[U-Boot] [PATCH 5/7 V5] I2C: Modify the I2C driver for EXYNOS5
Simon Glass
sjg at chromium.org
Wed Jul 18 22:06:03 CEST 2012
Hi,
On Thu, Jul 5, 2012 at 12:59 PM, Rajeshwari Shinde
<rajeshwari.s at samsung.com> wrote:
> 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
> - Channel initialisation is moved to a commom funation
> as it is required by i2c_init.
> - Hardcoding for I2CCON_ACKGEN removed.
> - Replaced printf with debug.
> - Checkpatch issues resolved.
> - Pinmux setting will be done in board/samsung/smdk5250/smdk5250.c
> to avoid repeated setting of gpio lines, as it have multi bus support.
>
> 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>
> ---
One more comment on this if not too late. I wonder if the
g_current_bus variable could exist for all variants, but always be
zero, so you can get rid of some of the #ifdef EXYNOS5 stuff? It seems
like it might be a harmless change?
Regards,
Simon
> 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.
> Changes in V5:
> - Pinmux setting will be done in board/samsung/smdk5250/smdk5250.c
> to avoid repeated setting of gpio lines, as it have multi bus support.
> - I2C bus offset calulation done based on EXYNOS_I2C_SPACING
> - Peripharal related code removed.
> drivers/i2c/s3c24x0_i2c.c | 193 +++++++++++++++++++++++++++-----------------
> 1 files changed, 118 insertions(+), 75 deletions(-)
>
> diff --git a/drivers/i2c/s3c24x0_i2c.c b/drivers/i2c/s3c24x0_i2c.c
> index ba6f39b..bbd2ef8 100644
> --- a/drivers/i2c/s3c24x0_i2c.c
> +++ b/drivers/i2c/s3c24x0_i2c.c
> @@ -27,10 +27,15 @@
> */
>
> #include <common.h>
> +#ifdef CONFIG_EXYNOS5
> +#include <asm/arch/clk.h>
> +#include <asm/arch/cpu.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 +50,7 @@
>
> #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 +59,10 @@
>
> #define I2C_TIMEOUT 1 /* 1 second */
>
> +
> +#ifdef CONFIG_EXYNOS5
> +static unsigned int g_current_bus; /* Stores Current I2C Bus */
> +#else
> static int GetI2CSDA(void)
> {
> struct s3c24x0_gpio *gpio = s3c24x0_get_base_gpio();
> @@ -77,16 +87,17 @@ 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;
> @@ -98,35 +109,77 @@ 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(void)
> +{
> +#ifdef CONFIG_EXYNOS5
> + struct s3c24x0_i2c *i2c = (struct s3c24x0_i2c *)(samsung_get_base_i2c()
> + + (EXYNOS_I2C_SPACING
> + * g_current_bus));
> + return i2c;
> +#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);
> +}
> +
> void i2c_init(int speed, int slaveadd)
> {
> - struct s3c24x0_i2c *i2c = s3c24x0_get_base_i2c();
> + struct s3c24x0_i2c *i2c = get_base_i2c();
> +#ifndef CONFIG_EXYNOS5
> struct s3c24x0_gpio *gpio = s3c24x0_get_base_gpio();
> - ulong freq, pres = 16, div;
> +#endif
> int i;
>
> - /* wait for some time to give previous transfer a chance to finish */
> +#ifdef CONFIG_EXYNOS5
> + /* By default i2c channel 0 is the current bus */
> + g_current_bus = 0;
>
> + i2c_ch_init(i2c, CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
> +#endif
> + /* 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--;
> }
>
> +#ifndef CONFIG_EXYNOS5
> if ((readl(&i2c->iicstat) & I2CSTAT_BSY) || GetI2CSDA() == 0) {
> #ifdef CONFIG_S3C2410
> ulong old_gpecon = readl(&gpio->gpecon);
> @@ -171,26 +224,8 @@ 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 /* #ifndef CONFIG_EXYNOS5 */
> }
>
> /*
> @@ -200,19 +235,19 @@ 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 +261,7 @@ 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 +273,16 @@ 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 +292,19 @@ 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 +314,13 @@ 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 +328,17 @@ 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 +352,18 @@ 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 +374,24 @@ 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();
> buf[0] = 0;
>
> /*
> @@ -360,16 +399,17 @@ 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 +436,11 @@ 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();
> + 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 +448,11 @@ 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 +478,9 @@ 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();
> 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 */
> --
> 1.7.4.4
>
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