Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935657AbcJRW6m (ORCPT ); Tue, 18 Oct 2016 18:58:42 -0400 Received: from mail.pqgruber.com ([178.189.19.235]:62258 "EHLO mail.pqgruber.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935052AbcJRW6g (ORCPT ); Tue, 18 Oct 2016 18:58:36 -0400 X-Greylist: delayed 584 seconds by postgrey-1.27 at vger.kernel.org; Tue, 18 Oct 2016 18:58:34 EDT From: Clemens Gruber To: linux-hwmon@vger.kernel.org Cc: Guenter Roeck , Jean Delvare , devicetree@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Clemens Gruber Subject: [PATCH] mcp3021: rework for DT support of reference-voltage Date: Wed, 19 Oct 2016 00:44:44 +0200 Message-Id: <20161018224444.11225-1-clemens.gruber@pqgruber.com> X-Mailer: git-send-email 2.10.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 9142 Lines: 321 Support setting the reference voltage in the device tree. Rework of driver structure, put chip specific data in a separate structure and assign it depending on device id from platform data or DT match. Extend the device documentation and add new documentation for the devicetree bindings. Also change S_IRUGO to the better readable 0444, which fixes a checkpatch warning. Signed-off-by: Clemens Gruber --- .../devicetree/bindings/hwmon/mcp3021.txt | 21 +++ Documentation/hwmon/mcp3021 | 5 + drivers/hwmon/mcp3021.c | 184 ++++++++++++++------- 3 files changed, 149 insertions(+), 61 deletions(-) create mode 100644 Documentation/devicetree/bindings/hwmon/mcp3021.txt diff --git a/Documentation/devicetree/bindings/hwmon/mcp3021.txt b/Documentation/devicetree/bindings/hwmon/mcp3021.txt new file mode 100644 index 0000000..e1d1e62 --- /dev/null +++ b/Documentation/devicetree/bindings/hwmon/mcp3021.txt @@ -0,0 +1,21 @@ +mcp3021 properties + +Required properties: +- compatible: Must be one of the following: + - "microchip,mcp3021" for mcp3021 + - "microchip,mcp3221" for mcp3221 +- reg: I2C address + +Optional properties: + +- reference-voltage + Reference voltage in millivolt (mV) + +Example: + +mcp3021@4d { + compatible = "microchip,mcp3021"; + reg = <0x4d>; + + reference-voltage = <4500>; /* 4.5 V */ +}; diff --git a/Documentation/hwmon/mcp3021 b/Documentation/hwmon/mcp3021 index 74a6b72..55792c3 100644 --- a/Documentation/hwmon/mcp3021 +++ b/Documentation/hwmon/mcp3021 @@ -12,6 +12,7 @@ Supported chips: Authors: Mingkai Hu Sven Schuchmann + Clemens Gruber Description ----------- @@ -27,3 +28,7 @@ Communication to the MCP3021/MCP3221 is performed using a 2-wire I2C compatible interface. Standard (100 kHz) and Fast (400 kHz) I2C modes are available. The default I2C device address is 0x4d (contact the Microchip factory for additional address options). + +The reference-voltage used in the conversion can be set via platform data or +device tree. Please refer to Documentation/devicetree/bindings/i2c/mcp3021.txt +for information about the bindings if the device tree is used. diff --git a/drivers/hwmon/mcp3021.c b/drivers/hwmon/mcp3021.c index 972444a..ebbd3d2 100644 --- a/drivers/hwmon/mcp3021.c +++ b/drivers/hwmon/mcp3021.c @@ -4,6 +4,7 @@ * Copyright (C) 2008-2009, 2012 Freescale Semiconductor, Inc. * Author: Mingkai Hu * Reworked by Sven Schuchmann + * Copyright (C) 2016 Clemens Gruber * * This driver export the value of analog input voltage to sysfs, the * voltage unit is mV. Through the sysfs interface, lm-sensors tool @@ -22,35 +23,74 @@ #include #include #include +#include +#include -/* Vdd info */ +/* Vdd / reference voltage */ #define MCP3021_VDD_MAX 5500 #define MCP3021_VDD_MIN 2700 -#define MCP3021_VDD_REF 3300 +#define MCP3021_VDD_DEFAULT 3300 -/* output format */ -#define MCP3021_SAR_SHIFT 2 -#define MCP3021_SAR_MASK 0x3ff -#define MCP3021_OUTPUT_RES 10 /* 10-bit resolution */ +struct mcp3021_chip_info { + u16 sar_shift; + u16 sar_mask; + u8 output_res; +}; + +struct mcp3021_data { + struct device *hwmon_dev; + const struct mcp3021_chip_info *chip_info; + u32 vdd; /* Supply and reference voltage for AD conversion */ +}; -#define MCP3221_SAR_SHIFT 0 -#define MCP3221_SAR_MASK 0xfff -#define MCP3221_OUTPUT_RES 12 /* 12-bit resolution */ +static int mcp3021_probe(struct i2c_client *client, + const struct i2c_device_id *id); +static int mcp3021_remove(struct i2c_client *client); -enum chips { +enum { mcp3021, mcp3221 }; -/* - * Client data (each client gets its own) - */ -struct mcp3021_data { - struct device *hwmon_dev; - u32 vdd; /* device power supply */ - u16 sar_shift; - u16 sar_mask; - u8 output_res; +static const struct i2c_device_id mcp3021_id[] = { + { "mcp3021", mcp3021 }, + { "mcp3221", mcp3221 }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(i2c, mcp3021_id); + +static const struct mcp3021_chip_info mcp3021_chip_info_tbl[] = { + [mcp3021] = { + .sar_shift = 2, + .sar_mask = 0x3ff, + .output_res = 10, /* 10-bit resolution */ + }, + [mcp3221] = { + .sar_shift = 0, + .sar_mask = 0xfff, + .output_res = 12, /* 12-bit resolution */ + }, +}; + +#ifdef CONFIG_OF +static const struct of_device_id of_mcp3021_match[] = { + { .compatible = "microchip,mcp3021", .data = (void *)mcp3021 }, + { .compatible = "microchip,mcp3221", .data = (void *)mcp3221 }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, of_mcp3021_match); +#endif + +static struct i2c_driver mcp3021_driver = { + .driver = { + .name = "mcp3021", +#ifdef CONFIG_OF + .of_match_table = of_match_ptr(of_mcp3021_match), +#endif + }, + .probe = mcp3021_probe, + .remove = mcp3021_remove, + .id_table = mcp3021_id, }; static int mcp3021_read16(struct i2c_client *client) @@ -73,14 +113,15 @@ static int mcp3021_read16(struct i2c_client *client) * The ten-bit output code is composed of the lower 4-bit of the * first byte and the upper 6-bit of the second byte. */ - reg = (reg >> data->sar_shift) & data->sar_mask; + reg = (reg >> data->chip_info->sar_shift) & data->chip_info->sar_mask; return reg; } static inline u16 volts_from_reg(struct mcp3021_data *data, u16 val) { - return DIV_ROUND_CLOSEST(data->vdd * val, 1 << data->output_res); + return DIV_ROUND_CLOSEST(data->vdd * val, + 1 << data->chip_info->output_res); } static ssize_t show_in_input(struct device *dev, struct device_attribute *attr, @@ -99,46 +140,83 @@ static ssize_t show_in_input(struct device *dev, struct device_attribute *attr, return sprintf(buf, "%d\n", in_input); } -static DEVICE_ATTR(in0_input, S_IRUGO, show_in_input, NULL); +static DEVICE_ATTR(in0_input, 0444, show_in_input, NULL); -static int mcp3021_probe(struct i2c_client *client, +#ifdef CONFIG_OF +static int mcp3021_probe_dt(struct i2c_client *client, const struct i2c_device_id *id) { - int err; - struct mcp3021_data *data = NULL; + struct mcp3021_data *data = i2c_get_clientdata(client); + struct device_node *np = client->dev.of_node; + const struct of_device_id *match; + int devid, ret; - if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) + match = of_match_device(of_mcp3021_match, &client->dev); + if (!match) return -ENODEV; - data = devm_kzalloc(&client->dev, sizeof(struct mcp3021_data), - GFP_KERNEL); - if (!data) - return -ENOMEM; + devid = (int)(uintptr_t)match->data; + data->chip_info = &mcp3021_chip_info_tbl[devid]; - i2c_set_clientdata(client, data); - - switch (id->driver_data) { - case mcp3021: - data->sar_shift = MCP3021_SAR_SHIFT; - data->sar_mask = MCP3021_SAR_MASK; - data->output_res = MCP3021_OUTPUT_RES; - break; - - case mcp3221: - data->sar_shift = MCP3221_SAR_SHIFT; - data->sar_mask = MCP3221_SAR_MASK; - data->output_res = MCP3221_OUTPUT_RES; - break; + ret = of_property_read_u32(np, "reference-voltage", &data->vdd); + if (ret) { + /* Fallback: Use default value */ + data->vdd = MCP3021_VDD_DEFAULT; + return 0; } + if (data->vdd > MCP3021_VDD_MAX || data->vdd < MCP3021_VDD_MIN) + return -EINVAL; + + return 0; +} +#else +static int mcp3021_probe_dt(struct i2c_client *client, + const struct i2c_device_id *id) +{ + return 1; +} +#endif + +static int mcp3021_probe_pdata(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct mcp3021_data *data = i2c_get_clientdata(client); + + data->chip_info = &mcp3021_chip_info_tbl[id->driver_data]; + if (dev_get_platdata(&client->dev)) { data->vdd = *(u32 *)dev_get_platdata(&client->dev); if (data->vdd > MCP3021_VDD_MAX || data->vdd < MCP3021_VDD_MIN) return -EINVAL; } else { - data->vdd = MCP3021_VDD_REF; + data->vdd = MCP3021_VDD_DEFAULT; } + return 0; +} + +static int mcp3021_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct mcp3021_data *data = NULL; + int err; + + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) + return -ENODEV; + + data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + i2c_set_clientdata(client, data); + + err = mcp3021_probe_dt(client, id); + if (err > 0) + mcp3021_probe_pdata(client, id); + else if (err < 0) + return err; + err = sysfs_create_file(&client->dev.kobj, &dev_attr_in0_input.attr); if (err) return err; @@ -166,22 +244,6 @@ static int mcp3021_remove(struct i2c_client *client) return 0; } -static const struct i2c_device_id mcp3021_id[] = { - { "mcp3021", mcp3021 }, - { "mcp3221", mcp3221 }, - { } -}; -MODULE_DEVICE_TABLE(i2c, mcp3021_id); - -static struct i2c_driver mcp3021_driver = { - .driver = { - .name = "mcp3021", - }, - .probe = mcp3021_probe, - .remove = mcp3021_remove, - .id_table = mcp3021_id, -}; - module_i2c_driver(mcp3021_driver); MODULE_AUTHOR("Mingkai Hu "); -- 2.10.0