From 35a56c5b821c1a5ab904018f322a8e45afd116f0 Mon Sep 17 00:00:00 2001
From: Joe Perches <joe@perches.com>
Date: Wed, 11 Aug 2010 18:20:54 +0200
Subject: [PATCH 01/10] i2c-dev: Remove unnecessary kmalloc casts
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
---
drivers/i2c/i2c-dev.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c
index e0694e4d86c7..b3fcb59a5a10 100644
--- a/drivers/i2c/i2c-dev.c
+++ b/drivers/i2c/i2c-dev.c
@@ -219,9 +219,7 @@ static noinline int i2cdev_ioctl_rdrw(struct i2c_client *client,
if (rdwr_arg.nmsgs > I2C_RDRW_IOCTL_MAX_MSGS)
return -EINVAL;
- rdwr_pa = (struct i2c_msg *)
- kmalloc(rdwr_arg.nmsgs * sizeof(struct i2c_msg),
- GFP_KERNEL);
+ rdwr_pa = kmalloc(rdwr_arg.nmsgs * sizeof(struct i2c_msg), GFP_KERNEL);
if (!rdwr_pa)
return -ENOMEM;
From f1c2e33c295de423db5740647bfaa5e2ad139192 Mon Sep 17 00:00:00 2001
From: Julia Lawall <julia@diku.dk>
Date: Wed, 11 Aug 2010 18:20:55 +0200
Subject: [PATCH 02/10] i2c-dev: Use memdup_user
Use memdup_user when user data is immediately copied into the allocated
region. Note that in the second case, the ++i is no longer necessary, as
the last value is already freed if needed by the call to memdup_user.
The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@@
expression from,to,size,flag;
position p;
identifier l1,l2;
@@
- to = \(kmalloc@p\|kzalloc@p\)(size,flag);
+ to = memdup_user(from,size);
if (
- to==NULL
+ IS_ERR(to)
|| ...) {
<+... when != goto l1;
- -ENOMEM
+ PTR_ERR(to)
...+>
}
- if (copy_from_user(to, from, size) != 0) {
- <+... when != goto l2;
- -EFAULT
- ...+>
- }
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
---
drivers/i2c/i2c-dev.c | 22 ++++++----------------
1 file changed, 6 insertions(+), 16 deletions(-)
diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c
index b3fcb59a5a10..0b0427f7d348 100644
--- a/drivers/i2c/i2c-dev.c
+++ b/drivers/i2c/i2c-dev.c
@@ -167,13 +167,9 @@ static ssize_t i2cdev_write(struct file *file, const char __user *buf,
if (count > 8192)
count = 8192;
- tmp = kmalloc(count, GFP_KERNEL);
- if (tmp == NULL)
- return -ENOMEM;
- if (copy_from_user(tmp, buf, count)) {
- kfree(tmp);
- return -EFAULT;
- }
+ tmp = memdup_user(buf, count);
+ if (IS_ERR(tmp))
+ return PTR_ERR(tmp);
pr_debug("i2c-dev: i2c-%d writing %zu bytes.\n",
iminor(file->f_path.dentry->d_inode), count);
@@ -245,15 +241,9 @@ static noinline int i2cdev_ioctl_rdrw(struct i2c_client *client,
break;
}
data_ptrs[i] = (u8 __user *)rdwr_pa[i].buf;
- rdwr_pa[i].buf = kmalloc(rdwr_pa[i].len, GFP_KERNEL);
- if (rdwr_pa[i].buf == NULL) {
- res = -ENOMEM;
- break;
- }
- if (copy_from_user(rdwr_pa[i].buf, data_ptrs[i],
- rdwr_pa[i].len)) {
- ++i; /* Needs to be kfreed too */
- res = -EFAULT;
+ rdwr_pa[i].buf = memdup_user(data_ptrs[i], rdwr_pa[i].len);
+ if (IS_ERR(rdwr_pa[i].buf)) {
+ res = PTR_ERR(rdwr_pa[i].buf);
break;
}
}
From 9a94241afcc9a481691a9c29b7460217925b59b8 Mon Sep 17 00:00:00 2001
From: Jean Delvare <khali@linux-fr.org>
Date: Wed, 11 Aug 2010 18:20:56 +0200
Subject: [PATCH 03/10] i2c: Add support for custom probe function
The probe method used by i2c_new_probed_device() may not be suitable
for all cases. Let the caller provide its own, optional probe
function.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
---
Documentation/i2c/instantiating-devices | 2 +-
drivers/i2c/i2c-core.c | 16 ++++++++++------
drivers/macintosh/therm_windtunnel.c | 4 ++--
drivers/media/video/bt8xx/bttv-i2c.c | 2 +-
drivers/media/video/cx18/cx18-i2c.c | 3 ++-
drivers/media/video/em28xx/em28xx-cards.c | 2 +-
drivers/media/video/ivtv/ivtv-i2c.c | 9 +++++----
drivers/media/video/v4l2-common.c | 3 ++-
drivers/usb/host/ohci-pnx4008.c | 2 +-
drivers/video/matrox/i2c-matroxfb.c | 2 +-
include/linux/i2c.h | 7 +++++--
11 files changed, 31 insertions(+), 21 deletions(-)
diff --git a/Documentation/i2c/instantiating-devices b/Documentation/i2c/instantiating-devices
index e89490270aba..87da405a8597 100644
--- a/Documentation/i2c/instantiating-devices
+++ b/Documentation/i2c/instantiating-devices
@@ -102,7 +102,7 @@ static int __devinit usb_hcd_pnx4008_probe(struct platform_device *pdev)
memset(&i2c_info, 0, sizeof(struct i2c_board_info));
strlcpy(i2c_info.name, "isp1301_pnx", I2C_NAME_SIZE);
isp1301_i2c_client = i2c_new_probed_device(i2c_adap, &i2c_info,
- normal_i2c);
+ normal_i2c, NULL);
i2c_put_adapter(i2c_adap);
(...)
}
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index df937df845eb..cf14ca063181 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -1464,14 +1464,18 @@ static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver)
struct i2c_client *
i2c_new_probed_device(struct i2c_adapter *adap,
struct i2c_board_info *info,
- unsigned short const *addr_list)
+ unsigned short const *addr_list,
+ int (*probe)(struct i2c_adapter *, unsigned short addr))
{
int i;
- /* Stop here if the bus doesn't support probing */
- if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) {
- dev_err(&adap->dev, "Probing not supported\n");
- return NULL;
+ if (!probe) {
+ /* Stop here if the bus doesn't support probing */
+ if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) {
+ dev_err(&adap->dev, "Probing not supported\n");
+ return NULL;
+ }
+ probe = i2c_default_probe;
}
for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) {
@@ -1490,7 +1494,7 @@ i2c_new_probed_device(struct i2c_adapter *adap,
}
/* Test address responsiveness */
- if (i2c_default_probe(adap, addr_list[i]))
+ if (probe(adap, addr_list[i]))
break;
}
diff --git a/drivers/macintosh/therm_windtunnel.c b/drivers/macintosh/therm_windtunnel.c
index 5c9367acf0cf..7d1bfeb6a82c 100644
--- a/drivers/macintosh/therm_windtunnel.c
+++ b/drivers/macintosh/therm_windtunnel.c
@@ -322,10 +322,10 @@ do_attach( struct i2c_adapter *adapter )
memset(&info, 0, sizeof(struct i2c_board_info));
strlcpy(info.type, "therm_ds1775", I2C_NAME_SIZE);
- i2c_new_probed_device(adapter, &info, scan_ds1775);
+ i2c_new_probed_device(adapter, &info, scan_ds1775, NULL);
strlcpy(info.type, "therm_adm1030", I2C_NAME_SIZE);
- i2c_new_probed_device(adapter, &info, scan_adm1030);
+ i2c_new_probed_device(adapter, &info, scan_adm1030, NULL);
if( x.thermostat && x.fan ) {
x.running = 1;
diff --git a/drivers/media/video/bt8xx/bttv-i2c.c b/drivers/media/video/bt8xx/bttv-i2c.c
index 407fa61e4cda..685d6597ee79 100644
--- a/drivers/media/video/bt8xx/bttv-i2c.c
+++ b/drivers/media/video/bt8xx/bttv-i2c.c
@@ -411,7 +411,7 @@ void __devinit init_bttv_i2c_ir(struct bttv *btv)
memset(&info, 0, sizeof(struct i2c_board_info));
strlcpy(info.type, "ir_video", I2C_NAME_SIZE);
- i2c_new_probed_device(&btv->c.i2c_adap, &info, addr_list);
+ i2c_new_probed_device(&btv->c.i2c_adap, &info, addr_list, NULL);
}
}
diff --git a/drivers/media/video/cx18/cx18-i2c.c b/drivers/media/video/cx18/cx18-i2c.c
index 809f7d37129c..73ce90c2f577 100644
--- a/drivers/media/video/cx18/cx18-i2c.c
+++ b/drivers/media/video/cx18/cx18-i2c.c
@@ -117,7 +117,8 @@ static int cx18_i2c_new_ir(struct cx18 *cx, struct i2c_adapter *adap, u32 hw,
break;
}
- return i2c_new_probed_device(adap, &info, addr_list) == NULL ? -1 : 0;
+ return i2c_new_probed_device(adap, &info, addr_list, NULL) == NULL ?
+ -1 : 0;
}
int cx18_i2c_register(struct cx18 *cx, unsigned idx)
diff --git a/drivers/media/video/em28xx/em28xx-cards.c b/drivers/media/video/em28xx/em28xx-cards.c
index ffbe544e30f4..e7efb4bffabd 100644
--- a/drivers/media/video/em28xx/em28xx-cards.c
+++ b/drivers/media/video/em28xx/em28xx-cards.c
@@ -2385,7 +2385,7 @@ void em28xx_register_i2c_ir(struct em28xx *dev)
if (dev->init_data.name)
info.platform_data = &dev->init_data;
- i2c_new_probed_device(&dev->i2c_adap, &info, addr_list);
+ i2c_new_probed_device(&dev->i2c_adap, &info, addr_list, NULL);
}
void em28xx_card_setup(struct em28xx *dev)
diff --git a/drivers/media/video/ivtv/ivtv-i2c.c b/drivers/media/video/ivtv/ivtv-i2c.c
index d391bbdb0b8a..a74fa099c565 100644
--- a/drivers/media/video/ivtv/ivtv-i2c.c
+++ b/drivers/media/video/ivtv/ivtv-i2c.c
@@ -183,8 +183,8 @@ static int ivtv_i2c_new_ir(struct ivtv *itv, u32 hw, const char *type, u8 addr)
return -1;
memset(&info, 0, sizeof(struct i2c_board_info));
strlcpy(info.type, type, I2C_NAME_SIZE);
- return i2c_new_probed_device(adap, &info, addr_list) == NULL
- ? -1 : 0;
+ return i2c_new_probed_device(adap, &info, addr_list, NULL)
+ == NULL ? -1 : 0;
}
/* Only allow one IR receiver to be registered per board */
@@ -221,7 +221,8 @@ static int ivtv_i2c_new_ir(struct ivtv *itv, u32 hw, const char *type, u8 addr)
info.platform_data = init_data;
strlcpy(info.type, type, I2C_NAME_SIZE);
- return i2c_new_probed_device(adap, &info, addr_list) == NULL ? -1 : 0;
+ return i2c_new_probed_device(adap, &info, addr_list, NULL) == NULL ?
+ -1 : 0;
}
/* Instantiate the IR receiver device using probing -- undesirable */
@@ -249,7 +250,7 @@ struct i2c_client *ivtv_i2c_new_ir_legacy(struct ivtv *itv)
memset(&info, 0, sizeof(struct i2c_board_info));
strlcpy(info.type, "ir_video", I2C_NAME_SIZE);
- return i2c_new_probed_device(&itv->i2c_adap, &info, addr_list);
+ return i2c_new_probed_device(&itv->i2c_adap, &info, addr_list, NULL);
}
int ivtv_i2c_register(struct ivtv *itv, unsigned idx)
diff --git a/drivers/media/video/v4l2-common.c b/drivers/media/video/v4l2-common.c
index 3ce7c64e5789..8ee1179be926 100644
--- a/drivers/media/video/v4l2-common.c
+++ b/drivers/media/video/v4l2-common.c
@@ -381,7 +381,8 @@ struct v4l2_subdev *v4l2_i2c_new_subdev_board(struct v4l2_device *v4l2_dev,
/* Create the i2c client */
if (info->addr == 0 && probe_addrs)
- client = i2c_new_probed_device(adapter, info, probe_addrs);
+ client = i2c_new_probed_device(adapter, info, probe_addrs,
+ NULL);
else
client = i2c_new_device(adapter, info);
diff --git a/drivers/usb/host/ohci-pnx4008.c b/drivers/usb/host/ohci-pnx4008.c
index cd74bbdd007c..653d6a60edb5 100644
--- a/drivers/usb/host/ohci-pnx4008.c
+++ b/drivers/usb/host/ohci-pnx4008.c
@@ -329,7 +329,7 @@ static int __devinit usb_hcd_pnx4008_probe(struct platform_device *pdev)
memset(&i2c_info, 0, sizeof(struct i2c_board_info));
strlcpy(i2c_info.type, "isp1301_pnx", I2C_NAME_SIZE);
isp1301_i2c_client = i2c_new_probed_device(i2c_adap, &i2c_info,
- normal_i2c);
+ normal_i2c, NULL);
i2c_put_adapter(i2c_adap);
if (!isp1301_i2c_client) {
err("failed to connect I2C to ISP1301 USB Transceiver");
diff --git a/drivers/video/matrox/i2c-matroxfb.c b/drivers/video/matrox/i2c-matroxfb.c
index 403b14445a78..0fb280ead3dc 100644
--- a/drivers/video/matrox/i2c-matroxfb.c
+++ b/drivers/video/matrox/i2c-matroxfb.c
@@ -191,7 +191,7 @@ static void* i2c_matroxfb_probe(struct matrox_fb_info* minfo) {
};
i2c_new_probed_device(&m2info->maven.adapter,
- &maven_info, addr_list);
+ &maven_info, addr_list, NULL);
}
}
return m2info;
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 38dd4025aa4e..59a9f3cdc0b5 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -284,12 +284,15 @@ i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info);
/* If you don't know the exact address of an I2C device, use this variant
* instead, which can probe for device presence in a list of possible
- * addresses.
+ * addresses. The "probe" callback function is optional. If it is provided,
+ * it must return 1 on successful probe, 0 otherwise. If it is not provided,
+ * a default probing method is used.
*/
extern struct i2c_client *
i2c_new_probed_device(struct i2c_adapter *adap,
struct i2c_board_info *info,
- unsigned short const *addr_list);
+ unsigned short const *addr_list,
+ int (*probe)(struct i2c_adapter *, unsigned short addr));
/* For devices that use several addresses, use i2c_new_dummy() to make
* client handles for the extra addresses.
From d44f19d586b6113fb5db10e1a36457f0db3b01aa Mon Sep 17 00:00:00 2001
From: Jean Delvare <khali@linux-fr.org>
Date: Wed, 11 Aug 2010 18:20:57 +0200
Subject: [PATCH 04/10] V4L/DVB: Use custom I2C probing function mechanism
Now that i2c-core offers the possibility to provide custom probing
function for I2C devices, let's make use of it.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
---
drivers/i2c/i2c-core.c | 7 +++++++
drivers/media/video/cx23885/cx23885-i2c.c | 15 ++++-----------
drivers/media/video/cx88/cx88-i2c.c | 19 ++++---------------
include/linux/i2c.h | 3 +++
4 files changed, 18 insertions(+), 26 deletions(-)
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index cf14ca063181..6e1c2f54d9cf 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -1461,6 +1461,13 @@ static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver)
return err;
}
+int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr)
+{
+ return i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0,
+ I2C_SMBUS_QUICK, NULL) >= 0;
+}
+EXPORT_SYMBOL_GPL(i2c_probe_func_quick_read);
+
struct i2c_client *
i2c_new_probed_device(struct i2c_adapter *adap,
struct i2c_board_info *info,
diff --git a/drivers/media/video/cx23885/cx23885-i2c.c b/drivers/media/video/cx23885/cx23885-i2c.c
index 1a391486e551..ed3d8f55029b 100644
--- a/drivers/media/video/cx23885/cx23885-i2c.c
+++ b/drivers/media/video/cx23885/cx23885-i2c.c
@@ -364,17 +364,10 @@ int cx23885_i2c_register(struct cx23885_i2c *bus)
memset(&info, 0, sizeof(struct i2c_board_info));
strlcpy(info.type, "ir_video", I2C_NAME_SIZE);
- /*
- * We can't call i2c_new_probed_device() because it uses
- * quick writes for probing and the IR receiver device only
- * replies to reads.
- */
- if (i2c_smbus_xfer(&bus->i2c_adap, addr_list[0], 0,
- I2C_SMBUS_READ, 0, I2C_SMBUS_QUICK,
- NULL) >= 0) {
- info.addr = addr_list[0];
- i2c_new_device(&bus->i2c_adap, &info);
- }
+ /* Use quick read command for probe, some IR chips don't
+ * support writes */
+ i2c_new_probed_device(&bus->i2c_adap, &info, addr_list,
+ i2c_probe_func_quick_read);
}
return bus->i2c_rc;
diff --git a/drivers/media/video/cx88/cx88-i2c.c b/drivers/media/video/cx88/cx88-i2c.c
index 375ad53f7961..82db555b22dd 100644
--- a/drivers/media/video/cx88/cx88-i2c.c
+++ b/drivers/media/video/cx88/cx88-i2c.c
@@ -193,24 +193,13 @@ void cx88_i2c_init_ir(struct cx88_core *core)
0x18, 0x6b, 0x71,
I2C_CLIENT_END
};
- const unsigned short *addrp;
memset(&info, 0, sizeof(struct i2c_board_info));
strlcpy(info.type, "ir_video", I2C_NAME_SIZE);
- /*
- * We can't call i2c_new_probed_device() because it uses
- * quick writes for probing and at least some R receiver
- * devices only reply to reads.
- */
- for (addrp = addr_list; *addrp != I2C_CLIENT_END; addrp++) {
- if (i2c_smbus_xfer(&core->i2c_adap, *addrp, 0,
- I2C_SMBUS_READ, 0,
- I2C_SMBUS_QUICK, NULL) >= 0) {
- info.addr = *addrp;
- i2c_new_device(&core->i2c_adap, &info);
- break;
- }
- }
+ /* Use quick read command for probe, some IR chips don't
+ * support writes */
+ i2c_new_probed_device(&core->i2c_adap, &info, addr_list,
+ i2c_probe_func_quick_read);
}
}
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 59a9f3cdc0b5..c8627e453e97 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -294,6 +294,9 @@ i2c_new_probed_device(struct i2c_adapter *adap,
unsigned short const *addr_list,
int (*probe)(struct i2c_adapter *, unsigned short addr));
+/* Common custom probe functions */
+extern int i2c_probe_func_quick_read(struct i2c_adapter *, unsigned short addr);
+
/* For devices that use several addresses, use i2c_new_dummy() to make
* client handles for the extra addresses.
*/
From fe61e07e9ebc890c70d97a1f72ddaad4bee2d848 Mon Sep 17 00:00:00 2001
From: Jean Delvare <khali@linux-fr.org>
Date: Wed, 11 Aug 2010 18:20:58 +0200
Subject: [PATCH 05/10] i2c: Move adapter locking helpers to i2c-core
Uninline i2c adapter locking helper functions, move them to i2c-core,
and use them in i2c-core itself. The functions are still exported for
external users. This makes future updates to the locking model (which
will be needed for multiplexing support) possible and transparent.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Michael Lawnick <ml.lawnick@gmx.de>
---
drivers/i2c/i2c-core.c | 39 ++++++++++++++++++++++++++++++++++-----
include/linux/i2c.h | 20 +++-----------------
2 files changed, 37 insertions(+), 22 deletions(-)
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 6e1c2f54d9cf..e09e143379b1 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -429,6 +429,35 @@ static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr)
__i2c_check_addr_busy);
}
+/**
+ * i2c_lock_adapter - Get exclusive access to an I2C bus segment
+ * @adapter: Target I2C bus segment
+ */
+void i2c_lock_adapter(struct i2c_adapter *adapter)
+{
+ rt_mutex_lock(&adapter->bus_lock);
+}
+EXPORT_SYMBOL_GPL(i2c_lock_adapter);
+
+/**
+ * i2c_trylock_adapter - Try to get exclusive access to an I2C bus segment
+ * @adapter: Target I2C bus segment
+ */
+static int i2c_trylock_adapter(struct i2c_adapter *adapter)
+{
+ return rt_mutex_trylock(&adapter->bus_lock);
+}
+
+/**
+ * i2c_unlock_adapter - Release exclusive access to an I2C bus segment
+ * @adapter: Target I2C bus segment
+ */
+void i2c_unlock_adapter(struct i2c_adapter *adapter)
+{
+ rt_mutex_unlock(&adapter->bus_lock);
+}
+EXPORT_SYMBOL_GPL(i2c_unlock_adapter);
+
/**
* i2c_new_device - instantiate an i2c device
* @adap: the adapter managing the device
@@ -1238,12 +1267,12 @@ int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
#endif
if (in_atomic() || irqs_disabled()) {
- ret = rt_mutex_trylock(&adap->bus_lock);
+ ret = i2c_trylock_adapter(adap);
if (!ret)
/* I2C activity is ongoing. */
return -EAGAIN;
} else {
- rt_mutex_lock(&adap->bus_lock);
+ i2c_lock_adapter(adap);
}
/* Retry automatically on arbitration loss */
@@ -1255,7 +1284,7 @@ int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
if (time_after(jiffies, orig_jiffies + adap->timeout))
break;
}
- rt_mutex_unlock(&adap->bus_lock);
+ i2c_unlock_adapter(adap);
return ret;
} else {
@@ -2013,7 +2042,7 @@ s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags,
flags &= I2C_M_TEN | I2C_CLIENT_PEC;
if (adapter->algo->smbus_xfer) {
- rt_mutex_lock(&adapter->bus_lock);
+ i2c_lock_adapter(adapter);
/* Retry automatically on arbitration loss */
orig_jiffies = jiffies;
@@ -2027,7 +2056,7 @@ s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags,
orig_jiffies + adapter->timeout))
break;
}
- rt_mutex_unlock(&adapter->bus_lock);
+ i2c_unlock_adapter(adapter);
} else
res = i2c_smbus_xfer_emulated(adapter, addr, flags, read_write,
command, protocol, data);
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index c8627e453e97..5bf0f4beea31 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -382,23 +382,9 @@ static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data)
dev_set_drvdata(&dev->dev, data);
}
-/**
- * i2c_lock_adapter - Prevent access to an I2C bus segment
- * @adapter: Target I2C bus segment
- */
-static inline void i2c_lock_adapter(struct i2c_adapter *adapter)
-{
- rt_mutex_lock(&adapter->bus_lock);
-}
-
-/**
- * i2c_unlock_adapter - Reauthorize access to an I2C bus segment
- * @adapter: Target I2C bus segment
- */
-static inline void i2c_unlock_adapter(struct i2c_adapter *adapter)
-{
- rt_mutex_unlock(&adapter->bus_lock);
-}
+/* Adapter locking functions, exported for shared pin cases */
+void i2c_lock_adapter(struct i2c_adapter *);
+void i2c_unlock_adapter(struct i2c_adapter *);
/*flags for the client struct: */
#define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */
From d6703281ff20df6c2c0ea7c39a0cc2fa8be3e680 Mon Sep 17 00:00:00 2001
From: Jean Delvare <khali@linux-fr.org>
Date: Wed, 11 Aug 2010 18:20:59 +0200
Subject: [PATCH 06/10] i2c: Drop dummy variable
Now that bus_for_each_drv() is no longer __must_check, we can drop the
dummy variable that was used to store the returned value.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Justin P. Mattock <justinmattock@gmail.com>
---
drivers/i2c/i2c-core.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index e09e143379b1..bb02f8e21a3b 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -789,7 +789,7 @@ static int __process_new_adapter(struct device_driver *d, void *data)
static int i2c_register_adapter(struct i2c_adapter *adap)
{
- int res = 0, dummy;
+ int res = 0;
/* Can't register until after driver model init */
if (unlikely(WARN_ON(!i2c_bus_type.p))) {
@@ -830,8 +830,7 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
/* Notify drivers */
mutex_lock(&core_lock);
- dummy = bus_for_each_drv(&i2c_bus_type, NULL, adap,
- __process_new_adapter);
+ bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_new_adapter);
mutex_unlock(&core_lock);
return 0;
From 8031d79baedabd44590d047d97a310eb0e0e4e0c Mon Sep 17 00:00:00 2001
From: Jean Delvare <khali@linux-fr.org>
Date: Wed, 11 Aug 2010 18:21:00 +0200
Subject: [PATCH 07/10] i2c: Make i2c_default_probe self-sufficient
Make i2c_default_probe self-sufficient, so that callers don't have to
do functionality checks themselves. This ensures everything is and
will stay consistent.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
---
drivers/i2c/i2c-core.c | 32 ++++++++++----------------------
1 file changed, 10 insertions(+), 22 deletions(-)
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index bb02f8e21a3b..ba86af63f5cf 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -1378,13 +1378,17 @@ static int i2c_default_probe(struct i2c_adapter *adap, unsigned short addr)
I2C_SMBUS_BYTE_DATA, &dummy);
else
#endif
- if ((addr & ~0x07) == 0x30 || (addr & ~0x0f) == 0x50
- || !i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK))
- err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0,
- I2C_SMBUS_BYTE, &dummy);
- else
+ if (!((addr & ~0x07) == 0x30 || (addr & ~0x0f) == 0x50)
+ && i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK))
err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_WRITE, 0,
I2C_SMBUS_QUICK, NULL);
+ else if (i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE))
+ err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0,
+ I2C_SMBUS_BYTE, &dummy);
+ else {
+ dev_warn(&adap->dev, "No suitable probing method supported\n");
+ err = -EOPNOTSUPP;
+ }
return err >= 0;
}
@@ -1465,16 +1469,6 @@ static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver)
if (!(adapter->class & driver->class))
goto exit_free;
- /* Stop here if the bus doesn't support probing */
- if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_BYTE)) {
- if (address_list[0] == I2C_CLIENT_END)
- goto exit_free;
-
- dev_warn(&adapter->dev, "Probing not supported\n");
- err = -EOPNOTSUPP;
- goto exit_free;
- }
-
for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) {
dev_dbg(&adapter->dev, "found normal entry for adapter %d, "
"addr 0x%02x\n", adap_id, address_list[i]);
@@ -1504,14 +1498,8 @@ i2c_new_probed_device(struct i2c_adapter *adap,
{
int i;
- if (!probe) {
- /* Stop here if the bus doesn't support probing */
- if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) {
- dev_err(&adap->dev, "Probing not supported\n");
- return NULL;
- }
+ if (!probe)
probe = i2c_default_probe;
- }
for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) {
/* Check address validity */
From dafc50d141c27959dbd3a1cfe9857a86d23402a7 Mon Sep 17 00:00:00 2001
From: Jean Delvare <khali@linux-fr.org>
Date: Wed, 11 Aug 2010 18:21:01 +0200
Subject: [PATCH 08/10] i2c: Use a separate mutex for userspace client lists
Moving userspace-instantiated clients to separate lists wasn't nearly
enough to avoid deadlocks in multiplexed bus cases. We also want to
have a dedicated mutex to protect each list.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Michael Lawnick <ml.lawnick@gmx.de>
---
drivers/i2c/i2c-core.c | 13 +++++++------
include/linux/i2c.h | 1 +
2 files changed, 8 insertions(+), 6 deletions(-)
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index ba86af63f5cf..97f96b66653c 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -662,9 +662,9 @@ i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr,
return -EINVAL;
/* Keep track of the added device */
- i2c_lock_adapter(adap);
+ mutex_lock(&adap->userspace_clients_lock);
list_add_tail(&client->detected, &adap->userspace_clients);
- i2c_unlock_adapter(adap);
+ mutex_unlock(&adap->userspace_clients_lock);
dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device",
info.type, info.addr);
@@ -703,7 +703,7 @@ i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr,
/* Make sure the device was added through sysfs */
res = -ENOENT;
- i2c_lock_adapter(adap);
+ mutex_lock(&adap->userspace_clients_lock);
list_for_each_entry_safe(client, next, &adap->userspace_clients,
detected) {
if (client->addr == addr) {
@@ -716,7 +716,7 @@ i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr,
break;
}
}
- i2c_unlock_adapter(adap);
+ mutex_unlock(&adap->userspace_clients_lock);
if (res < 0)
dev_err(dev, "%s: Can't find device in list\n",
@@ -798,6 +798,7 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
}
rt_mutex_init(&adap->bus_lock);
+ mutex_init(&adap->userspace_clients_lock);
INIT_LIST_HEAD(&adap->userspace_clients);
/* Set default timeout to 1 second if not already set */
@@ -1003,7 +1004,7 @@ int i2c_del_adapter(struct i2c_adapter *adap)
return res;
/* Remove devices instantiated from sysfs */
- i2c_lock_adapter(adap);
+ mutex_lock(&adap->userspace_clients_lock);
list_for_each_entry_safe(client, next, &adap->userspace_clients,
detected) {
dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name,
@@ -1011,7 +1012,7 @@ int i2c_del_adapter(struct i2c_adapter *adap)
list_del(&client->detected);
i2c_unregister_device(client);
}
- i2c_unlock_adapter(adap);
+ mutex_unlock(&adap->userspace_clients_lock);
/* Detach any active clients. This can't fail, thus we do not
checking the returned value. */
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 5bf0f4beea31..798bad8741e4 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -368,6 +368,7 @@ struct i2c_adapter {
char name[48];
struct completion dev_released;
+ struct mutex userspace_clients_lock;
struct list_head userspace_clients;
};
#define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
From 0826374bff57411d239f2fcb15da3c35af0a93cd Mon Sep 17 00:00:00 2001
From: Michael Lawnick <ml.lawnick@gmx.de>
Date: Wed, 11 Aug 2010 18:21:02 +0200
Subject: [PATCH 09/10] i2c: Multiplexed I2C bus core support
Add multiplexed bus core support. I2C multiplexer and switches
like pca954x get instantiated as new adapters per port.
Signed-off-by: Michael Lawnick <ml.lawnick@gmx.de>
Acked-by: Rodolfo Giometti <giometti@linux.it>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
---
drivers/i2c/Kconfig | 11 +++
drivers/i2c/Makefile | 1 +
drivers/i2c/i2c-core.c | 64 ++++++++++++++--
drivers/i2c/i2c-dev.c | 40 +++++++++-
drivers/i2c/i2c-mux.c | 165 ++++++++++++++++++++++++++++++++++++++++
include/linux/i2c-mux.h | 46 +++++++++++
include/linux/i2c.h | 8 ++
7 files changed, 327 insertions(+), 8 deletions(-)
create mode 100644 drivers/i2c/i2c-mux.c
create mode 100644 include/linux/i2c-mux.h
diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig
index d06083fdffbb..efb48ad1ba34 100644
--- a/drivers/i2c/Kconfig
+++ b/drivers/i2c/Kconfig
@@ -47,6 +47,17 @@ config I2C_CHARDEV
This support is also available as a module. If so, the module
will be called i2c-dev.
+config I2C_MUX
+ tristate "I2C bus multiplexing support"
+ depends on EXPERIMENTAL
+ help
+ Say Y here if you want the I2C core to support the ability to
+ handle multiplexed I2C bus topologies, by presenting each
+ multiplexed segment as a I2C adapter.
+
+ This support is also available as a module. If so, the module
+ will be called i2c-mux.
+
config I2C_HELPER_AUTO
bool "Autoselect pertinent helper modules"
default y
diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile
index a7d9b4be9bb3..f363258daa3d 100644
--- a/drivers/i2c/Makefile
+++ b/drivers/i2c/Makefile
@@ -6,6 +6,7 @@ obj-$(CONFIG_I2C_BOARDINFO) += i2c-boardinfo.o
obj-$(CONFIG_I2C) += i2c-core.o
obj-$(CONFIG_I2C_SMBUS) += i2c-smbus.o
obj-$(CONFIG_I2C_CHARDEV) += i2c-dev.o
+obj-$(CONFIG_I2C_MUX) += i2c-mux.o
obj-y += algos/ busses/
ifeq ($(CONFIG_I2C_DEBUG_CORE),y)
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 97f96b66653c..6649176de940 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -20,7 +20,9 @@
/* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi>.
All SMBus-related things are written by Frodo Looijaard <frodol@dds.nl>
SMBus 2.0 support by Mark Studebaker <mdsxyz123@yahoo.com> and
- Jean Delvare <khali@linux-fr.org> */
+ Jean Delvare <khali@linux-fr.org>
+ Mux support by Rodolfo Giometti <giometti@enneenne.com> and
+ Michael Lawnick <michael.lawnick.ext@nsn.com> */
#include <linux/module.h>
#include <linux/kernel.h>
@@ -423,10 +425,48 @@ static int __i2c_check_addr_busy(struct device *dev, void *addrp)
return 0;
}
+/* walk up mux tree */
+static int i2c_check_mux_parents(struct i2c_adapter *adapter, int addr)
+{
+ int result;
+
+ result = device_for_each_child(&adapter->dev, &addr,
+ __i2c_check_addr_busy);
+
+ if (!result && i2c_parent_is_i2c_adapter(adapter))
+ result = i2c_check_mux_parents(
+ to_i2c_adapter(adapter->dev.parent), addr);
+
+ return result;
+}
+
+/* recurse down mux tree */
+static int i2c_check_mux_children(struct device *dev, void *addrp)
+{
+ int result;
+
+ if (dev->type == &i2c_adapter_type)
+ result = device_for_each_child(dev, addrp,
+ i2c_check_mux_children);
+ else
+ result = __i2c_check_addr_busy(dev, addrp);
+
+ return result;
+}
+
static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr)
{
- return device_for_each_child(&adapter->dev, &addr,
- __i2c_check_addr_busy);
+ int result = 0;
+
+ if (i2c_parent_is_i2c_adapter(adapter))
+ result = i2c_check_mux_parents(
+ to_i2c_adapter(adapter->dev.parent), addr);
+
+ if (!result)
+ result = device_for_each_child(&adapter->dev, &addr,
+ i2c_check_mux_children);
+
+ return result;
}
/**
@@ -435,7 +475,10 @@ static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr)
*/
void i2c_lock_adapter(struct i2c_adapter *adapter)
{
- rt_mutex_lock(&adapter->bus_lock);
+ if (i2c_parent_is_i2c_adapter(adapter))
+ i2c_lock_adapter(to_i2c_adapter(adapter->dev.parent));
+ else
+ rt_mutex_lock(&adapter->bus_lock);
}
EXPORT_SYMBOL_GPL(i2c_lock_adapter);
@@ -445,7 +488,10 @@ EXPORT_SYMBOL_GPL(i2c_lock_adapter);
*/
static int i2c_trylock_adapter(struct i2c_adapter *adapter)
{
- return rt_mutex_trylock(&adapter->bus_lock);
+ if (i2c_parent_is_i2c_adapter(adapter))
+ return i2c_trylock_adapter(to_i2c_adapter(adapter->dev.parent));
+ else
+ return rt_mutex_trylock(&adapter->bus_lock);
}
/**
@@ -454,7 +500,10 @@ static int i2c_trylock_adapter(struct i2c_adapter *adapter)
*/
void i2c_unlock_adapter(struct i2c_adapter *adapter)
{
- rt_mutex_unlock(&adapter->bus_lock);
+ if (i2c_parent_is_i2c_adapter(adapter))
+ i2c_unlock_adapter(to_i2c_adapter(adapter->dev.parent));
+ else
+ rt_mutex_unlock(&adapter->bus_lock);
}
EXPORT_SYMBOL_GPL(i2c_unlock_adapter);
@@ -743,10 +792,11 @@ static const struct attribute_group *i2c_adapter_attr_groups[] = {
NULL
};
-static struct device_type i2c_adapter_type = {
+struct device_type i2c_adapter_type = {
.groups = i2c_adapter_attr_groups,
.release = i2c_adapter_dev_release,
};
+EXPORT_SYMBOL_GPL(i2c_adapter_type);
#ifdef CONFIG_I2C_COMPAT
static struct class_compat *i2c_adapter_compat_class;
diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c
index 0b0427f7d348..5f3a52d517c3 100644
--- a/drivers/i2c/i2c-dev.c
+++ b/drivers/i2c/i2c-dev.c
@@ -189,12 +189,50 @@ static int i2cdev_check(struct device *dev, void *addrp)
return dev->driver ? -EBUSY : 0;
}
+/* walk up mux tree */
+static int i2cdev_check_mux_parents(struct i2c_adapter *adapter, int addr)
+{
+ int result;
+
+ result = device_for_each_child(&adapter->dev, &addr, i2cdev_check);
+
+ if (!result && i2c_parent_is_i2c_adapter(adapter))
+ result = i2cdev_check_mux_parents(
+ to_i2c_adapter(adapter->dev.parent), addr);
+
+ return result;
+}
+
+/* recurse down mux tree */
+static int i2cdev_check_mux_children(struct device *dev, void *addrp)
+{
+ int result;
+
+ if (dev->type == &i2c_adapter_type)
+ result = device_for_each_child(dev, addrp,
+ i2cdev_check_mux_children);
+ else
+ result = i2cdev_check(dev, addrp);
+
+ return result;
+}
+
/* This address checking function differs from the one in i2c-core
in that it considers an address with a registered device, but no
driver bound to it, as NOT busy. */
static int i2cdev_check_addr(struct i2c_adapter *adapter, unsigned int addr)
{
- return device_for_each_child(&adapter->dev, &addr, i2cdev_check);
+ int result = 0;
+
+ if (i2c_parent_is_i2c_adapter(adapter))
+ result = i2cdev_check_mux_parents(
+ to_i2c_adapter(adapter->dev.parent), addr);
+
+ if (!result)
+ result = device_for_each_child(&adapter->dev, &addr,
+ i2cdev_check_mux_children);
+
+ return result;
}
static noinline int i2cdev_ioctl_rdrw(struct i2c_client *client,
diff --git a/drivers/i2c/i2c-mux.c b/drivers/i2c/i2c-mux.c
new file mode 100644
index 000000000000..d32a4843fc3a
--- /dev/null
+++ b/drivers/i2c/i2c-mux.c
@@ -0,0 +1,165 @@
+/*
+ * Multiplexed I2C bus driver.
+ *
+ * Copyright (c) 2008-2009 Rodolfo Giometti <giometti@linux.it>
+ * Copyright (c) 2008-2009 Eurotech S.p.A. <info@eurotech.it>
+ * Copyright (c) 2009-2010 NSN GmbH & Co KG <michael.lawnick.ext@nsn.com>
+ *
+ * Simplifies access to complex multiplexed I2C bus topologies, by presenting
+ * each multiplexed bus segment as an additional I2C adapter.
+ * Supports multi-level mux'ing (mux behind a mux).
+ *
+ * Based on:
+ * i2c-virt.c from Kumar Gala <galak@kernel.crashing.org>
+ * i2c-virtual.c from Ken Harrenstien, Copyright (c) 2004 Google, Inc.
+ * i2c-virtual.c from Brian Kuschak <bkuschak@yahoo.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/i2c-mux.h>
+
+/* multiplexer per channel data */
+struct i2c_mux_priv {
+ struct i2c_adapter adap;
+ struct i2c_algorithm algo;
+
+ struct i2c_adapter *parent;
+ void *mux_dev; /* the mux chip/device */
+ u32 chan_id; /* the channel id */
+
+ int (*select)(struct i2c_adapter *, void *mux_dev, u32 chan_id);
+ int (*deselect)(struct i2c_adapter *, void *mux_dev, u32 chan_id);
+};
+
+static int i2c_mux_master_xfer(struct i2c_adapter *adap,
+ struct i2c_msg msgs[], int num)
+{
+ struct i2c_mux_priv *priv = adap->algo_data;
+ struct i2c_adapter *parent = priv->parent;
+ int ret;
+
+ /* Switch to the right mux port and perform the transfer. */
+
+ ret = priv->select(parent, priv->mux_dev, priv->chan_id);
+ if (ret >= 0)
+ ret = parent->algo->master_xfer(parent, msgs, num);
+ if (priv->deselect)
+ priv->deselect(parent, priv->mux_dev, priv->chan_id);
+
+ return ret;
+}
+
+static int i2c_mux_smbus_xfer(struct i2c_adapter *adap,
+ u16 addr, unsigned short flags,
+ char read_write, u8 command,
+ int size, union i2c_smbus_data *data)
+{
+ struct i2c_mux_priv *priv = adap->algo_data;
+ struct i2c_adapter *parent = priv->parent;
+ int ret;
+
+ /* Select the right mux port and perform the transfer. */
+
+ ret = priv->select(parent, priv->mux_dev, priv->chan_id);
+ if (ret >= 0)
+ ret = parent->algo->smbus_xfer(parent, addr, flags,
+ read_write, command, size, data);
+ if (priv->deselect)
+ priv->deselect(parent, priv->mux_dev, priv->chan_id);
+
+ return ret;
+}
+
+/* Return the parent's functionality */
+static u32 i2c_mux_functionality(struct i2c_adapter *adap)
+{
+ struct i2c_mux_priv *priv = adap->algo_data;
+ struct i2c_adapter *parent = priv->parent;
+
+ return parent->algo->functionality(parent);
+}
+
+struct i2c_adapter *i2c_add_mux_adapter(struct i2c_adapter *parent,
+ void *mux_dev, u32 force_nr, u32 chan_id,
+ int (*select) (struct i2c_adapter *,
+ void *, u32),
+ int (*deselect) (struct i2c_adapter *,
+ void *, u32))
+{
+ struct i2c_mux_priv *priv;
+ int ret;
+
+ priv = kzalloc(sizeof(struct i2c_mux_priv), GFP_KERNEL);
+ if (!priv)
+ return NULL;
+
+ /* Set up private adapter data */
+ priv->parent = parent;
+ priv->mux_dev = mux_dev;
+ priv->chan_id = chan_id;
+ priv->select = select;
+ priv->deselect = deselect;
+
+ /* Need to do algo dynamically because we don't know ahead
+ * of time what sort of physical adapter we'll be dealing with.
+ */
+ if (parent->algo->master_xfer)
+ priv->algo.master_xfer = i2c_mux_master_xfer;
+ if (parent->algo->smbus_xfer)
+ priv->algo.smbus_xfer = i2c_mux_smbus_xfer;
+ priv->algo.functionality = i2c_mux_functionality;
+
+ /* Now fill out new adapter structure */
+ snprintf(priv->adap.name, sizeof(priv->adap.name),
+ "i2c-%d-mux (chan_id %d)", i2c_adapter_id(parent), chan_id);
+ priv->adap.owner = THIS_MODULE;
+ priv->adap.id = parent->id;
+ priv->adap.algo = &priv->algo;
+ priv->adap.algo_data = priv;
+ priv->adap.dev.parent = &parent->dev;
+
+ if (force_nr) {
+ priv->adap.nr = force_nr;
+ ret = i2c_add_numbered_adapter(&priv->adap);
+ } else {
+ ret = i2c_add_adapter(&priv->adap);
+ }
+ if (ret < 0) {
+ dev_err(&parent->dev,
+ "failed to add mux-adapter (error=%d)\n",
+ ret);
+ kfree(priv);
+ return NULL;
+ }
+
+ dev_info(&parent->dev, "Added multiplexed i2c bus %d\n",
+ i2c_adapter_id(&priv->adap));
+
+ return &priv->adap;
+}
+EXPORT_SYMBOL_GPL(i2c_add_mux_adapter);
+
+int i2c_del_mux_adapter(struct i2c_adapter *adap)
+{
+ struct i2c_mux_priv *priv = adap->algo_data;
+ int ret;
+
+ ret = i2c_del_adapter(adap);
+ if (ret < 0)
+ return ret;
+ kfree(priv);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(i2c_del_mux_adapter);
+
+MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
+MODULE_DESCRIPTION("I2C driver for multiplexed I2C busses");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/i2c-mux.h b/include/linux/i2c-mux.h
new file mode 100644
index 000000000000..34536effd652
--- /dev/null
+++ b/include/linux/i2c-mux.h
@@ -0,0 +1,46 @@
+/*
+ *
+ * i2c-mux.h - functions for the i2c-bus mux support
+ *
+ * Copyright (c) 2008-2009 Rodolfo Giometti <giometti@linux.it>
+ * Copyright (c) 2008-2009 Eurotech S.p.A. <info@eurotech.it>
+ * Michael Lawnick <michael.lawnick.ext@nsn.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef _LINUX_I2C_MUX_H
+#define _LINUX_I2C_MUX_H
+
+#ifdef __KERNEL__
+
+/*
+ * Called to create a i2c bus on a multiplexed bus segment.
+ * The mux_dev and chan_id parameters are passed to the select
+ * and deselect callback functions to perform hardware-specific
+ * mux control.
+ */
+struct i2c_adapter *i2c_add_mux_adapter(struct i2c_adapter *parent,
+ void *mux_dev, u32 force_nr, u32 chan_id,
+ int (*select) (struct i2c_adapter *,
+ void *mux_dev, u32 chan_id),
+ int (*deselect) (struct i2c_adapter *,
+ void *mux_dev, u32 chan_id));
+
+int i2c_del_mux_adapter(struct i2c_adapter *adap);
+
+#endif /* __KERNEL__ */
+
+#endif /* _LINUX_I2C_MUX_H */
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 798bad8741e4..4bae0b72ed3c 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -37,6 +37,7 @@
#include <linux/of.h> /* for struct device_node */
extern struct bus_type i2c_bus_type;
+extern struct device_type i2c_adapter_type;
/* --- General options ------------------------------------------------ */
@@ -383,6 +384,13 @@ static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data)
dev_set_drvdata(&dev->dev, data);
}
+static inline int i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
+{
+ return adapter->dev.parent != NULL
+ && adapter->dev.parent->bus == &i2c_bus_type
+ && adapter->dev.parent->type == &i2c_adapter_type;
+}
+
/* Adapter locking functions, exported for shared pin cases */
void i2c_lock_adapter(struct i2c_adapter *);
void i2c_unlock_adapter(struct i2c_adapter *);
From 7f528135da9704d67db1f727162024b078e1cd8f Mon Sep 17 00:00:00 2001
From: Michael Lawnick <ml.lawnick@gmx.de>
Date: Wed, 11 Aug 2010 18:21:03 +0200
Subject: [PATCH 10/10] i2c: I2C bus multiplexer driver pca954x
I2C driver for PCA954x I2C multiplexer series.
Signed-off-by: Michael Lawnick <ml.lawnick@gmx.de>
Acked-by: Rodolfo Giometti <giometti@linux.it>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
---
drivers/i2c/Kconfig | 2 +
drivers/i2c/Makefile | 2 +-
drivers/i2c/muxes/Kconfig | 18 +++
drivers/i2c/muxes/Makefile | 8 +
drivers/i2c/muxes/pca954x.c | 301 ++++++++++++++++++++++++++++++++++++
include/linux/i2c/pca954x.h | 47 ++++++
6 files changed, 377 insertions(+), 1 deletion(-)
create mode 100644 drivers/i2c/muxes/Kconfig
create mode 100644 drivers/i2c/muxes/Makefile
create mode 100644 drivers/i2c/muxes/pca954x.c
create mode 100644 include/linux/i2c/pca954x.h
diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig
index efb48ad1ba34..30f06e956bfb 100644
--- a/drivers/i2c/Kconfig
+++ b/drivers/i2c/Kconfig
@@ -58,6 +58,8 @@ config I2C_MUX
This support is also available as a module. If so, the module
will be called i2c-mux.
+source drivers/i2c/muxes/Kconfig
+
config I2C_HELPER_AUTO
bool "Autoselect pertinent helper modules"
default y
diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile
index f363258daa3d..c00fd66388f5 100644
--- a/drivers/i2c/Makefile
+++ b/drivers/i2c/Makefile
@@ -7,7 +7,7 @@ obj-$(CONFIG_I2C) += i2c-core.o
obj-$(CONFIG_I2C_SMBUS) += i2c-smbus.o
obj-$(CONFIG_I2C_CHARDEV) += i2c-dev.o
obj-$(CONFIG_I2C_MUX) += i2c-mux.o
-obj-y += algos/ busses/
+obj-y += algos/ busses/ muxes/
ifeq ($(CONFIG_I2C_DEBUG_CORE),y)
EXTRA_CFLAGS += -DDEBUG
diff --git a/drivers/i2c/muxes/Kconfig b/drivers/i2c/muxes/Kconfig
new file mode 100644
index 000000000000..4c9a99c4fcb0
--- /dev/null
+++ b/drivers/i2c/muxes/Kconfig
@@ -0,0 +1,18 @@
+#
+# Multiplexer I2C chip drivers configuration
+#
+
+menu "Multiplexer I2C Chip support"
+ depends on I2C_MUX
+
+config I2C_MUX_PCA954x
+ tristate "Philips PCA954x I2C Mux/switches"
+ depends on EXPERIMENTAL
+ help
+ If you say yes here you get support for the Philips PCA954x
+ I2C mux/switch devices.
+
+ This driver can also be built as a module. If so, the module
+ will be called pca954x.
+
+endmenu
diff --git a/drivers/i2c/muxes/Makefile b/drivers/i2c/muxes/Makefile
new file mode 100644
index 000000000000..bd83b5274815
--- /dev/null
+++ b/drivers/i2c/muxes/Makefile
@@ -0,0 +1,8 @@
+#
+# Makefile for multiplexer I2C chip drivers.
+
+obj-$(CONFIG_I2C_MUX_PCA954x) += pca954x.o
+
+ifeq ($(CONFIG_I2C_DEBUG_BUS),y)
+EXTRA_CFLAGS += -DDEBUG
+endif
diff --git a/drivers/i2c/muxes/pca954x.c b/drivers/i2c/muxes/pca954x.c
new file mode 100644
index 000000000000..6f9accf3189d
--- /dev/null
+++ b/drivers/i2c/muxes/pca954x.c
@@ -0,0 +1,301 @@
+/*
+ * I2C multiplexer
+ *
+ * Copyright (c) 2008-2009 Rodolfo Giometti <giometti@linux.it>
+ * Copyright (c) 2008-2009 Eurotech S.p.A. <info@eurotech.it>
+ *
+ * This module supports the PCA954x series of I2C multiplexer/switch chips
+ * made by Philips Semiconductors.
+ * This includes the:
+ * PCA9540, PCA9542, PCA9543, PCA9544, PCA9545, PCA9546, PCA9547
+ * and PCA9548.
+ *
+ * These chips are all controlled via the I2C bus itself, and all have a
+ * single 8-bit register. The upstream "parent" bus fans out to two,
+ * four, or eight downstream busses or channels; which of these
+ * are selected is determined by the chip type and register contents. A
+ * mux can select only one sub-bus at a time; a switch can select any
+ * combination simultaneously.
+ *
+ * Based on:
+ * pca954x.c from Kumar Gala <galak@kernel.crashing.org>
+ * Copyright (C) 2006
+ *
+ * Based on:
+ * pca954x.c from Ken Harrenstien
+ * Copyright (C) 2004 Google, Inc. (Ken Harrenstien)
+ *
+ * Based on:
+ * i2c-virtual_cb.c from Brian Kuschak <bkuschak@yahoo.com>
+ * and
+ * pca9540.c from Jean Delvare <khali@linux-fr.org>.
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/device.h>
+#include <linux/i2c.h>
+#include <linux/i2c-mux.h>
+
+#include <linux/i2c/pca954x.h>
+
+#define PCA954X_MAX_NCHANS 8
+
+enum pca_type {
+ pca_9540,
+ pca_9542,
+ pca_9543,
+ pca_9544,
+ pca_9545,
+ pca_9546,
+ pca_9547,
+ pca_9548,
+};
+
+struct pca954x {
+ enum pca_type type;
+ struct i2c_adapter *virt_adaps[PCA954X_MAX_NCHANS];
+
+ u8 last_chan; /* last register value */
+};
+
+struct chip_desc {
+ u8 nchans;
+ u8 enable; /* used for muxes only */
+ enum muxtype {
+ pca954x_ismux = 0,
+ pca954x_isswi
+ } muxtype;
+};
+
+/* Provide specs for the PCA954x types we know about */
+static const struct chip_desc chips[] = {
+ [pca_9540] = {
+ .nchans = 2,
+ .enable = 0x4,
+ .muxtype = pca954x_ismux,
+ },
+ [pca_9543] = {
+ .nchans = 2,
+ .muxtype = pca954x_isswi,
+ },
+ [pca_9544] = {
+ .nchans = 4,
+ .enable = 0x4,
+ .muxtype = pca954x_ismux,
+ },
+ [pca_9545] = {
+ .nchans = 4,
+ .muxtype = pca954x_isswi,
+ },
+ [pca_9547] = {
+ .nchans = 8,
+ .enable = 0x8,
+ .muxtype = pca954x_ismux,
+ },
+ [pca_9548] = {
+ .nchans = 8,
+ .muxtype = pca954x_isswi,
+ },
+};
+
+static const struct i2c_device_id pca954x_id[] = {
+ { "pca9540", pca_9540 },
+ { "pca9542", pca_9540 },
+ { "pca9543", pca_9543 },
+ { "pca9544", pca_9544 },
+ { "pca9545", pca_9545 },
+ { "pca9546", pca_9545 },
+ { "pca9547", pca_9547 },
+ { "pca9548", pca_9548 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, pca954x_id);
+
+/* Write to mux register. Don't use i2c_transfer()/i2c_smbus_xfer()
+ for this as they will try to lock adapter a second time */
+static int pca954x_reg_write(struct i2c_adapter *adap,
+ struct i2c_client *client, u8 val)
+{
+ int ret = -ENODEV;
+
+ if (adap->algo->master_xfer) {
+ struct i2c_msg msg;
+ char buf[1];
+
+ msg.addr = client->addr;
+ msg.flags = 0;
+ msg.len = 1;
+ buf[0] = val;
+ msg.buf = buf;
+ ret = adap->algo->master_xfer(adap, &msg, 1);
+ } else {
+ union i2c_smbus_data data;
+ ret = adap->algo->smbus_xfer(adap, client->addr,
+ client->flags,
+ I2C_SMBUS_WRITE,
+ val, I2C_SMBUS_BYTE, &data);
+ }
+
+ return ret;
+}
+
+static int pca954x_select_chan(struct i2c_adapter *adap,
+ void *client, u32 chan)
+{
+ struct pca954x *data = i2c_get_clientdata(client);
+ const struct chip_desc *chip = &chips[data->type];
+ u8 regval;
+ int ret = 0;
+
+ /* we make switches look like muxes, not sure how to be smarter */
+ if (chip->muxtype == pca954x_ismux)
+ regval = chan | chip->enable;
+ else
+ regval = 1 << chan;
+
+ /* Only select the channel if its different from the last channel */
+ if (data->last_chan != regval) {
+ ret = pca954x_reg_write(adap, client, regval);
+ data->last_chan = regval;
+ }
+
+ return ret;
+}
+
+static int pca954x_deselect_mux(struct i2c_adapter *adap,
+ void *client, u32 chan)
+{
+ struct pca954x *data = i2c_get_clientdata(client);
+
+ /* Deselect active channel */
+ data->last_chan = 0;
+ return pca954x_reg_write(adap, client, data->last_chan);
+}
+
+/*
+ * I2C init/probing/exit functions
+ */
+static int __devinit pca954x_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct i2c_adapter *adap = to_i2c_adapter(client->dev.parent);
+ struct pca954x_platform_data *pdata = client->dev.platform_data;
+ int num, force;
+ struct pca954x *data;
+ int ret = -ENODEV;
+
+ if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_BYTE))
+ goto err;
+
+ data = kzalloc(sizeof(struct pca954x), GFP_KERNEL);
+ if (!data) {
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ i2c_set_clientdata(client, data);
+
+ /* Read the mux register at addr to verify
+ * that the mux is in fact present.
+ */
+ if (i2c_smbus_read_byte(client) < 0) {
+ dev_warn(&client->dev, "probe failed\n");
+ goto exit_free;
+ }
+
+ data->type = id->driver_data;
+ data->last_chan = 0; /* force the first selection */
+
+ /* Now create an adapter for each channel */
+ for (num = 0; num < chips[data->type].nchans; num++) {
+ force = 0; /* dynamic adap number */
+ if (pdata) {
+ if (num < pdata->num_modes)
+ /* force static number */
+ force = pdata->modes[num].adap_id;
+ else
+ /* discard unconfigured channels */
+ break;
+ }
+
+ data->virt_adaps[num] =
+ i2c_add_mux_adapter(adap, client,
+ force, num, pca954x_select_chan,
+ (pdata && pdata->modes[num].deselect_on_exit)
+ ? pca954x_deselect_mux : NULL);
+
+ if (data->virt_adaps[num] == NULL) {
+ ret = -ENODEV;
+ dev_err(&client->dev,
+ "failed to register multiplexed adapter"
+ " %d as bus %d\n", num, force);
+ goto virt_reg_failed;
+ }
+ }
+
+ dev_info(&client->dev,
+ "registered %d multiplexed busses for I2C %s %s\n",
+ num, chips[data->type].muxtype == pca954x_ismux
+ ? "mux" : "switch", client->name);
+
+ return 0;
+
+virt_reg_failed:
+ for (num--; num >= 0; num--)
+ i2c_del_mux_adapter(data->virt_adaps[num]);
+exit_free:
+ kfree(data);
+err:
+ return ret;
+}
+
+static int __devexit pca954x_remove(struct i2c_client *client)
+{
+ struct pca954x *data = i2c_get_clientdata(client);
+ const struct chip_desc *chip = &chips[data->type];
+ int i, err;
+
+ for (i = 0; i < chip->nchans; ++i)
+ if (data->virt_adaps[i]) {
+ err = i2c_del_mux_adapter(data->virt_adaps[i]);
+ if (err)
+ return err;
+ data->virt_adaps[i] = NULL;
+ }
+
+ kfree(data);
+ return 0;
+}
+
+static struct i2c_driver pca954x_driver = {
+ .driver = {
+ .name = "pca954x",
+ .owner = THIS_MODULE,
+ },
+ .probe = pca954x_probe,
+ .remove = __devexit_p(pca954x_remove),
+ .id_table = pca954x_id,
+};
+
+static int __init pca954x_init(void)
+{
+ return i2c_add_driver(&pca954x_driver);
+}
+
+static void __exit pca954x_exit(void)
+{
+ i2c_del_driver(&pca954x_driver);
+}
+
+module_init(pca954x_init);
+module_exit(pca954x_exit);
+
+MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
+MODULE_DESCRIPTION("PCA954x I2C mux/switch driver");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/i2c/pca954x.h b/include/linux/i2c/pca954x.h
new file mode 100644
index 000000000000..28f1f8d5ab1f
--- /dev/null
+++ b/include/linux/i2c/pca954x.h
@@ -0,0 +1,47 @@
+/*
+ *
+ * pca954x.h - I2C multiplexer/switch support
+ *
+ * Copyright (c) 2008-2009 Rodolfo Giometti <giometti@linux.it>
+ * Copyright (c) 2008-2009 Eurotech S.p.A. <info@eurotech.it>
+ * Michael Lawnick <michael.lawnick.ext@nsn.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+
+#ifndef _LINUX_I2C_PCA954X_H
+#define _LINUX_I2C_PCA954X_H
+
+/* Platform data for the PCA954x I2C multiplexers */
+
+/* Per channel initialisation data:
+ * @adap_id: bus number for the adapter. 0 = don't care
+ * @deselect_on_exit: set this entry to 1, if your H/W needs deselection
+ * of this channel after transaction.
+ *
+ */
+struct pca954x_platform_mode {
+ int adap_id;
+ unsigned int deselect_on_exit:1;
+};
+
+/* Per mux/switch data, used with i2c_register_board_info */
+struct pca954x_platform_data {
+ struct pca954x_platform_mode *modes;
+ int num_modes;
+};
+
+#endif /* _LINUX_I2C_PCA954X_H */