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path: root/drivers/rtc/rtc-v3020.c
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Diffstat (limited to 'drivers/rtc/rtc-v3020.c')
-rw-r--r--drivers/rtc/rtc-v3020.c393
1 files changed, 393 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-v3020.c b/drivers/rtc/rtc-v3020.c
new file mode 100644
index 000000000..bfbfa7ed7
--- /dev/null
+++ b/drivers/rtc/rtc-v3020.c
@@ -0,0 +1,393 @@
+/* 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 = dev_get_platdata(&pdev->dev);
+ struct v3020 *chip;
+ int retval = -EBUSY;
+ int i;
+ int temp;
+
+ 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++)
+ 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 = 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");