Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757917AbXFSL26 (ORCPT ); Tue, 19 Jun 2007 07:28:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756448AbXFSL2t (ORCPT ); Tue, 19 Jun 2007 07:28:49 -0400 Received: from nz-out-0506.google.com ([64.233.162.239]:26889 "EHLO nz-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756327AbXFSL2s (ORCPT ); Tue, 19 Jun 2007 07:28:48 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=uiXrDCbvKIl/o7MSTHl/Hk4cYoPicrsU7u5OqDQ5HDW3h7G74FbvJQdtowrRX4pTIsJyZjRpDIt7u7SZ+rsU/3VNjUEGhcbPBG9hXLjD2pe4mg+cuZudsXrf6w/BJRfyq1eAVtR9JhWed/agSDeDw7sK0SJj72GFUSkTnOMfBNA= Message-ID: <5d5443650706190428q341a50a1obae68b2565d0ed7@mail.gmail.com> Date: Tue, 19 Jun 2007 16:58:46 +0530 From: "Trilok Soni" To: "Rodolfo Giometti" Subject: Re: [PATCH] I2C: TSL2550 support. Cc: i2c@lm-sensors.org, linux-kernel@vger.kernel.org, "Andrew Morton" In-Reply-To: <20070619105551.GA3199@enneenne.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20070619105551.GA3199@enneenne.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 17350 Lines: 514 Hi Rodolfo, On 6/19/07, Rodolfo Giometti wrote: > Add support for Taos TSL2550 ambient light sensors. > (http://www.taosinc.com/product_detail.asp?cateid=4&proid=18). > > Signed-off-by: Rodolfo Giometti > --- > drivers/i2c/chips/Kconfig | 10 + > drivers/i2c/chips/Makefile | 1 + > drivers/i2c/chips/tsl2550.c | 427 +++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 438 insertions(+), 0 deletions(-) > create mode 100644 drivers/i2c/chips/tsl2550.c > > diff --git a/drivers/i2c/chips/Kconfig b/drivers/i2c/chips/Kconfig > index ea085a0..b59c013 100644 > --- a/drivers/i2c/chips/Kconfig > +++ b/drivers/i2c/chips/Kconfig > @@ -124,4 +124,14 @@ config SENSORS_MAX6875 > This driver can also be built as a module. If so, the module > will be called max6875. > > +config SENSORS_TSL2550 > + tristate "Taos TSL2550 ambient light sensor" > + depends on I2C && EXPERIMENTAL > + help > + If you say yes here you get support for the Taos TSL2550 > + ambient light sensor. > + > + This driver can also be built as a module. If so, the module > + will be called tsl2550. > + > endmenu > diff --git a/drivers/i2c/chips/Makefile b/drivers/i2c/chips/Makefile > index 779868e..1ef6a04 100644 > --- a/drivers/i2c/chips/Makefile > +++ b/drivers/i2c/chips/Makefile > @@ -12,6 +12,7 @@ obj-$(CONFIG_SENSORS_PCF8574) += pcf8574.o > obj-$(CONFIG_SENSORS_PCF8591) += pcf8591.o > obj-$(CONFIG_ISP1301_OMAP) += isp1301_omap.o > obj-$(CONFIG_TPS65010) += tps65010.o > +obj-$(CONFIG_SENSORS_TSL2550) += tsl2550.o > > ifeq ($(CONFIG_I2C_DEBUG_CHIP),y) > EXTRA_CFLAGS += -DDEBUG > diff --git a/drivers/i2c/chips/tsl2550.c b/drivers/i2c/chips/tsl2550.c > new file mode 100644 > index 0000000..fd7f87c > --- /dev/null > +++ b/drivers/i2c/chips/tsl2550.c > @@ -0,0 +1,427 @@ > +/* > + * tsl2550.c - Linux kernel modules for ambient light sensor > + * > + * Copyright (C) 2007 Rodolfo Giometti > + * Copyright (C) 2007 Eurotech S.p.A. > + * > + * 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 > + * the Free Software Foundation; either version 2 of the License, or > + * (at your option) any later version. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + * > + * You should have received a copy of the GNU General Public License > + * along with this program; if not, write to the Free Software > + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > + > +#define TSL2550_DRV_NAME "tsl2550" > +#define DRIVER_VERSION "1.1.0" > + > +/* --- Defines ------------------------------------------------------------- */ > + > +#define TSL2550_POWER_DOWN 0x00 > +#define TSL2550_POWER_UP 0x03 > +#define TSL2550_STANDARD_RANGE 0x18 > +#define TSL2550_EXTENDED_RANGE 0x1d > +#define TSL2550_READ_ADC0 0x43 > +#define TSL2550_READ_ADC1 0x83 > + > +/* --- Structs ------------------------------------------------------------- */ > + > +struct tsl2550_data { > + struct i2c_client *client; > + struct mutex update_lock; > + > + unsigned int power_state : 1; > + unsigned int operating_mode : 1; > +}; > + > +/* --- Management functions ------------------------------------------------ */ > + > +static int tsl2550_set_operating_mode(struct i2c_client *client, int mode) > +{ > + struct tsl2550_data *data = i2c_get_clientdata(client); > + int ret; > + > + mode = !!mode; > + if (mode == data->operating_mode) > + return 0; > + > + if (mode == 0) > + ret = i2c_smbus_write_byte(client, TSL2550_STANDARD_RANGE); > + else > + ret = i2c_smbus_write_byte(client, TSL2550_EXTENDED_RANGE); > + > + data->operating_mode = mode; > + > + return ret; > +} > + > +static int tsl2550_set_power_state(struct i2c_client *client, int state) > +{ > + struct tsl2550_data *data = i2c_get_clientdata(client); > + int ret; > + > + state = !!state; > + if (state == data->power_state) > + return 0; > + > + if (state == 0) > + ret = i2c_smbus_write_byte(client, TSL2550_POWER_DOWN); > + else { > + ret = i2c_smbus_write_byte(client, TSL2550_POWER_UP); > + > + /* On power up we should reset operating mode also... */ > + tsl2550_set_operating_mode(client, data->operating_mode); > + } > + > + data->power_state = state; > + > + return ret; > +} > + > +static int tsl2550_get_adc_value(struct i2c_client *client, int channel) > +{ > + u8 cmd = channel == 0 ? TSL2550_READ_ADC0 : TSL2550_READ_ADC1; > + unsigned long end; > + int loop = 0, ret = 0; > + > + /* Read ADC channel waiting at most 400ms (see data sheet for further > + * info). > + * To avoid long busy wait we spin for few milliseconds then > + * start sleeping. */ multi-line comment block format is not correct. It should be > + /* > + * Read ADC channel waiting at most 400ms (see data sheet for further > + * info). > + * To avoid long busy wait we spin for few milliseconds then > + * start sleeping. > + */ please change it to other places in driver also. > + end = jiffies + msecs_to_jiffies(400); > + while (time_before(jiffies, end)) { > + i2c_smbus_write_byte(client, cmd); > + > + if (loop++ < 5) > + mdelay(1); > + else > + msleep(1); > + > + ret = i2c_smbus_read_byte(client); > + if (ret < 0) > + return ret; > + else if (ret & 0x0080) > + break; > + } > + if (!(ret & 0x0080)) > + return -EIO; > + return ((u8) ret) & 0x7f; /* remove the "valid" bit */ > +} > + > +/* --- LUX calculation ----------------------------------------------------- */ > + > +#define TSL2550_MAX_LUX 1846 > + > +static const u8 ratio_lut[] = { > + 100, 100, 100, 100, 100, 100, 100, 100, > + 100, 100, 100, 100, 100, 100, 99, 99, > + 99, 99, 99, 99, 99, 99, 99, 99, > + 99, 99, 99, 98, 98, 98, 98, 98, > + 98, 98, 97, 97, 97, 97, 97, 96, > + 96, 96, 96, 95, 95, 95, 94, 94, > + 93, 93, 93, 92, 92, 91, 91, 90, > + 89, 89, 88, 87, 87, 86, 85, 84, > + 83, 82, 81, 80, 79, 78, 77, 75, > + 74, 73, 71, 69, 68, 66, 64, 62, > + 60, 58, 56, 54, 52, 49, 47, 44, > + 42, 41, 40, 40, 39, 39, 38, 38, > + 37, 37, 37, 36, 36, 36, 35, 35, > + 35, 35, 34, 34, 34, 34, 33, 33, > + 33, 33, 32, 32, 32, 32, 32, 31, > + 31, 31, 31, 31, 30, 30, 30, 30, > + 30, > +}; > + > +static const u16 count_lut[] = { > + 0, 1, 2, 3, 4, 5, 6, 7, > + 8, 9, 10, 11, 12, 13, 14, 15, > + 16, 18, 20, 22, 24, 26, 28, 30, > + 32, 34, 36, 38, 40, 42, 44, 46, > + 49, 53, 57, 61, 65, 69, 73, 77, > + 81, 85, 89, 93, 97, 101, 105, 109, > + 115, 123, 131, 139, 147, 155, 163, 171, > + 179, 187, 195, 203, 211, 219, 227, 235, > + 247, 263, 279, 295, 311, 327, 343, 359, > + 375, 391, 407, 423, 439, 455, 471, 487, > + 511, 543, 575, 607, 639, 671, 703, 735, > + 767, 799, 831, 863, 895, 927, 959, 991, > + 1039, 1103, 1167, 1231, 1295, 1359, 1423, 1487, > + 1551, 1615, 1679, 1743, 1807, 1871, 1935, 1999, > + 2095, 2223, 2351, 2479, 2607, 2735, 2863, 2991, > + 3119, 3247, 3375, 3503, 3631, 3759, 3887, 4015 > +}; > + > +/* This function is described into Taos TSL2550 Designer's Notebook > + * pages 2, 3 */ > +static int tsl2550_calculate_lux(u8 ch0, u8 ch1) > +{ > + unsigned int lux; > + > + /* Look up count from channel values */ > + u16 c0 = count_lut[ch0]; > + u16 c1 = count_lut[ch1]; > + > + /* Calculate ratio. > + * Note: the "128" is a scaling factor */ > + u8 r = 128; > + > + /* Avoid division by 0 and count 1 cannot be greater than count 0 */ > + if (c0 && (c1 <= c0)) > + r = c1 * 128 / c0; > + else > + return -1; > + > + /* Calculare LUX */ > + lux = ((c0 - c1) * ratio_lut[r]) / 256; > + > + /* LUX range check */ > + return lux > TSL2550_MAX_LUX ? TSL2550_MAX_LUX : lux; > +} > + > +/* --- SysFS support ------------------------------------------------------- */ > + > +static ssize_t tsl2550_show_power_state(struct device *dev, struct device_attribute *attr, char *buf) > +{ > + struct tsl2550_data *data = i2c_get_clientdata(to_i2c_client(dev)); > + > + return sprintf(buf, "%u\n", data->power_state); > +} > + > +static ssize_t tsl2550_store_power_state(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) > +{ > + struct i2c_client *client = to_i2c_client(dev); > + struct tsl2550_data *data = i2c_get_clientdata(client); > + unsigned long val = simple_strtoul(buf, NULL, 10); > + int ret; > + > + mutex_lock(&data->update_lock); > + ret = tsl2550_set_power_state(client, val); > + mutex_unlock(&data->update_lock); > + > + if (ret < 0) > + return ret; > + > + return count; > +} > + > +static DEVICE_ATTR(power_state, S_IWUSR | S_IRUGO, > + tsl2550_show_power_state, tsl2550_store_power_state); > + > +static ssize_t tsl2550_show_operating_mode(struct device *dev, struct device_attribute *attr, char *buf) > +{ > + struct tsl2550_data *data = i2c_get_clientdata(to_i2c_client(dev)); > + > + return sprintf(buf, "%u\n", data->operating_mode); > +} > + > +static ssize_t tsl2550_store_operating_mode(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) > +{ > + struct i2c_client *client = to_i2c_client(dev); > + struct tsl2550_data *data = i2c_get_clientdata(client); > + unsigned long val = simple_strtoul(buf, NULL, 10); > + int ret; > + > + mutex_lock(&data->update_lock); > + ret = tsl2550_set_operating_mode(client, val); > + mutex_unlock(&data->update_lock); > + > + if (ret < 0) > + return ret; > + > + return count; > +} > + > +static DEVICE_ATTR(operating_mode, S_IWUSR | S_IRUGO, > + tsl2550_show_operating_mode, tsl2550_store_operating_mode); > + > +static ssize_t __tsl2550_show_lux(struct i2c_client *client, struct device_attribute *attr, char *buf) > +{ > + u8 ch0, ch1; > + int ret; > + > + ret = tsl2550_get_adc_value(client, 0); > + if (ret < 0) > + return ret; > + ch0 = (u8) ret; > + > + mdelay(1); > + > + ret = tsl2550_get_adc_value(client, 1); > + if (ret < 0) > + return ret; > + ch1 = (u8) ret; > + > + /* Do the job */ > + ret = tsl2550_calculate_lux(ch0, ch1); > + if (ret < 0) > + return ret; > + > + return sprintf(buf, "%u\n", ret); > +} > + > +static ssize_t tsl2550_show_lux(struct device *dev, struct device_attribute *attr, char *buf) > +{ > + struct i2c_client *client = to_i2c_client(dev); > + struct tsl2550_data *data = i2c_get_clientdata(client); > + int ret; > + > + /* No LUX data if not operational */ > + if (!data->power_state) > + return -EBUSY; > + > + mutex_lock(&data->update_lock); > + ret = __tsl2550_show_lux(client, attr, buf); > + mutex_unlock(&data->update_lock); > + > + return ret; > +} > + > +static DEVICE_ATTR(lux, S_IRUGO, > + tsl2550_show_lux, NULL); > + > +static struct attribute *tsl2550_attributes[] = { > + &dev_attr_power_state.attr, > + &dev_attr_operating_mode.attr, > + &dev_attr_lux.attr, > + NULL > +}; > + > +static const struct attribute_group tsl2550_attr_group = { > + .attrs = tsl2550_attributes, > +}; > + > +/* --- Initialization function --------------------------------------------- */ > + > +static void tsl2550_init_client(struct i2c_client *client) > +{ > + struct tsl2550_data *data = i2c_get_clientdata(client); > + > + /* Power up the device and set the default operating mode */ > + tsl2550_set_power_state(client, 1); > + tsl2550_set_operating_mode(client, data->operating_mode); > +} > + > +/* --- I2C init/probing/exit functions ------------------------------------- */ > + > +static struct i2c_driver tsl2550_driver; > +static int __devinit tsl2550_probe(struct i2c_client *client) > +{ > + struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent); > + struct tsl2550_data *data; > + int *opmode, err = 0; > + > + if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE > + | I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) > + goto exit; On "exit" you are returning value of "err" which is zero as per first exit above. You should first set "err" to relevant error flag and then exit. > + > + data = kzalloc(sizeof(struct tsl2550_data), GFP_KERNEL); > + if (!data) { > + err = -ENOMEM; > + goto exit; > + } > + data->client = client; > + strncpy(client->name, TSL2550_DRV_NAME, I2C_NAME_SIZE); You can use "type" field in i2c_board_info structure to pass the client's name. As this name is being copied to client->name by i2c_new_device, and it could be useful in future to different next version of the very much similar chips using this field. > + i2c_set_clientdata(client, data); > + > + /* Check platform data */ > + opmode = client->dev.platform_data; > + if (opmode) { > + if (*opmode < 0 || *opmode > 1) { > + dev_err(&client->dev, "invalid operating_mode (%d)\n", > + *opmode); > + err = -EINVAL; > + goto exit_kfree; > + } > + data->operating_mode = *opmode; > + } > + else "else" should be with closing "}" bracket not after that. > + data->operating_mode = 0; /* default mode is standard */ > + dev_info(&client->dev, "%s operating mode\n", > + data->operating_mode ? "extended" : "standard"); > + > + /* Probe the chip. To do so we try to power up the device and then to > + * read back the 0x03 code */ > + err = i2c_smbus_write_byte(client, TSL2550_POWER_UP); > + if (err < 0) > + goto exit_kfree; > + mdelay(1); > + err = i2c_smbus_read_byte(client); > + if (err != TSL2550_POWER_UP) { > + err = -ENODEV; > + goto exit_kfree; > + } > + > + mutex_init(&data->update_lock); > + > + /* Initialize the TSL2550 chip */ > + tsl2550_init_client(client); > + > + /* Register sysfs hooks */ > + err = sysfs_create_group(&client->dev.kobj, &tsl2550_attr_group); > + if (err) > + goto exit_kfree; > + > + dev_info(&client->dev, > + "TSL2550 I2C support enabled - ver. %s\n", DRIVER_VERSION); > + dev_info(&client->dev, > + "Copyright (C) 2007 Rodolfo Giometti \n"); > + > + return 0; > + > +exit_kfree: > + kfree(data); > +exit: > + return err; > +} > + > +static int __devexit tsl2550_remove(struct i2c_client *client) > +{ > + sysfs_remove_group(&client->dev.kobj, &tsl2550_attr_group); > + > + /* Power doen the device */ > + tsl2550_set_power_state(client, 0); > + > + kfree(i2c_get_clientdata(client)); > + > + return 0; > +} > + > +static struct i2c_driver tsl2550_driver = { > + .driver = { > + .name = TSL2550_DRV_NAME, > + .owner = THIS_MODULE, > + }, > + .probe = tsl2550_probe, > + .remove = __devexit_p(tsl2550_remove), > +}; > + > +static int __init tsl2550_init(void) > +{ > + return i2c_add_driver(&tsl2550_driver); > +} > + > +static void __exit tsl2550_exit(void) > +{ > + i2c_del_driver(&tsl2550_driver); > +} > + > +MODULE_AUTHOR("Rodolfo Giometti "); > +MODULE_DESCRIPTION("TSL2550 ambient light sensor driver"); > +MODULE_LICENSE("GPL"); > + > +module_init(tsl2550_init); > +module_exit(tsl2550_exit); -- --Trilok Soni - 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/