[U-Boot] [PATCH] I2C: adding new "i2c bus" Command to the I2C Subsystem.
Heiko Schocher
hs at denx.de
Mon Sep 29 09:56:11 CEST 2008
With this Command it is possible to add new I2C Busses,
which are behind 1 .. n I2C Muxes. Details see README.
Signed-off-by: Heiko Schocher <hs at denx.de>
---
README | 47 ++++++++
common/cmd_i2c.c | 269 +++++++++++++++++++++++++++++++++++++++++++++-
cpu/mpc8260/i2c.c | 15 +++-
drivers/i2c/soft_i2c.c | 15 +++-
include/configs/mgcoge.h | 1 +
include/configs/mgsuvd.h | 1 +
include/i2c.h | 23 ++++
7 files changed, 368 insertions(+), 3 deletions(-)
diff --git a/README b/README
index ccd839c..363b68b 100644
--- a/README
+++ b/README
@@ -1426,6 +1426,53 @@ The following options need to be configured:
Define this option if you want to use Freescale's I2C driver in
drivers/i2c/fsl_i2c.c.
+ CONFIG_I2C_MUX
+
+ Define this option if you have I2C devices reached over 1 .. n
+ I2C Muxes like the pca9544a. This option addes a new I2C
+ Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
+ new I2C Bus to the existing I2C Busses. If you select the
+ new Bus with "i2c dev", u-bbot sends first the commandos for
+ the muxes to activate this new "bus".
+
+ CONFIG_I2C_MULTI_BUS must be also defined, to use this
+ feature!
+
+ Example:
+ Adding a new I2C Bus reached over 2 pca9544a muxes
+ The First mux with address 70 and channel 6
+ The Second mux with address 71 and channel 4
+
+ => i2c bus pca9544a:70:6:pca9544a:71:4
+
+ Use the "i2c bus" command without parameter, to get a list
+ of I2C Busses with muxes:
+
+ => i2c bus
+ Busses reached over muxes:
+ Bus ID: 2
+ reached over Mux(es):
+ pca9544a at 70 ch: 4
+ Bus ID: 3
+ reached over Mux(es):
+ pca9544a at 70 ch: 6
+ pca9544a at 71 ch: 4
+ =>
+
+ If you now switch to the new I2C Bus 3 with "i2c dev 3"
+ u-boot sends First the Commando to the mux at 70 to enable
+ channel 6, and then the Commando to the mux at 71 to enable
+ the channel 4.
+
+ After that, you can use the "normal" i2c commands as
+ usual, to communicate with your I2C devices behind
+ the 2 muxes.
+
+ This option is actually implemented for the bitbanging
+ algorithm in common/soft_i2c.c and for the Hardware I2C
+ Bus on the MPC8260. But it should be not so difficult
+ to add this option to other architectures.
+
- SPI Support: CONFIG_SPI
diff --git a/common/cmd_i2c.c b/common/cmd_i2c.c
index 414c888..3710fc0 100644
--- a/common/cmd_i2c.c
+++ b/common/cmd_i2c.c
@@ -83,7 +83,9 @@
#include <common.h>
#include <command.h>
+#include <environment.h>
#include <i2c.h>
+#include <malloc.h>
#include <asm/byteorder.h>
/* Display values from last command.
@@ -125,6 +127,14 @@ static uchar i2c_no_probes[] = CFG_I2C_NOPROBES;
#define NUM_ELEMENTS_NOPROBE (sizeof(i2c_no_probes)/sizeof(i2c_no_probes[0]))
#endif
+#if defined(CONFIG_I2C_MUX)
+static I2C_MUX_DEVICE *i2c_mux_devices = NULL;
+static int i2c_mux_busid = CFG_MAX_I2C_BUS;
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#endif
+
static int
mod_i2c_mem(cmd_tbl_t *cmdtp, int incrflag, int flag, int argc, char *argv[]);
@@ -1188,6 +1198,37 @@ int do_i2c_res(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
return 0;
}
+#if defined(CONFIG_I2C_MUX)
+int do_i2c_add_bus(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
+{
+ int ret=0;
+
+ if (argc == 1) {
+ /* show all busses */
+ I2C_MUX *mux;
+ I2C_MUX_DEVICE *device = i2c_mux_devices;
+
+ printf ("Busses reached over muxes:\n");
+ while (device != NULL) {
+ printf ("Bus ID: %x\n", device->busid);
+ printf (" reached over Mux(es):\n");
+ mux = device->mux;
+ while (mux != NULL) {
+ printf (" %s@%x ch: %x\n", mux->name, mux->chip, mux->channel);
+ mux = mux->next;
+ }
+ device = device->next;
+ }
+ } else {
+ I2C_MUX_DEVICE *dev;
+
+ dev = i2c_mux_ident_muxstring ((uchar *)argv[1]);
+ ret = 0;
+ }
+ return ret;
+}
+#endif /* CONFIG_I2C_MUX */
+
#if defined(CONFIG_I2C_MULTI_BUS)
int do_i2c_bus_num(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
{
@@ -1226,6 +1267,10 @@ int do_i2c_bus_speed(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
int do_i2c(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
{
+#if defined(CONFIG_I2C_MUX)
+ if (!strncmp(argv[1], "bu", 2))
+ return do_i2c_add_bus(cmdtp, flag, --argc, ++argv);
+#endif /* CONFIG_I2C_MUX */
#if defined(CONFIG_I2C_MULTI_BUS)
if (!strncmp(argv[1], "de", 2))
return do_i2c_bus_num(cmdtp, flag, --argc, ++argv);
@@ -1264,8 +1309,11 @@ int do_i2c(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
U_BOOT_CMD(
i2c, 6, 1, do_i2c,
"i2c - I2C sub-system\n",
+#if defined(CONFIG_I2C_MUX)
+ "bus [muxtype:muxaddr:muxchannel] - add a new bus\n"
+#endif /* CONFIG_I2C_MUX */
#if defined(CONFIG_I2C_MULTI_BUS)
- "dev [dev] - show or set current I2C bus\n"
+ "i2c dev [dev] - show or set current I2C bus\n"
#endif /* CONFIG_I2C_MULTI_BUS */
"i2c speed [speed] - show or set I2C bus speed\n"
"i2c md chip address[.0, .1, .2] [# of objects] - read from I2C device\n"
@@ -1335,3 +1383,222 @@ U_BOOT_CMD(
" (valid chip values 50..57)\n"
);
#endif
+
+#if defined(CONFIG_I2C_MUX)
+
+int i2c_mux_add_device(I2C_MUX_DEVICE *dev)
+{
+ I2C_MUX_DEVICE *devtmp = i2c_mux_devices;
+
+ if (i2c_mux_devices == NULL) {
+ i2c_mux_devices = dev;
+ return 0;
+ }
+ while (devtmp->next != NULL)
+ devtmp = devtmp->next;
+
+ devtmp->next = dev;
+ return 0;
+}
+
+I2C_MUX_DEVICE *i2c_mux_search_device(int id)
+{
+ I2C_MUX_DEVICE *device = i2c_mux_devices;
+
+ while (device != NULL) {
+ if (device->busid == id)
+ return device;
+ device = device->next;
+ }
+ return NULL;
+}
+
+/* searches in the buf from *pos the next ':'.
+ * returns:
+ * 0 if found (with *pos = where)
+ * < 0 if an error occured
+ * > 0 if the end of buf is reached
+ */
+static int i2c_mux_search_next (int *pos, uchar *buf, int len)
+{
+ while ((buf[*pos] != ':') && (*pos < len)) {
+ *pos += 1;
+ }
+ if (*pos >= len)
+ return 1;
+ if (buf[*pos] != ':')
+ return -1;
+ return 0;
+}
+
+static int i2c_mux_get_busid (void)
+{
+ int tmp = i2c_mux_busid;
+
+ i2c_mux_busid ++;
+ return tmp;
+}
+
+/* Analyses a Muxstring and sends immediately the
+ Commands to the Muxes. Runs from Flash.
+ */
+int i2c_mux_ident_muxstring_f (uchar *buf)
+{
+ int pos = 0;
+ int oldpos;
+ int ret = 0;
+ int len = strlen((char *)buf);
+ int chip;
+ uchar channel;
+ int was = 0;
+
+ while (ret == 0) {
+ oldpos = pos;
+ /* search name */
+ ret = i2c_mux_search_next(&pos, buf, len);
+ if (ret != 0)
+ printf ("ERROR\n");
+ /* search address */
+ pos ++;
+ oldpos = pos;
+ ret = i2c_mux_search_next(&pos, buf, len);
+ if (ret != 0)
+ printf ("ERROR\n");
+ buf[pos] = 0;
+ chip = simple_strtoul((char *)&buf[oldpos], NULL, 16);
+ buf[pos] = ':';
+ /* search channel */
+ pos ++;
+ oldpos = pos;
+ ret = i2c_mux_search_next(&pos, buf, len);
+ if (ret < 0)
+ printf ("ERROR\n");
+ was = 0;
+ if (buf[pos] != 0) {
+ buf[pos] = 0;
+ was = 1;
+ }
+ channel = simple_strtoul((char *)&buf[oldpos], NULL, 16);
+ if (was)
+ buf[pos] = ':';
+ if (i2c_write(chip, 0, 0, &channel, 1) != 0) {
+ printf ("Error setting Mux: chip:%x channel: \
+ %x\n", chip, channel);
+ return -1;
+ }
+ pos ++;
+ oldpos = pos;
+
+ }
+
+ return 0;
+}
+
+/* Analyses a Muxstring and if this String is correct
+ * adds a new I2C Bus.
+ */
+I2C_MUX_DEVICE *i2c_mux_ident_muxstring (uchar *buf)
+{
+ I2C_MUX_DEVICE *device;
+ I2C_MUX *mux;
+ int pos = 0;
+ int oldpos;
+ int ret = 0;
+ int len = strlen((char *)buf);
+ int was = 0;
+
+ device = (I2C_MUX_DEVICE *)malloc (sizeof(I2C_MUX_DEVICE));
+ device->mux = NULL;
+ device->busid = i2c_mux_get_busid ();
+ device->next = NULL;
+ while (ret == 0) {
+ mux = (I2C_MUX *)malloc (sizeof(I2C_MUX));
+ mux->next = NULL;
+ /* search name of mux */
+ oldpos = pos;
+ ret = i2c_mux_search_next(&pos, buf, len);
+ if (ret != 0)
+ printf ("%s no name.\n", __FUNCTION__);
+ mux->name = (char *)malloc (pos - oldpos + 1);
+ memcpy (mux->name, &buf[oldpos], pos - oldpos);
+ mux->name[pos - oldpos] = 0;
+ /* search address */
+ pos ++;
+ oldpos = pos;
+ ret = i2c_mux_search_next(&pos, buf, len);
+ if (ret != 0)
+ printf ("%s no mux address.\n", __FUNCTION__);
+ buf[pos] = 0;
+ mux->chip = simple_strtoul((char *)&buf[oldpos], NULL, 16);
+ buf[pos] = ':';
+ /* search channel */
+ pos ++;
+ oldpos = pos;
+ ret = i2c_mux_search_next(&pos, buf, len);
+ if (ret < 0)
+ printf ("%s no mux channel.\n", __FUNCTION__);
+ was = 0;
+ if (buf[pos] != 0) {
+ buf[pos] = 0;
+ was = 1;
+ }
+ mux->channel = simple_strtoul((char *)&buf[oldpos], NULL, 16);
+ if (was)
+ buf[pos] = ':';
+ if (device->mux == NULL)
+ device->mux = mux;
+ else {
+ I2C_MUX *muxtmp = device->mux;
+ while (muxtmp->next != NULL) {
+ muxtmp = muxtmp->next;
+ }
+ muxtmp->next = mux;
+ }
+ pos ++;
+ oldpos = pos;
+ }
+ if (ret > 0) {
+ /* Add Device */
+ i2c_mux_add_device (device);
+ return device;
+ }
+
+ return NULL;
+}
+
+int i2x_mux_select_mux(int bus)
+{
+ I2C_MUX_DEVICE *dev;
+ I2C_MUX *mux;
+
+ if ((gd->flags & GD_FLG_RELOC) != GD_FLG_RELOC) {
+ /* select Default Mux Bus */
+#if defined(CFG_I2C_IVM_BUS)
+ i2c_mux_ident_muxstring_f ((uchar *)CFG_I2C_IVM_BUS);
+#else
+ {
+ unsigned char *buf;
+ buf = (unsigned char *) getenv("EEprom_ivm");
+ if (buf != NULL)
+ i2c_mux_ident_muxstring_f (buf);
+ }
+#endif
+ return 0;
+ }
+ dev = i2c_mux_search_device(bus);
+ if (dev == NULL)
+ return -1;
+
+ mux = dev->mux;
+ while (mux != NULL) {
+ if (i2c_write(mux->chip, 0, 0, &mux->channel, 1) != 0) {
+ printf ("Error setting Mux: chip:%x channel: \
+ %x\n", mux->chip, mux->channel);
+ return -1;
+ }
+ mux = mux->next;
+ }
+ return 0;
+}
+#endif /* CONFIG_I2C_MUX */
+
diff --git a/cpu/mpc8260/i2c.c b/cpu/mpc8260/i2c.c
index 335177f..a96fbf8 100644
--- a/cpu/mpc8260/i2c.c
+++ b/cpu/mpc8260/i2c.c
@@ -780,10 +780,23 @@ unsigned int i2c_get_bus_num(void)
int i2c_set_bus_num(unsigned int bus)
{
+#if defined(CONFIG_I2C_MUX)
+ if (bus < CFG_MAX_I2C_BUS) {
+ i2c_bus_num = bus;
+ } else {
+ int ret;
+
+ ret = i2x_mux_select_mux(bus);
+ if (ret == 0)
+ i2c_bus_num = bus;
+ else
+ return ret;
+ }
+#else
if (bus >= CFG_MAX_I2C_BUS)
return -1;
i2c_bus_num = bus;
-
+#endif
return 0;
}
/* TODO: add 100/400k switching */
diff --git a/drivers/i2c/soft_i2c.c b/drivers/i2c/soft_i2c.c
index 983b14b..f426bbb 100644
--- a/drivers/i2c/soft_i2c.c
+++ b/drivers/i2c/soft_i2c.c
@@ -249,10 +249,23 @@ unsigned int i2c_get_bus_num(void)
int i2c_set_bus_num(unsigned int bus)
{
+#if defined(CONFIG_I2C_MUX)
+ if (bus < CFG_MAX_I2C_BUS) {
+ i2c_bus_num = bus;
+ } else {
+ int ret;
+
+ ret = i2x_mux_select_mux(bus);
+ if (ret == 0)
+ i2c_bus_num = bus;
+ else
+ return ret;
+ }
+#else
if (bus >= CFG_MAX_I2C_BUS)
return -1;
i2c_bus_num = bus;
-
+#endif
return 0;
}
diff --git a/include/configs/mgcoge.h b/include/configs/mgcoge.h
index 398e092..6564c15 100644
--- a/include/configs/mgcoge.h
+++ b/include/configs/mgcoge.h
@@ -203,6 +203,7 @@
#define CONFIG_I2C_CMD_TREE 1
#define CFG_MAX_I2C_BUS 2
#define CFG_I2C_INIT_BOARD 1
+#define CONFIG_I2C_MUX 1
/* EEprom support */
#define CFG_I2C_EEPROM_ADDR_LEN 1
diff --git a/include/configs/mgsuvd.h b/include/configs/mgsuvd.h
index 17ad6b4..79954fe 100644
--- a/include/configs/mgsuvd.h
+++ b/include/configs/mgsuvd.h
@@ -373,6 +373,7 @@
#define CONFIG_I2C_CMD_TREE 1
#define CFG_MAX_I2C_BUS 2
#define CFG_I2C_INIT_BOARD 1
+#define CONFIG_I2C_MUX 1
/* EEprom support */
#define CFG_I2C_EEPROM_ADDR_LEN 1
diff --git a/include/i2c.h b/include/i2c.h
index a51c164..2ad2db0 100644
--- a/include/i2c.h
+++ b/include/i2c.h
@@ -76,6 +76,29 @@ void i2c_init(int speed, int slaveaddr);
void i2c_init_board(void);
#endif
+#if defined(CONFIG_I2C_MUX)
+
+typedef struct _mux {
+ uchar chip;
+ uchar channel;
+ char *name;
+ struct _mux *next;
+} I2C_MUX;
+
+typedef struct _mux_device {
+ int busid;
+ I2C_MUX *mux; /* List of muxes, to reach the device */
+ struct _mux_device *next;
+} I2C_MUX_DEVICE;
+
+int i2c_mux_add_device(I2C_MUX_DEVICE *dev);
+
+I2C_MUX_DEVICE *i2c_mux_search_device(int id);
+I2C_MUX_DEVICE *i2c_mux_ident_muxstring (uchar *buf);
+int i2x_mux_select_mux(int bus);
+int i2c_mux_ident_muxstring_f (uchar *buf);
+#endif
+
/*
* Probe the given I2C chip address. Returns 0 if a chip responded,
* not 0 on failure.
--
1.5.6.1
--
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HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
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