From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- drivers/misc/eeprom/eeprom_93xx46.c | 398 ++++++++++++++++++++++++++++++++++++ 1 file changed, 398 insertions(+) create mode 100644 drivers/misc/eeprom/eeprom_93xx46.c (limited to 'drivers/misc/eeprom/eeprom_93xx46.c') diff --git a/drivers/misc/eeprom/eeprom_93xx46.c b/drivers/misc/eeprom/eeprom_93xx46.c new file mode 100644 index 000000000..9ebeacdb8 --- /dev/null +++ b/drivers/misc/eeprom/eeprom_93xx46.c @@ -0,0 +1,398 @@ +/* + * Driver for 93xx46 EEPROMs + * + * (C) 2011 DENX Software Engineering, Anatolij Gustschin + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define OP_START 0x4 +#define OP_WRITE (OP_START | 0x1) +#define OP_READ (OP_START | 0x2) +#define ADDR_EWDS 0x00 +#define ADDR_ERAL 0x20 +#define ADDR_EWEN 0x30 + +struct eeprom_93xx46_dev { + struct spi_device *spi; + struct eeprom_93xx46_platform_data *pdata; + struct bin_attribute bin; + struct mutex lock; + int addrlen; +}; + +static ssize_t +eeprom_93xx46_bin_read(struct file *filp, struct kobject *kobj, + struct bin_attribute *bin_attr, + char *buf, loff_t off, size_t count) +{ + struct eeprom_93xx46_dev *edev; + struct device *dev; + struct spi_message m; + struct spi_transfer t[2]; + int bits, ret; + u16 cmd_addr; + + dev = container_of(kobj, struct device, kobj); + edev = dev_get_drvdata(dev); + + if (unlikely(off >= edev->bin.size)) + return 0; + if ((off + count) > edev->bin.size) + count = edev->bin.size - off; + if (unlikely(!count)) + return count; + + cmd_addr = OP_READ << edev->addrlen; + + if (edev->addrlen == 7) { + cmd_addr |= off & 0x7f; + bits = 10; + } else { + cmd_addr |= off & 0x3f; + bits = 9; + } + + dev_dbg(&edev->spi->dev, "read cmd 0x%x, %d Hz\n", + cmd_addr, edev->spi->max_speed_hz); + + spi_message_init(&m); + memset(t, 0, sizeof(t)); + + t[0].tx_buf = (char *)&cmd_addr; + t[0].len = 2; + t[0].bits_per_word = bits; + spi_message_add_tail(&t[0], &m); + + t[1].rx_buf = buf; + t[1].len = count; + t[1].bits_per_word = 8; + spi_message_add_tail(&t[1], &m); + + mutex_lock(&edev->lock); + + if (edev->pdata->prepare) + edev->pdata->prepare(edev); + + ret = spi_sync(edev->spi, &m); + /* have to wait at least Tcsl ns */ + ndelay(250); + if (ret) { + dev_err(&edev->spi->dev, "read %zu bytes at %d: err. %d\n", + count, (int)off, ret); + } + + if (edev->pdata->finish) + edev->pdata->finish(edev); + + mutex_unlock(&edev->lock); + return ret ? : count; +} + +static int eeprom_93xx46_ew(struct eeprom_93xx46_dev *edev, int is_on) +{ + struct spi_message m; + struct spi_transfer t; + int bits, ret; + u16 cmd_addr; + + cmd_addr = OP_START << edev->addrlen; + if (edev->addrlen == 7) { + cmd_addr |= (is_on ? ADDR_EWEN : ADDR_EWDS) << 1; + bits = 10; + } else { + cmd_addr |= (is_on ? ADDR_EWEN : ADDR_EWDS); + bits = 9; + } + + dev_dbg(&edev->spi->dev, "ew cmd 0x%04x\n", cmd_addr); + + spi_message_init(&m); + memset(&t, 0, sizeof(t)); + + t.tx_buf = &cmd_addr; + t.len = 2; + t.bits_per_word = bits; + spi_message_add_tail(&t, &m); + + mutex_lock(&edev->lock); + + if (edev->pdata->prepare) + edev->pdata->prepare(edev); + + ret = spi_sync(edev->spi, &m); + /* have to wait at least Tcsl ns */ + ndelay(250); + if (ret) + dev_err(&edev->spi->dev, "erase/write %sable error %d\n", + is_on ? "en" : "dis", ret); + + if (edev->pdata->finish) + edev->pdata->finish(edev); + + mutex_unlock(&edev->lock); + return ret; +} + +static ssize_t +eeprom_93xx46_write_word(struct eeprom_93xx46_dev *edev, + const char *buf, unsigned off) +{ + struct spi_message m; + struct spi_transfer t[2]; + int bits, data_len, ret; + u16 cmd_addr; + + cmd_addr = OP_WRITE << edev->addrlen; + + if (edev->addrlen == 7) { + cmd_addr |= off & 0x7f; + bits = 10; + data_len = 1; + } else { + cmd_addr |= off & 0x3f; + bits = 9; + data_len = 2; + } + + dev_dbg(&edev->spi->dev, "write cmd 0x%x\n", cmd_addr); + + spi_message_init(&m); + memset(t, 0, sizeof(t)); + + t[0].tx_buf = (char *)&cmd_addr; + t[0].len = 2; + t[0].bits_per_word = bits; + spi_message_add_tail(&t[0], &m); + + t[1].tx_buf = buf; + t[1].len = data_len; + t[1].bits_per_word = 8; + spi_message_add_tail(&t[1], &m); + + ret = spi_sync(edev->spi, &m); + /* have to wait program cycle time Twc ms */ + mdelay(6); + return ret; +} + +static ssize_t +eeprom_93xx46_bin_write(struct file *filp, struct kobject *kobj, + struct bin_attribute *bin_attr, + char *buf, loff_t off, size_t count) +{ + struct eeprom_93xx46_dev *edev; + struct device *dev; + int i, ret, step = 1; + + dev = container_of(kobj, struct device, kobj); + edev = dev_get_drvdata(dev); + + if (unlikely(off >= edev->bin.size)) + return -EFBIG; + if ((off + count) > edev->bin.size) + count = edev->bin.size - off; + if (unlikely(!count)) + return count; + + /* only write even number of bytes on 16-bit devices */ + if (edev->addrlen == 6) { + step = 2; + count &= ~1; + } + + /* erase/write enable */ + ret = eeprom_93xx46_ew(edev, 1); + if (ret) + return ret; + + mutex_lock(&edev->lock); + + if (edev->pdata->prepare) + edev->pdata->prepare(edev); + + for (i = 0; i < count; i += step) { + ret = eeprom_93xx46_write_word(edev, &buf[i], off + i); + if (ret) { + dev_err(&edev->spi->dev, "write failed at %d: %d\n", + (int)off + i, ret); + break; + } + } + + if (edev->pdata->finish) + edev->pdata->finish(edev); + + mutex_unlock(&edev->lock); + + /* erase/write disable */ + eeprom_93xx46_ew(edev, 0); + return ret ? : count; +} + +static int eeprom_93xx46_eral(struct eeprom_93xx46_dev *edev) +{ + struct eeprom_93xx46_platform_data *pd = edev->pdata; + struct spi_message m; + struct spi_transfer t; + int bits, ret; + u16 cmd_addr; + + cmd_addr = OP_START << edev->addrlen; + if (edev->addrlen == 7) { + cmd_addr |= ADDR_ERAL << 1; + bits = 10; + } else { + cmd_addr |= ADDR_ERAL; + bits = 9; + } + + spi_message_init(&m); + memset(&t, 0, sizeof(t)); + + t.tx_buf = &cmd_addr; + t.len = 2; + t.bits_per_word = bits; + spi_message_add_tail(&t, &m); + + mutex_lock(&edev->lock); + + if (edev->pdata->prepare) + edev->pdata->prepare(edev); + + ret = spi_sync(edev->spi, &m); + if (ret) + dev_err(&edev->spi->dev, "erase error %d\n", ret); + /* have to wait erase cycle time Tec ms */ + mdelay(6); + + if (pd->finish) + pd->finish(edev); + + mutex_unlock(&edev->lock); + return ret; +} + +static ssize_t eeprom_93xx46_store_erase(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct eeprom_93xx46_dev *edev = dev_get_drvdata(dev); + int erase = 0, ret; + + sscanf(buf, "%d", &erase); + if (erase) { + ret = eeprom_93xx46_ew(edev, 1); + if (ret) + return ret; + ret = eeprom_93xx46_eral(edev); + if (ret) + return ret; + ret = eeprom_93xx46_ew(edev, 0); + if (ret) + return ret; + } + return count; +} +static DEVICE_ATTR(erase, S_IWUSR, NULL, eeprom_93xx46_store_erase); + +static int eeprom_93xx46_probe(struct spi_device *spi) +{ + struct eeprom_93xx46_platform_data *pd; + struct eeprom_93xx46_dev *edev; + int err; + + pd = spi->dev.platform_data; + if (!pd) { + dev_err(&spi->dev, "missing platform data\n"); + return -ENODEV; + } + + edev = kzalloc(sizeof(*edev), GFP_KERNEL); + if (!edev) + return -ENOMEM; + + if (pd->flags & EE_ADDR8) + edev->addrlen = 7; + else if (pd->flags & EE_ADDR16) + edev->addrlen = 6; + else { + dev_err(&spi->dev, "unspecified address type\n"); + err = -EINVAL; + goto fail; + } + + mutex_init(&edev->lock); + + edev->spi = spi_dev_get(spi); + edev->pdata = pd; + + sysfs_bin_attr_init(&edev->bin); + edev->bin.attr.name = "eeprom"; + edev->bin.attr.mode = S_IRUSR; + edev->bin.read = eeprom_93xx46_bin_read; + edev->bin.size = 128; + if (!(pd->flags & EE_READONLY)) { + edev->bin.write = eeprom_93xx46_bin_write; + edev->bin.attr.mode |= S_IWUSR; + } + + err = sysfs_create_bin_file(&spi->dev.kobj, &edev->bin); + if (err) + goto fail; + + dev_info(&spi->dev, "%d-bit eeprom %s\n", + (pd->flags & EE_ADDR8) ? 8 : 16, + (pd->flags & EE_READONLY) ? "(readonly)" : ""); + + if (!(pd->flags & EE_READONLY)) { + if (device_create_file(&spi->dev, &dev_attr_erase)) + dev_err(&spi->dev, "can't create erase interface\n"); + } + + spi_set_drvdata(spi, edev); + return 0; +fail: + kfree(edev); + return err; +} + +static int eeprom_93xx46_remove(struct spi_device *spi) +{ + struct eeprom_93xx46_dev *edev = spi_get_drvdata(spi); + + if (!(edev->pdata->flags & EE_READONLY)) + device_remove_file(&spi->dev, &dev_attr_erase); + + sysfs_remove_bin_file(&spi->dev.kobj, &edev->bin); + kfree(edev); + return 0; +} + +static struct spi_driver eeprom_93xx46_driver = { + .driver = { + .name = "93xx46", + .owner = THIS_MODULE, + }, + .probe = eeprom_93xx46_probe, + .remove = eeprom_93xx46_remove, +}; + +module_spi_driver(eeprom_93xx46_driver); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Driver for 93xx46 EEPROMs"); +MODULE_AUTHOR("Anatolij Gustschin "); +MODULE_ALIAS("spi:93xx46"); -- cgit v1.2.3-54-g00ecf