diff options
Diffstat (limited to 'drivers/rtc/rtc-v3020.c')
| -rw-r--r-- | drivers/rtc/rtc-v3020.c | 369 |
1 files changed, 369 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-v3020.c b/drivers/rtc/rtc-v3020.c new file mode 100644 index 000000000..d2da92187 --- /dev/null +++ b/drivers/rtc/rtc-v3020.c @@ -0,0 +1,369 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* drivers/rtc/rtc-v3020.c + * + * Copyright (C) 2006 8D Technologies inc. + * Copyright (C) 2004 Compulab Ltd. + * + * 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/platform_data/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 { + /* MMIO access */ + void __iomem *ioaddress; + int leftshift; + + /* GPIO access */ + struct gpio *gpio; + + const 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 const 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 gpio v3020_gpio[] = { + { 0, GPIOF_OUT_INIT_HIGH, "RTC CS"}, + { 0, GPIOF_OUT_INIT_HIGH, "RTC WR"}, + { 0, GPIOF_OUT_INIT_HIGH, "RTC RD"}, + { 0, GPIOF_OUT_INIT_HIGH, "RTC IO"}, +}; + +static int v3020_gpio_map(struct v3020 *chip, struct platform_device *pdev, + struct v3020_platform_data *pdata) +{ + int 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; + + err = gpio_request_array(v3020_gpio, ARRAY_SIZE(v3020_gpio)); + + if (!err) + chip->gpio = v3020_gpio; + + return err; +} + +static void v3020_gpio_unmap(struct v3020 *chip) +{ + gpio_free_array(v3020_gpio, ARRAY_SIZE(v3020_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 const 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 = dev_get_platdata(&pdev->dev); + struct v3020 *chip; + int retval = -EBUSY; + int i; + + chip = devm_kzalloc(&pdev->dev, 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) + return retval; + + /* Make sure the v3020 expects a communication cycle + * by reading 8 times */ + for (i = 0; i < 8; i++) + 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 = devm_rtc_device_register(&pdev->dev, "v3020", + &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); + + return retval; +} + +static int rtc_remove(struct platform_device *dev) +{ + struct v3020 *chip = platform_get_drvdata(dev); + + chip->ops->unmap_io(chip); + + return 0; +} + +static struct platform_driver rtc_device_driver = { + .probe = rtc_probe, + .remove = rtc_remove, + .driver = { + .name = "v3020", + }, +}; + +module_platform_driver(rtc_device_driver); + +MODULE_DESCRIPTION("V3020 RTC"); +MODULE_AUTHOR("Raphael Assenat"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:v3020"); |