/*
- * i2c driver for Freescale mx31
+ * i2c driver for Freescale i.MX series
*
* (c) 2007 Pengutronix, Sascha Hauer <s.hauer@pengutronix.de>
+ * (c) 2011 Marek Vasut <marek.vasut@gmail.com>
+ *
+ * Based on i2c-imx.c from linux kernel:
+ * Copyright (C) 2005 Torsten Koschorrek <koschorrek at synertronixx.de>
+ * Copyright (C) 2005 Matthias Blaschke <blaschke at synertronixx.de>
+ * Copyright (C) 2007 RightHand Technologies, Inc.
+ * Copyright (C) 2008 Darius Augulis <darius.augulis at teltonika.lt>
+ *
*
* See file CREDITS for list of people who contributed to this
* project.
*/
#include <common.h>
-
-#if defined(CONFIG_HARD_I2C) && defined(CONFIG_I2C_MXC)
-
-#include <asm/arch/mx31.h>
-#include <asm/arch/mx31-regs.h>
-
-#define IADR 0x00
-#define IFDR 0x04
-#define I2CR 0x08
-#define I2SR 0x0c
-#define I2DR 0x10
+#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;
+ uint32_t ifdr;
+ uint32_t i2cr;
+ uint32_t i2sr;
+ uint32_t i2dr;
+};
#define I2CR_IEN (1 << 7)
#define I2CR_IIEN (1 << 6)
#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 CFG_I2C_MX31_PORT1
-#define I2C_BASE 0x43f80000
-#elif defined(CFG_I2C_MX31_PORT2)
-#define I2C_BASE 0x43f98000
-#elif defined(CFG_I2C_MX31_PORT3)
-#define I2C_BASE 0x43f84000
-#else
-#error "define CFG_I2C_MX31_PORTx to use the mx31 I2C driver"
+#if defined(CONFIG_HARD_I2C) && !defined(CONFIG_SYS_I2C_BASE)
+#error "define CONFIG_SYS_I2C_BASE to use the mxc_i2c driver"
#endif
-#ifdef DEBUG
-#define DPRINTF(args...) printf(args)
-#else
-#define DPRINTF(args...)
+static u16 i2c_clk_div[50][2] = {
+ { 22, 0x20 }, { 24, 0x21 }, { 26, 0x22 }, { 28, 0x23 },
+ { 30, 0x00 }, { 32, 0x24 }, { 36, 0x25 }, { 40, 0x26 },
+ { 42, 0x03 }, { 44, 0x27 }, { 48, 0x28 }, { 52, 0x05 },
+ { 56, 0x29 }, { 60, 0x06 }, { 64, 0x2A }, { 72, 0x2B },
+ { 80, 0x2C }, { 88, 0x09 }, { 96, 0x2D }, { 104, 0x0A },
+ { 112, 0x2E }, { 128, 0x2F }, { 144, 0x0C }, { 160, 0x30 },
+ { 192, 0x31 }, { 224, 0x32 }, { 240, 0x0F }, { 256, 0x33 },
+ { 288, 0x10 }, { 320, 0x34 }, { 384, 0x35 }, { 448, 0x36 },
+ { 480, 0x13 }, { 512, 0x37 }, { 576, 0x14 }, { 640, 0x38 },
+ { 768, 0x39 }, { 896, 0x3A }, { 960, 0x17 }, { 1024, 0x3B },
+ { 1152, 0x18 }, { 1280, 0x3C }, { 1536, 0x3D }, { 1792, 0x3E },
+ { 1920, 0x1B }, { 2048, 0x3F }, { 2304, 0x1C }, { 2560, 0x1D },
+ { 3072, 0x1E }, { 3840, 0x1F }
+};
+
+/*
+ * Calculate and set proper clock divider
+ */
+static uint8_t i2c_imx_get_clk(unsigned int rate)
+{
+ unsigned int i2c_clk_rate;
+ unsigned int div;
+ u8 clk_div;
+
+#if defined(CONFIG_MX31)
+ struct clock_control_regs *sc_regs =
+ (struct clock_control_regs *)CCM_BASE;
+
+ /* start the required I2C clock */
+ writel(readl(&sc_regs->cgr0) | (3 << CONFIG_SYS_I2C_CLK_OFFSET),
+ &sc_regs->cgr0);
#endif
-static u16 div[] = { 30, 32, 36, 42, 48, 52, 60, 72, 80, 88, 104, 128, 144,
- 160, 192, 240, 288, 320, 384, 480, 576, 640, 768, 960,
- 1152, 1280, 1536, 1920, 2304, 2560, 3072, 3840};
+ /* Divider value calculation */
+ i2c_clk_rate = mxc_get_clock(MXC_I2C_CLK);
+ div = (i2c_clk_rate + rate - 1) / rate;
+ if (div < i2c_clk_div[0][0])
+ clk_div = 0;
+ else if (div > i2c_clk_div[ARRAY_SIZE(i2c_clk_div) - 1][0])
+ clk_div = ARRAY_SIZE(i2c_clk_div) - 1;
+ else
+ for (clk_div = 0; i2c_clk_div[clk_div][0] < div; clk_div++)
+ ;
+
+ /* Store divider value */
+ return clk_div;
+}
-void i2c_init(int speed, int unused)
+/*
+ * Set I2C Bus speed
+ */
+int bus_i2c_set_bus_speed(void *base, int speed)
{
- int freq = mx31_get_ipg_clk();
- int i;
+ 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];
- for (i = 0; i < 0x1f; i++)
- if (freq / div[i] <= speed)
- break;
-
- DPRINTF("%s: speed: %d\n", __FUNCTION__, speed);
+ /* Store divider value */
+ writeb(idx, &i2c_regs->ifdr);
- __REG16(I2C_BASE + I2CR) = 0; /* Reset module */
- __REG16(I2C_BASE + IFDR) = i;
- __REG16(I2C_BASE + I2CR) = I2CR_IEN;
- __REG16(I2C_BASE + I2SR) = 0;
+ /* Reset module */
+ writeb(0, &i2c_regs->i2cr);
+ writeb(0, &i2c_regs->i2sr);
+ return 0;
}
-static int wait_busy(void)
+/*
+ * Get I2C Speed
+ */
+unsigned int bus_i2c_get_bus_speed(void *base)
{
- int timeout = 10000;
+ struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)base;
+ u8 clk_idx = readb(&i2c_regs->ifdr);
+ u8 clk_div;
- while (!(__REG16(I2C_BASE + I2SR) & I2SR_IIF) && --timeout)
- udelay(1);
- __REG16(I2C_BASE + I2SR) = 0; /* clear interrupt */
+ for (clk_div = 0; i2c_clk_div[clk_div][1] != clk_idx; clk_div++)
+ ;
- return timeout;
+ return mxc_get_clock(MXC_I2C_CLK) / i2c_clk_div[clk_div][0];
}
-static int tx_byte(u8 byte)
+#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))
+
+static int wait_for_sr_state(struct mxc_i2c_regs *i2c_regs, unsigned state)
{
- __REG16(I2C_BASE + I2DR) = byte;
+ 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;
+ }
+ printf("%s: failed sr=%x cr=%x state=%x\n", __func__,
+ sr, readb(&i2c_regs->i2cr), state);
+ return -ETIMEDOUT;
+}
- if (!wait_busy() || __REG16(I2C_BASE + I2SR) & I2SR_RX_NO_AK)
- return -1;
+static int tx_byte(struct mxc_i2c_regs *i2c_regs, u8 byte)
+{
+ int ret;
+
+ 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;
}
-static int rx_byte(void)
+/*
+ * Stop I2C transaction
+ */
+static void i2c_imx_stop(struct mxc_i2c_regs *i2c_regs)
{
- if (!wait_busy())
- return -1;
+ int ret;
+ unsigned int temp = readb(&i2c_regs->i2cr);
- return __REG16(I2C_BASE + I2DR);
+ 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__);
}
-int i2c_probe(uchar chip)
+/*
+ * Send start signal, chip address and
+ * write register address
+ */
+static int i2c_init_transfer_(struct mxc_i2c_regs *i2c_regs,
+ uchar chip, uint addr, int alen)
{
+ unsigned int temp;
int ret;
- __REG16(I2C_BASE + I2CR) = 0; /* Reset module */
- __REG16(I2C_BASE + I2CR) = I2CR_IEN;
+ /* 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);
+ 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);
+
+ 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);
+
+ /* write slave address */
+ ret = tx_byte(i2c_regs, chip << 1);
+ if (ret < 0)
+ return ret;
+
+ while (alen--) {
+ ret = tx_byte(i2c_regs, (addr >> (alen * 8)) & 0xff);
+ if (ret < 0)
+ return ret;
+ }
+ return 0;
+}
- __REG16(I2C_BASE + I2CR) = I2CR_IEN | I2CR_MSTA | I2CR_MTX;
- ret = tx_byte(chip << 1);
- __REG16(I2C_BASE + I2CR) = I2CR_IEN | I2CR_MTX;
+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;
+
+ 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;
}
-static int i2c_addr(uchar chip, uint addr, int alen)
+/*
+ * Read data from I2C device
+ */
+int bus_i2c_read(void *base, uchar chip, uint addr, int alen, uchar *buf,
+ int len)
{
- __REG16(I2C_BASE + I2SR) = 0; /* clear interrupt */
- __REG16(I2C_BASE + I2CR) = I2CR_IEN | I2CR_MSTA | I2CR_MTX;
+ int ret;
+ unsigned int temp;
+ int i;
+ struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)base;
- if (tx_byte(chip << 1))
- return -1;
+ ret = i2c_init_transfer(i2c_regs, chip, addr, alen);
+ if (ret < 0)
+ return ret;
- while (alen--)
- if (tx_byte((addr >> (alen * 8)) & 0xff))
- return -1;
+ temp = readb(&i2c_regs->i2cr);
+ temp |= I2CR_RSTA;
+ writeb(temp, &i2c_regs->i2cr);
+
+ 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);
+ temp &= ~(I2CR_MTX | I2CR_TX_NO_AK);
+ if (len == 1)
+ temp |= I2CR_TX_NO_AK;
+ writeb(temp, &i2c_regs->i2cr);
+ writeb(0, &i2c_regs->i2sr);
+ readb(&i2c_regs->i2dr); /* dummy read to clear ICF */
+
+ /* read data */
+ for (i = 0; i < len; i++) {
+ 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)) {
+ 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(i2c_regs);
return 0;
}
-int i2c_read(uchar chip, uint addr, int alen, uchar *buf, int len)
+/*
+ * Write data to I2C device
+ */
+int bus_i2c_write(void *base, uchar chip, uint addr, int alen,
+ const uchar *buf, int len)
{
- int timeout = 10000;
int ret;
+ int i;
+ struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)base;
- DPRINTF("%s chip: 0x%02x addr: 0x%04x alen: %d len: +%d\n", \
- __FUNCTION__, chip, addr, alen, len);
+ ret = i2c_init_transfer(i2c_regs, chip, addr, alen);
+ if (ret < 0)
+ return ret;
- if (i2c_addr(chip, addr, alen)) {
- printf("i2c_addr failed\n");
- return -1;
+ for (i = 0; i < len; i++) {
+ ret = tx_byte(i2c_regs, buf[i]);
+ if (ret < 0)
+ break;
}
+ i2c_imx_stop(i2c_regs);
+ return ret;
+}
- __REG16(I2C_BASE + I2CR) = I2CR_IEN | I2CR_MSTA | \
- I2CR_MTX | I2CR_RSTA;
+struct i2c_parms {
+ void *base;
+ void *idle_bus_data;
+ int (*idle_bus_fn)(void *p);
+};
- if (tx_byte(chip << 1 | 1))
- return -1;
+struct sram_data {
+ unsigned curr_i2c_bus;
+ struct i2c_parms i2c_data[3];
+};
- __REG16(I2C_BASE + I2CR) = I2CR_IEN | I2CR_MSTA | ((len == 1) \
- ? I2CR_TX_NO_AK : 0);
+/*
+ * 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;
- ret = __REG16(I2C_BASE + I2DR);
+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
+}
- while (len--) {
- if ((ret = rx_byte()) < 0)
- return -1;
- *buf++ = ret;
- if (len <= 1)
- __REG16(I2C_BASE + I2CR) = I2CR_IEN | \
- I2CR_MSTA | I2CR_TX_NO_AK;
+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;
+}
- wait_busy();
-
- __REG16(I2C_BASE + I2CR) = I2CR_IEN;
+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;
+}
- while (__REG16(I2C_BASE + I2SR) & I2SR_IBB && --timeout)
- udelay(1);
+#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_write(uchar chip, uint addr, int alen, uchar *buf, int len)
+int i2c_read(uchar chip, uint addr, int alen, uchar *buf, int len)
{
- int timeout = 10000;
- DPRINTF("%s chip: 0x%02x addr: 0x%04x alen: %d len: %d\n", \
- __FUNCTION__, chip, addr, alen, len);
+ return bus_i2c_read(get_base(), chip, addr, alen, buf, len);
+}
- if (i2c_addr(chip, addr, alen))
- return -1;
+int i2c_write(uchar chip, uint addr, int alen, uchar *buf, int len)
+{
+ return bus_i2c_write(get_base(), chip, addr, alen, buf, len);
+}
- while (len--)
- if (tx_byte(*buf++))
- return -1;
+/*
+ * 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);
+}
- __REG16(I2C_BASE + I2CR) = I2CR_IEN;
+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);
+}
- while (__REG16(I2C_BASE + I2SR) & I2SR_IBB && --timeout)
- udelay(1);
+/*
+ * Init I2C Bus
+ */
+void i2c_init(int speed, int unused)
+{
+ bus_i2c_init(get_base(), speed, unused, NULL, NULL);
+}
- return 0;
+/*
+ * Set I2C Speed
+ */
+int i2c_set_bus_speed(unsigned int speed)
+{
+ return bus_i2c_set_bus_speed(get_base(), speed);
}
-#endif /* CONFIG_HARD_I2C */
+/*
+ * Get I2C Speed
+ */
+unsigned int i2c_get_bus_speed(void)
+{
+ return bus_i2c_get_bus_speed(get_base());
+}