diff options
Diffstat (limited to 'drivers/misc/eeprom/ee1004.c')
| -rw-r--r-- | drivers/misc/eeprom/ee1004.c | 131 |
1 files changed, 83 insertions, 48 deletions
diff --git a/drivers/misc/eeprom/ee1004.c b/drivers/misc/eeprom/ee1004.c index 21feebc3044c..d4aeeb2b2169 100644 --- a/drivers/misc/eeprom/ee1004.c +++ b/drivers/misc/eeprom/ee1004.c @@ -9,12 +9,14 @@ * Copyright (C) 2008 Wolfram Sang, Pengutronix */ +#include <linux/device.h> #include <linux/i2c.h> #include <linux/init.h> #include <linux/kernel.h> #include <linux/mod_devicetable.h> #include <linux/module.h> #include <linux/mutex.h> +#include <linux/nvmem-provider.h> /* * DDR4 memory modules use special EEPROMs following the Jedec EE1004 @@ -52,7 +54,7 @@ static struct ee1004_bus_data { } ee1004_bus_data[EE1004_MAX_BUSSES]; static const struct i2c_device_id ee1004_ids[] = { - { "ee1004", 0 }, + { "ee1004" }, { } }; MODULE_DEVICE_TABLE(i2c, ee1004_ids); @@ -144,13 +146,17 @@ static ssize_t ee1004_eeprom_read(struct i2c_client *client, char *buf, return i2c_smbus_read_i2c_block_data_or_emulated(client, offset, count, buf); } -static ssize_t eeprom_read(struct file *filp, struct kobject *kobj, - struct bin_attribute *bin_attr, - char *buf, loff_t off, size_t count) +static int ee1004_read(void *priv, unsigned int off, void *val, size_t count) { - struct i2c_client *client = kobj_to_i2c_client(kobj); - size_t requested = count; - int ret = 0; + struct i2c_client *client = priv; + char *buf = val; + int ret; + + if (unlikely(!count)) + return count; + + if (off + count > EE1004_EEPROM_SIZE) + return -EINVAL; /* * Read data from chip, protecting against concurrent access to @@ -160,42 +166,52 @@ static ssize_t eeprom_read(struct file *filp, struct kobject *kobj, while (count) { ret = ee1004_eeprom_read(client, buf, off, count); - if (ret < 0) - goto out; + if (ret < 0) { + mutex_unlock(&ee1004_bus_lock); + return ret; + } buf += ret; off += ret; count -= ret; } -out: + mutex_unlock(&ee1004_bus_lock); - return ret < 0 ? ret : requested; + return 0; } -static BIN_ATTR_RO(eeprom, EE1004_EEPROM_SIZE); - -static struct bin_attribute *ee1004_attrs[] = { - &bin_attr_eeprom, - NULL -}; - -BIN_ATTRIBUTE_GROUPS(ee1004); - static void ee1004_probe_temp_sensor(struct i2c_client *client) { struct i2c_board_info info = { .type = "jc42" }; - u8 byte14; + unsigned short addr = 0x18 | (client->addr & 7); + unsigned short addr_list[] = { addr, I2C_CLIENT_END }; + u8 data[2]; int ret; /* byte 14, bit 7 is set if temp sensor is present */ - ret = ee1004_eeprom_read(client, &byte14, 14, 1); - if (ret != 1 || !(byte14 & BIT(7))) + ret = ee1004_eeprom_read(client, data, 14, 1); + if (ret != 1) return; - info.addr = 0x18 | (client->addr & 7); - - i2c_new_client_device(client->adapter, &info); + if (!(data[0] & BIT(7))) { + /* + * If the SPD data suggests that there is no temperature + * sensor, it may still be there for SPD revision 1.0. + * See SPD Annex L, Revision 1 and 2, for details. + * Check DIMM type and SPD revision; if it is a DDR4 + * with SPD revision 1.0, check the thermal sensor address + * and instantiate the jc42 driver if a chip is found at + * that address. + * It is not necessary to check if there is a chip at the + * temperature sensor address since i2c_new_scanned_device() + * will do that and return silently if no chip is found. + */ + ret = ee1004_eeprom_read(client, data, 1, 2); + if (ret != 2 || data[0] != 0x10 || data[1] != 0x0c) + return; + } + i2c_new_scanned_device(client->adapter, &info, addr_list, NULL); } static void ee1004_cleanup(int idx, struct ee1004_bus_data *bd) @@ -207,9 +223,36 @@ static void ee1004_cleanup(int idx, struct ee1004_bus_data *bd) } } +static void ee1004_cleanup_bus_data(void *data) +{ + struct ee1004_bus_data *bd = data; + + /* Remove page select clients if this is the last device */ + mutex_lock(&ee1004_bus_lock); + ee1004_cleanup(EE1004_NUM_PAGES, bd); + mutex_unlock(&ee1004_bus_lock); +} + static int ee1004_probe(struct i2c_client *client) { + struct nvmem_config config = { + .dev = &client->dev, + .name = dev_name(&client->dev), + .id = NVMEM_DEVID_NONE, + .owner = THIS_MODULE, + .type = NVMEM_TYPE_EEPROM, + .read_only = true, + .root_only = false, + .reg_read = ee1004_read, + .size = EE1004_EEPROM_SIZE, + .word_size = 1, + .stride = 1, + .priv = client, + .compat = true, + .base_dev = &client->dev, + }; struct ee1004_bus_data *bd; + struct nvmem_device *ndev; int err, cnr = 0; /* Make sure we can operate on this adapter */ @@ -228,6 +271,10 @@ static int ee1004_probe(struct i2c_client *client) "Only %d busses supported", EE1004_MAX_BUSSES); } + err = devm_add_action_or_reset(&client->dev, ee1004_cleanup_bus_data, bd); + if (err < 0) + return err; + i2c_set_clientdata(client, bd); if (++bd->dev_count == 1) { @@ -237,16 +284,18 @@ static int ee1004_probe(struct i2c_client *client) cl = i2c_new_dummy_device(client->adapter, EE1004_ADDR_SET_PAGE + cnr); if (IS_ERR(cl)) { - err = PTR_ERR(cl); - goto err_clients; + mutex_unlock(&ee1004_bus_lock); + return PTR_ERR(cl); } bd->set_page[cnr] = cl; } /* Remember current page to avoid unneeded page select */ err = ee1004_get_current_page(bd); - if (err < 0) - goto err_clients; + if (err < 0) { + mutex_unlock(&ee1004_bus_lock); + return err; + } dev_dbg(&client->dev, "Currently selected page: %d\n", err); bd->current_page = err; } @@ -255,27 +304,15 @@ static int ee1004_probe(struct i2c_client *client) mutex_unlock(&ee1004_bus_lock); + ndev = devm_nvmem_register(&client->dev, &config); + if (IS_ERR(ndev)) + return PTR_ERR(ndev); + dev_info(&client->dev, "%u byte EE1004-compliant SPD EEPROM, read-only\n", EE1004_EEPROM_SIZE); return 0; - - err_clients: - ee1004_cleanup(cnr, bd); - mutex_unlock(&ee1004_bus_lock); - - return err; -} - -static void ee1004_remove(struct i2c_client *client) -{ - struct ee1004_bus_data *bd = i2c_get_clientdata(client); - - /* Remove page select clients if this is the last device */ - mutex_lock(&ee1004_bus_lock); - ee1004_cleanup(EE1004_NUM_PAGES, bd); - mutex_unlock(&ee1004_bus_lock); } /*-------------------------------------------------------------------------*/ @@ -283,10 +320,8 @@ static void ee1004_remove(struct i2c_client *client) static struct i2c_driver ee1004_driver = { .driver = { .name = "ee1004", - .dev_groups = ee1004_groups, }, .probe = ee1004_probe, - .remove = ee1004_remove, .id_table = ee1004_ids, }; module_i2c_driver(ee1004_driver); |