^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0-or-later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * ee1004 - driver for DDR4 SPD EEPROMs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Copyright (C) 2017-2019 Jean Delvare
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * Based on the at24 driver:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) * Copyright (C) 2005-2007 David Brownell
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) * Copyright (C) 2008 Wolfram Sang, Pengutronix
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/i2c.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/mod_devicetable.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <linux/mutex.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) * DDR4 memory modules use special EEPROMs following the Jedec EE1004
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) * specification. These are 512-byte EEPROMs using a single I2C address
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) * in the 0x50-0x57 range for data. One of two 256-byte page is selected
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) * by writing a command to I2C address 0x36 or 0x37 on the same I2C bus.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) * Therefore we need to request these 2 additional addresses, and serialize
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) * access to all such EEPROMs with a single mutex.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) * We assume it is safe to read up to 32 bytes at once from these EEPROMs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) * We use SMBus access even if I2C is available, these EEPROMs are small
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) * enough, and reading from them infrequent enough, that we favor simplicity
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) * over performance.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) #define EE1004_ADDR_SET_PAGE 0x36
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) #define EE1004_EEPROM_SIZE 512
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) #define EE1004_PAGE_SIZE 256
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) #define EE1004_PAGE_SHIFT 8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) * Mutex protects ee1004_set_page and ee1004_dev_count, and must be held
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) * from page selection to end of read.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) static DEFINE_MUTEX(ee1004_bus_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) static struct i2c_client *ee1004_set_page[2];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) static unsigned int ee1004_dev_count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) static int ee1004_current_page;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) static const struct i2c_device_id ee1004_ids[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) { "ee1004", 0 },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) MODULE_DEVICE_TABLE(i2c, ee1004_ids);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) /*-------------------------------------------------------------------------*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) static int ee1004_get_current_page(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) err = i2c_smbus_read_byte(ee1004_set_page[0]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) if (err == -ENXIO) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) /* Nack means page 1 is selected */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) if (err < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) /* Anything else is a real error, bail out */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) /* Ack means page 0 is selected, returned value meaningless */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) static ssize_t ee1004_eeprom_read(struct i2c_client *client, char *buf,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) unsigned int offset, size_t count)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) int status;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) if (count > I2C_SMBUS_BLOCK_MAX)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) count = I2C_SMBUS_BLOCK_MAX;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) /* Can't cross page boundaries */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) if (unlikely(offset + count > EE1004_PAGE_SIZE))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) count = EE1004_PAGE_SIZE - offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) if (count > I2C_SMBUS_BLOCK_MAX)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) count = I2C_SMBUS_BLOCK_MAX;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) status = i2c_smbus_read_i2c_block_data_or_emulated(client, offset,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) count, buf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) dev_dbg(&client->dev, "read %zu@%d --> %d\n", count, offset, status);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) return status;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) static ssize_t ee1004_read(struct file *filp, struct kobject *kobj,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) struct bin_attribute *bin_attr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) char *buf, loff_t off, size_t count)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) struct device *dev = kobj_to_dev(kobj);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) struct i2c_client *client = to_i2c_client(dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) size_t requested = count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) int page;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) if (unlikely(!count))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) return count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) page = off >> EE1004_PAGE_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) if (unlikely(page > 1))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) off &= (1 << EE1004_PAGE_SHIFT) - 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) * Read data from chip, protecting against concurrent access to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) * other EE1004 SPD EEPROMs on the same adapter.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) mutex_lock(&ee1004_bus_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) while (count) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) int status;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) /* Select page */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) if (page != ee1004_current_page) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) /* Data is ignored */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) status = i2c_smbus_write_byte(ee1004_set_page[page],
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 0x00);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) if (status == -ENXIO) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) * Don't give up just yet. Some memory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) * modules will select the page but not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) * ack the command. Check which page is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) * selected now.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) if (ee1004_get_current_page() == page)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) status = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) if (status < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) dev_err(dev, "Failed to select page %d (%d)\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) page, status);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) mutex_unlock(&ee1004_bus_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) return status;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) dev_dbg(dev, "Selected page %d\n", page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) ee1004_current_page = page;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) status = ee1004_eeprom_read(client, buf, off, count);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) if (status < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) mutex_unlock(&ee1004_bus_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) return status;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) buf += status;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) off += status;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) count -= status;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) if (off == EE1004_PAGE_SIZE) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) page++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) off = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) mutex_unlock(&ee1004_bus_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) return requested;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) static const struct bin_attribute eeprom_attr = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) .attr = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) .name = "eeprom",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) .mode = 0444,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) .size = EE1004_EEPROM_SIZE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) .read = ee1004_read,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) static int ee1004_probe(struct i2c_client *client,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) const struct i2c_device_id *id)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) int err, cnr = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) const char *slow = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) /* Make sure we can operate on this adapter */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) if (!i2c_check_functionality(client->adapter,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) I2C_FUNC_SMBUS_READ_BYTE |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) if (i2c_check_functionality(client->adapter,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) I2C_FUNC_SMBUS_READ_BYTE |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) I2C_FUNC_SMBUS_READ_WORD_DATA))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) slow = "word";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) else if (i2c_check_functionality(client->adapter,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) I2C_FUNC_SMBUS_READ_BYTE |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) I2C_FUNC_SMBUS_READ_BYTE_DATA))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) slow = "byte";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) return -EPFNOSUPPORT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) /* Use 2 dummy devices for page select command */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) mutex_lock(&ee1004_bus_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) if (++ee1004_dev_count == 1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) for (cnr = 0; cnr < 2; cnr++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) ee1004_set_page[cnr] = i2c_new_dummy_device(client->adapter,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) EE1004_ADDR_SET_PAGE + cnr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) if (IS_ERR(ee1004_set_page[cnr])) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) dev_err(&client->dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) "address 0x%02x unavailable\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) EE1004_ADDR_SET_PAGE + cnr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) err = PTR_ERR(ee1004_set_page[cnr]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) goto err_clients;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) } else if (i2c_adapter_id(client->adapter) !=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) i2c_adapter_id(ee1004_set_page[0]->adapter)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) dev_err(&client->dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) "Driver only supports devices on a single I2C bus\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) err = -EOPNOTSUPP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) goto err_clients;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) /* Remember current page to avoid unneeded page select */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) err = ee1004_get_current_page();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) if (err < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) goto err_clients;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) ee1004_current_page = err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) dev_dbg(&client->dev, "Currently selected page: %d\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) ee1004_current_page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) mutex_unlock(&ee1004_bus_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) /* Create the sysfs eeprom file */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) err = sysfs_create_bin_file(&client->dev.kobj, &eeprom_attr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) goto err_clients_lock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) dev_info(&client->dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) "%u byte EE1004-compliant SPD EEPROM, read-only\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) EE1004_EEPROM_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) if (slow)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) dev_notice(&client->dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) "Falling back to %s reads, performance will suffer\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) slow);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) err_clients_lock:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) mutex_lock(&ee1004_bus_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) err_clients:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) if (--ee1004_dev_count == 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) for (cnr--; cnr >= 0; cnr--) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) i2c_unregister_device(ee1004_set_page[cnr]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) ee1004_set_page[cnr] = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) mutex_unlock(&ee1004_bus_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) static int ee1004_remove(struct i2c_client *client)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) sysfs_remove_bin_file(&client->dev.kobj, &eeprom_attr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) /* Remove page select clients if this is the last device */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) mutex_lock(&ee1004_bus_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) if (--ee1004_dev_count == 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) for (i = 0; i < 2; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) i2c_unregister_device(ee1004_set_page[i]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) ee1004_set_page[i] = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) mutex_unlock(&ee1004_bus_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) /*-------------------------------------------------------------------------*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) static struct i2c_driver ee1004_driver = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) .driver = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) .name = "ee1004",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) .probe = ee1004_probe,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) .remove = ee1004_remove,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) .id_table = ee1004_ids,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) module_i2c_driver(ee1004_driver);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) MODULE_DESCRIPTION("Driver for EE1004-compliant DDR4 SPD EEPROMs");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) MODULE_AUTHOR("Jean Delvare");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) MODULE_LICENSE("GPL");
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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