Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756750Ab2JBWKN (ORCPT ); Tue, 2 Oct 2012 18:10:13 -0400 Received: from mail.savoirfairelinux.com ([209.172.62.77]:32829 "EHLO mail.savoirfairelinux.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753527Ab2JBWKK (ORCPT ); Tue, 2 Oct 2012 18:10:10 -0400 From: Vivien Didelot To: lm-sensors@lm-sensors.org Cc: Vivien Didelot , Guenter Roeck , Jean Delvare , linux-kernel@vger.kernel.org, Steve Hardy Subject: [PATCH v3 1/2] hwmon: (ads7828) driver cleanup Date: Tue, 2 Oct 2012 18:10:02 -0400 Message-Id: <1349215803-10999-1-git-send-email-vivien.didelot@savoirfairelinux.com> X-Mailer: git-send-email 1.7.11.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 14483 Lines: 435 * Remove module parameters, add a ads7828_platform_data; * Move driver declaration to avoid adding function prototypes; * Remove unused macros; * Coding Style fixes. Signed-off-by: Vivien Didelot --- Documentation/hwmon/ads7828 | 31 +++-- drivers/hwmon/ads7828.c | 216 +++++++++++++++++----------------- include/linux/platform_data/ads7828.h | 29 +++++ 3 files changed, 155 insertions(+), 121 deletions(-) create mode 100644 include/linux/platform_data/ads7828.h diff --git a/Documentation/hwmon/ads7828 b/Documentation/hwmon/ads7828 index 2bbebe6..b35668c 100644 --- a/Documentation/hwmon/ads7828 +++ b/Documentation/hwmon/ads7828 @@ -5,21 +5,32 @@ Supported chips: * Texas Instruments/Burr-Brown ADS7828 Prefix: 'ads7828' Addresses scanned: I2C 0x48, 0x49, 0x4a, 0x4b - Datasheet: Publicly available at the Texas Instruments website : + Datasheet: Publicly available at the Texas Instruments website: http://focus.ti.com/lit/ds/symlink/ads7828.pdf Authors: Steve Hardy -Module Parameters ------------------ - -* se_input: bool (default Y) - Single ended operation - set to N for differential mode -* int_vref: bool (default Y) - Operate with the internal 2.5V reference - set to N for external reference -* vref_mv: int (default 2500) - If using an external reference, set this to the reference voltage in mV +Platform data +------------- + +The ads7828 driver accepts an optional ads7828_platform_data structure (defined +in include/linux/platform_data/ads7828.h). If no structure is provided, the +configuration defaults to single ended operation and internal vref (2.5V). + +The structure fields are: + +* diff_input: bool + Differential operation - set to true for differential mode, + false for default single ended mode. +* ext_vref: bool + External reference - set to true if it operates with an external reference, + false for default internal reference. +* vref_mv: int + Voltage reference - if using an external reference, set this to the reference + voltage in mV, otherwise, it will default to the internal value (2500mV). + This value will be bounded with limits accepted by the chip, described in the + datasheet. Description ----------- diff --git a/drivers/hwmon/ads7828.c b/drivers/hwmon/ads7828.c index bf3fdf4..0a13bf8 100644 --- a/drivers/hwmon/ads7828.c +++ b/drivers/hwmon/ads7828.c @@ -6,7 +6,7 @@ * * Written by Steve Hardy * - * 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 @@ -23,63 +23,48 @@ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ -#include -#include -#include -#include -#include +#include #include #include -#include +#include +#include +#include +#include #include +#include +#include /* 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_PD1 0x04 /* Internal vref OFF && A/D ON */ +#define ADS7828_CMD_PD3 0x0C /* Internal vref ON && A/D ON */ +#define ADS7828_INT_VREF_MV 2500 /* Internal vref is 2.5V, 2500mV */ +#define ADS7828_EXT_VREF_MV_MIN 50 /* External vref min value 0.05V */ +#define ADS7828_EXT_VREF_MV_MAX 5250 /* External vref max value 5.25V */ /* Addresses to scan */ static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, I2C_CLIENT_END }; -/* Module parameters */ -static bool se_input = 1; /* Default is SE, 0 == diff */ -static bool int_vref = 1; /* Default is internal ref ON */ -static int vref_mv = ADS7828_INT_VREF_MV; /* set if vref != 2.5V */ -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 */ - -/* Each client has this additional data */ +/* Client specific data */ 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; /* Mutex protecting updates */ + unsigned long last_updated; /* Last updated time (in jiffies) */ + u16 adc_input[ADS7828_NCH]; /* ADS7828_NCH samples */ + bool valid; /* Validity flag */ + bool diff_input; /* Differential input */ + bool ext_vref; /* External voltage reference */ + unsigned int vref_mv; /* voltage reference value */ + u8 cmd_byte; /* Command byte without channel bits */ + unsigned int lsb_resol; /* Resolution of the ADC sample LSB */ }; -/* 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) +/* Command byte C2,C1,C0 - see datasheet */ +static inline u8 ads7828_cmd_byte(u8 cmd, int ch) { - /* cmd byte C2,C1,C0 - see datasheet */ - u8 cmd = (((ch>>1) | (ch&0x01)<<2)<<4); - cmd |= ads7828_cmd_byte; - return cmd; + return cmd | (((ch >> 1) | (ch & 0x01) << 2) << 4); } /* Update data for the device (all 8 channels) */ @@ -96,12 +81,12 @@ static struct ads7828_data *ads7828_update_device(struct device *dev) dev_dbg(&client->dev, "Starting ads7828 update\n"); for (ch = 0; ch < ADS7828_NCH; ch++) { - u8 cmd = channel_cmd_byte(ch); + u8 cmd = ads7828_cmd_byte(data->cmd_byte, ch); data->adc_input[ch] = i2c_smbus_read_word_swapped(client, cmd); } data->last_updated = jiffies; - data->valid = 1; + data->valid = true; } mutex_unlock(&data->update_lock); @@ -110,28 +95,25 @@ static struct ads7828_data *ads7828_update_device(struct device *dev) } /* sysfs callback function */ -static ssize_t show_in(struct device *dev, struct device_attribute *da, - char *buf) +static ssize_t ads7828_show_in(struct device *dev, struct device_attribute *da, + char *buf) { 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); -} + unsigned int value = DIV_ROUND_CLOSEST(data->adc_input[attr->index] * + data->lsb_resol, 1000); -#define in_reg(offset)\ -static SENSOR_DEVICE_ATTR(in##offset##_input, S_IRUGO, show_in,\ - NULL, offset) + return sprintf(buf, "%d\n", value); +} -in_reg(0); -in_reg(1); -in_reg(2); -in_reg(3); -in_reg(4); -in_reg(5); -in_reg(6); -in_reg(7); +static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, ads7828_show_in, NULL, 0); +static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, ads7828_show_in, NULL, 1); +static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, ads7828_show_in, NULL, 2); +static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, ads7828_show_in, NULL, 3); +static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, ads7828_show_in, NULL, 4); +static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, ads7828_show_in, NULL, 5); +static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, ads7828_show_in, NULL, 6); +static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, ads7828_show_in, NULL, 7); static struct attribute *ads7828_attributes[] = { &sensor_dev_attr_in0_input.dev_attr.attr, @@ -152,36 +134,20 @@ static const struct attribute_group ads7828_group = { static int ads7828_remove(struct i2c_client *client) { struct ads7828_data *data = i2c_get_clientdata(client); + hwmon_device_unregister(data->hwmon_dev); sysfs_remove_group(&client->dev.kobj, &ads7828_group); - kfree(i2c_get_clientdata(client)); + i2c_set_clientdata(client, NULL); + 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; + u8 default_cmd_byte = ADS7828_CMD_SD_SE | ADS7828_CMD_PD3; int ch; /* Check we have a valid client */ @@ -196,9 +162,12 @@ static int ads7828_detect(struct i2c_client *client, * - Check the top 4 bits of each result are not set (12 data bits) */ 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); + u8 cmd = ads7828_cmd_byte(default_cmd_byte, ch); + u16 in_data = i2c_smbus_read_word_swapped(client, cmd); + + if (in_data < 0) + return -ENODEV; + if (in_data & 0xF000) { pr_debug("%s : Doesn't look like an ads7828 device\n", __func__); @@ -214,61 +183,86 @@ static int ads7828_detect(struct i2c_client *client, static int ads7828_probe(struct i2c_client *client, const struct i2c_device_id *id) { - struct ads7828_data *data; int err; - - data = kzalloc(sizeof(struct ads7828_data), GFP_KERNEL); - if (!data) { - err = -ENOMEM; - goto exit; + struct ads7828_data *data; + struct ads7828_platform_data *pdata = client->dev.platform_data; + + data = devm_kzalloc(&client->dev, sizeof(struct ads7828_data), + GFP_KERNEL); + if (!data) + return -ENOMEM; + + if (pdata) { + data->diff_input = pdata->diff_input; + data->ext_vref = pdata->ext_vref; + if (data->ext_vref) + data->vref_mv = pdata->vref_mv; } + /* Bound Vref with min/max values if it was provided */ + if (data->vref_mv) + data->vref_mv = SENSORS_LIMIT(data->vref_mv, + ADS7828_EXT_VREF_MV_MIN, + ADS7828_EXT_VREF_MV_MAX); + else + data->vref_mv = ADS7828_INT_VREF_MV; + + data->lsb_resol = DIV_ROUND_CLOSEST(data->vref_mv * 1000, 4096); + + data->cmd_byte = data->ext_vref ? ADS7828_CMD_PD1 : ADS7828_CMD_PD3; + if (!data->diff_input) + data->cmd_byte |= ADS7828_CMD_SD_SE; + i2c_set_clientdata(client, data); mutex_init(&data->update_lock); - /* Register sysfs hooks */ err = sysfs_create_group(&client->dev.kobj, &ads7828_group); if (err) - goto exit_free; + return err; data->hwmon_dev = hwmon_device_register(&client->dev); if (IS_ERR(data->hwmon_dev)) { err = PTR_ERR(data->hwmon_dev); - goto exit_remove; + goto error; } return 0; -exit_remove: +error: sysfs_remove_group(&client->dev.kobj, &ads7828_group); -exit_free: - kfree(data); -exit: return err; } -static int __init sensors_ads7828_init(void) -{ - /* Initialize the command byte according to module parameters */ - ads7828_cmd_byte = se_input ? - ADS7828_CMD_SD_SE : ADS7828_CMD_SD_DIFF; - ads7828_cmd_byte |= int_vref ? - ADS7828_CMD_PD3 : ADS7828_CMD_PD1; +static const struct i2c_device_id ads7828_ids[] = { + { "ads7828", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, ads7828_ids); - /* Calculate the LSB resolution */ - ads7828_lsb_resol = (vref_mv*1000)/4096; +static struct i2c_driver ads7828_driver = { + .class = I2C_CLASS_HWMON, + .driver = { + .name = "ads7828", + }, + .address_list = normal_i2c, + .detect = ads7828_detect, + .probe = ads7828_probe, + .remove = ads7828_remove, + .id_table = ads7828_ids, +}; +static int __init sensors_ads7828_init(void) +{ return i2c_add_driver(&ads7828_driver); } +module_init(sensors_ads7828_init); static void __exit sensors_ads7828_exit(void) { i2c_del_driver(&ads7828_driver); } +module_exit(sensors_ads7828_exit); MODULE_AUTHOR("Steve Hardy "); -MODULE_DESCRIPTION("ADS7828 driver"); +MODULE_DESCRIPTION("Driver for TI ADS7828 A/D converter"); MODULE_LICENSE("GPL"); - -module_init(sensors_ads7828_init); -module_exit(sensors_ads7828_exit); diff --git a/include/linux/platform_data/ads7828.h b/include/linux/platform_data/ads7828.h new file mode 100644 index 0000000..3245f45 --- /dev/null +++ b/include/linux/platform_data/ads7828.h @@ -0,0 +1,29 @@ +/* + * TI ADS7828 A/D Converter platform data definition + * + * Copyright (c) 2012 Savoir-faire Linux Inc. + * Vivien Didelot + * + * 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 version 2 as + * published by the Free Software Foundation. + */ + +#ifndef _PDATA_ADS7828_H +#define _PDATA_ADS7828_H + +/** + * struct ads7828_platform_data - optional ADS7828 connectivity info + * @diff_input: Differential input mode. + * @ext_vref: Use an external voltage reference. + * @vref_mv: Voltage reference value, if external. + */ +struct ads7828_platform_data { + bool diff_input; + bool ext_vref; + unsigned int vref_mv; +}; + +#endif /* _PDATA_ADS7828_H */ -- 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/