There are systems with more than 8 memory slots where the i2c bus for
SPD is multiplexed. i2c_register_spd() isn't used yet on such systems,
but it's planned. So we need to extend ee1004 accordingly.
With this extension a maximum of 8 i2c busses is supported.
I don't have such a system for testing, therefore I just verified
that the driver still works on a system with a single i2c bus.
For the sake of simplicity the extension uses the existing global
mutex to protect access on all busses. This could be improved,
but we support 8 busses only, and SPD data is small and rarely
accessed, so it shouldn't be a problem.
Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx>
---
drivers/misc/eeprom/ee1004.c | 101 ++++++++++++++++++++++++-----------
1 file changed, 69 insertions(+), 32 deletions(-)
diff --git a/drivers/misc/eeprom/ee1004.c b/drivers/misc/eeprom/ee1004.c
index a1acd7713..e154caf5a 100644
--- a/drivers/misc/eeprom/ee1004.c
+++ b/drivers/misc/eeprom/ee1004.c
@@ -31,6 +31,7 @@
* over performance.
*/
+#define EE1004_MAX_BUSSES 8
#define EE1004_ADDR_SET_PAGE 0x36
#define EE1004_NUM_PAGES 2
#define EE1004_PAGE_SIZE 256
@@ -42,9 +43,13 @@
* from page selection to end of read.
*/
static DEFINE_MUTEX(ee1004_bus_lock);
-static struct i2c_client *ee1004_set_page[EE1004_NUM_PAGES];
-static unsigned int ee1004_dev_count;
-static int ee1004_current_page;
+
+static struct ee1004_bus_data {
+ struct i2c_adapter *adap;
+ struct i2c_client *set_page[EE1004_NUM_PAGES];
+ unsigned int dev_count;
+ int current_page;
+} ee1004_bus_data[EE1004_MAX_BUSSES];
static const struct i2c_device_id ee1004_ids[] = {
{ "ee1004", 0 },
@@ -54,11 +59,30 @@ MODULE_DEVICE_TABLE(i2c, ee1004_ids);
/*-------------------------------------------------------------------------*/
-static int ee1004_get_current_page(void)
+static int ee1004_get_bus_data_idx(struct i2c_adapter *adap)
+{
+ int i;
+
+ for (i = 0; i < EE1004_MAX_BUSSES; i++)
+ if (ee1004_bus_data[i].adap == adap)
+ return i;
+
+ /* If not existent yet, create new entry */
+ for (i = 0; i < EE1004_MAX_BUSSES; i++)
+ if (!ee1004_bus_data[i].adap) {
+ ee1004_bus_data[i].adap = adap;
+ return i;
+ }
+
+ return -ENOSPC;
+}
+
+static int ee1004_get_current_page(int bus_data_idx)
{
+ struct ee1004_bus_data *bd = ee1004_bus_data + bus_data_idx;
int err;
- err = i2c_smbus_read_byte(ee1004_set_page[0]);
+ err = i2c_smbus_read_byte(bd->set_page[0]);
if (err == -ENXIO) {
/* Nack means page 1 is selected */
return 1;
@@ -72,28 +96,30 @@ static int ee1004_get_current_page(void)
return 0;
}
-static int ee1004_set_current_page(struct device *dev, int page)
+static int ee1004_set_current_page(struct i2c_client *client, int page)
{
+ int bd_idx = ee1004_get_bus_data_idx(client->adapter);
+ struct ee1004_bus_data *bd = ee1004_bus_data + bd_idx;
int ret;
- if (page == ee1004_current_page)
+ if (page == bd->current_page)
return 0;
/* Data is ignored */
- ret = i2c_smbus_write_byte(ee1004_set_page[page], 0x00);
+ ret = i2c_smbus_write_byte(bd->set_page[page], 0x00);
/*
* Don't give up just yet. Some memory modules will select the page
* but not ack the command. Check which page is selected now.
*/
- if (ret == -ENXIO && ee1004_get_current_page() == page)
+ if (ret == -ENXIO && ee1004_get_current_page(bd_idx) == page)
ret = 0;
if (ret < 0) {
- dev_err(dev, "Failed to select page %d (%d)\n", page, ret);
+ dev_err(&client->dev, "Failed to select page %d (%d)\n", page, ret);
return ret;
}
- dev_dbg(dev, "Selected page %d\n", page);
- ee1004_current_page = page;
+ dev_dbg(&client->dev, "Selected page %d\n", page);
+ bd->current_page = page;
return 0;
}
@@ -106,7 +132,7 @@ static ssize_t ee1004_eeprom_read(struct i2c_client *client, char *buf,
page = offset >> EE1004_PAGE_SHIFT;
offset &= (1 << EE1004_PAGE_SHIFT) - 1;
- status = ee1004_set_current_page(&client->dev, page);
+ status = ee1004_set_current_page(client, page);
if (status)
return status;
@@ -158,18 +184,21 @@ static struct bin_attribute *ee1004_attrs[] = {
BIN_ATTRIBUTE_GROUPS(ee1004);
-static void ee1004_cleanup(int idx)
+static void ee1004_cleanup(int idx, int bus_data_idx)
{
- if (--ee1004_dev_count == 0)
- while (--idx >= 0) {
- i2c_unregister_device(ee1004_set_page[idx]);
- ee1004_set_page[idx] = NULL;
- }
+ struct ee1004_bus_data *bd = ee1004_bus_data + bus_data_idx;
+
+ if (--bd->dev_count == 0) {
+ while (--idx >= 0)
+ i2c_unregister_device(bd->set_page[idx]);
+ memset(bd, 0, sizeof(struct ee1004_bus_data));
+ }
}
static int ee1004_probe(struct i2c_client *client)
{
- int err, cnr = 0;
+ struct ee1004_bus_data *bd;
+ int err, bd_idx, cnr = 0;
/* Make sure we can operate on this adapter */
if (!i2c_check_functionality(client->adapter,
@@ -178,9 +207,19 @@ static int ee1004_probe(struct i2c_client *client)
I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_READ_BYTE_DATA))
return -EPFNOSUPPORT;
- /* Use 2 dummy devices for page select command */
mutex_lock(&ee1004_bus_lock);
- if (++ee1004_dev_count == 1) {
+
+ bd_idx = ee1004_get_bus_data_idx(client->adapter);
+ if (bd_idx < 0) {
+ mutex_unlock(&ee1004_bus_lock);
+ return dev_err_probe(&client->dev, bd_idx,
+ "Only %d busses supported", EE1004_MAX_BUSSES);
+ }
+
+ bd = ee1004_bus_data + bd_idx;
+
+ if (++bd->dev_count == 1) {
+ /* Use 2 dummy devices for page select command */
for (cnr = 0; cnr < EE1004_NUM_PAGES; cnr++) {
struct i2c_client *cl;
@@ -189,20 +228,15 @@ static int ee1004_probe(struct i2c_client *client)
err = PTR_ERR(cl);
goto err_clients;
}
- ee1004_set_page[cnr] = cl;
+ bd->set_page[cnr] = cl;
}
/* Remember current page to avoid unneeded page select */
- err = ee1004_get_current_page();
+ err = ee1004_get_current_page(bd_idx);
if (err < 0)
goto err_clients;
dev_dbg(&client->dev, "Currently selected page: %d\n", err);
- ee1004_current_page = err;
- } else if (client->adapter != ee1004_set_page[0]->adapter) {
- dev_err(&client->dev,
- "Driver only supports devices on a single I2C bus\n");
- err = -EOPNOTSUPP;
- goto err_clients;
+ bd->current_page = err;
}
mutex_unlock(&ee1004_bus_lock);
@@ -213,7 +247,7 @@ static int ee1004_probe(struct i2c_client *client)
return 0;
err_clients:
- ee1004_cleanup(cnr);
+ ee1004_cleanup(cnr, bd_idx);
mutex_unlock(&ee1004_bus_lock);
return err;
@@ -221,9 +255,12 @@ static int ee1004_probe(struct i2c_client *client)
static void ee1004_remove(struct i2c_client *client)
{
+ int bd_idx;
+
/* Remove page select clients if this is the last device */
mutex_lock(&ee1004_bus_lock);
- ee1004_cleanup(EE1004_NUM_PAGES);
+ bd_idx = ee1004_get_bus_data_idx(client->adapter);
+ ee1004_cleanup(EE1004_NUM_PAGES, bd_idx);
mutex_unlock(&ee1004_bus_lock);
}
--
2.42.1
