diff options
Diffstat (limited to 'drivers/rtc/rtc-v3020.c')
| -rw-r--r-- | drivers/rtc/rtc-v3020.c | 190 |
1 files changed, 170 insertions, 20 deletions
diff --git a/drivers/rtc/rtc-v3020.c b/drivers/rtc/rtc-v3020.c index 66955cc9c74..ad164056feb 100644 --- a/drivers/rtc/rtc-v3020.c +++ b/drivers/rtc/rtc-v3020.c @@ -27,17 +27,162 @@ #include <linux/bcd.h> #include <linux/rtc-v3020.h> #include <linux/delay.h> +#include <linux/gpio.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) { @@ -46,7 +191,7 @@ static void v3020_set_reg(struct v3020 *chip, unsigned char address, tmp = address; for (i = 0; i < 4; i++) { - writel((tmp & 1) << chip->leftshift, chip->ioaddress); + chip->ops->write_bit(chip, (tmp & 1)); tmp >>= 1; udelay(1); } @@ -54,7 +199,7 @@ static void v3020_set_reg(struct v3020 *chip, unsigned char address, /* Commands dont have data */ if (!V3020_IS_COMMAND(address)) { for (i = 0; i < 8; i++) { - writel((data & 1) << chip->leftshift, chip->ioaddress); + chip->ops->write_bit(chip, (data & 1)); data >>= 1; udelay(1); } @@ -67,14 +212,14 @@ static unsigned char v3020_get_reg(struct v3020 *chip, unsigned char address) int i; for (i = 0; i < 4; i++) { - writel((address & 1) << chip->leftshift, chip->ioaddress); + chip->ops->write_bit(chip, (address & 1)); address >>= 1; udelay(1); } for (i = 0; i < 8; i++) { data >>= 1; - if (readl(chip->ioaddress) & (1 << chip->leftshift)) + if (chip->ops->read_bit(chip)) data |= 0x80; udelay(1); } @@ -164,25 +309,23 @@ static int rtc_probe(struct platform_device *pdev) int i; int temp; - if (pdev->num_resources != 1) - return -EBUSY; - - if (pdev->resource[0].flags != IORESOURCE_MEM) - 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) + 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 = readl(chip->ioaddress); + temp = chip->ops->read_bit(chip); /* Test chip by doing a write/read sequence * to the chip ram */ @@ -196,10 +339,17 @@ static int rtc_probe(struct platform_device *pdev) * are all disabled */ v3020_set_reg(chip, V3020_STATUS_0, 0x0); - 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); + 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); @@ -214,7 +364,7 @@ static int rtc_probe(struct platform_device *pdev) return 0; err_io: - iounmap(chip->ioaddress); + chip->ops->unmap_io(chip); err_chip: kfree(chip); @@ -229,7 +379,7 @@ static int rtc_remove(struct platform_device *dev) if (rtc) rtc_device_unregister(rtc); - iounmap(chip->ioaddress); + chip->ops->unmap_io(chip); kfree(chip); return 0; |