diff options
Diffstat (limited to 'drivers/i2c/mxc_i2c.c')
| -rw-r--r-- | drivers/i2c/mxc_i2c.c | 477 |
1 files changed, 264 insertions, 213 deletions
diff --git a/drivers/i2c/mxc_i2c.c b/drivers/i2c/mxc_i2c.c index fc68062..73d8958 100644 --- a/drivers/i2c/mxc_i2c.c +++ b/drivers/i2c/mxc_i2c.c @@ -31,13 +31,12 @@ */ #include <common.h> -#include <asm/io.h> - -#if defined(CONFIG_HARD_I2C) - #include <asm/arch/clock.h> #include <asm/arch/imx-regs.h> +#include <asm/errno.h> +#include <asm/io.h> #include <i2c.h> +#include <watchdog.h> struct mxc_i2c_regs { uint32_t iadr; @@ -56,17 +55,14 @@ struct mxc_i2c_regs { #define I2SR_ICF (1 << 7) #define I2SR_IBB (1 << 5) +#define I2SR_IAL (1 << 4) #define I2SR_IIF (1 << 1) #define I2SR_RX_NO_AK (1 << 0) -#ifdef CONFIG_SYS_I2C_BASE -#define I2C_BASE CONFIG_SYS_I2C_BASE -#else +#if defined(CONFIG_HARD_I2C) && !defined(CONFIG_SYS_I2C_BASE) #error "define CONFIG_SYS_I2C_BASE to use the mxc_i2c driver" #endif -#define I2C_MAX_TIMEOUT 10000 - static u16 i2c_clk_div[50][2] = { { 22, 0x20 }, { 24, 0x21 }, { 26, 0x22 }, { 28, 0x23 }, { 30, 0x00 }, { 32, 0x24 }, { 36, 0x25 }, { 40, 0x26 }, @@ -117,46 +113,29 @@ static uint8_t i2c_imx_get_clk(unsigned int rate) } /* - * Reset I2C Controller + * Set I2C Bus speed */ -void i2c_reset(void) +int bus_i2c_set_bus_speed(void *base, int speed) { - struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)I2C_BASE; - - writeb(0, &i2c_regs->i2cr); /* Reset module */ - writeb(0, &i2c_regs->i2sr); -} - -/* - * Init I2C Bus - */ -void i2c_init(int speed, int unused) -{ - struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)I2C_BASE; + struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)base; u8 clk_idx = i2c_imx_get_clk(speed); u8 idx = i2c_clk_div[clk_idx][1]; /* Store divider value */ writeb(idx, &i2c_regs->ifdr); - i2c_reset(); -} - -/* - * Set I2C Speed - */ -int i2c_set_bus_speed(unsigned int speed) -{ - i2c_init(speed, 0); + /* Reset module */ + writeb(0, &i2c_regs->i2cr); + writeb(0, &i2c_regs->i2sr); return 0; } /* * Get I2C Speed */ -unsigned int i2c_get_bus_speed(void) +unsigned int bus_i2c_get_bus_speed(void *base) { - struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)I2C_BASE; + struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)base; u8 clk_idx = readb(&i2c_regs->ifdr); u8 clk_div; @@ -166,210 +145,163 @@ unsigned int i2c_get_bus_speed(void) return mxc_get_clock(MXC_IPG_PERCLK) / i2c_clk_div[clk_div][0]; } -/* - * Wait for bus to be busy (or free if for_busy = 0) - * - * for_busy = 1: Wait for IBB to be asserted - * for_busy = 0: Wait for IBB to be de-asserted - */ -int i2c_imx_bus_busy(int for_busy) -{ - struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)I2C_BASE; - unsigned int temp; +#define ST_BUS_IDLE (0 | (I2SR_IBB << 8)) +#define ST_BUS_BUSY (I2SR_IBB | (I2SR_IBB << 8)) +#define ST_IIF (I2SR_IIF | (I2SR_IIF << 8)) - int timeout = I2C_MAX_TIMEOUT; - - while (timeout--) { - temp = readb(&i2c_regs->i2sr); - - if (for_busy && (temp & I2SR_IBB)) - return 0; - if (!for_busy && !(temp & I2SR_IBB)) - return 0; - - udelay(1); +static int wait_for_sr_state(struct mxc_i2c_regs *i2c_regs, unsigned state) +{ + unsigned sr; + ulong elapsed; + ulong start_time = get_timer(0); + for (;;) { + sr = readb(&i2c_regs->i2sr); + if (sr & I2SR_IAL) { + writeb(sr & ~I2SR_IAL, &i2c_regs->i2sr); + printf("%s: Arbitration lost sr=%x cr=%x state=%x\n", + __func__, sr, readb(&i2c_regs->i2cr), state); + return -ERESTART; + } + if ((sr & (state >> 8)) == (unsigned char)state) + return sr; + WATCHDOG_RESET(); + elapsed = get_timer(start_time); + if (elapsed > (CONFIG_SYS_HZ / 10)) /* .1 seconds */ + break; } - - return 1; + printf("%s: failed sr=%x cr=%x state=%x\n", __func__, + sr, readb(&i2c_regs->i2cr), state); + return -ETIMEDOUT; } -/* - * Wait for transaction to complete - */ -int i2c_imx_trx_complete(void) +static int tx_byte(struct mxc_i2c_regs *i2c_regs, u8 byte) { - struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)I2C_BASE; - int timeout = I2C_MAX_TIMEOUT; - - while (timeout--) { - if (readb(&i2c_regs->i2sr) & I2SR_IIF) { - writeb(0, &i2c_regs->i2sr); - return 0; - } - - udelay(1); - } + int ret; - return 1; + writeb(0, &i2c_regs->i2sr); + writeb(byte, &i2c_regs->i2dr); + ret = wait_for_sr_state(i2c_regs, ST_IIF); + if (ret < 0) + return ret; + if (ret & I2SR_RX_NO_AK) + return -ENODEV; + return 0; } /* - * Check if the transaction was ACKed + * Stop I2C transaction */ -int i2c_imx_acked(void) +static void i2c_imx_stop(struct mxc_i2c_regs *i2c_regs) { - struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)I2C_BASE; + int ret; + unsigned int temp = readb(&i2c_regs->i2cr); - return readb(&i2c_regs->i2sr) & I2SR_RX_NO_AK; + temp &= ~(I2CR_MSTA | I2CR_MTX); + writeb(temp, &i2c_regs->i2cr); + ret = wait_for_sr_state(i2c_regs, ST_BUS_IDLE); + if (ret < 0) + printf("%s:trigger stop failed\n", __func__); } /* - * Start the controller + * Send start signal, chip address and + * write register address */ -int i2c_imx_start(void) +static int i2c_init_transfer_(struct mxc_i2c_regs *i2c_regs, + uchar chip, uint addr, int alen) { - struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)I2C_BASE; - unsigned int temp = 0; - int result; + unsigned int temp; + int ret; /* Enable I2C controller */ + if (!(readb(&i2c_regs->i2cr) & I2CR_IEN)) { + writeb(I2CR_IEN, &i2c_regs->i2cr); + /* Wait for controller to be stable */ + udelay(50); + } + if (readb(&i2c_regs->iadr) == (chip << 1)) + writeb((chip << 1) ^ 2, &i2c_regs->iadr); writeb(0, &i2c_regs->i2sr); - writeb(I2CR_IEN, &i2c_regs->i2cr); - - /* Wait controller to be stable */ - udelay(50); + ret = wait_for_sr_state(i2c_regs, ST_BUS_IDLE); + if (ret < 0) + return ret; /* Start I2C transaction */ temp = readb(&i2c_regs->i2cr); temp |= I2CR_MSTA; writeb(temp, &i2c_regs->i2cr); - result = i2c_imx_bus_busy(1); - if (result) - return result; + ret = wait_for_sr_state(i2c_regs, ST_BUS_BUSY); + if (ret < 0) + return ret; temp |= I2CR_MTX | I2CR_TX_NO_AK; writeb(temp, &i2c_regs->i2cr); - return 0; -} - -/* - * Stop the controller - */ -void i2c_imx_stop(void) -{ - struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)I2C_BASE; - unsigned int temp = 0; - - /* Stop I2C transaction */ - temp = readb(&i2c_regs->i2cr); - temp |= ~(I2CR_MSTA | I2CR_MTX); - writeb(temp, &i2c_regs->i2cr); - - i2c_imx_bus_busy(0); - - /* Disable I2C controller */ - writeb(0, &i2c_regs->i2cr); -} - -/* - * Set chip address and access mode - * - * read = 1: READ access - * read = 0: WRITE access - */ -int i2c_imx_set_chip_addr(uchar chip, int read) -{ - struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)I2C_BASE; - int ret; - - writeb((chip << 1) | read, &i2c_regs->i2dr); - - ret = i2c_imx_trx_complete(); - if (ret) - return ret; - - ret = i2c_imx_acked(); - if (ret) + /* write slave address */ + ret = tx_byte(i2c_regs, chip << 1); + if (ret < 0) return ret; - return ret; -} - -/* - * Write register address - */ -int i2c_imx_set_reg_addr(uint addr, int alen) -{ - struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)I2C_BASE; - int ret = 0; - while (alen--) { - writeb((addr >> (alen * 8)) & 0xff, &i2c_regs->i2dr); - - ret = i2c_imx_trx_complete(); - if (ret) - break; - - ret = i2c_imx_acked(); - if (ret) - break; + ret = tx_byte(i2c_regs, (addr >> (alen * 8)) & 0xff); + if (ret < 0) + return ret; } - - return ret; + return 0; } -/* - * Try if a chip add given address responds (probe the chip) - */ -int i2c_probe(uchar chip) +static int i2c_idle_bus(void *base); + +static int i2c_init_transfer(struct mxc_i2c_regs *i2c_regs, + uchar chip, uint addr, int alen) { + int retry; int ret; + for (retry = 0; retry < 3; retry++) { + ret = i2c_init_transfer_(i2c_regs, chip, addr, alen); + if (ret >= 0) + return 0; + i2c_imx_stop(i2c_regs); + if (ret == -ENODEV) + return ret; - ret = i2c_imx_start(); - if (ret) - return ret; - - ret = i2c_imx_set_chip_addr(chip, 0); - if (ret) - return ret; - - i2c_imx_stop(); - + printf("%s: failed for chip 0x%x retry=%d\n", __func__, chip, + retry); + if (ret != -ERESTART) + writeb(0, &i2c_regs->i2cr); /* Disable controller */ + udelay(100); + if (i2c_idle_bus(i2c_regs) < 0) + break; + } + printf("%s: give up i2c_regs=%p\n", __func__, i2c_regs); return ret; } /* * Read data from I2C device */ -int i2c_read(uchar chip, uint addr, int alen, uchar *buf, int len) +int bus_i2c_read(void *base, uchar chip, uint addr, int alen, uchar *buf, + int len) { - struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)I2C_BASE; int ret; unsigned int temp; int i; + struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)base; - ret = i2c_imx_start(); - if (ret) - return ret; - - /* write slave address */ - ret = i2c_imx_set_chip_addr(chip, 0); - if (ret) - return ret; - - ret = i2c_imx_set_reg_addr(addr, alen); - if (ret) + ret = i2c_init_transfer(i2c_regs, chip, addr, alen); + if (ret < 0) return ret; temp = readb(&i2c_regs->i2cr); temp |= I2CR_RSTA; writeb(temp, &i2c_regs->i2cr); - ret = i2c_imx_set_chip_addr(chip, 1); - if (ret) + ret = tx_byte(i2c_regs, (chip << 1) | 1); + if (ret < 0) { + i2c_imx_stop(i2c_regs); return ret; + } /* setup bus to read data */ temp = readb(&i2c_regs->i2cr); @@ -377,73 +309,192 @@ int i2c_read(uchar chip, uint addr, int alen, uchar *buf, int len) if (len == 1) temp |= I2CR_TX_NO_AK; writeb(temp, &i2c_regs->i2cr); - readb(&i2c_regs->i2dr); + writeb(0, &i2c_regs->i2sr); + readb(&i2c_regs->i2dr); /* dummy read to clear ICF */ /* read data */ for (i = 0; i < len; i++) { - ret = i2c_imx_trx_complete(); - if (ret) + ret = wait_for_sr_state(i2c_regs, ST_IIF); + if (ret < 0) { + i2c_imx_stop(i2c_regs); return ret; + } /* * It must generate STOP before read I2DR to prevent * controller from generating another clock cycle */ if (i == (len - 1)) { - temp = readb(&i2c_regs->i2cr); - temp &= ~(I2CR_MSTA | I2CR_MTX); - writeb(temp, &i2c_regs->i2cr); - i2c_imx_bus_busy(0); + i2c_imx_stop(i2c_regs); } else if (i == (len - 2)) { temp = readb(&i2c_regs->i2cr); temp |= I2CR_TX_NO_AK; writeb(temp, &i2c_regs->i2cr); } - + writeb(0, &i2c_regs->i2sr); buf[i] = readb(&i2c_regs->i2dr); } - - i2c_imx_stop(); - - return ret; + i2c_imx_stop(i2c_regs); + return 0; } /* * Write data to I2C device */ -int i2c_write(uchar chip, uint addr, int alen, uchar *buf, int len) +int bus_i2c_write(void *base, uchar chip, uint addr, int alen, + const uchar *buf, int len) { - struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)I2C_BASE; int ret; int i; + struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)base; - ret = i2c_imx_start(); - if (ret) + ret = i2c_init_transfer(i2c_regs, chip, addr, alen); + if (ret < 0) return ret; - /* write slave address */ - ret = i2c_imx_set_chip_addr(chip, 0); - if (ret) - return ret; + for (i = 0; i < len; i++) { + ret = tx_byte(i2c_regs, buf[i]); + if (ret < 0) + break; + } + i2c_imx_stop(i2c_regs); + return ret; +} + +struct i2c_parms { + void *base; + void *idle_bus_data; + int (*idle_bus_fn)(void *p); +}; + +struct sram_data { + unsigned curr_i2c_bus; + struct i2c_parms i2c_data[3]; +}; - ret = i2c_imx_set_reg_addr(addr, alen); +/* + * For SPL boot some boards need i2c before SDRAM is initialized so force + * variables to live in SRAM + */ +static struct sram_data __attribute__((section(".data"))) srdata; + +void *get_base(void) +{ +#ifdef CONFIG_SYS_I2C_BASE +#ifdef CONFIG_I2C_MULTI_BUS + void *ret = srdata.i2c_data[srdata.curr_i2c_bus].base; if (ret) return ret; +#endif + return (void *)CONFIG_SYS_I2C_BASE; +#elif defined(CONFIG_I2C_MULTI_BUS) + return srdata.i2c_data[srdata.curr_i2c_bus].base; +#else + return srdata.i2c_data[0].base; +#endif +} - for (i = 0; i < len; i++) { - writeb(buf[i], &i2c_regs->i2dr); +static struct i2c_parms *i2c_get_parms(void *base) +{ + int i = 0; + struct i2c_parms *p = srdata.i2c_data; + while (i < ARRAY_SIZE(srdata.i2c_data)) { + if (p->base == base) + return p; + p++; + i++; + } + printf("Invalid I2C base: %p\n", base); + return NULL; +} - ret = i2c_imx_trx_complete(); - if (ret) - return ret; +static int i2c_idle_bus(void *base) +{ + struct i2c_parms *p = i2c_get_parms(base); + if (p && p->idle_bus_fn) + return p->idle_bus_fn(p->idle_bus_data); + return 0; +} - ret = i2c_imx_acked(); - if (ret) - return ret; +#ifdef CONFIG_I2C_MULTI_BUS +unsigned int i2c_get_bus_num(void) +{ + return srdata.curr_i2c_bus; +} + +int i2c_set_bus_num(unsigned bus_idx) +{ + if (bus_idx >= ARRAY_SIZE(srdata.i2c_data)) + return -1; + if (!srdata.i2c_data[bus_idx].base) + return -1; + srdata.curr_i2c_bus = bus_idx; + return 0; +} +#endif + +int i2c_read(uchar chip, uint addr, int alen, uchar *buf, int len) +{ + return bus_i2c_read(get_base(), chip, addr, alen, buf, len); +} + +int i2c_write(uchar chip, uint addr, int alen, uchar *buf, int len) +{ + return bus_i2c_write(get_base(), chip, addr, alen, buf, len); +} + +/* + * Test if a chip at a given address responds (probe the chip) + */ +int i2c_probe(uchar chip) +{ + return bus_i2c_write(get_base(), chip, 0, 0, NULL, 0); +} + +void bus_i2c_init(void *base, int speed, int unused, + int (*idle_bus_fn)(void *p), void *idle_bus_data) +{ + int i = 0; + struct i2c_parms *p = srdata.i2c_data; + if (!base) + return; + for (;;) { + if (!p->base || (p->base == base)) { + p->base = base; + if (idle_bus_fn) { + p->idle_bus_fn = idle_bus_fn; + p->idle_bus_data = idle_bus_data; + } + break; + } + p++; + i++; + if (i >= ARRAY_SIZE(srdata.i2c_data)) + return; } + bus_i2c_set_bus_speed(base, speed); +} + +/* + * Init I2C Bus + */ +void i2c_init(int speed, int unused) +{ + bus_i2c_init(get_base(), speed, unused, NULL, NULL); +} - i2c_imx_stop(); +/* + * Set I2C Speed + */ +int i2c_set_bus_speed(unsigned int speed) +{ + return bus_i2c_set_bus_speed(get_base(), speed); +} - return ret; +/* + * Get I2C Speed + */ +unsigned int i2c_get_bus_speed(void) +{ + return bus_i2c_get_bus_speed(get_base()); } -#endif /* CONFIG_HARD_I2C */ |