Add Device Model based I2C driver for ast2500/ast2400 SoCs. The driver is very limited, it only supports master mode and synchronous byte-by-byte reads/writes, no DMA or Pool Buffers.
Signed-off-by: Maxim Sloyko maxims@google.com
---
Changes in v1: - Style fixes
--- drivers/i2c/Kconfig | 9 ++ drivers/i2c/Makefile | 1 + drivers/i2c/ast_i2c.c | 357 ++++++++++++++++++++++++++++++++++++++++++++++++++ drivers/i2c/ast_i2c.h | 132 +++++++++++++++++++ 4 files changed, 499 insertions(+) create mode 100644 drivers/i2c/ast_i2c.c create mode 100644 drivers/i2c/ast_i2c.h
diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig index 39f62daf5d..e661a308b0 100644 --- a/drivers/i2c/Kconfig +++ b/drivers/i2c/Kconfig @@ -100,6 +100,15 @@ config SYS_I2C_DW_ENABLE_STATUS_UNSUPPORTED enable status register. This config option can be enabled in such cases.
+config SYS_I2C_ASPEED + bool "Aspeed I2C Controller" + depends on DM_I2C && ARCH_ASPEED + help + Say yes here to select Aspeed I2C Host Controller. The driver + supports AST2500 and AST2400 controllers, but is very limited. + Only single master mode is supported and only byte-by-byte + synchronous reads and writes are supported, no Pool Buffers or DMA. + config SYS_I2C_INTEL bool "Intel I2C/SMBUS driver" depends on DM_I2C diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile index 7c86198863..229fd476db 100644 --- a/drivers/i2c/Makefile +++ b/drivers/i2c/Makefile @@ -16,6 +16,7 @@ obj-$(CONFIG_PCA9564_I2C) += pca9564_i2c.o obj-$(CONFIG_TSI108_I2C) += tsi108_i2c.o obj-$(CONFIG_SH_SH7734_I2C) += sh_sh7734_i2c.o obj-$(CONFIG_SYS_I2C) += i2c_core.o +obj-$(CONFIG_SYS_I2C_ASPEED) += ast_i2c.o obj-$(CONFIG_SYS_I2C_AT91) += at91_i2c.o obj-$(CONFIG_SYS_I2C_CADENCE) += i2c-cdns.o obj-$(CONFIG_SYS_I2C_DAVINCI) += davinci_i2c.o diff --git a/drivers/i2c/ast_i2c.c b/drivers/i2c/ast_i2c.c new file mode 100644 index 0000000000..16dfb57066 --- /dev/null +++ b/drivers/i2c/ast_i2c.c @@ -0,0 +1,357 @@ +/* + * Copyright (C) 2012-2020 ASPEED Technology Inc. + * Copyright 2016 IBM Corporation + * Copyright 2017 Google, Inc. + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> +#include <clk.h> +#include <dm.h> +#include <errno.h> +#include <fdtdec.h> +#include <i2c.h> +#include <asm/io.h> +#include <asm/arch/scu_ast2500.h> + +#include "ast_i2c.h" + +#define I2C_TIMEOUT_US 100000 +#define I2C_SLEEP_STEP_US 20 + +#define HIGHSPEED_TTIMEOUT 3 + +DECLARE_GLOBAL_DATA_PTR; + +/* + * Device private data + */ +struct ast_i2c_priv { + /* This device's clock */ + struct clk clk; + /* Device registers */ + struct ast_i2c_regs *regs; + /* I2C speed in Hz */ + int speed; +}; + +/* + * Given desired divider ratio, return the value that needs to be set + * in Clock and AC Timing Control register + */ +static u32 get_clk_reg_val(ulong divider_ratio) +{ + ulong inc = 0, div; + ulong scl_low, scl_high, data; + + for (div = 0; divider_ratio >= 16; div++) { + inc |= (divider_ratio & 1); + divider_ratio >>= 1; + } + divider_ratio += inc; + scl_low = (divider_ratio >> 1) - 1; + scl_high = divider_ratio - scl_low - 2; + data = I2CD_CACTC_BASE + | (scl_high << I2CD_TCKHIGH_SHIFT) + | (scl_low << I2CD_TCKLOW_SHIFT) + | (div << I2CD_BASE_DIV_SHIFT); + + return data; +} + +static void ast_i2c_clear_interrupts(struct udevice *dev) +{ + struct ast_i2c_priv *priv = dev_get_priv(dev); + + writel(~0, &priv->regs->isr); +} + +static void ast_i2c_init_bus(struct udevice *dev) +{ + struct ast_i2c_priv *priv = dev_get_priv(dev); + + /* Reset device */ + writel(0, &priv->regs->fcr); + /* Enable Master Mode. Assuming single-master */ + writel(I2CD_MASTER_EN + | I2CD_M_SDA_LOCK_EN + | I2CD_MULTI_MASTER_DIS | I2CD_M_SCL_DRIVE_EN, + &priv->regs->fcr); + /* Enable Interrupts */ + writel(I2CD_INTR_TX_ACK + | I2CD_INTR_TX_NAK + | I2CD_INTR_RX_DONE + | I2CD_INTR_BUS_RECOVER_DONE + | I2CD_INTR_NORMAL_STOP + | I2CD_INTR_ABNORMAL, &priv->regs->icr); +} + +static int ast_i2c_ofdata_to_platdata(struct udevice *dev) +{ + struct ast_i2c_priv *priv = dev_get_priv(dev); + int ret; + + priv->regs = dev_get_addr_ptr(dev); + if (IS_ERR(priv->regs)) + return PTR_ERR(priv->regs); + + ret = clk_get_by_index(dev, 0, &priv->clk); + if (ret < 0) { + debug("%s: Can't get clock for %s: %d\n", __func__, dev->name, + ret); + return ret; + } + + return 0; +} + +static int ast_i2c_probe(struct udevice *dev) +{ + struct ast2500_scu *scu; + + debug("Enabling I2C%u\n", dev->seq); + + /* + * Get all I2C devices out of Reset. + * Only needs to be done once, but doing it for every + * device does not hurt. + */ + scu = ast_get_scu(); + ast_scu_unlock(scu); + clrbits_le32(&scu->sysreset_ctrl1, SCU_SYSRESET_I2C); + ast_scu_lock(scu); + + ast_i2c_init_bus(dev); + + return 0; +} + +static int ast_i2c_wait_isr(struct udevice *dev, u32 flag) +{ + struct ast_i2c_priv *priv = dev_get_priv(dev); + int timeout = I2C_TIMEOUT_US; + + while (!(readl(&priv->regs->isr) & flag) && timeout > 0) { + udelay(I2C_SLEEP_STEP_US); + timeout -= I2C_SLEEP_STEP_US; + } + + ast_i2c_clear_interrupts(dev); + if (timeout <= 0) + return -ETIMEDOUT; + + return 0; +} + +static int ast_i2c_send_stop(struct udevice *dev) +{ + struct ast_i2c_priv *priv = dev_get_priv(dev); + + writel(I2CD_M_STOP_CMD, &priv->regs->csr); + + return ast_i2c_wait_isr(dev, I2CD_INTR_NORMAL_STOP); +} + +static int ast_i2c_wait_tx(struct udevice *dev) +{ + struct ast_i2c_priv *priv = dev_get_priv(dev); + int timeout = I2C_TIMEOUT_US; + u32 flag = I2CD_INTR_TX_ACK | I2CD_INTR_TX_NAK; + u32 status = readl(&priv->regs->isr) & flag; + int ret = 0; + + while (!status && timeout > 0) { + status = readl(&priv->regs->isr) & flag; + udelay(I2C_SLEEP_STEP_US); + timeout -= I2C_SLEEP_STEP_US; + } + + if (status == I2CD_INTR_TX_NAK) + ret = -EREMOTEIO; + + if (timeout <= 0) + ret = -ETIMEDOUT; + + ast_i2c_clear_interrupts(dev); + + return ret; +} + +static int ast_i2c_start_txn(struct udevice *dev, uint devaddr) +{ + struct ast_i2c_priv *priv = dev_get_priv(dev); + + /* Start and Send Device Address */ + writel(devaddr, &priv->regs->trbbr); + writel(I2CD_M_START_CMD | I2CD_M_TX_CMD, &priv->regs->csr); + + return ast_i2c_wait_tx(dev); +} + +static int ast_i2c_read_data(struct udevice *dev, u8 chip_addr, u8 *buffer, + size_t len, bool send_stop) +{ + struct ast_i2c_priv *priv = dev_get_priv(dev); + u32 i2c_cmd = I2CD_M_RX_CMD; + int ret; + + ret = ast_i2c_start_txn(dev, (chip_addr << 1) | I2C_M_RD); + if (ret < 0) + return ret; + + for (; len > 0; len--, buffer++) { + if (len == 1) + i2c_cmd |= I2CD_M_S_RX_CMD_LAST; + writel(i2c_cmd, &priv->regs->csr); + ret = ast_i2c_wait_isr(dev, I2CD_INTR_RX_DONE); + if (ret < 0) + return ret; + *buffer = (readl(&priv->regs->trbbr) & I2CD_RX_DATA_MASK) + >> I2CD_RX_DATA_SHIFT; + } + ast_i2c_clear_interrupts(dev); + + if (send_stop) + return ast_i2c_send_stop(dev); + + return 0; +} + +static int ast_i2c_write_data(struct udevice *dev, u8 chip_addr, u8 + *buffer, size_t len, bool send_stop) +{ + struct ast_i2c_priv *priv = dev_get_priv(dev); + int ret; + + ret = ast_i2c_start_txn(dev, (chip_addr << 1)); + if (ret < 0) + return ret; + + for (; len > 0; len--, buffer++) { + writel(*buffer, &priv->regs->trbbr); + writel(I2CD_M_TX_CMD, &priv->regs->csr); + ret = ast_i2c_wait_tx(dev); + if (ret < 0) + return ret; + } + + if (send_stop) + return ast_i2c_send_stop(dev); + + return 0; +} + +static int ast_i2c_deblock(struct udevice *dev) +{ + struct ast_i2c_priv *priv = dev_get_priv(dev); + struct ast_i2c_regs *regs = priv->regs; + u32 csr = readl(®s->csr); + bool sda_high = csr & I2CD_SDA_LINE_STS; + bool scl_high = csr & I2CD_SCL_LINE_STS; + int ret = 0; + + if (sda_high && scl_high) { + /* Bus is idle, no deblocking needed. */ + return 0; + } else if (sda_high) { + /* Send stop command */ + debug("Unterminated TXN in (%x), sending stop\n", csr); + ret = ast_i2c_send_stop(dev); + } else if (scl_high) { + /* Possibly stuck slave */ + debug("Bus stuck (%x), attempting recovery\n", csr); + writel(I2CD_BUS_RECOVER_CMD, ®s->csr); + ret = ast_i2c_wait_isr(dev, I2CD_INTR_BUS_RECOVER_DONE); + } else { + /* Just try to reinit the device. */ + ast_i2c_init_bus(dev); + } + + return ret; +} + +static int ast_i2c_xfer(struct udevice *dev, struct i2c_msg *msg, int nmsgs) +{ + int ret; + + ret = ast_i2c_deblock(dev); + if (ret < 0) + return ret; + + debug("i2c_xfer: %d messages\n", nmsgs); + for (; nmsgs > 0; nmsgs--, msg++) { + if (msg->flags & I2C_M_RD) { + debug("i2c_read: chip=0x%x, len=0x%x, flags=0x%x\n", + msg->addr, msg->len, msg->flags); + ret = ast_i2c_read_data(dev, msg->addr, msg->buf, + msg->len, (nmsgs == 1)); + } else { + debug("i2c_write: chip=0x%x, len=0x%x, flags=0x%x\n", + msg->addr, msg->len, msg->flags); + ret = ast_i2c_write_data(dev, msg->addr, msg->buf, + msg->len, (nmsgs == 1)); + } + if (ret) { + debug("%s: error (%d)\n", __func__, ret); + return -EREMOTEIO; + } + } + + return 0; +} + +static int ast_i2c_set_speed(struct udevice *dev, unsigned int speed) +{ + struct ast_i2c_priv *priv = dev_get_priv(dev); + struct ast_i2c_regs *regs = priv->regs; + ulong i2c_rate, divider; + + debug("Setting speed for I2C%d to <%u>\n", dev->seq, speed); + if (!speed) { + debug("No valid speed specified\n"); + return -EINVAL; + } + + i2c_rate = clk_get_rate(&priv->clk); + divider = i2c_rate / speed; + + priv->speed = speed; + if (speed > I2C_HIGHSPEED_RATE) { + debug("Enable High Speed\n"); + setbits_le32(®s->fcr, I2CD_M_HIGH_SPEED_EN + | I2CD_M_SDA_DRIVE_1T_EN + | I2CD_SDA_DRIVE_1T_EN); + writel(HIGHSPEED_TTIMEOUT, ®s->cactcr2); + } else { + debug("Enabling Normal Speed\n"); + writel(I2CD_NO_TIMEOUT_CTRL, ®s->cactcr2); + } + + writel(get_clk_reg_val(divider), ®s->cactcr1); + ast_i2c_clear_interrupts(dev); + + return 0; +} + +static const struct dm_i2c_ops ast_i2c_ops = { + .xfer = ast_i2c_xfer, + .set_bus_speed = ast_i2c_set_speed, + .deblock = ast_i2c_deblock, +}; + +static const struct udevice_id ast_i2c_ids[] = { + { .compatible = "aspeed,ast2400-i2c-bus" }, + { .compatible = "aspeed,ast2500-i2c-bus" }, + { }, +}; + +U_BOOT_DRIVER(ast_i2c) = { + .name = "ast_i2c", + .id = UCLASS_I2C, + .of_match = ast_i2c_ids, + .probe = ast_i2c_probe, + .ofdata_to_platdata = ast_i2c_ofdata_to_platdata, + .priv_auto_alloc_size = sizeof(struct ast_i2c_priv), + .ops = &ast_i2c_ops, +}; diff --git a/drivers/i2c/ast_i2c.h b/drivers/i2c/ast_i2c.h new file mode 100644 index 0000000000..e5dec7a480 --- /dev/null +++ b/drivers/i2c/ast_i2c.h @@ -0,0 +1,132 @@ +/* + * Copyright (C) 2012-2020 ASPEED Technology Inc. + * Copyright 2016 IBM Corporation + * Copyright 2017 Google, Inc. + * + * SPDX-License-Identifier: GPL-2.0+ + */ +#ifndef __AST_I2C_H_ +#define __AST_I2C_H_ + +struct ast_i2c_regs { + u32 fcr; + u32 cactcr1; + u32 cactcr2; + u32 icr; + u32 isr; + u32 csr; + u32 sdar; + u32 pbcr; + u32 trbbr; +#ifdef CONFIG_ASPEED_AST2500 + u32 dma_mbar; + u32 dma_tlr; +#endif +}; + +/* Device Register Definition */ +/* 0x00 : I2CD Function Control Register */ +#define I2CD_BUFF_SEL_MASK (0x7 << 20) +#define I2CD_BUFF_SEL(x) (x << 20) +#define I2CD_M_SDA_LOCK_EN (0x1 << 16) +#define I2CD_MULTI_MASTER_DIS (0x1 << 15) +#define I2CD_M_SCL_DRIVE_EN (0x1 << 14) +#define I2CD_MSB_STS (0x1 << 9) +#define I2CD_SDA_DRIVE_1T_EN (0x1 << 8) +#define I2CD_M_SDA_DRIVE_1T_EN (0x1 << 7) +#define I2CD_M_HIGH_SPEED_EN (0x1 << 6) +#define I2CD_DEF_ADDR_EN (0x1 << 5) +#define I2CD_DEF_ALERT_EN (0x1 << 4) +#define I2CD_DEF_ARP_EN (0x1 << 3) +#define I2CD_DEF_GCALL_EN (0x1 << 2) +#define I2CD_SLAVE_EN (0x1 << 1) +#define I2CD_MASTER_EN (0x1) + +/* 0x04 : I2CD Clock and AC Timing Control Register #1 */ +/* Base register value. These bits are always set by the driver. */ +#define I2CD_CACTC_BASE 0xfff00300 +#define I2CD_TCKHIGH_SHIFT 16 +#define I2CD_TCKLOW_SHIFT 12 +#define I2CD_THDDAT_SHIFT 10 +#define I2CD_TO_DIV_SHIFT 8 +#define I2CD_BASE_DIV_SHIFT 0 + +/* 0x08 : I2CD Clock and AC Timing Control Register #2 */ +#define I2CD_tTIMEOUT 1 +#define I2CD_NO_TIMEOUT_CTRL 0 + +/* 0x0c : I2CD Interrupt Control Register & + * 0x10 : I2CD Interrupt Status Register + * + * These share bit definitions, so use the same values for the enable & + * status bits. + */ +#define I2CD_INTR_SDA_DL_TIMEOUT (0x1 << 14) +#define I2CD_INTR_BUS_RECOVER_DONE (0x1 << 13) +#define I2CD_INTR_SMBUS_ALERT (0x1 << 12) +#define I2CD_INTR_SMBUS_ARP_ADDR (0x1 << 11) +#define I2CD_INTR_SMBUS_DEV_ALERT_ADDR (0x1 << 10) +#define I2CD_INTR_SMBUS_DEF_ADDR (0x1 << 9) +#define I2CD_INTR_GCALL_ADDR (0x1 << 8) +#define I2CD_INTR_SLAVE_MATCH (0x1 << 7) +#define I2CD_INTR_SCL_TIMEOUT (0x1 << 6) +#define I2CD_INTR_ABNORMAL (0x1 << 5) +#define I2CD_INTR_NORMAL_STOP (0x1 << 4) +#define I2CD_INTR_ARBIT_LOSS (0x1 << 3) +#define I2CD_INTR_RX_DONE (0x1 << 2) +#define I2CD_INTR_TX_NAK (0x1 << 1) +#define I2CD_INTR_TX_ACK (0x1 << 0) + +/* 0x14 : I2CD Command/Status Register */ +#define I2CD_SDA_OE (0x1 << 28) +#define I2CD_SDA_O (0x1 << 27) +#define I2CD_SCL_OE (0x1 << 26) +#define I2CD_SCL_O (0x1 << 25) +#define I2CD_TX_TIMING (0x1 << 24) +#define I2CD_TX_STATUS (0x1 << 23) + +/* Tx State Machine */ +#define I2CD_IDLE 0x0 +#define I2CD_MACTIVE 0x8 +#define I2CD_MSTART 0x9 +#define I2CD_MSTARTR 0xa +#define I2CD_MSTOP 0xb +#define I2CD_MTXD 0xc +#define I2CD_MRXACK 0xd +#define I2CD_MRXD 0xe +#define I2CD_MTXACK 0xf +#define I2CD_SWAIT 0x1 +#define I2CD_SRXD 0x4 +#define I2CD_STXACK 0x5 +#define I2CD_STXD 0x6 +#define I2CD_SRXACK 0x7 +#define I2CD_RECOVER 0x3 + +#define I2CD_SCL_LINE_STS (0x1 << 18) +#define I2CD_SDA_LINE_STS (0x1 << 17) +#define I2CD_BUS_BUSY_STS (0x1 << 16) +#define I2CD_SDA_OE_OUT_DIR (0x1 << 15) +#define I2CD_SDA_O_OUT_DIR (0x1 << 14) +#define I2CD_SCL_OE_OUT_DIR (0x1 << 13) +#define I2CD_SCL_O_OUT_DIR (0x1 << 12) +#define I2CD_BUS_RECOVER_CMD (0x1 << 11) +#define I2CD_S_ALT_EN (0x1 << 10) +#define I2CD_RX_DMA_ENABLE (0x1 << 9) +#define I2CD_TX_DMA_ENABLE (0x1 << 8) + +/* Command Bit */ +#define I2CD_RX_BUFF_ENABLE (0x1 << 7) +#define I2CD_TX_BUFF_ENABLE (0x1 << 6) +#define I2CD_M_STOP_CMD (0x1 << 5) +#define I2CD_M_S_RX_CMD_LAST (0x1 << 4) +#define I2CD_M_RX_CMD (0x1 << 3) +#define I2CD_S_TX_CMD (0x1 << 2) +#define I2CD_M_TX_CMD (0x1 << 1) +#define I2CD_M_START_CMD 0x1 + +#define I2CD_RX_DATA_SHIFT 8 +#define I2CD_RX_DATA_MASK (0xff << I2CD_RX_DATA_SHIFT) + +#define I2C_HIGHSPEED_RATE 400000 + +#endif /* __AST_I2C_H_ */