diff options
Diffstat (limited to 'drivers/rtc/rtc-v3020.c')
| -rw-r--r-- | drivers/rtc/rtc-v3020.c | 264 |
1 files changed, 264 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-v3020.c b/drivers/rtc/rtc-v3020.c new file mode 100644 index 00000000000..a40f400acff --- /dev/null +++ b/drivers/rtc/rtc-v3020.c @@ -0,0 +1,264 @@ +/* drivers/rtc/rtc-v3020.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 the V3020 RTC + * + * Changelog: + * + * 10-May-2006: Raphael Assenat <raph@8d.com> + * - Converted to platform driver + * - Use the generic rtc class + * + * ??-???-2004: Someone at Compulab + * - Initial driver creation. + * + */ +#include <linux/platform_device.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/rtc.h> +#include <linux/types.h> +#include <linux/bcd.h> +#include <linux/rtc-v3020.h> + +#include <asm/io.h> + +#undef DEBUG + +struct v3020 { + void __iomem *ioaddress; + int leftshift; + struct rtc_device *rtc; +}; + +static void v3020_set_reg(struct v3020 *chip, unsigned char address, + unsigned char data) +{ + int i; + unsigned char tmp; + + tmp = address; + for (i = 0; i < 4; i++) { + writel((tmp & 1) << chip->leftshift, chip->ioaddress); + tmp >>= 1; + } + + /* Commands dont have data */ + if (!V3020_IS_COMMAND(address)) { + for (i = 0; i < 8; i++) { + writel((data & 1) << chip->leftshift, chip->ioaddress); + data >>= 1; + } + } +} + +static unsigned char v3020_get_reg(struct v3020 *chip, unsigned char address) +{ + unsigned int data=0; + int i; + + for (i = 0; i < 4; i++) { + writel((address & 1) << chip->leftshift, chip->ioaddress); + address >>= 1; + } + + for (i = 0; i < 8; i++) { + data >>= 1; + if (readl(chip->ioaddress) & (1 << chip->leftshift)) + data |= 0x80; + } + + return data; +} + +static int v3020_read_time(struct device *dev, struct rtc_time *dt) +{ + struct v3020 *chip = dev_get_drvdata(dev); + int tmp; + + /* Copy the current time to ram... */ + v3020_set_reg(chip, V3020_CMD_CLOCK2RAM, 0); + + /* ...and then read constant values. */ + tmp = v3020_get_reg(chip, V3020_SECONDS); + dt->tm_sec = BCD2BIN(tmp); + tmp = v3020_get_reg(chip, V3020_MINUTES); + dt->tm_min = BCD2BIN(tmp); + tmp = v3020_get_reg(chip, V3020_HOURS); + dt->tm_hour = BCD2BIN(tmp); + tmp = v3020_get_reg(chip, V3020_MONTH_DAY); + dt->tm_mday = BCD2BIN(tmp); + tmp = v3020_get_reg(chip, V3020_MONTH); + dt->tm_mon = BCD2BIN(tmp); + tmp = v3020_get_reg(chip, V3020_WEEK_DAY); + dt->tm_wday = BCD2BIN(tmp); + tmp = v3020_get_reg(chip, V3020_YEAR); + dt->tm_year = BCD2BIN(tmp)+100; + +#ifdef 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 v3020_set_time(struct device *dev, struct rtc_time *dt) +{ + struct v3020 *chip = dev_get_drvdata(dev); + +#ifdef 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 + + /* Write all the values to ram... */ + v3020_set_reg(chip, V3020_SECONDS, BIN2BCD(dt->tm_sec)); + v3020_set_reg(chip, V3020_MINUTES, BIN2BCD(dt->tm_min)); + v3020_set_reg(chip, V3020_HOURS, BIN2BCD(dt->tm_hour)); + v3020_set_reg(chip, V3020_MONTH_DAY, BIN2BCD(dt->tm_mday)); + v3020_set_reg(chip, V3020_MONTH, BIN2BCD(dt->tm_mon)); + v3020_set_reg(chip, V3020_WEEK_DAY, BIN2BCD(dt->tm_wday)); + v3020_set_reg(chip, V3020_YEAR, BIN2BCD(dt->tm_year % 100)); + + /* ...and set the clock. */ + v3020_set_reg(chip, V3020_CMD_RAM2CLOCK, 0); + + /* Compulab used this delay here. I dont know why, + * the datasheet does not specify a delay. */ + /*mdelay(5);*/ + + return 0; +} + +static struct rtc_class_ops v3020_rtc_ops = { + .read_time = v3020_read_time, + .set_time = v3020_set_time, +}; + +static int rtc_probe(struct platform_device *pdev) +{ + struct v3020_platform_data *pdata = pdev->dev.platform_data; + struct v3020 *chip; + struct rtc_device *rtc; + int retval = -EBUSY; + int i; + int temp; + + if (pdev->num_resources != 1) + return -EBUSY; + + if (pdev->resource[0].flags != IORESOURCE_MEM) + return -EBUSY; + + if (pdev == NULL) + return -EBUSY; + + chip = kzalloc(sizeof *chip, GFP_KERNEL); + if (!chip) + return -ENOMEM; + + chip->leftshift = pdata->leftshift; + chip->ioaddress = ioremap(pdev->resource[0].start, 1); + if (chip->ioaddress == NULL) + goto err_chip; + + /* Make sure the v3020 expects a communication cycle + * by reading 8 times */ + for (i = 0; i < 8; i++) + temp = readl(chip->ioaddress); + + /* Test chip by doing a write/read sequence + * to the chip ram */ + v3020_set_reg(chip, V3020_SECONDS, 0x33); + if(v3020_get_reg(chip, V3020_SECONDS) != 0x33) { + retval = -ENODEV; + goto err_io; + } + + /* Make sure frequency measurment mode, test modes, and lock + * are all disabled */ + v3020_set_reg(chip, V3020_STATUS_0, 0x0); + + dev_info(&pdev->dev, "Chip available at physical address 0x%p," + "data connected to D%d\n", + (void*)pdev->resource[0].start, + chip->leftshift); + + platform_set_drvdata(pdev, chip); + + rtc = rtc_device_register("v3020", + &pdev->dev, &v3020_rtc_ops, THIS_MODULE); + if (IS_ERR(rtc)) { + retval = PTR_ERR(rtc); + goto err_io; + } + chip->rtc = rtc; + + return 0; + +err_io: + iounmap(chip->ioaddress); +err_chip: + kfree(chip); + + return retval; +} + +static int rtc_remove(struct platform_device *dev) +{ + struct v3020 *chip = platform_get_drvdata(dev); + struct rtc_device *rtc = chip->rtc; + + if (rtc) + rtc_device_unregister(rtc); + + iounmap(chip->ioaddress); + kfree(chip); + + return 0; +} + +static struct platform_driver rtc_device_driver = { + .probe = rtc_probe, + .remove = rtc_remove, + .driver = { + .name = "v3020", + .owner = THIS_MODULE, + }, +}; + +static __init int v3020_init(void) +{ + return platform_driver_register(&rtc_device_driver); +} + +static __exit void v3020_exit(void) +{ + platform_driver_unregister(&rtc_device_driver); +} + +module_init(v3020_init); +module_exit(v3020_exit); + +MODULE_DESCRIPTION("V3020 RTC"); +MODULE_AUTHOR("Raphael Assenat"); +MODULE_LICENSE("GPL"); |