[U-Boot] [PATCH v4 17/23] keymile, common; fix i2c deblocking support
Heiko Schocher
hs at denx.de
Fri Apr 1 09:16:29 CEST 2011
This patch fix the i2c deblocking facility with the i2c HW-Controller.
The required delays for byte reading, the enhanced criteria for stop
the dummy read and required 5 start/stop sequences are added.
Add i2c deblocking before ivm eeprom read.
Improve i2c deblocking sequence by respecting stop hold time.
Cleaned function for deblocking. Have now one function i2c_make_abort()
available for bitbang, mpc82xx and mpc83xx harware controller.
Signed-off-by: Stefan Bigler <stefan.bigler at keymile.com>
Signed-off-by: Holger Brunck <holger.brunck at keymile.com>
Signed-off-by: Heiko Schocher <hs at denx.de>
cc: Valentin Longchamp <valentin.longchamp at keymile.com>
---
Changes for v2:
- fix checkpatch.pl errors and warnings
Changes for v3:
- rebased only
board/keymile/common/common.c | 121 ++++++++++++++++++++++++++++++-----------
1 files changed, 89 insertions(+), 32 deletions(-)
diff --git a/board/keymile/common/common.c b/board/keymile/common/common.c
index 2d0aee9..6600e08 100644
--- a/board/keymile/common/common.c
+++ b/board/keymile/common/common.c
@@ -40,6 +40,9 @@
#if defined(CONFIG_HARD_I2C) || defined(CONFIG_SOFT_I2C)
#include <i2c.h>
+static void i2c_write_start_seq(void);
+static int i2c_make_abort(void);
+
int ivm_calc_crc(unsigned char *buf, int len)
{
const unsigned short crc_tab[16] = {
@@ -329,8 +332,11 @@ int ivm_read_eeprom(void)
if (buf != NULL)
dev_addr = simple_strtoul((char *)buf, NULL, 16);
+ /* add deblocking here */
+ i2c_make_abort();
+
ret = i2c_read(dev_addr, 0, 1, i2c_buffer,
- CONFIG_SYS_IVM_EEPROM_MAX_LEN);
+ CONFIG_SYS_IVM_EEPROM_MAX_LEN);
if (ret != 0) {
printf ("Error reading EEprom\n");
return -2;
@@ -340,7 +346,7 @@ int ivm_read_eeprom(void)
}
#if defined(CONFIG_SYS_I2C_INIT_BOARD)
-#define DELAY_ABORT_SEQ 62
+#define DELAY_ABORT_SEQ 62 /* @200kHz 9 clocks = 44us, 62us is ok */
#define DELAY_HALF_PERIOD (500 / (CONFIG_SYS_I2C_SPEED / 1000))
#if defined(CONFIG_MGCOGE) || defined(CONFIG_MGCOGE2NE)
@@ -404,7 +410,7 @@ static void setports(int gpio)
#endif
#if !defined(CONFIG_MPC83xx)
-static void writeStartSeq(void)
+static void i2c_write_start_seq(void)
{
set_sda(1);
udelay(DELAY_HALF_PERIOD);
@@ -426,6 +432,21 @@ static void writeStartSeq(void)
*/
static int i2c_make_abort(void)
{
+
+#if defined(CONFIG_HARD_I2C) && !defined(MACH_TYPE_KM_KIRKWOOD)
+ immap_t *immap = (immap_t *)CONFIG_SYS_IMMR ;
+ i2c8260_t *i2c = (i2c8260_t *)&immap->im_i2c;
+
+ /*
+ * disable I2C controller first, otherwhise it thinks we want to
+ * talk to the slave port...
+ */
+ clrbits_8(&i2c->i2c_i2mod, 0x01);
+
+ /* Set the PortPins to GPIO */
+ setports(1);
+#endif
+
int scl_state = 0;
int sda_state = 0;
int i = 0;
@@ -449,57 +470,93 @@ static int i2c_make_abort(void)
}
if (ret == 0)
for (i = 0; i < 5; i++)
- writeStartSeq();
+ i2c_write_start_seq();
+ /* respect stop setup time */
+ udelay(DELAY_ABORT_SEQ);
+ set_scl(1);
+ udelay(DELAY_ABORT_SEQ);
+ set_sda(1);
get_sda();
+
+#if defined(CONFIG_HARD_I2C)
+ /* Set the PortPins back to use for I2C */
+ setports(0);
+#endif
return ret;
}
#endif
-/*
- * i2c_init_board - reset i2c bus. When the board is powercycled during a
- * bus transfer it might hang; for details see doc/I2C_Edge_Conditions.
- */
-void i2c_init_board(void)
-{
#if defined(CONFIG_MPC83xx)
+static void i2c_write_start_seq(void)
+{
+ struct fsl_i2c *dev;
+ dev = (struct fsl_i2c *) (CONFIG_SYS_IMMR + CONFIG_SYS_I2C_OFFSET);
+ udelay(DELAY_ABORT_SEQ);
+ out_8(&dev->cr, (I2C_CR_MEN | I2C_CR_MSTA));
+ udelay(DELAY_ABORT_SEQ);
+ out_8(&dev->cr, (I2C_CR_MEN));
+}
+
+static int i2c_make_abort(void)
+{
struct fsl_i2c *dev;
dev = (struct fsl_i2c *) (CONFIG_SYS_IMMR + CONFIG_SYS_I2C_OFFSET);
uchar dummy;
+ uchar last;
+ int nbr_read = 0;
+ int i = 0;
+ int ret = 0;
+ /* wait after each operation to finsh with a delay */
out_8(&dev->cr, (I2C_CR_MSTA));
+ udelay(DELAY_ABORT_SEQ);
out_8(&dev->cr, (I2C_CR_MEN | I2C_CR_MSTA));
+ udelay(DELAY_ABORT_SEQ);
dummy = in_8(&dev->dr);
- dummy = in_8(&dev->dr);
- if (dummy != 0xff) {
- dummy = in_8(&dev->dr);
- }
- out_8(&dev->cr, (I2C_CR_MEN));
- out_8(&dev->cr, 0x00);
- out_8(&dev->cr, (I2C_CR_MEN));
-#else
-#if defined(CONFIG_HARD_I2C) && !defined(MACH_TYPE_KM_KIRKWOOD)
- immap_t *immap = (immap_t *)CONFIG_SYS_IMMR ;
- i2c8260_t *i2c = (i2c8260_t *)&immap->im_i2c;
+ udelay(DELAY_ABORT_SEQ);
+ last = in_8(&dev->dr);
+ nbr_read++;
/*
- * disable I2C controller first, otherwhise it thinks we want to
- * talk to the slave port...
+ * do read until the last bit is 1, but stop if the full eeprom is
+ * read.
*/
- clrbits_8(&i2c->i2c_i2mod, 0x01);
+ while (((last & 0x01) != 0x01) &&
+ (nbr_read < CONFIG_SYS_IVM_EEPROM_MAX_LEN)) {
+ udelay(DELAY_ABORT_SEQ);
+ last = in_8(&dev->dr);
+ nbr_read++;
+ }
+ if ((last & 0x01) != 0x01)
+ ret = -2;
+ if ((last != 0xff) || (nbr_read > 1))
+ printf("[INFO] i2c abort after %d bytes (0x%02x)\n",
+ nbr_read, last);
+ udelay(DELAY_ABORT_SEQ);
+ out_8(&dev->cr, (I2C_CR_MEN));
+ udelay(DELAY_ABORT_SEQ);
+ /* clear status reg */
+ out_8(&dev->sr, 0);
- /* Set the PortPins to GPIO */
- setports(1);
+ for (i = 0; i < 5; i++)
+ i2c_write_start_seq();
+ if (ret != 0)
+ printf("[ERROR] i2c abort failed after %d bytes (0x%02x)\n",
+ nbr_read, last);
+
+ return ret;
+}
#endif
+/**
+ * i2c_init_board - reset i2c bus. When the board is powercycled during a
+ * bus transfer it might hang; for details see doc/I2C_Edge_Conditions.
+ */
+void i2c_init_board(void)
+{
/* Now run the AbortSequence() */
i2c_make_abort();
-
-#if defined(CONFIG_HARD_I2C)
- /* Set the PortPins back to use for I2C */
- setports(0);
-#endif
-#endif
}
#endif
#endif
--
1.7.4
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