From: Guillaume Roguez <[email protected]> The ADS7830 is almost the same chip, except that it does 8-bit sampling. This patch extends the ads7828 driver to support this device.
Signed-off-by: Guillaume Roguez <[email protected]> Also clean the driver a bit by removing unused macros, and moving the driver declaration to avoid some function prototypes. Signed-off-by: Vivien Didelot <[email protected]> --- Documentation/hwmon/ads7828 | 12 +++- drivers/hwmon/Kconfig | 7 ++- drivers/hwmon/ads7828.c | 137 +++++++++++++++++++++++++------------------- 3 files changed, 93 insertions(+), 63 deletions(-) diff --git a/Documentation/hwmon/ads7828 b/Documentation/hwmon/ads7828 index 2bbebe6..4366a87 100644 --- a/Documentation/hwmon/ads7828 +++ b/Documentation/hwmon/ads7828 @@ -8,8 +8,15 @@ Supported chips: Datasheet: Publicly available at the Texas Instruments website : http://focus.ti.com/lit/ds/symlink/ads7828.pdf + * Texas Instruments ADS7830 + Prefix: 'ads7830' + Addresses scanned: I2C 0x48, 0x49, 0x4a, 0x4b + Datasheet: Publicly available at the Texas Instruments website: + http://focus.ti.com/lit/ds/symlink/ads7830.pdf + Authors: Steve Hardy <[email protected]> + Guillaume Roguez <[email protected]> Module Parameters ----------------- @@ -24,9 +31,10 @@ Module Parameters Description ----------- -This driver implements support for the Texas Instruments ADS7828. +This driver implements support for the Texas Instruments ADS7828, and ADS7830. -This device is a 12-bit 8-channel A-D converter. +The ADS7828 device is a 12-bit 8-channel A/D converter, while the ADS7830 does +8-bit sampling. It can operate in single ended mode (8 +ve inputs) or in differential mode, where 4 differential pairs can be measured. diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index 83e3e9d..960c8c5 100644 --- a/drivers/hwmon/Kconfig +++ b/drivers/hwmon/Kconfig @@ -1060,11 +1060,12 @@ config SENSORS_ADS1015 will be called ads1015. config SENSORS_ADS7828 - tristate "Texas Instruments ADS7828" + tristate "Texas Instruments ADS7828 and compatibles" depends on I2C help - If you say yes here you get support for Texas Instruments ADS7828 - 12-bit 8-channel ADC device. + If you say yes here you get support for Texas Instruments ADS7828 and + ADS7830 8-channel A/D converters. ADS7828 resolution is 12-bit, while + it is 8-bit on ADS7830. This driver can also be built as a module. If so, the module will be called ads7828. diff --git a/drivers/hwmon/ads7828.c b/drivers/hwmon/ads7828.c index bf3fdf4..58f28ea 100644 --- a/drivers/hwmon/ads7828.c +++ b/drivers/hwmon/ads7828.c @@ -1,12 +1,12 @@ /* - * ads7828.c - lm_sensors driver for ads7828 12-bit 8-channel ADC - * (C) 2007 EADS Astrium + * ads7828.c - driver for TI ADS7828 8-channel A/D converter and compatibles * - * This driver is based on the lm75 and other lm_sensors/hwmon drivers + * Copyright (C) 2007 EADS Astrium + * Copyright (C) Steve Hardy <[email protected]> + * Copyright (C) 2012 Savoir-faire Linux Inc. + * Guillaume Roguez <[email protected]> * - * Written by Steve Hardy <[email protected]> - * - * Datasheet available at: http://focus.ti.com/lit/ds/symlink/ads7828.pdf + * For further information, see the Documentation/hwmon/ads7828 file. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by @@ -34,14 +34,15 @@ #include <linux/mutex.h> /* The ADS7828 registers */ -#define ADS7828_NCH 8 /* 8 channels of 12-bit A-D supported */ -#define ADS7828_CMD_SD_SE 0x80 /* Single ended inputs */ -#define ADS7828_CMD_SD_DIFF 0x00 /* Differential inputs */ -#define ADS7828_CMD_PD0 0x0 /* Power Down between A-D conversions */ -#define ADS7828_CMD_PD1 0x04 /* Internal ref OFF && A-D ON */ -#define ADS7828_CMD_PD2 0x08 /* Internal ref ON && A-D OFF */ -#define ADS7828_CMD_PD3 0x0C /* Internal ref ON && A-D ON */ -#define ADS7828_INT_VREF_MV 2500 /* Internal vref is 2.5V, 2500mV */ +#define ADS7828_NCH 8 /* 8 channels supported */ +#define ADS7828_CMD_SD_SE 0x80 /* Single ended inputs */ +#define ADS7828_CMD_SD_DIFF 0x00 /* Differential inputs */ +#define ADS7828_CMD_PD1 0x04 /* Internal ref OFF && A/D ON */ +#define ADS7828_CMD_PD3 0x0C /* Internal ref ON && A/D ON */ +#define ADS7828_INT_VREF_MV 2500 /* Internal vref is 2.5V, 2500mV */ + +/* List of supported devices */ +enum ads7828_chips { ads7828, ads7830 }; /* Addresses to scan */ static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, @@ -57,23 +58,27 @@ module_param(vref_mv, int, S_IRUGO); /* Global Variables */ static u8 ads7828_cmd_byte; /* cmd byte without channel bits */ -static unsigned int ads7828_lsb_resol; /* resolution of the ADC sample lsb */ -/* Each client has this additional data */ +/** + * struct ads7828_data - client specific data + * @hwmon_dev: The hwmon device. + * @update_lock: Mutex protecting updates. + * @valid: Validity flag. + * @last_updated: Last updated time (in jiffies). + * @adc_input: ADS7828_NCH samples. + * @lsb_resol: Resolution of the A/D converter sample LSB. + * @read_channel: Function used to read a channel. + */ struct ads7828_data { struct device *hwmon_dev; - struct mutex update_lock; /* mutex protect updates */ - char valid; /* !=0 if following fields are valid */ - unsigned long last_updated; /* In jiffies */ - u16 adc_input[ADS7828_NCH]; /* ADS7828_NCH 12-bit samples */ + struct mutex update_lock; + char valid; + unsigned long last_updated; + u16 adc_input[ADS7828_NCH]; + unsigned int lsb_resol; + s32 (*read_channel)(const struct i2c_client *client, u8 command); }; -/* Function declaration - necessary due to function dependencies */ -static int ads7828_detect(struct i2c_client *client, - struct i2c_board_info *info); -static int ads7828_probe(struct i2c_client *client, - const struct i2c_device_id *id); - static inline u8 channel_cmd_byte(int ch) { /* cmd byte C2,C1,C0 - see datasheet */ @@ -97,8 +102,7 @@ static struct ads7828_data *ads7828_update_device(struct device *dev) for (ch = 0; ch < ADS7828_NCH; ch++) { u8 cmd = channel_cmd_byte(ch); - data->adc_input[ch] = - i2c_smbus_read_word_swapped(client, cmd); + data->adc_input[ch] = data->read_channel(client, cmd); } data->last_updated = jiffies; data->valid = 1; @@ -116,8 +120,8 @@ static ssize_t show_in(struct device *dev, struct device_attribute *da, struct sensor_device_attribute *attr = to_sensor_dev_attr(da); struct ads7828_data *data = ads7828_update_device(dev); /* Print value (in mV as specified in sysfs-interface documentation) */ - return sprintf(buf, "%d\n", (data->adc_input[attr->index] * - ads7828_lsb_resol)/1000); + return sprintf(buf, "%d\n", + (data->adc_input[attr->index] * data->lsb_resol) / 1000); } #define in_reg(offset)\ @@ -158,31 +162,13 @@ static int ads7828_remove(struct i2c_client *client) return 0; } -static const struct i2c_device_id ads7828_id[] = { - { "ads7828", 0 }, - { } -}; -MODULE_DEVICE_TABLE(i2c, ads7828_id); - -/* This is the driver that will be inserted */ -static struct i2c_driver ads7828_driver = { - .class = I2C_CLASS_HWMON, - .driver = { - .name = "ads7828", - }, - .probe = ads7828_probe, - .remove = ads7828_remove, - .id_table = ads7828_id, - .detect = ads7828_detect, - .address_list = normal_i2c, -}; - /* Return 0 if detection is successful, -ENODEV otherwise */ static int ads7828_detect(struct i2c_client *client, struct i2c_board_info *info) { struct i2c_adapter *adapter = client->adapter; int ch; + bool is_8bit = false; /* Check we have a valid client */ if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_WORD_DATA)) @@ -193,20 +179,30 @@ static int ads7828_detect(struct i2c_client *client, * dedicated register so attempt to sanity check using knowledge of * the chip * - Read from the 8 channel addresses - * - Check the top 4 bits of each result are not set (12 data bits) + * - Check the top 4 bits of each result: + * - They should not be set in case of 12-bit samples + * - The two bytes should be equal in case of 8-bit samples */ for (ch = 0; ch < ADS7828_NCH; ch++) { u16 in_data; u8 cmd = channel_cmd_byte(ch); in_data = i2c_smbus_read_word_swapped(client, cmd); if (in_data & 0xF000) { - pr_debug("%s : Doesn't look like an ads7828 device\n", - __func__); - return -ENODEV; + if ((in_data >> 8) == (in_data & 0xFF)) { + /* Seems to be an ADS7830 (8-bit sample) */ + is_8bit = true; + } else { + dev_dbg(&client->dev, "doesn't look like an " + "ADS7828 compatible device\n"); + return -ENODEV; + } } } - strlcpy(info->type, "ads7828", I2C_NAME_SIZE); + if (is_8bit) + strlcpy(info->type, "ads7830", I2C_NAME_SIZE); + else + strlcpy(info->type, "ads7828", I2C_NAME_SIZE); return 0; } @@ -223,6 +219,15 @@ static int ads7828_probe(struct i2c_client *client, goto exit; } + /* ADS7828 uses 12-bit samples, while ADS7830 is 8-bit */ + if (id->driver_data == ads7828) { + data->read_channel = i2c_smbus_read_word_swapped; + data->lsb_resol = (vref_mv * 1000) / 4096; + } else { + data->read_channel = i2c_smbus_read_byte_data; + data->lsb_resol = (vref_mv * 1000) / 256; + } + i2c_set_clientdata(client, data); mutex_init(&data->update_lock); @@ -247,6 +252,25 @@ exit: return err; } +static const struct i2c_device_id ads7828_ids[] = { + { "ads7828", ads7828 }, + { "ads7830", ads7830 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, ads7828_ids); + +static struct i2c_driver ads7828_driver = { + .class = I2C_CLASS_HWMON, + .driver = { + .name = "ads7828", + }, + .probe = ads7828_probe, + .remove = ads7828_remove, + .id_table = ads7828_ids, + .detect = ads7828_detect, + .address_list = normal_i2c, +}; + static int __init sensors_ads7828_init(void) { /* Initialize the command byte according to module parameters */ @@ -255,9 +279,6 @@ static int __init sensors_ads7828_init(void) ads7828_cmd_byte |= int_vref ? ADS7828_CMD_PD3 : ADS7828_CMD_PD1; - /* Calculate the LSB resolution */ - ads7828_lsb_resol = (vref_mv*1000)/4096; - return i2c_add_driver(&ads7828_driver); } @@ -267,7 +288,7 @@ static void __exit sensors_ads7828_exit(void) } MODULE_AUTHOR("Steve Hardy <[email protected]>"); -MODULE_DESCRIPTION("ADS7828 driver"); +MODULE_DESCRIPTION("Driver for TI ADS7828 A/D converter and compatibles"); MODULE_LICENSE("GPL"); module_init(sensors_ads7828_init); -- 1.7.11.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
