After contemplating the vast amounts of feedback I received on the
first version of this patch I reworked it to reduce it's impact. This
version can go in without changing any existing drivers in the kernel.
Currently i2c uses a driver_name/type pair to handle drivers which
support more than one device. This version leaves driver_name/type
alone and create a parallel, alternative naming scheme - aliases. When
the grand merge to remove legacy style i2c drivers happens, the
driver_name/type scheme can be removed and converted to use the alias
strings.
If we can get agreement on this patch, I'll post a new version of the
i2c-mpc.c rewrite patch.
Extend i2c-core to support lists of device tree compatible names when
matching drivers
From: Jon Smirl <[EMAIL PROTECTED]>
---
arch/powerpc/sysdev/fsl_soc.c | 46 ++++++-----------------------------------
drivers/i2c/i2c-core.c | 16 +++++++++++++-
drivers/rtc/rtc-ds1307.c | 14 ++++++++++++
drivers/rtc/rtc-ds1374.c | 1 +
drivers/rtc/rtc-pcf8563.c | 1 +
drivers/rtc/rtc-rs5c372.c | 18 +++++++++++++---
include/linux/i2c.h | 13 +++++++++---
7 files changed, 63 insertions(+), 46 deletions(-)
diff --git a/arch/powerpc/sysdev/fsl_soc.c b/arch/powerpc/sysdev/fsl_soc.c
index 3ace747..cb95a72 100644
--- a/arch/powerpc/sysdev/fsl_soc.c
+++ b/arch/powerpc/sysdev/fsl_soc.c
@@ -320,48 +320,12 @@ arch_initcall(gfar_of_init);
#ifdef CONFIG_I2C_BOARDINFO
#include <linux/i2c.h>
-struct i2c_driver_device {
- char *of_device;
- char *i2c_driver;
- char *i2c_type;
-};
-
-static struct i2c_driver_device i2c_devices[] __initdata = {
- {"ricoh,rs5c372a", "rtc-rs5c372", "rs5c372a",},
- {"ricoh,rs5c372b", "rtc-rs5c372", "rs5c372b",},
- {"ricoh,rv5c386", "rtc-rs5c372", "rv5c386",},
- {"ricoh,rv5c387a", "rtc-rs5c372", "rv5c387a",},
- {"dallas,ds1307", "rtc-ds1307", "ds1307",},
- {"dallas,ds1337", "rtc-ds1307", "ds1337",},
- {"dallas,ds1338", "rtc-ds1307", "ds1338",},
- {"dallas,ds1339", "rtc-ds1307", "ds1339",},
- {"dallas,ds1340", "rtc-ds1307", "ds1340",},
- {"stm,m41t00", "rtc-ds1307", "m41t00"},
- {"dallas,ds1374", "rtc-ds1374", "rtc-ds1374",},
-};
-
-static int __init of_find_i2c_driver(struct device_node *node,
- struct i2c_board_info *info)
-{
- int i;
-
- for (i = 0; i < ARRAY_SIZE(i2c_devices); i++) {
- if (!of_device_is_compatible(node, i2c_devices[i].of_device))
- continue;
- if (strlcpy(info->driver_name, i2c_devices[i].i2c_driver,
- KOBJ_NAME_LEN) >= KOBJ_NAME_LEN ||
- strlcpy(info->type, i2c_devices[i].i2c_type,
- I2C_NAME_SIZE) >= I2C_NAME_SIZE)
- return -ENOMEM;
- return 0;
- }
- return -ENODEV;
-}
static void __init of_register_i2c_devices(struct device_node *adap_node,
int bus_num)
{
struct device_node *node = NULL;
+ const char *compatible;
while ((node = of_get_next_child(adap_node, node))) {
struct i2c_board_info info = {};
@@ -378,9 +342,13 @@ static void __init of_register_i2c_devices(struct
device_node *adap_node,
if (info.irq == NO_IRQ)
info.irq = -1;
- if (of_find_i2c_driver(node, &info) < 0)
+ compatible = of_get_property(node, "compatible", &len);
+ if (!compatible) {
+ printk(KERN_WARNING "i2c-mpc.c: invalid entry, missing
compatible
attribute\n");
continue;
-
+ }
+ strncpy(info.name, compatible, sizeof(info.name));
+
info.addr = *addr;
i2c_register_board_info(bus_num, &info, 1);
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 1a4e8dc..8b49860 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -51,6 +51,7 @@ static int i2c_device_match(struct device *dev,
struct device_driver *drv)
{
struct i2c_client *client = to_i2c_client(dev);
struct i2c_driver *driver = to_i2c_driver(drv);
+ char const **alias;
/* make legacy i2c drivers bypass driver model probing entirely;
* such drivers scan each i2c adapter/bus themselves.
@@ -61,7 +62,20 @@ static int i2c_device_match(struct device *dev,
struct device_driver *drv)
/* new style drivers use the same kind of driver matching policy
* as platform devices or SPI: compare device and driver IDs.
*/
- return strcmp(client->driver_name, drv->name) == 0;
+ if (strcmp(client->driver_name, drv->name) == 0)
+ return true;
+
+ /* Match against arrary of alias device tree names. When a match
+ * is found change the reference to point at the copy inside the
+ * chip driver allowing the caller's string to be freed.
+ */
+ alias = driver->aliases;
+ while (alias && *alias) {
+ if (strnicmp(client->driver_name, *alias, sizeof
client->driver_name) == 0)
+ return true;
+ alias++;
+ }
+ return 0;
}
#ifdef CONFIG_HOTPLUG
diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index db6f3f0..456b7ca 100644
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -135,6 +135,11 @@ static inline const struct chip_desc
*find_chip(const char *s)
for (i = 0; i < ARRAY_SIZE(chips); i++)
if (strnicmp(s, chips[i].name, sizeof chips[i].name) == 0)
return &chips[i];
+ /* check the alias names */
+ for (i = ds_1307; i <= m41t00; i++)
+ if (strnicmp(client->driver_name, ds1307_driver.aliases[i],
sizeof
client->driver_name) == 0)
+ return &chips[i];
+
return NULL;
}
@@ -442,6 +447,15 @@ static struct i2c_driver ds1307_driver = {
.name = "rtc-ds1307",
.owner = THIS_MODULE,
},
+ .aliases = (char const *[]){
+ [ds_1307] = "dallas,ds1307",
+ [ds_1337] = "dallas,ds1337",
+ [ds_1338] = "dallas,ds1338",
+ [ds_1339] = "dallas,ds1339",
+ [ds_1340] = "dallas,ds1340",
+ [m41t00] = "stm,m41t00",
+ 0
+ },
.probe = ds1307_probe,
.remove = __devexit_p(ds1307_remove),
};
diff --git a/drivers/rtc/rtc-ds1374.c b/drivers/rtc/rtc-ds1374.c
index 45bda18..df8eca4 100644
--- a/drivers/rtc/rtc-ds1374.c
+++ b/drivers/rtc/rtc-ds1374.c
@@ -427,6 +427,7 @@ static struct i2c_driver ds1374_driver = {
.name = "rtc-ds1374",
.owner = THIS_MODULE,
},
+ .aliases = (char const *[]){"dallas,ds1374", 0},
.probe = ds1374_probe,
.remove = __devexit_p(ds1374_remove),
};
diff --git a/drivers/rtc/rtc-pcf8563.c b/drivers/rtc/rtc-pcf8563.c
index 0242d80..fa04dc5 100644
--- a/drivers/rtc/rtc-pcf8563.c
+++ b/drivers/rtc/rtc-pcf8563.c
@@ -266,6 +266,7 @@ static struct i2c_driver pcf8563_driver = {
.driver = {
.name = "pcf8563",
},
+ .aliases = (char const *[]){"philips,pcf8563", "epson,rtc8564", 0},
.id = I2C_DRIVERID_PCF8563,
.attach_adapter = &pcf8563_attach,
.detach_client = &pcf8563_detach,
diff --git a/drivers/rtc/rtc-rs5c372.c b/drivers/rtc/rtc-rs5c372.c
index 6b67b50..b458f5f 100644
--- a/drivers/rtc/rtc-rs5c372.c
+++ b/drivers/rtc/rtc-rs5c372.c
@@ -62,7 +62,6 @@
enum rtc_type {
- rtc_undef = 0,
rtc_rs5c372a,
rtc_rs5c372b,
rtc_rv5c386,
@@ -531,8 +530,14 @@ static int rs5c372_probe(struct i2c_client *client)
else if (strcmp(client->name, "rv5c387a") == 0)
rs5c372->type = rtc_rv5c387a;
else {
- rs5c372->type = rtc_rs5c372b;
- dev_warn(&client->dev, "assuming rs5c372b\n");
+ /* check the alias names */
+ for (rs5c372->type = rtc_rs5c372a; rs5c372->type <=
rtc_rv5c387a;
rs5c372->type++)
+ if (strnicmp(client->driver_name,
rs5c372_driver.aliases[rs5c372->type], sizeof client->driver_name) ==
0)
+ break;
+ if (rs5c372->type > rtc_rv5c387a) {
+ rs5c372->type = rtc_rs5c372b;
+ dev_warn(&client->dev, "assuming rs5c372b\n");
+ }
}
/* clock may be set for am/pm or 24 hr time */
@@ -649,6 +654,13 @@ static struct i2c_driver rs5c372_driver = {
.driver = {
.name = "rtc-rs5c372",
},
+ .aliases = (char const *[]){
+ [rtc_rs5c372a] = "ricoh,rs5c372a",
+ [rtc_rs5c372b] = "ricoh,rs5c372b",
+ [rtc_rv5c386] = "ricoh,rv5c386",
+ [rtc_rv5c387a] = "ricoh,rv5c387a",
+ 0
+ },
.probe = rs5c372_probe,
.remove = rs5c372_remove,
};
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 8033e6b..b952c8a 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -105,6 +105,13 @@ extern s32 i2c_smbus_write_i2c_block_data(struct
i2c_client * client,
struct i2c_driver {
int id;
unsigned int class;
+
+ /* Alias names for the driver. Used to support device trees on
+ * the PowerPC architecture. Device tree names take the form of
+ * vendor,chip. For example "epson,rtc8564". Alias is a list of
+ * strings terminated by a zero entry.
+ */
+ char const **aliases;
/* Notifies the driver that a new bus has appeared. This routine
* can be used by the driver to test if the bus meets its conditions
@@ -144,7 +151,7 @@ struct i2c_driver {
};
#define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
-#define I2C_NAME_SIZE 20
+#define I2C_NAME_SIZE 40
/**
* struct i2c_client - represent an I2C slave device
@@ -179,7 +186,7 @@ struct i2c_client {
/* to the client */
struct device dev; /* the device structure */
int irq; /* irq issued by device (or -1) */
- char driver_name[KOBJ_NAME_LEN];
+ char driver_name[I2C_NAME_SIZE];
struct list_head list;
struct completion released;
};
@@ -223,7 +230,7 @@ static inline void i2c_set_clientdata (struct
i2c_client *dev, void *data)
* with the adapter already known.
*/
struct i2c_board_info {
- char driver_name[KOBJ_NAME_LEN];
+ char driver_name[I2C_NAME_SIZE];
char type[I2C_NAME_SIZE];
unsigned short flags;
unsigned short addr;
--
Jon Smirl
[EMAIL PROTECTED]
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