CTRL_SI) { + bus->isr_status = readl(bus->base + MPFS_I2C_STATUS); + ret = mpfs_i2c_service_handler(bus); + } + /* Clear the si flag */ + mpfs_i2c_int_clear(bus); + si_bit = readl(bus->base + MPFS_I2C_CTRL); + + return ret; +} + +static int mpfs_i2c_check_service_change(struct mpfs_i2c_bus *bus) +{ + u8 ctrl; + u32 count = 0; + + while (1) { + ctrl = readl(bus->base + MPFS_I2C_CTRL); + if (ctrl & CTRL_SI) + break; + udelay(1); + count += 1; + if (count == MICROCHIP_I2C_TIMEOUT) + return -ETIMEDOUT; + } + return 0; +} + +static int mpfs_i2c_poll_device(struct mpfs_i2c_bus *bus) +{ + int ret; + + while (1) { + ret = mpfs_i2c_check_service_change(bus); + if (ret) + return ret; + + ret = mpfs_i2c_service(bus); + if (!ret) + /* all messages have been transferred */ + return ret; + } +} + +static int mpfs_i2c_xfer_msg(struct mpfs_i2c_bus *bus, struct i2c_msg *msg) +{ + u8 ctrl; + int ret; + + if (!msg->len || !msg->buf) + return -EINVAL; + + bus->addr = i2c_8bit_addr_from_msg(msg); + bus->msg_len = msg->len; + bus->buf = msg->buf; + bus->msg_err = 0; + + mpfs_i2c_core_enable(bus); + + ctrl = readl(bus->base + MPFS_I2C_CTRL); + + ctrl |= CTRL_STA; + + writel(ctrl, bus->base + MPFS_I2C_CTRL); + + ret = mpfs_i2c_poll_device(bus); + if (ret) + return ret; + + return bus->msg_err; +} + +static int mpfs_i2c_xfer(struct udevice *dev, struct i2c_msg *msgs, int num_msgs) +{ + struct mpfs_i2c_bus *bus = dev_get_priv(dev); + int idx, ret; + + if (!msgs || !num_msgs) + return -EINVAL; + + for (idx = 0; idx < num_msgs; idx++) { + ret = mpfs_i2c_xfer_msg(bus, msgs++); + if (ret) + return ret; + } + + return ret; +} + +static int mpfs_i2c_probe_chip(struct udevice *dev, uint addr, uint flags) +{ + struct mpfs_i2c_bus *bus = dev_get_priv(dev); + int ret; + u8 ctrl, reg = 0; + + /* + * Send the chip address and verify that the + * address was <ACK>ed. + */ + bus->addr = addr << 1 | I2C_M_RD; + bus->buf = ® + bus->msg_len = 0; + bus->msg_err = 0; + + mpfs_i2c_core_enable(bus); + + ctrl = readl(bus->base + MPFS_I2C_CTRL); + + ctrl |= CTRL_STA; + + writel(ctrl, bus->base + MPFS_I2C_CTRL); + + ret = mpfs_i2c_poll_device(bus); + if (ret) + return ret; + + return bus->msg_err; +} + +static int mpfs_i2c_probe(struct udevice *dev) +{ + int ret; + u32 val; + struct mpfs_i2c_bus *bus = dev_get_priv(dev); + + bus->base = dev_read_addr_ptr(dev); + if (!bus->base) + return -EINVAL; + + val = dev_read_u32(dev, "clock-frequency", &bus->clk_rate); + if (val) { + printf("Default to 100kHz\n"); + /* default clock rate */ + bus->clk_rate = 100000; + } + + if (bus->clk_rate > 400000 || bus->clk_rate <= 0) { + printf("Invalid clock-frequency %d\n", bus->clk_rate); + return -EINVAL; + } + + ret = mpfs_i2c_init(bus, dev); + + return ret; +} + +static const struct dm_i2c_ops mpfs_i2c_ops = { + .xfer = mpfs_i2c_xfer, + .probe_chip = mpfs_i2c_probe_chip, +}; + +static const struct udevice_id mpfs_i2c_ids[] = { + {.compatible = "microchip,mpfs-i2c"}, + {} +}; + +U_BOOT_DRIVER(mpfs_i2c) = { + .name = "mpfs_i2c", + .id = UCLASS_I2C, + .of_match = mpfs_i2c_ids, + .ops = &mpfs_i2c_ops, + .probe = mpfs_i2c_probe, + .priv_auto = sizeof(struct mpfs_i2c_bus), +};