Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932389AbWE3S5C (ORCPT ); Tue, 30 May 2006 14:57:02 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932393AbWE3S5B (ORCPT ); Tue, 30 May 2006 14:57:01 -0400 Received: from mout.perfora.net ([217.160.230.41]:56059 "EHLO mout.perfora.net") by vger.kernel.org with ESMTP id S932389AbWE3S5A (ORCPT ); Tue, 30 May 2006 14:57:00 -0400 Date: Tue, 30 May 2006 14:49:49 -0400 From: Raphael Assenat To: Alessandro Zummo Cc: linux-kernel@vger.kernel.org, akpm@osdl.org Subject: Re: [PATCH] Add max6902 RTC support Message-ID: <20060530184949.GF797@aramis.lan.raphnet.net> References: <20060530150913.GE797@aramis.lan.raphnet.net> <20060530203241.4a4de734@inspiron> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060530203241.4a4de734@inspiron> User-Agent: Mutt/1.5.10i X-Provags-ID: perfora.net abuse@perfora.net login:76030ac055994e103dbcd370532942c0 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8719 Lines: 331 This is the second version of my patch to add support for the MAX6902 SPI RTC chip. Renamed RTC_DEBUG to MAX6902_DEBUG and use #undef instead of a comment, as suggested by Alessandro Zummo. Applies on 2.6.17-rc5. Tested on a pxa2xx cpu. Signed-off-by: Raphael Assenat --- --- linux-2.6.17-rc5/drivers/rtc/Kconfig 2006-05-24 21:50:17.000000000 -0400 +++ linux-2.6.17-rc5-8d/drivers/rtc/Kconfig 2006-05-25 15:59:53.000000000 -0400 @@ -172,4 +172,14 @@ This driver can also be built as a module. If so, the module will be called rtc-test. +config RTC_DRV_MAX6902 + tristate "Maxim 6902" + depends on RTC_CLASS && SPI + help + If you say yes here you will get support for the + Maxim MAX6902 spi RTC chip. + + This driver can also be built as a module. If so, the module + will be called rtc-max6902. + endmenu --- linux-2.6.17-rc5/drivers/rtc/Makefile 2006-05-24 21:50:17.000000000 -0400 +++ linux-2.6.17-rc5-8d/drivers/rtc/Makefile 2006-05-25 15:58:38.000000000 -0400 @@ -20,3 +20,4 @@ obj-$(CONFIG_RTC_DRV_EP93XX) += rtc-ep93xx.o obj-$(CONFIG_RTC_DRV_SA1100) += rtc-sa1100.o obj-$(CONFIG_RTC_DRV_VR41XX) += rtc-vr41xx.o +obj-$(CONFIG_RTC_DRV_MAX6902) += rtc-max6902.o --- linux-2.6.17-rc5/drivers/rtc/rtc-max6902.c 1969-12-31 19:00:00.000000000 -0500 +++ linux-2.6.17-rc5-8d/drivers/rtc/rtc-max6902.c 2006-05-30 14:38:10.000000000 -0400 @@ -0,0 +1,289 @@ +/* drivers/char/max6902.c + * + * Copyright (C) 2006 8D Technologies inc. + * Copyright (C) 2004 Compulab Ltd. + * + * 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. + * + * Driver for MAX6902 spi RTC + * + * Changelog: + * + * 24-May-2006: Raphael Assenat + * - Major rework + * Converted to rtc_device and uses the SPI layer. + * + * ??-???-2005: Someone at Compulab + * - Initial driver creation. + */ + +#include +#include +#include + +#include +#include +#include +#include +#include +#include + +#include + +#define MAX6902_REG_SECONDS 0x01 +#define MAX6902_REG_MINUTES 0x03 +#define MAX6902_REG_HOURS 0x05 +#define MAX6902_REG_DATE 0x07 +#define MAX6902_REG_MONTH 0x09 +#define MAX6902_REG_DAY 0x0B +#define MAX6902_REG_YEAR 0x0D +#define MAX6902_REG_CONTROL 0x0F +#define MAX6902_REG_CENTURY 0x13 + + +#undef MAX6902_DEBUG + +struct max6902 { + struct rtc_device *rtc; + u8 buf[9]; /* Burst read cmd + 8 registers */ + u8 tx_buf[2]; + u8 rx_buf[2]; +}; + +static void max6902_set_reg(struct device *dev, unsigned char address, + unsigned char data) +{ + struct spi_device *spi = to_spi_device(dev); + unsigned char buf[2]; + + /* MSB must be '0' to write */ + buf[0] = address & 0x7f; + buf[1] = data; + + spi_write(spi, buf, 2); +} + +static int max6902_get_reg(struct device *dev, unsigned char address, unsigned char *data) +{ + struct spi_device *spi = to_spi_device(dev); + struct max6902 *chip = dev_get_drvdata(dev); + struct spi_message message; + struct spi_transfer xfer; + int status; + + if (!data) return -EINVAL; + + /* Build our spi message */ + spi_message_init(&message); + memset(&xfer, 0, sizeof(xfer)); + xfer.len = 2; + /* Can tx_buf and rx_buf be equal? The doc in spi.h is not sure... */ + xfer.tx_buf = chip->tx_buf; + xfer.rx_buf = chip->rx_buf; + + /* Set MSB to indicate read */ + chip->tx_buf[0] = address | 0x80; + + spi_message_add_tail(&xfer, &message); + + /* do the i/o */ + status = spi_sync(spi, &message); + if (status == 0) { + status = message.status; + } + else + return status; + + *data = chip->rx_buf[1]; + + return status; +} + +static int max6902_get_datetime(struct device *dev, struct rtc_time *dt) +{ + unsigned char tmp; + int century; + int err; + + struct spi_device *spi = to_spi_device(dev); + struct max6902 *chip = dev_get_drvdata(dev); + struct spi_message message; + struct spi_transfer xfer; + int status; + + err = max6902_get_reg(dev, MAX6902_REG_CENTURY, &tmp); + if (err) + return err; + + /* build the message */ + spi_message_init(&message); + memset(&xfer, 0, sizeof(xfer)); + xfer.len = 1 + 7; /* Burst read command + 7 registers */ + xfer.tx_buf = chip->buf; + xfer.rx_buf = chip->buf; + chip->buf[0] = 0xbf; // Burst read + spi_message_add_tail(&xfer, &message); + + /* do the i/o */ + status = spi_sync(spi, &message); + if (status == 0) { + status = message.status; + } + else + return status; + + /* The chip sends data in this order: + * Seconds, Minutes, Hours, Date, Month, Day, Year */ + dt->tm_sec = BCD2BIN(chip->buf[1]); + dt->tm_min = BCD2BIN(chip->buf[2]); + dt->tm_hour = BCD2BIN(chip->buf[3]); + dt->tm_mday = BCD2BIN(chip->buf[4]); + dt->tm_mon = BCD2BIN(chip->buf[5] - 1); + dt->tm_wday = BCD2BIN(chip->buf[6]); + dt->tm_year = BCD2BIN(chip->buf[7]); + + + century = BCD2BIN(tmp) * 100; + + dt->tm_year += century; + dt->tm_year -= 1900; + +#ifdef MAX6902_DEBUG + printk("\n%s : Read RTC values\n",__FUNCTION__); + printk("tm_hour: %i\n",dt->tm_hour); + printk("tm_min : %i\n",dt->tm_min); + printk("tm_sec : %i\n",dt->tm_sec); + printk("tm_year: %i\n",dt->tm_year); + printk("tm_mon : %i\n",dt->tm_mon); + printk("tm_mday: %i\n",dt->tm_mday); + printk("tm_wday: %i\n",dt->tm_wday); +#endif + + return 0; +} + +static int max6902_set_datetime(struct device *dev, struct rtc_time *dt) +{ + dt->tm_year = dt->tm_year+1900; + +#ifdef MAX6902_DEBUG + printk("\n%s : Setting RTC values\n",__FUNCTION__); + printk("tm_sec : %i\n",dt->tm_sec); + printk("tm_min : %i\n",dt->tm_min); + printk("tm_hour: %i\n",dt->tm_hour); + printk("tm_mday: %i\n",dt->tm_mday); + printk("tm_wday: %i\n",dt->tm_wday); + printk("tm_year: %i\n",dt->tm_year); +#endif + + // Remove write protection + max6902_set_reg(dev, 0xF, 0); + + max6902_set_reg(dev, 0x01, BIN2BCD(dt->tm_sec)); + max6902_set_reg(dev, 0x03, BIN2BCD(dt->tm_min)); + max6902_set_reg(dev, 0x05, BIN2BCD(dt->tm_hour)); + + max6902_set_reg(dev, 0x07, BIN2BCD(dt->tm_mday)); + max6902_set_reg(dev, 0x09, BIN2BCD(dt->tm_mon+1)); + max6902_set_reg(dev, 0x0B, BIN2BCD(dt->tm_wday)); + max6902_set_reg(dev, 0x0D, BIN2BCD(dt->tm_year%100)); + max6902_set_reg(dev, 0x13, BIN2BCD(dt->tm_year/100)); + + /* Compulab used a delay here. However, the datasheet + * does not mention a delay being required anywhere... */ + /* delay(2000); */ + + // Write protect + max6902_set_reg(dev, 0xF, 0x80); + + return 0; +} + +static int max6902_read_time(struct device *dev, struct rtc_time *tm) +{ + return max6902_get_datetime(dev, tm); +} + +static int max6902_set_time(struct device *dev, struct rtc_time *tm) +{ + return max6902_set_datetime(dev, tm); +} + +static struct rtc_class_ops max6902_rtc_ops = { + .read_time = max6902_read_time, + .set_time = max6902_set_time, +}; + +static int __devinit max6902_probe(struct spi_device *spi) +{ + struct rtc_device *rtc; + unsigned char tmp; + struct max6902 *chip; + int res; + + rtc = rtc_device_register("max6902", + &spi->dev, &max6902_rtc_ops, THIS_MODULE); + if (IS_ERR(rtc)) { + return PTR_ERR(rtc); + } + + spi->mode = SPI_MODE_3; + spi->bits_per_word = 8; + spi_setup(spi); + + chip = kzalloc(sizeof *chip, GFP_KERNEL); + if (!chip) { + rtc_device_unregister(rtc); + return -ENOMEM; + } + chip->rtc = rtc; + dev_set_drvdata(&spi->dev, chip); + + res = max6902_get_reg(&spi->dev, MAX6902_REG_SECONDS, &tmp); + if (res) { + rtc_device_unregister(rtc); + return res; + } + + return 0; +} + +static int __devexit max6902_remove(struct spi_device *spi) +{ + struct max6902 *chip = platform_get_drvdata(spi); + struct rtc_device *rtc = chip->rtc; + + if (rtc) + rtc_device_unregister(rtc); + + return 0; +} + +static struct spi_driver max6902_driver = { + .driver = { + .name = "max6902", + .bus = &spi_bus_type, + .owner = THIS_MODULE, + }, + .probe = max6902_probe, + .remove = __devexit_p(max6902_remove), +}; + +static __init int max6902_init(void) +{ + printk("max6902 spi driver\n"); + return spi_register_driver(&max6902_driver); +} +module_init(max6902_init); + +static __exit void max6902_exit(void) +{ + spi_unregister_driver(&max6902_driver); +} +module_exit(max6902_exit); + +MODULE_DESCRIPTION ("max6902 spi RTC driver"); +MODULE_AUTHOR ("Raphael Assenat"); +MODULE_LICENSE ("GPL"); - 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/