From e53537653791b4aaa9ec88a9eb5fd187d44ff6ac Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Wed, 20 Dec 2017 13:17:49 +0100 Subject: i2c/ARM: davinci: Deep refactoring of I2C recovery Alter the DaVinci GPIO recovery fetch to use descriptors all the way down into the board files. Signed-off-by: Linus Walleij Acked-by: Sekhar Nori Tested-by: Sekhar Nori Acked-by: Arnd Bergmann Signed-off-by: Wolfram Sang --- include/linux/platform_data/i2c-davinci.h | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'include/linux/platform_data') diff --git a/include/linux/platform_data/i2c-davinci.h b/include/linux/platform_data/i2c-davinci.h index 89fd34727a24..98967df07468 100644 --- a/include/linux/platform_data/i2c-davinci.h +++ b/include/linux/platform_data/i2c-davinci.h @@ -16,9 +16,8 @@ struct davinci_i2c_platform_data { unsigned int bus_freq; /* standard bus frequency (kHz) */ unsigned int bus_delay; /* post-transaction delay (usec) */ - unsigned int sda_pin; /* GPIO pin ID to use for SDA */ - unsigned int scl_pin; /* GPIO pin ID to use for SCL */ - bool has_pfunc; /*chip has a ICPFUNC register */ + bool gpio_recovery; /* Use GPIO recovery method */ + bool has_pfunc; /* Chip has a ICPFUNC register */ }; /* for board setup code */ -- cgit v1.2.3-71-gd317 From e32213fbc5432c28268dced0dc8735dcf8532d36 Mon Sep 17 00:00:00 2001 From: Sven Van Asbroeck Date: Fri, 8 Dec 2017 11:28:30 -0500 Subject: eeprom: at24: support eeproms that do not auto-rollover reads Some multi-address eeproms in the at24 family may not automatically roll-over reads to the next slave address. On those eeproms, reads that straddle slave boundaries will not work correctly. Solution: Mark such eeproms with a flag that prevents reads straddling slave boundaries. Add the AT24_FLAG_NO_RDROL flag to the eeprom entry in the device_id table, or add 'no-read-rollover' to the eeprom devicetree entry. Note that I have not personally enountered an at24 chip that does not support read rollovers. They may or may not exist. However, my hardware requires this functionality because of a quirk. Signed-off-by: Sven Van Asbroeck Signed-off-by: Bartosz Golaszewski --- drivers/misc/eeprom/at24.c | 39 ++++++++++++++++++++++++++------------ include/linux/platform_data/at24.h | 2 ++ 2 files changed, 29 insertions(+), 12 deletions(-) (limited to 'include/linux/platform_data') diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c index 3fd26d7cb50e..848fda8be314 100644 --- a/drivers/misc/eeprom/at24.c +++ b/drivers/misc/eeprom/at24.c @@ -251,15 +251,6 @@ MODULE_DEVICE_TABLE(acpi, at24_acpi_ids); * Slave address and byte offset derive from the offset. Always * set the byte address; on a multi-master board, another master * may have changed the chip's "current" address pointer. - * - * REVISIT some multi-address chips don't rollover page reads to - * the next slave address, so we may need to truncate the count. - * Those chips might need another quirk flag. - * - * If the real hardware used four adjacent 24c02 chips and that - * were misconfigured as one 24c08, that would be a similar effect: - * one "eeprom" file not four, but larger reads would fail when - * they crossed certain pages. */ static struct at24_client *at24_translate_offset(struct at24_data *at24, unsigned int *offset) @@ -277,6 +268,30 @@ static struct at24_client *at24_translate_offset(struct at24_data *at24, return &at24->client[i]; } +static size_t at24_adjust_read_count(struct at24_data *at24, + unsigned int offset, size_t count) +{ + unsigned int bits; + size_t remainder; + + /* + * In case of multi-address chips that don't rollover reads to + * the next slave address: truncate the count to the slave boundary, + * so that the read never straddles slaves. + */ + if (at24->chip.flags & AT24_FLAG_NO_RDROL) { + bits = (at24->chip.flags & AT24_FLAG_ADDR16) ? 16 : 8; + remainder = BIT(bits) - offset; + if (count > remainder) + count = remainder; + } + + if (count > io_limit) + count = io_limit; + + return count; +} + static ssize_t at24_regmap_read(struct at24_data *at24, char *buf, unsigned int offset, size_t count) { @@ -289,9 +304,7 @@ static ssize_t at24_regmap_read(struct at24_data *at24, char *buf, at24_client = at24_translate_offset(at24, &offset); regmap = at24_client->regmap; client = at24_client->client; - - if (count > io_limit) - count = io_limit; + count = at24_adjust_read_count(at24, offset, count); /* adjust offset for mac and serial read ops */ offset += at24->offset_adj; @@ -457,6 +470,8 @@ static void at24_get_pdata(struct device *dev, struct at24_platform_data *chip) if (device_property_present(dev, "read-only")) chip->flags |= AT24_FLAG_READONLY; + if (device_property_present(dev, "no-read-rollover")) + chip->flags |= AT24_FLAG_NO_RDROL; err = device_property_read_u32(dev, "size", &val); if (!err) diff --git a/include/linux/platform_data/at24.h b/include/linux/platform_data/at24.h index 271a4e25af67..841bb2815a41 100644 --- a/include/linux/platform_data/at24.h +++ b/include/linux/platform_data/at24.h @@ -50,6 +50,8 @@ struct at24_platform_data { #define AT24_FLAG_TAKE8ADDR BIT(4) /* take always 8 addresses (24c00) */ #define AT24_FLAG_SERIAL BIT(3) /* factory-programmed serial number */ #define AT24_FLAG_MAC BIT(2) /* factory-programmed mac address */ +#define AT24_FLAG_NO_RDROL BIT(1) /* does not auto-rollover reads to */ + /* the next slave address */ void (*setup)(struct nvmem_device *nvmem, void *context); void *context; -- cgit v1.2.3-71-gd317 From 98fb3a34736dec1e14e43382c0df30f815560e5f Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Thu, 21 Dec 2017 17:53:09 +0100 Subject: eeprom: at24: fix a whitespace error in platform data Replace spaces with tabs in the definition of AT24_FLAG_NO_RDROL. Fixes: 9d404411091c ("eeprom: at24: support eeproms that do not auto-rollover reads") Signed-off-by: Bartosz Golaszewski --- include/linux/platform_data/at24.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/platform_data') diff --git a/include/linux/platform_data/at24.h b/include/linux/platform_data/at24.h index 841bb2815a41..63507ff464ee 100644 --- a/include/linux/platform_data/at24.h +++ b/include/linux/platform_data/at24.h @@ -50,7 +50,7 @@ struct at24_platform_data { #define AT24_FLAG_TAKE8ADDR BIT(4) /* take always 8 addresses (24c00) */ #define AT24_FLAG_SERIAL BIT(3) /* factory-programmed serial number */ #define AT24_FLAG_MAC BIT(2) /* factory-programmed mac address */ -#define AT24_FLAG_NO_RDROL BIT(1) /* does not auto-rollover reads to */ +#define AT24_FLAG_NO_RDROL BIT(1) /* does not auto-rollover reads to */ /* the next slave address */ void (*setup)(struct nvmem_device *nvmem, void *context); -- cgit v1.2.3-71-gd317