/* 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 <linux/delay.h> #include <linux/gpio.h> #include <linux/slab.h> #include <linux/io.h> #undef DEBUG struct v3020; struct v3020_chip_ops { int (*map_io)(struct v3020 *chip, struct platform_device *pdev, struct v3020_platform_data *pdata); void (*unmap_io)(struct v3020 *chip); unsigned char (*read_bit)(struct v3020 *chip); void (*write_bit)(struct v3020 *chip, unsigned char bit); }; #define V3020_CS 0 #define V3020_WR 1 #define V3020_RD 2 #define V3020_IO 3 struct v3020_gpio { const char *name; unsigned int gpio; }; struct v3020 { /* MMIO access */ void __iomem *ioaddress; int leftshift; /* GPIO access */ struct v3020_gpio *gpio; struct v3020_chip_ops *ops; struct rtc_device *rtc; }; static int v3020_mmio_map(struct v3020 *chip, struct platform_device *pdev, struct v3020_platform_data *pdata) { if (pdev->num_resources != 1) return -EBUSY; if (pdev->resource[0].flags != IORESOURCE_MEM) return -EBUSY; chip->leftshift = pdata->leftshift; chip->ioaddress = ioremap(pdev->resource[0].start, 1); if (chip->ioaddress == NULL) return -EBUSY; return 0; } static void v3020_mmio_unmap(struct v3020 *chip) { iounmap(chip->ioaddress); } static void v3020_mmio_write_bit(struct v3020 *chip, unsigned char bit) { writel(bit << chip->leftshift, chip->ioaddress); } static unsigned char v3020_mmio_read_bit(struct v3020 *chip) { return !!(readl(chip->ioaddress) & (1 << chip->leftshift)); } static struct v3020_chip_ops v3020_mmio_ops = { .map_io = v3020_mmio_map, .unmap_io = v3020_mmio_unmap, .read_bit = v3020_mmio_read_bit, .write_bit = v3020_mmio_write_bit, }; static struct v3020_gpio v3020_gpio[] = { { "RTC CS", 0 }, { "RTC WR", 0 }, { "RTC RD", 0 }, { "RTC IO", 0 }, }; static int v3020_gpio_map(struct v3020 *chip, struct platform_device *pdev, struct v3020_platform_data *pdata) { int i, err; v3020_gpio[V3020_CS].gpio = pdata->gpio_cs; v3020_gpio[V3020_WR].gpio = pdata->gpio_wr; v3020_gpio[V3020_RD].gpio = pdata->gpio_rd; v3020_gpio[V3020_IO].gpio = pdata->gpio_io; for (i = 0; i < ARRAY_SIZE(v3020_gpio); i++) { err = gpio_request(v3020_gpio[i].gpio, v3020_gpio[i].name); if (err) goto err_request; gpio_direction_output(v3020_gpio[i].gpio, 1); } chip->gpio = v3020_gpio; return 0; err_request: while (--i >= 0) gpio_free(v3020_gpio[i].gpio); return err; } static void v3020_gpio_unmap(struct v3020 *chip) { int i; for (i = 0; i < ARRAY_SIZE(v3020_gpio); i++) gpio_free(v3020_gpio[i].gpio); } static void v3020_gpio_write_bit(struct v3020 *chip, unsigned char bit) { gpio_direction_output(chip->gpio[V3020_IO].gpio, bit); gpio_set_value(chip->gpio[V3020_CS].gpio, 0); gpio_set_value(chip->gpio[V3020_WR].gpio, 0); udelay(1); gpio_set_value(chip->gpio[V3020_WR].gpio, 1); gpio_set_value(chip->gpio[V3020_CS].gpio, 1); } static unsigned char v3020_gpio_read_bit(struct v3020 *chip) { int bit; gpio_direction_input(chip->gpio[V3020_IO].gpio); gpio_set_value(chip->gpio[V3020_CS].gpio, 0); gpio_set_value(chip->gpio[V3020_RD].gpio, 0); udelay(1); bit = !!gpio_get_value(chip->gpio[V3020_IO].gpio); udelay(1); gpio_set_value(chip->gpio[V3020_RD].gpio, 1); gpio_set_value(chip->gpio[V3020_CS].gpio, 1); return bit; } static struct v3020_chip_ops v3020_gpio_ops = { .map_io = v3020_gpio_map, .unmap_io = v3020_gpio_unmap, .read_bit = v3020_gpio_read_bit, .write_bit = v3020_gpio_write_bit, }; 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++) { chip->ops->write_bit(chip, (tmp & 1)); tmp >>= 1; udelay(1); } /* Commands dont have data */ if (!V3020_IS_COMMAND(address)) { for (i = 0; i < 8; i++) { chip->ops->write_bit(chip, (data & 1)); data >>= 1; udelay(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++) { chip->ops->write_bit(chip, (address & 1)); address >>= 1; udelay(1); } for (i = 0; i < 8; i++) { data >>= 1; if (chip->ops->read_bit(chip)) data |= 0x80; udelay(1); } 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) - 1; 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; dev_dbg(dev, "\n%s : Read RTC values\n", __func__); dev_dbg(dev, "tm_hour: %i\n", dt->tm_hour); dev_dbg(dev, "tm_min : %i\n", dt->tm_min); dev_dbg(dev, "tm_sec : %i\n", dt->tm_sec); dev_dbg(dev, "tm_year: %i\n", dt->tm_year); dev_dbg(dev, "tm_mon : %i\n", dt->tm_mon); dev_dbg(dev, "tm_mday: %i\n", dt->tm_mday); dev_dbg(dev, "tm_wday: %i\n", dt->tm_wday); return 0; } static int v3020_set_time(struct device *dev, struct rtc_time *dt) { struct v3020 *chip = dev_get_drvdata(dev); dev_dbg(dev, "\n%s : Setting RTC values\n", __func__); dev_dbg(dev, "tm_sec : %i\n", dt->tm_sec); dev_dbg(dev, "tm_min : %i\n", dt->tm_min); dev_dbg(dev, "tm_hour: %i\n", dt->tm_hour); dev_dbg(dev, "tm_mday: %i\n", dt->tm_mday); dev_dbg(dev, "tm_wday: %i\n", dt->tm_wday); dev_dbg(dev, "tm_year: %i\n", dt->tm_year); /* 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 + 1)); 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 const 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; int retval = -EBUSY; int i; int temp; chip = kzalloc(sizeof *chip, GFP_KERNEL); if (!chip) return -ENOMEM; if (pdata->use_gpio) chip->ops = &v3020_gpio_ops; else chip->ops = &v3020_mmio_ops; retval = chip->ops->map_io(chip, pdev, pdata); if (retval) goto err_chip; /* Make sure the v3020 expects a communication cycle * by reading 8 times */ for (i = 0; i < 8; i++) temp = chip->ops->read_bit(chip); /* 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 measurement mode, test modes, and lock * are all disabled */ v3020_set_reg(chip, V3020_STATUS_0, 0x0); if (pdata->use_gpio) dev_info(&pdev->dev, "Chip available at GPIOs " "%d, %d, %d, %d\n", chip->gpio[V3020_CS].gpio, chip->gpio[V3020_WR].gpio, chip->gpio[V3020_RD].gpio, chip->gpio[V3020_IO].gpio); else dev_info(&pdev->dev, "Chip available at " "physical address 0x%llx," "data connected to D%d\n", (unsigned long long)pdev->resource[0].start, chip->leftshift); platform_set_drvdata(pdev, chip); chip->rtc = rtc_device_register("v3020", &pdev->dev, &v3020_rtc_ops, THIS_MODULE); if (IS_ERR(chip->rtc)) { retval = PTR_ERR(chip->rtc); goto err_io; } return 0; err_io: chip->ops->unmap_io(chip); 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); chip->ops->unmap_io(chip); kfree(chip); return 0; } static struct platform_driver rtc_device_driver = { .probe = rtc_probe, .remove = rtc_remove, .driver = { .name = "v3020", .owner = THIS_MODULE, }, }; module_platform_driver(rtc_device_driver); MODULE_DESCRIPTION("V3020 RTC"); MODULE_AUTHOR("Raphael Assenat"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:v3020");