[U-Boot] [PATCH u-boot 5/5] aspeed: I2C driver.
Simon Glass
sjg at google.com
Wed Nov 23 17:13:38 CET 2016
Hi Maxim,
On 22 November 2016 at 16:56, <maxims at google.com> wrote:
> From: Maxim Sloyko <maxims at google.com>
>
> The driver 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.
Please add that into the Kconfig help too.
>
> Signed-off-by: Maxim Sloyko <maxims at google.com>
> ---
> drivers/i2c/Kconfig | 7 ++
> drivers/i2c/Makefile | 1 +
> drivers/i2c/ast_i2c.c | 305 ++++++++++++++++++++++++++++++++++++++++++++++++++
> drivers/i2c/ast_i2c.h | 143 +++++++++++++++++++++++
> 4 files changed, 456 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 6e22bba..720c475 100644
> --- a/drivers/i2c/Kconfig
> +++ b/drivers/i2c/Kconfig
> @@ -90,6 +90,13 @@ config SYS_I2C_DW_ENABLE_STATUS_UNSUPPORTED
> enable status register. This config option can be enabled in such
> cases.
>
> +config SYS_I2C_AST
> + bool "Aspeed I2C Controller"
> + depends on DM_I2C
> + help
> + Say yes here to select Aspeed I2C Host Controller. The driver
> + supports AST2500 and AST2400 controllers.
> +
> config SYS_I2C_INTEL
> bool "Intel I2C/SMBUS driver"
> depends on DM_I2C
> diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile
> index 167424d..89e046e 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-$(CONFIG_SYS_I2C_AST) += ast_i2c.o
> obj-$(CONFIG_SYS_I2C_CADENCE) += i2c-cdns.o
> obj-$(CONFIG_SYS_I2C_DAVINCI) += davinci_i2c.o
> obj-$(CONFIG_SYS_I2C_DW) += designware_i2c.o
> diff --git a/drivers/i2c/ast_i2c.c b/drivers/i2c/ast_i2c.c
> new file mode 100644
> index 0000000..f2c132e
> --- /dev/null
> +++ b/drivers/i2c/ast_i2c.c
> @@ -0,0 +1,305 @@
> +/*
> + * Copyright (C) 2012-2020 ASPEED Technology Inc.
> + * Copyright 2016 IBM Corporation
> + * Copyright 2016 Google, Inc.
> + *
> + * SPDX-License-Identifier: GPL-2.0+
> + */
> +
> +#include <common.h>
> +#include <dm.h>
> +#include <fdtdec.h>
> +#include <i2c.h>
> +
> +#include <asm/arch/ast_scu.h>
> +#include <asm/arch/regs-scu.h>
> +#include <asm/io.h>
> +
> +#include "ast_i2c.h"
> +
> +#define I2C_TIMEOUT_US (100000)
> +#define I2C_SLEEP_STEP (20)
I2C_SLEEP_STEP_US
> +#define EI2C_TIMEOUT (1001)
EI2C_TIMEOUT_US
Please drop the () on those
> +
> +DECLARE_GLOBAL_DATA_PTR;
> +
> +struct ast_i2c {
Please add a struct comment with member info.
> + u32 id;
> + struct ast_i2c_regs *regs;
> + int speed;
> +};
> +
> +static u32 get_clk_reg_val(u32 divider_ratio)
Function comment. Consider returning ulong.
> +{
> + unsigned int inc = 0, div;
> + u32 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 = 0x77700300 | (scl_high << 16) | (scl_low << 12) | div;
blank link here. What is the magic 0x77700300 for? Should either have
a comment or a #define
> + return data;
> +}
> +
> +static inline void ast_i2c_clear_interrupts(struct ast_i2c_regs *i2c_base)
> +{
> + writel(~0, &i2c_base->isr);
> +}
> +
> +static void ast_i2c_init_bus(struct ast_i2c *i2c_bus)
> +{
> + /* Reset device */
> + writel(0, &i2c_bus->regs->fcr);
> + /* Enable Master Mode. Assuming single-master. */
nit: Please avoid '.' at end of comments
> + debug("Enable Master for %p\n", i2c_bus->regs);
> + writel(AST_I2CD_MASTER_EN
> + | AST_I2CD_M_SDA_LOCK_EN
> + | AST_I2CD_MULTI_MASTER_DIS | AST_I2CD_M_SCL_DRIVE_EN,
> + &i2c_bus->regs->fcr);
> + debug("FCR: %p\n", &i2c_bus->regs->fcr);
> + /* Enable Interrupts */
> + writel(AST_I2CD_INTR_TX_ACK
> + | AST_I2CD_INTR_TX_NAK
> + | AST_I2CD_INTR_RX_DONE
> + | AST_I2CD_INTR_BUS_RECOVER_DONE
> + | AST_I2CD_INTR_NORMAL_STOP
> + | AST_I2CD_INTR_ABNORMAL, &i2c_bus->regs->icr);
> +}
> +
> +static int ast_i2c_probe(struct udevice *dev)
> +{
> + struct ast_i2c *i2c_bus = dev_get_priv(dev);
> +
> + debug("Enabling I2C%u\n", dev->seq);
> + ast_scu_enable_i2c(dev->seq);
> +
> + i2c_bus->id = dev->seq;
> + struct ast_i2c_regs *i2c_base =
> + (struct ast_i2c_regs *)dev_get_addr(dev);
Can you use dev_get_addr_ptr()? Need to check for NULL and return
-EINVAL. Also, reading the device tree should really be in the
ofdata_to_platdata() method, not probe().
> + i2c_bus->regs = i2c_base;
> +
> + ast_i2c_init_bus(i2c_bus);
> + return 0;
> +}
> +
> +static inline int ast_i2c_wait_isr(struct ast_i2c_regs *i2c_base, u32 flag)
> +{
> + int timeout = I2C_TIMEOUT_US;
blank line here
> + while (!(readl(&i2c_base->isr) & flag) && timeout > 0) {
> + udelay(I2C_SLEEP_STEP);
> + timeout -= I2C_SLEEP_STEP;
> + }
> +
> + ast_i2c_clear_interrupts(i2c_base);
> + if (timeout <= 0)
> + return -EI2C_TIMEOUT;
return -ETIMEDOUT
> + return 0;
> +}
> +
> +static inline int ast_i2c_send_stop(struct ast_i2c_regs *i2c_base)
> +{
> + writel(AST_I2CD_M_STOP_CMD, &i2c_base->csr);
blank line (please do this before each return)
> + return ast_i2c_wait_isr(i2c_base, AST_I2CD_INTR_NORMAL_STOP);
> +}
> +
> +static inline int ast_i2c_wait_tx(struct ast_i2c_regs *i2c_base)
> +{
> + int timeout = I2C_TIMEOUT_US;
> + u32 flag = AST_I2CD_INTR_TX_ACK | AST_I2CD_INTR_TX_NAK;
> + u32 status = readl(&i2c_base->isr) & flag;
blank line (please do this after all decl blocks)
> + while (!status && timeout > 0) {
> + status = readl(&i2c_base->isr) & flag;
> + udelay(I2C_SLEEP_STEP);
> + timeout -= I2C_SLEEP_STEP;
> + }
> +
> + int ret = 0;
Move this to top of function. Declarations should all be at the start
of the block.
> + if (status == AST_I2CD_INTR_TX_NAK)
> + ret = -EREMOTEIO;
> +
> + if (timeout <= 0)
> + ret = -EI2C_TIMEOUT;
> +
> + ast_i2c_clear_interrupts(i2c_base);
> + return ret;
> +}
> +
> +static inline int ast_i2c_start_txn(struct ast_i2c_regs *i2c_base, u8 devaddr)
Why inline? The compiler will do that anyway so I think you can drop
it. Also please use int or uint for devaddr - particularly on ARM it
isn't good to have non-register-sized parameters and return values.
> +{
> + /* Start and Send Device Address */
> + writel(devaddr, &i2c_base->trbbr);
> + writel(AST_I2CD_M_START_CMD | AST_I2CD_M_TX_CMD, &i2c_base->csr);
> + return ast_i2c_wait_tx(i2c_base);
> +}
> +
> +static int ast_i2c_read_data(struct ast_i2c *i2c_bus, u8 chip_addr, u8 *buffer,
> + size_t len, bool send_stop)
> +{
> + struct ast_i2c_regs *i2c_base = i2c_bus->regs;
> +
> + int i2c_error =
> + ast_i2c_start_txn(i2c_base, (chip_addr << 1) | I2C_M_RD);
> + if (i2c_error < 0)
> + return i2c_error;
> +
> + u32 i2c_cmd = AST_I2CD_M_RX_CMD;
> + for (; len > 0; len--, buffer++) {
> + if (len == 1)
> + i2c_cmd |= AST_I2CD_M_S_RX_CMD_LAST;
> + writel(i2c_cmd, &i2c_base->csr);
> + i2c_error = ast_i2c_wait_isr(i2c_base, AST_I2CD_INTR_RX_DONE);
> + if (i2c_error < 0)
> + return i2c_error;
> + *buffer = AST_I2CD_RX_DATA_BUF_GET(readl(&i2c_base->trbbr));
Instead of AST_I2CD_RX_DATA_BUF_GET(), please define something like
AST_I2CD_RX_DATA_SHIFT and _MASK and use then here.
#define AST_I2CD_RX_DATA_SHIFT 8
#define AST_I2CD_RX_DATA_MASK (0xff << AST_I2CD_RX_DATA_SHIFT)
> + }
> + ast_i2c_clear_interrupts(i2c_base);
> +
> + if (send_stop)
> + return ast_i2c_send_stop(i2c_base);
> +
> + return 0;
> +}
> +
> +static int ast_i2c_write_data(struct ast_i2c *i2c_bus, u8 chip_addr, u8
> + *buffer, size_t len, bool send_stop)
> +{
> + struct ast_i2c_regs *i2c_base = i2c_bus->regs;
> +
> + int i2c_error = ast_i2c_start_txn(i2c_base, (chip_addr << 1));
> + if (i2c_error < 0)
> + return i2c_error;
> +
> + for (; len > 0; len--, buffer++) {
> + writel(*buffer, &i2c_base->trbbr);
> + writel(AST_I2CD_M_TX_CMD, &i2c_base->csr);
> + i2c_error = ast_i2c_wait_tx(i2c_base);
> + if (i2c_error < 0)
> + return i2c_error;
> + }
> +
> + if (send_stop)
> + return ast_i2c_send_stop(i2c_base);
> +
> + return 0;
> +}
> +
> +static int ast_i2c_deblock(struct udevice *dev)
> +{
> + struct ast_i2c *i2c_bus = dev_get_priv(dev);
> + struct ast_i2c_regs *i2c_base = i2c_bus->regs;
> +
> + u32 csr = readl(&i2c_base->csr);
> +
> + int deblock_error = 0;
Just 'ret' is good enough.
> + bool sda_high = csr & AST_I2CD_SDA_LINE_STS;
> + bool scl_high = csr & AST_I2CD_SCL_LINE_STS;
> + 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);
> + deblock_error = ast_i2c_send_stop(i2c_base);
> + } else if (scl_high) {
> + /* Possibly stuck slave */
> + debug("Bus stuck (%x), attempting recovery\n", csr);
> + writel(AST_I2CD_BUS_RECOVER_CMD, &i2c_base->csr);
> + deblock_error = ast_i2c_wait_isr(
> + i2c_base, AST_I2CD_INTR_BUS_RECOVER_DONE);
> + } else {
> + /* Just try to reinit the device. */
> + ast_i2c_init_bus(i2c_bus);
> + }
> +
> + return deblock_error;
> +}
> +
> +static int ast_i2c_xfer(struct udevice *dev, struct i2c_msg *msg, int nmsgs)
> +{
> + struct ast_i2c *i2c_bus = dev_get_priv(dev);
> + int ret;
> +
> + (void)ast_i2c_deblock(dev);
> + 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 =
Can you break the line in the parameters instead of at '=' ?
> + ast_i2c_read_data(i2c_bus, 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(i2c_bus, 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)
> +{
> + debug("Setting speed ofr I2C%d to <%u>\n", dev->seq, speed);
> + if (!speed) {
> + debug("No valid speed specified.\n");
Drop '.'
> + return -EINVAL;
> + }
> + struct ast_i2c *i2c_bus = dev_get_priv(dev);
> +
> + i2c_bus->speed = speed;
> + /* TODO: get this from device tree */
> + u32 pclk = ast_get_apbclk();
> + u32 divider = pclk / speed;
> +
> + struct ast_i2c_regs *i2c_base = i2c_bus->regs;
> + if (speed > 400000) {
> + debug("Enabling High Speed\n");
> + setbits_le32(&i2c_base->fcr, AST_I2CD_M_HIGH_SPEED_EN
> + | AST_I2CD_M_SDA_DRIVE_1T_EN
> + | AST_I2CD_SDA_DRIVE_1T_EN);
> + writel(0x3, &i2c_base->cactcr2);
> + writel(get_clk_reg_val(divider), &i2c_base->cactcr1);
> + } else {
> + debug("Enabling Normal Speed\n");
> + writel(get_clk_reg_val(divider), &i2c_base->cactcr1);
> + writel(AST_NO_TIMEOUT_CTRL, &i2c_base->cactcr2);
> + }
> +
> + ast_i2c_clear_interrupts(i2c_base);
> + 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-controller",},
> + {.compatible = "aspeed,ast2400-i2c-bus",},
> + {},
> +};
> +
> +/* Tell GNU Indent to keep this as is: */
> +/* *INDENT-OFF* */
> +U_BOOT_DRIVER(i2c_aspeed) = {
> + .name = "i2c_aspeed",
> + .id = UCLASS_I2C,
> + .of_match = ast_i2c_ids,
> + .probe = ast_i2c_probe,
> + .priv_auto_alloc_size = sizeof(struct ast_i2c),
> + .ops = &ast_i2c_ops,
> +};
> +/* *INDENT-ON* */
> diff --git a/drivers/i2c/ast_i2c.h b/drivers/i2c/ast_i2c.h
> new file mode 100644
> index 0000000..8926fd2
> --- /dev/null
> +++ b/drivers/i2c/ast_i2c.h
> @@ -0,0 +1,143 @@
> +/*
> + * Copyright (C) 2012-2020 ASPEED Technology Inc.
> + * Copyright 2016 IBM Corporation
> + * Copyright 2016 Google, Inc.
> + *
> + * SPDX-License-Identifier: GPL-2.0+
> + */
> +#ifndef __AST_I2C_H_
> +#define __AST_I2C_H_
> +
> +struct ast_i2c_regs {
> + uint32_t fcr;
> + uint32_t cactcr1;
> + uint32_t cactcr2;
> + uint32_t icr;
> + uint32_t isr;
> + uint32_t csr;
> + uint32_t sdar;
> + uint32_t pbcr;
> + uint32_t trbbr;
> +#ifdef CONFIG_TARGET_AST_G5
> + uint32_t dma_mbar;
> + uint32_t dma_tlr;
> +#endif
> +};
> +
> +/* Device Register Definition */
> +/* 0x00 : I2CD Function Control Register */
> +#define AST_I2CD_BUFF_SEL_MASK (0x7 << 20)
It's fine to have the AST_I2CD_ prefix if you want it. But it does
make things longer, and this header will only be included in one file.
So feel free to prune to AST_ if you like.
> +#define AST_I2CD_BUFF_SEL(x) (x << 20)
> +#define AST_I2CD_M_SDA_LOCK_EN (0x1 << 16)
> +#define AST_I2CD_MULTI_MASTER_DIS (0x1 << 15)
> +#define AST_I2CD_M_SCL_DRIVE_EN (0x1 << 14)
> +#define AST_I2CD_MSB_STS (0x1 << 9)
> +#define AST_I2CD_SDA_DRIVE_1T_EN (0x1 << 8)
> +#define AST_I2CD_M_SDA_DRIVE_1T_EN (0x1 << 7)
> +#define AST_I2CD_M_HIGH_SPEED_EN (0x1 << 6)
> +#define AST_I2CD_DEF_ADDR_EN (0x1 << 5)
> +#define AST_I2CD_DEF_ALERT_EN (0x1 << 4)
> +#define AST_I2CD_DEF_ARP_EN (0x1 << 3)
> +#define AST_I2CD_DEF_GCALL_EN (0x1 << 2)
> +#define AST_I2CD_SLAVE_EN (0x1 << 1)
> +#define AST_I2CD_MASTER_EN (0x1)
Avoid brackets around simple constants
> +
> +/* 0x04 : I2CD Clock and AC Timing Control Register #1 */
> +#define AST_I2CD_tBUF (0x1 << 28)
> +#define AST_I2CD_tHDSTA (0x1 << 24)
> +#define AST_I2CD_tACST (0x1 << 20)
> +#define AST_I2CD_tCKHIGH (0x1 << 16)
> +#define AST_I2CD_tCKLOW (0x1 << 12)
> +#define AST_I2CD_tHDDAT (0x1 << 10)
> +#define AST_I2CD_CLK_TO_BASE_DIV (0x1 << 8)
> +#define AST_I2CD_CLK_BASE_DIV (0x1)
> +
> +/* 0x08 : I2CD Clock and AC Timing Control Register #2 */
> +#define AST_I2CD_tTIMEOUT (0x1)
> +#define AST_NO_TIMEOUT_CTRL 0x0
> +
> +/* 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 AST_I2CD_INTR_SDA_DL_TIMEOUT (0x1 << 14)
> +#define AST_I2CD_INTR_BUS_RECOVER_DONE (0x1 << 13)
> +#define AST_I2CD_INTR_SMBUS_ALERT (0x1 << 12)
> +#define AST_I2CD_INTR_SMBUS_ARP_ADDR (0x1 << 11)
> +#define AST_I2CD_INTR_SMBUS_DEV_ALERT_ADDR (0x1 << 10)
> +#define AST_I2CD_INTR_SMBUS_DEF_ADDR (0x1 << 9)
> +#define AST_I2CD_INTR_GCALL_ADDR (0x1 << 8)
> +#define AST_I2CD_INTR_SLAVE_MATCH (0x1 << 7)
> +#define AST_I2CD_INTR_SCL_TIMEOUT (0x1 << 6)
> +#define AST_I2CD_INTR_ABNORMAL (0x1 << 5)
> +#define AST_I2CD_INTR_NORMAL_STOP (0x1 << 4)
> +#define AST_I2CD_INTR_ARBIT_LOSS (0x1 << 3)
> +#define AST_I2CD_INTR_RX_DONE (0x1 << 2)
> +#define AST_I2CD_INTR_TX_NAK (0x1 << 1)
> +#define AST_I2CD_INTR_TX_ACK (0x1 << 0)
> +
> +/* 0x14 : I2CD Command/Status Register */
> +#define AST_I2CD_SDA_OE (0x1 << 28)
> +#define AST_I2CD_SDA_O (0x1 << 27)
> +#define AST_I2CD_SCL_OE (0x1 << 26)
> +#define AST_I2CD_SCL_O (0x1 << 25)
> +#define AST_I2CD_TX_TIMING (0x1 << 24)
> +#define AST_I2CD_TX_STATUS (0x1 << 23)
> +
> +/* Tx State Machine */
> +#define AST_I2CD_IDLE 0x0
> +#define AST_I2CD_MACTIVE 0x8
> +#define AST_I2CD_MSTART 0x9
> +#define AST_I2CD_MSTARTR 0xa
> +#define AST_I2CD_MSTOP 0xb
> +#define AST_I2CD_MTXD 0xc
> +#define AST_I2CD_MRXACK 0xd
> +#define AST_I2CD_MRXD 0xe
> +#define AST_I2CD_MTXACK 0xf
> +#define AST_I2CD_SWAIT 0x1
> +#define AST_I2CD_SRXD 0x4
> +#define AST_I2CD_STXACK 0x5
> +#define AST_I2CD_STXD 0x6
> +#define AST_I2CD_SRXACK 0x7
> +#define AST_I2CD_RECOVER 0x3
> +
> +#define AST_I2CD_SCL_LINE_STS (0x1 << 18)
> +#define AST_I2CD_SDA_LINE_STS (0x1 << 17)
> +#define AST_I2CD_BUS_BUSY_STS (0x1 << 16)
> +#define AST_I2CD_SDA_OE_OUT_DIR (0x1 << 15)
> +#define AST_I2CD_SDA_O_OUT_DIR (0x1 << 14)
> +#define AST_I2CD_SCL_OE_OUT_DIR (0x1 << 13)
> +#define AST_I2CD_SCL_O_OUT_DIR (0x1 << 12)
> +#define AST_I2CD_BUS_RECOVER_CMD (0x1 << 11)
> +#define AST_I2CD_S_ALT_EN (0x1 << 10)
> +#define AST_I2CD_RX_DMA_ENABLE (0x1 << 9)
> +#define AST_I2CD_TX_DMA_ENABLE (0x1 << 8)
> +
> +/* Command Bit */
> +#define AST_I2CD_RX_BUFF_ENABLE (0x1 << 7)
> +#define AST_I2CD_TX_BUFF_ENABLE (0x1 << 6)
> +#define AST_I2CD_M_STOP_CMD (0x1 << 5)
> +#define AST_I2CD_M_S_RX_CMD_LAST (0x1 << 4)
> +#define AST_I2CD_M_RX_CMD (0x1 << 3)
> +#define AST_I2CD_S_TX_CMD (0x1 << 2)
> +#define AST_I2CD_M_TX_CMD (0x1 << 1)
> +#define AST_I2CD_M_START_CMD (0x1)
> +
> +/* 0x18 : I2CD Slave Device Address Register */
> +
> +/* 0x1C : I2CD Pool Buffer Control Register */
> +#define AST_I2CD_RX_BUF_ADDR_GET(x) (((x) >> 24) & 0xff)
> +#define AST_I2CD_RX_BUF_END_ADDR_SET(x) ((x) << 16)
> +#define AST_I2CD_TX_DATA_BUF_END_SET(x) (((x) & 0xff) << 8)
> +#define AST_I2CD_RX_DATA_BUF_GET(x) (((x) >> 8) & 0xff)
> +#define AST_I2CD_BUF_BASE_ADDR_SET(x) ((x) & 0x3f)
Just use simple shift and mask values, and put the logic in your C code.
> +
> +/* 0x20 : I2CD Transmit/Receive Byte Buffer Register */
> +#define AST_I2CD_GET_MODE(x) (((x) >> 8) & 0x1)
> +
> +#define AST_I2CD_RX_BYTE_BUFFER (0xff << 8)
> +#define AST_I2CD_TX_BYTE_BUFFER (0xff)
> +
> +#endif /* __AST_I2C_H_ */
> --
> 2.8.0.rc3.226.g39d4020
>
Regards,
Simon
More information about the U-Boot
mailing list