[U-Boot] [PATCH 6/8 V4] I2C: Modify the I2C driver for EXYNOS5
Rajeshwari Shinde
rajeshwari.s at samsung.com
Tue Jun 19 09:30:30 CEST 2012
This patch modifies the S3C I2C driver to suppport EXYNOS5.
The cahnges made to driver are as follows:
- I2C base address is passed as a parameter to many
functions to avoid multiple #ifdef
- I2C init for Exynos5 is made as different function.
- Channel initialisation is moved to a commom funation
as it is required by both the i2c_init.
- Separate functions written to get I2C base address,
peripheral id for pinmux support.
- Hardcoding for I2CCON_ACKGEN removed.
- Replaced printf with debug.
- Checkpatch issues resolved.
Signed-off-by: Alim Akhtar <alim.akhtar at samsung.com>
Signed-off-by: Doug Anderson <dianders at chromium.org>
Signed-off-by: Rajeshwari Shinde <rajeshwari.s at samsung.com>
Acked-by: Simon Glass <sjg at chromium.org>
---
Changes in V2:
- Removed #define for I2C cahnnels from hearder file except for I2C0.
- Incorporated review comments from Simon Glass.
Changes in V3:
- Incorporated review comments from Joonyoung Shim.
- Reduced the number of #ifdef by modifying get_i2c_base function.
- Removed duplicate code.
Changes in V4:
- Resolved build error for s3c2410.
drivers/i2c/s3c24x0_i2c.c | 239 +++++++++++++++++++++++++++++++--------------
drivers/i2c/s3c24x0_i2c.h | 3 +
2 files changed, 168 insertions(+), 74 deletions(-)
diff --git a/drivers/i2c/s3c24x0_i2c.c b/drivers/i2c/s3c24x0_i2c.c
index ba6f39b..0b31cd1 100644
--- a/drivers/i2c/s3c24x0_i2c.c
+++ b/drivers/i2c/s3c24x0_i2c.c
@@ -27,10 +27,17 @@
*/
#include <common.h>
+#ifdef CONFIG_EXYNOS5
+#include <asm/arch/clk.h>
+#include <asm/arch/cpu.h>
+#include <asm/arch/gpio.h>
+#include <asm/arch/pinmux.h>
+#else
#include <asm/arch/s3c24x0_cpu.h>
-
+#endif
#include <asm/io.h>
#include <i2c.h>
+#include "s3c24x0_i2c.h"
#ifdef CONFIG_HARD_I2C
@@ -45,6 +52,7 @@
#define I2CSTAT_BSY 0x20 /* Busy bit */
#define I2CSTAT_NACK 0x01 /* Nack bit */
+#define I2CCON_ACKGEN 0x80 /* Acknowledge generation */
#define I2CCON_IRPND 0x10 /* Interrupt pending bit */
#define I2C_MODE_MT 0xC0 /* Master Transmit Mode */
#define I2C_MODE_MR 0x80 /* Master Receive Mode */
@@ -53,6 +61,32 @@
#define I2C_TIMEOUT 1 /* 1 second */
+static unsigned int g_current_bus; /* Stores Current I2C Bus */
+
+#ifdef CONFIG_EXYNOS5
+/* We should not rely on any particular ordering of these IDs */
+static enum periph_id periph_for_dev[] = {
+ PERIPH_ID_I2C0,
+ PERIPH_ID_I2C1,
+ PERIPH_ID_I2C2,
+ PERIPH_ID_I2C3,
+ PERIPH_ID_I2C4,
+ PERIPH_ID_I2C5,
+ PERIPH_ID_I2C6,
+ PERIPH_ID_I2C7,
+};
+
+static enum periph_id i2c_get_periph_id(unsigned dev_index)
+{
+ if (dev_index < ARRAY_SIZE(periph_for_dev))
+ return periph_for_dev[dev_index];
+
+ debug("%s: invalid bus %d", __func__, dev_index);
+
+ return PERIPH_ID_NONE;
+}
+
+#else
static int GetI2CSDA(void)
{
struct s3c24x0_gpio *gpio = s3c24x0_get_base_gpio();
@@ -77,16 +111,17 @@ static void SetI2CSCL(int x)
struct s3c24x0_gpio *gpio = s3c24x0_get_base_gpio();
#ifdef CONFIG_S3C2410
- writel((readl(&gpio->gpedat) & ~0x4000) | (x & 1) << 14, &gpio->gpedat);
+ writel((readl(&gpio->gpedat) & ~0x4000) |
+ (x & 1) << 14, &gpio->gpedat);
#endif
#ifdef CONFIG_S3C2400
writel((readl(&gpio->pgdat) & ~0x0040) | (x & 1) << 6, &gpio->pgdat);
#endif
}
+#endif
-static int WaitForXfer(void)
+static int WaitForXfer(struct s3c24x0_i2c *i2c)
{
- struct s3c24x0_i2c *i2c = s3c24x0_get_base_i2c();
int i;
i = I2C_TIMEOUT * 10000;
@@ -98,27 +133,93 @@ static int WaitForXfer(void)
return (readl(&i2c->iiccon) & I2CCON_IRPND) ? I2C_OK : I2C_NOK_TOUT;
}
-static int IsACK(void)
+static int IsACK(struct s3c24x0_i2c *i2c)
{
- struct s3c24x0_i2c *i2c = s3c24x0_get_base_i2c();
-
return !(readl(&i2c->iicstat) & I2CSTAT_NACK);
}
-static void ReadWriteByte(void)
+static void ReadWriteByte(struct s3c24x0_i2c *i2c)
{
- struct s3c24x0_i2c *i2c = s3c24x0_get_base_i2c();
-
writel(readl(&i2c->iiccon) & ~I2CCON_IRPND, &i2c->iiccon);
}
+static struct s3c24x0_i2c *get_base_i2c(int bus_idx)
+{
+#ifdef CONFIG_EXYNOS5
+ struct s3c24x0_i2c *i2c = (struct s3c24x0_i2c *)samsung_get_base_i2c();
+ return &i2c[bus_idx];
+#else
+ return s3c24x0_get_base_i2c();
+#endif
+}
+
+static void i2c_ch_init(struct s3c24x0_i2c *i2c, int speed, int slaveadd)
+{
+ ulong freq, pres = 16, div;
+#ifdef CONFIG_EXYNOS5
+ freq = get_i2c_clk();
+#else
+ freq = get_PCLK();
+#endif
+ /* calculate prescaler and divisor values */
+ if ((freq / pres / (16 + 1)) > speed)
+ /* set prescaler to 512 */
+ pres = 512;
+
+ div = 0;
+ while ((freq / pres / (div + 1)) > speed)
+ div++;
+
+ /* set prescaler, divisor according to freq, also set ACKGEN, IRQ */
+ writel((div & 0x0F) | 0xA0 | ((pres == 512) ? 0x40 : 0), &i2c->iiccon);
+
+ /* init to SLAVE REVEIVE and set slaveaddr */
+ writel(0, &i2c->iicstat);
+ writel(slaveadd, &i2c->iicadd);
+ /* program Master Transmit (and implicit STOP) */
+ writel(I2C_MODE_MT | I2C_TXRX_ENA, &i2c->iicstat);
+}
+
+static void i2c_bus_init(struct s3c24x0_i2c *i2c, unsigned int bus)
+{
+ int periph_id = i2c_get_periph_id(bus);
+
+ exynos_pinmux_config(periph_id, 0);
+
+ i2c_ch_init(i2c, CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
+}
+
+#ifdef CONFIG_EXYNOS5
void i2c_init(int speed, int slaveadd)
{
- struct s3c24x0_i2c *i2c = s3c24x0_get_base_i2c();
+ struct s3c24x0_i2c *i2c;
+ int i;
+
+ /* By default i2c channel 0 is the current bus */
+ g_current_bus = I2C0;
+
+ i2c = get_base_i2c(g_current_bus);
+
+ i2c_bus_init(i2c, g_current_bus);
+
+ /* wait for some time to give previous transfer a chance to finish */
+ i = I2C_TIMEOUT * 1000;
+ while ((readl(&i2c->iicstat) & I2CSTAT_BSY) && (i > 0)) {
+ udelay(1000);
+ i--;
+ }
+}
+
+#else
+void i2c_init(int speed, int slaveadd)
+{
+ struct s3c24x0_i2c *i2c = get_base_i2c();
struct s3c24x0_gpio *gpio = s3c24x0_get_base_gpio();
- ulong freq, pres = 16, div;
int i;
+ /* By default i2c channel 0 is the current bus */
+ g_current_bus = I2C0;
+
/* wait for some time to give previous transfer a chance to finish */
i = I2C_TIMEOUT * 1000;
@@ -171,27 +272,9 @@ void i2c_init(int speed, int slaveadd)
#endif
}
- /* calculate prescaler and divisor values */
- freq = get_PCLK();
- if ((freq / pres / (16 + 1)) > speed)
- /* set prescaler to 512 */
- pres = 512;
-
- div = 0;
- while ((freq / pres / (div + 1)) > speed)
- div++;
-
- /* set prescaler, divisor according to freq, also set
- * ACKGEN, IRQ */
- writel((div & 0x0F) | 0xA0 | ((pres == 512) ? 0x40 : 0), &i2c->iiccon);
-
- /* init to SLAVE REVEIVE and set slaveaddr */
- writel(0, &i2c->iicstat);
- writel(slaveadd, &i2c->iicadd);
- /* program Master Transmit (and implicit STOP) */
- writel(I2C_MODE_MT | I2C_TXRX_ENA, &i2c->iicstat);
-
+ i2c_ch_init(i2c, speed, slaveadd);
}
+#endif
/*
* cmd_type is 0 for write, 1 for read.
@@ -200,19 +283,19 @@ void i2c_init(int speed, int slaveadd)
* by the char, we could make it larger if needed. If it is
* 0 we skip the address write cycle.
*/
-static
-int i2c_transfer(unsigned char cmd_type,
- unsigned char chip,
- unsigned char addr[],
- unsigned char addr_len,
- unsigned char data[], unsigned short data_len)
+static int i2c_transfer(struct s3c24x0_i2c *i2c,
+ unsigned char cmd_type,
+ unsigned char chip,
+ unsigned char addr[],
+ unsigned char addr_len,
+ unsigned char data[],
+ unsigned short data_len)
{
- struct s3c24x0_i2c *i2c = s3c24x0_get_base_i2c();
int i, result;
if (data == 0 || data_len == 0) {
/*Don't support data transfer of no length or to address 0 */
- printf("i2c_transfer: bad call\n");
+ debug("i2c_transfer: bad call\n");
return I2C_NOK;
}
@@ -226,7 +309,7 @@ int i2c_transfer(unsigned char cmd_type,
if (readl(&i2c->iicstat) & I2CSTAT_BSY)
return I2C_NOK_TOUT;
- writel(readl(&i2c->iiccon) | 0x80, &i2c->iiccon);
+ writel(readl(&i2c->iiccon) | I2CCON_ACKGEN, &i2c->iiccon);
result = I2C_OK;
switch (cmd_type) {
@@ -238,16 +321,16 @@ int i2c_transfer(unsigned char cmd_type,
&i2c->iicstat);
i = 0;
while ((i < addr_len) && (result == I2C_OK)) {
- result = WaitForXfer();
+ result = WaitForXfer(i2c);
writel(addr[i], &i2c->iicds);
- ReadWriteByte();
+ ReadWriteByte(i2c);
i++;
}
i = 0;
while ((i < data_len) && (result == I2C_OK)) {
- result = WaitForXfer();
+ result = WaitForXfer(i2c);
writel(data[i], &i2c->iicds);
- ReadWriteByte();
+ ReadWriteByte(i2c);
i++;
}
} else {
@@ -257,19 +340,19 @@ int i2c_transfer(unsigned char cmd_type,
&i2c->iicstat);
i = 0;
while ((i < data_len) && (result = I2C_OK)) {
- result = WaitForXfer();
+ result = WaitForXfer(i2c);
writel(data[i], &i2c->iicds);
- ReadWriteByte();
+ ReadWriteByte(i2c);
i++;
}
}
if (result == I2C_OK)
- result = WaitForXfer();
+ result = WaitForXfer(i2c);
/* send STOP */
writel(I2C_MODE_MR | I2C_TXRX_ENA, &i2c->iicstat);
- ReadWriteByte();
+ ReadWriteByte(i2c);
break;
case I2C_READ:
@@ -279,13 +362,13 @@ int i2c_transfer(unsigned char cmd_type,
/* send START */
writel(readl(&i2c->iicstat) | I2C_START_STOP,
&i2c->iicstat);
- result = WaitForXfer();
- if (IsACK()) {
+ result = WaitForXfer(i2c);
+ if (IsACK(i2c)) {
i = 0;
while ((i < addr_len) && (result == I2C_OK)) {
writel(addr[i], &i2c->iicds);
- ReadWriteByte();
- result = WaitForXfer();
+ ReadWriteByte(i2c);
+ result = WaitForXfer(i2c);
i++;
}
@@ -293,16 +376,17 @@ int i2c_transfer(unsigned char cmd_type,
/* resend START */
writel(I2C_MODE_MR | I2C_TXRX_ENA |
I2C_START_STOP, &i2c->iicstat);
- ReadWriteByte();
- result = WaitForXfer();
+ ReadWriteByte(i2c);
+ result = WaitForXfer(i2c);
i = 0;
while ((i < data_len) && (result == I2C_OK)) {
/* disable ACK for final READ */
if (i == data_len - 1)
writel(readl(&i2c->iiccon)
- & ~0x80, &i2c->iiccon);
- ReadWriteByte();
- result = WaitForXfer();
+ & ~I2CCON_ACKGEN,
+ &i2c->iiccon);
+ ReadWriteByte(i2c);
+ result = WaitForXfer(i2c);
data[i] = readl(&i2c->iicds);
i++;
}
@@ -316,17 +400,18 @@ int i2c_transfer(unsigned char cmd_type,
/* send START */
writel(readl(&i2c->iicstat) | I2C_START_STOP,
&i2c->iicstat);
- result = WaitForXfer();
+ result = WaitForXfer(i2c);
- if (IsACK()) {
+ if (IsACK(i2c)) {
i = 0;
while ((i < data_len) && (result == I2C_OK)) {
/* disable ACK for final READ */
if (i == data_len - 1)
writel(readl(&i2c->iiccon) &
- ~0x80, &i2c->iiccon);
- ReadWriteByte();
- result = WaitForXfer();
+ ~I2CCON_ACKGEN,
+ &i2c->iiccon);
+ ReadWriteByte(i2c);
+ result = WaitForXfer(i2c);
data[i] = readl(&i2c->iicds);
i++;
}
@@ -337,22 +422,24 @@ int i2c_transfer(unsigned char cmd_type,
/* send STOP */
writel(I2C_MODE_MR | I2C_TXRX_ENA, &i2c->iicstat);
- ReadWriteByte();
+ ReadWriteByte(i2c);
break;
default:
- printf("i2c_transfer: bad call\n");
+ debug("i2c_transfer: bad call\n");
result = I2C_NOK;
break;
}
- return (result);
+ return result;
}
int i2c_probe(uchar chip)
{
+ struct s3c24x0_i2c *i2c;
uchar buf[1];
+ i2c = get_base_i2c(g_current_bus);
buf[0] = 0;
/*
@@ -360,16 +447,17 @@ int i2c_probe(uchar chip)
* address was <ACK>ed (i.e. there was a chip at that address which
* drove the data line low).
*/
- return i2c_transfer(I2C_READ, chip << 1, 0, 0, buf, 1) != I2C_OK;
+ return i2c_transfer(i2c, I2C_READ, chip << 1, 0, 0, buf, 1) != I2C_OK;
}
int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
{
+ struct s3c24x0_i2c *i2c;
uchar xaddr[4];
int ret;
if (alen > 4) {
- printf("I2C read: addr len %d not supported\n", alen);
+ debug("I2C read: addr len %d not supported\n", alen);
return 1;
}
@@ -396,10 +484,11 @@ int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
chip |= ((addr >> (alen * 8)) &
CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW);
#endif
- if ((ret =
- i2c_transfer(I2C_READ, chip << 1, &xaddr[4 - alen], alen,
- buffer, len)) != 0) {
- printf("I2c read: failed %d\n", ret);
+ i2c = get_base_i2c(g_current_bus);
+ ret = i2c_transfer(i2c, I2C_READ, chip << 1, &xaddr[4 - alen], alen,
+ buffer, len);
+ if (ret != 0) {
+ debug("I2c read: failed %d\n", ret);
return 1;
}
return 0;
@@ -407,10 +496,11 @@ int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
{
+ struct s3c24x0_i2c *i2c;
uchar xaddr[4];
if (alen > 4) {
- printf("I2C write: addr len %d not supported\n", alen);
+ debug("I2C write: addr len %d not supported\n", alen);
return 1;
}
@@ -436,8 +526,9 @@ int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
chip |= ((addr >> (alen * 8)) &
CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW);
#endif
+ i2c = get_base_i2c(g_current_bus);
return (i2c_transfer
- (I2C_WRITE, chip << 1, &xaddr[4 - alen], alen, buffer,
+ (i2c, I2C_WRITE, chip << 1, &xaddr[4 - alen], alen, buffer,
len) != 0);
}
#endif /* CONFIG_HARD_I2C */
diff --git a/drivers/i2c/s3c24x0_i2c.h b/drivers/i2c/s3c24x0_i2c.h
index d357a0a..57aafb1 100644
--- a/drivers/i2c/s3c24x0_i2c.h
+++ b/drivers/i2c/s3c24x0_i2c.h
@@ -23,6 +23,9 @@
#ifndef _S3C24X0_I2C_H
#define _S3C24X0_I2C_H
+/* I2C channels exynos5 has 8 i2c channel */
+#define I2C0 0
+
struct s3c24x0_i2c {
u32 iiccon;
u32 iicstat;
--
1.7.4.4
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