Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758331Ab2JAXQn (ORCPT ); Mon, 1 Oct 2012 19:16:43 -0400 Received: from mail.savoirfairelinux.com ([209.172.62.77]:47034 "EHLO mail.savoirfairelinux.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758287Ab2JAXQc (ORCPT ); Mon, 1 Oct 2012 19:16:32 -0400 From: Vivien Didelot To: lm-sensors@lm-sensors.org Cc: Guillaume Roguez , Guenter Roeck , Jean Delvare , linux-kernel@vger.kernel.org, Steve Hardy , Vivien Didelot Subject: [PATCH v2 2/2] hwmon: (ads7828) add support for ADS7830 Date: Mon, 1 Oct 2012 19:16:24 -0400 Message-Id: <1349133384-5181-2-git-send-email-vivien.didelot@savoirfairelinux.com> X-Mailer: git-send-email 1.7.11.4 In-Reply-To: <1349133384-5181-1-git-send-email-vivien.didelot@savoirfairelinux.com> References: <1349133384-5181-1-git-send-email-vivien.didelot@savoirfairelinux.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8493 Lines: 242 From: Guillaume Roguez The ADS7830 device is almost the same as the ADS7828, except that it does 8-bit sampling, instead of 12-bit. This patch extends the ads7828 driver to support this chip. Signed-off-by: Guillaume Roguez Signed-off-by: Vivien Didelot --- Documentation/hwmon/ads7828 | 12 ++++++++-- drivers/hwmon/Kconfig | 7 +++--- drivers/hwmon/ads7828.c | 58 ++++++++++++++++++++++++++++++++------------- 3 files changed, 55 insertions(+), 22 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 + Guillaume Roguez 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 fb3010d..91fc629 100644 --- a/drivers/hwmon/ads7828.c +++ b/drivers/hwmon/ads7828.c @@ -1,11 +1,13 @@ /* - * ads7828.c - lm_sensors driver for ads7828 12-bit 8-channel ADC + * ads7828.c - driver for TI ADS7828 8-channel A/D converter and compatibles * (C) 2007 EADS Astrium * * This driver is based on the lm75 and other lm_sensors/hwmon drivers * * Written by Steve Hardy * + * ADS7830 support by Guillaume Roguez + * * For further information, see the Documentation/hwmon/ads7828 file. * * This program is free software; you can redistribute it and/or modify @@ -41,6 +43,9 @@ #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, I2C_CLIENT_END }; @@ -53,9 +58,7 @@ module_param(se_input, bool, S_IRUGO); module_param(int_vref, bool, S_IRUGO); 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 */ /** * struct ads7828_data - client specific data @@ -64,6 +67,8 @@ static unsigned int ads7828_lsb_resol; /* resolution of the ADC sample lsb */ * @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; @@ -71,6 +76,8 @@ struct ads7828_data { 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); }; static inline u8 channel_cmd_byte(int ch) @@ -96,8 +103,7 @@ 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; @@ -115,8 +121,8 @@ 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) \ @@ -162,6 +168,7 @@ static int ads7828_detect(struct i2c_client *client, { 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)) @@ -172,20 +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; } @@ -202,6 +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); @@ -227,7 +253,8 @@ exit: } static const struct i2c_device_id ads7828_ids[] = { - { "ads7828", 0 }, + { "ads7828", ads7828 }, + { "ads7830", ads7830 }, { } }; MODULE_DEVICE_TABLE(i2c, ads7828_ids); @@ -250,9 +277,6 @@ static int __init sensors_ads7828_init(void) ads7828_cmd_byte = se_input ? ADS7828_CMD_SD_SE : ADS7828_CMD_SD_DIFF; 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); } @@ -262,7 +286,7 @@ static void __exit sensors_ads7828_exit(void) } MODULE_AUTHOR("Steve Hardy "); -MODULE_DESCRIPTION("Driver for TI ADS7828 A/D converter"); +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 majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/