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path: root/drivers/rtc/rtc-rp5c01.c
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-rw-r--r--drivers/rtc/rtc-rp5c01.c276
1 files changed, 276 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-rp5c01.c b/drivers/rtc/rtc-rp5c01.c
new file mode 100644
index 000000000..44afa6d99
--- /dev/null
+++ b/drivers/rtc/rtc-rp5c01.c
@@ -0,0 +1,276 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Ricoh RP5C01 RTC Driver
+ *
+ * Copyright 2009 Geert Uytterhoeven
+ *
+ * Based on the A3000 TOD code in arch/m68k/amiga/config.c
+ * Copyright (C) 1993 Hamish Macdonald
+ */
+
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+#include <linux/slab.h>
+
+
+enum {
+ RP5C01_1_SECOND = 0x0, /* MODE 00 */
+ RP5C01_10_SECOND = 0x1, /* MODE 00 */
+ RP5C01_1_MINUTE = 0x2, /* MODE 00 and MODE 01 */
+ RP5C01_10_MINUTE = 0x3, /* MODE 00 and MODE 01 */
+ RP5C01_1_HOUR = 0x4, /* MODE 00 and MODE 01 */
+ RP5C01_10_HOUR = 0x5, /* MODE 00 and MODE 01 */
+ RP5C01_DAY_OF_WEEK = 0x6, /* MODE 00 and MODE 01 */
+ RP5C01_1_DAY = 0x7, /* MODE 00 and MODE 01 */
+ RP5C01_10_DAY = 0x8, /* MODE 00 and MODE 01 */
+ RP5C01_1_MONTH = 0x9, /* MODE 00 */
+ RP5C01_10_MONTH = 0xa, /* MODE 00 */
+ RP5C01_1_YEAR = 0xb, /* MODE 00 */
+ RP5C01_10_YEAR = 0xc, /* MODE 00 */
+
+ RP5C01_12_24_SELECT = 0xa, /* MODE 01 */
+ RP5C01_LEAP_YEAR = 0xb, /* MODE 01 */
+
+ RP5C01_MODE = 0xd, /* all modes */
+ RP5C01_TEST = 0xe, /* all modes */
+ RP5C01_RESET = 0xf, /* all modes */
+};
+
+#define RP5C01_12_24_SELECT_12 (0 << 0)
+#define RP5C01_12_24_SELECT_24 (1 << 0)
+
+#define RP5C01_10_HOUR_AM (0 << 1)
+#define RP5C01_10_HOUR_PM (1 << 1)
+
+#define RP5C01_MODE_TIMER_EN (1 << 3) /* timer enable */
+#define RP5C01_MODE_ALARM_EN (1 << 2) /* alarm enable */
+
+#define RP5C01_MODE_MODE_MASK (3 << 0)
+#define RP5C01_MODE_MODE00 (0 << 0) /* time */
+#define RP5C01_MODE_MODE01 (1 << 0) /* alarm, 12h/24h, leap year */
+#define RP5C01_MODE_RAM_BLOCK10 (2 << 0) /* RAM 4 bits x 13 */
+#define RP5C01_MODE_RAM_BLOCK11 (3 << 0) /* RAM 4 bits x 13 */
+
+#define RP5C01_RESET_1HZ_PULSE (1 << 3)
+#define RP5C01_RESET_16HZ_PULSE (1 << 2)
+#define RP5C01_RESET_SECOND (1 << 1) /* reset divider stages for */
+ /* seconds or smaller units */
+#define RP5C01_RESET_ALARM (1 << 0) /* reset all alarm registers */
+
+
+struct rp5c01_priv {
+ u32 __iomem *regs;
+ struct rtc_device *rtc;
+ spinlock_t lock; /* against concurrent RTC/NVRAM access */
+};
+
+static inline unsigned int rp5c01_read(struct rp5c01_priv *priv,
+ unsigned int reg)
+{
+ return __raw_readl(&priv->regs[reg]) & 0xf;
+}
+
+static inline void rp5c01_write(struct rp5c01_priv *priv, unsigned int val,
+ unsigned int reg)
+{
+ __raw_writel(val, &priv->regs[reg]);
+}
+
+static void rp5c01_lock(struct rp5c01_priv *priv)
+{
+ rp5c01_write(priv, RP5C01_MODE_MODE00, RP5C01_MODE);
+}
+
+static void rp5c01_unlock(struct rp5c01_priv *priv)
+{
+ rp5c01_write(priv, RP5C01_MODE_TIMER_EN | RP5C01_MODE_MODE01,
+ RP5C01_MODE);
+}
+
+static int rp5c01_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct rp5c01_priv *priv = dev_get_drvdata(dev);
+
+ spin_lock_irq(&priv->lock);
+ rp5c01_lock(priv);
+
+ tm->tm_sec = rp5c01_read(priv, RP5C01_10_SECOND) * 10 +
+ rp5c01_read(priv, RP5C01_1_SECOND);
+ tm->tm_min = rp5c01_read(priv, RP5C01_10_MINUTE) * 10 +
+ rp5c01_read(priv, RP5C01_1_MINUTE);
+ tm->tm_hour = rp5c01_read(priv, RP5C01_10_HOUR) * 10 +
+ rp5c01_read(priv, RP5C01_1_HOUR);
+ tm->tm_mday = rp5c01_read(priv, RP5C01_10_DAY) * 10 +
+ rp5c01_read(priv, RP5C01_1_DAY);
+ tm->tm_wday = rp5c01_read(priv, RP5C01_DAY_OF_WEEK);
+ tm->tm_mon = rp5c01_read(priv, RP5C01_10_MONTH) * 10 +
+ rp5c01_read(priv, RP5C01_1_MONTH) - 1;
+ tm->tm_year = rp5c01_read(priv, RP5C01_10_YEAR) * 10 +
+ rp5c01_read(priv, RP5C01_1_YEAR);
+ if (tm->tm_year <= 69)
+ tm->tm_year += 100;
+
+ rp5c01_unlock(priv);
+ spin_unlock_irq(&priv->lock);
+
+ return 0;
+}
+
+static int rp5c01_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct rp5c01_priv *priv = dev_get_drvdata(dev);
+
+ spin_lock_irq(&priv->lock);
+ rp5c01_lock(priv);
+
+ rp5c01_write(priv, tm->tm_sec / 10, RP5C01_10_SECOND);
+ rp5c01_write(priv, tm->tm_sec % 10, RP5C01_1_SECOND);
+ rp5c01_write(priv, tm->tm_min / 10, RP5C01_10_MINUTE);
+ rp5c01_write(priv, tm->tm_min % 10, RP5C01_1_MINUTE);
+ rp5c01_write(priv, tm->tm_hour / 10, RP5C01_10_HOUR);
+ rp5c01_write(priv, tm->tm_hour % 10, RP5C01_1_HOUR);
+ rp5c01_write(priv, tm->tm_mday / 10, RP5C01_10_DAY);
+ rp5c01_write(priv, tm->tm_mday % 10, RP5C01_1_DAY);
+ if (tm->tm_wday != -1)
+ rp5c01_write(priv, tm->tm_wday, RP5C01_DAY_OF_WEEK);
+ rp5c01_write(priv, (tm->tm_mon + 1) / 10, RP5C01_10_MONTH);
+ rp5c01_write(priv, (tm->tm_mon + 1) % 10, RP5C01_1_MONTH);
+ if (tm->tm_year >= 100)
+ tm->tm_year -= 100;
+ rp5c01_write(priv, tm->tm_year / 10, RP5C01_10_YEAR);
+ rp5c01_write(priv, tm->tm_year % 10, RP5C01_1_YEAR);
+
+ rp5c01_unlock(priv);
+ spin_unlock_irq(&priv->lock);
+ return 0;
+}
+
+static const struct rtc_class_ops rp5c01_rtc_ops = {
+ .read_time = rp5c01_read_time,
+ .set_time = rp5c01_set_time,
+};
+
+
+/*
+ * The NVRAM is organized as 2 blocks of 13 nibbles of 4 bits.
+ * We provide access to them like AmigaOS does: the high nibble of each 8-bit
+ * byte is stored in BLOCK10, the low nibble in BLOCK11.
+ */
+
+static int rp5c01_nvram_read(void *_priv, unsigned int pos, void *val,
+ size_t bytes)
+{
+ struct rp5c01_priv *priv = _priv;
+ u8 *buf = val;
+
+ spin_lock_irq(&priv->lock);
+
+ for (; bytes; bytes--) {
+ u8 data;
+
+ rp5c01_write(priv,
+ RP5C01_MODE_TIMER_EN | RP5C01_MODE_RAM_BLOCK10,
+ RP5C01_MODE);
+ data = rp5c01_read(priv, pos) << 4;
+ rp5c01_write(priv,
+ RP5C01_MODE_TIMER_EN | RP5C01_MODE_RAM_BLOCK11,
+ RP5C01_MODE);
+ data |= rp5c01_read(priv, pos++);
+ rp5c01_write(priv, RP5C01_MODE_TIMER_EN | RP5C01_MODE_MODE01,
+ RP5C01_MODE);
+ *buf++ = data;
+ }
+
+ spin_unlock_irq(&priv->lock);
+ return 0;
+}
+
+static int rp5c01_nvram_write(void *_priv, unsigned int pos, void *val,
+ size_t bytes)
+{
+ struct rp5c01_priv *priv = _priv;
+ u8 *buf = val;
+
+ spin_lock_irq(&priv->lock);
+
+ for (; bytes; bytes--) {
+ u8 data = *buf++;
+
+ rp5c01_write(priv,
+ RP5C01_MODE_TIMER_EN | RP5C01_MODE_RAM_BLOCK10,
+ RP5C01_MODE);
+ rp5c01_write(priv, data >> 4, pos);
+ rp5c01_write(priv,
+ RP5C01_MODE_TIMER_EN | RP5C01_MODE_RAM_BLOCK11,
+ RP5C01_MODE);
+ rp5c01_write(priv, data & 0xf, pos++);
+ rp5c01_write(priv, RP5C01_MODE_TIMER_EN | RP5C01_MODE_MODE01,
+ RP5C01_MODE);
+ }
+
+ spin_unlock_irq(&priv->lock);
+ return 0;
+}
+
+static int __init rp5c01_rtc_probe(struct platform_device *dev)
+{
+ struct resource *res;
+ struct rp5c01_priv *priv;
+ struct rtc_device *rtc;
+ int error;
+ struct nvmem_config nvmem_cfg = {
+ .name = "rp5c01_nvram",
+ .word_size = 1,
+ .stride = 1,
+ .size = RP5C01_MODE,
+ .reg_read = rp5c01_nvram_read,
+ .reg_write = rp5c01_nvram_write,
+ };
+
+ res = platform_get_resource(dev, IORESOURCE_MEM, 0);
+ if (!res)
+ return -ENODEV;
+
+ priv = devm_kzalloc(&dev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->regs = devm_ioremap(&dev->dev, res->start, resource_size(res));
+ if (!priv->regs)
+ return -ENOMEM;
+
+ spin_lock_init(&priv->lock);
+
+ platform_set_drvdata(dev, priv);
+
+ rtc = devm_rtc_allocate_device(&dev->dev);
+ if (IS_ERR(rtc))
+ return PTR_ERR(rtc);
+
+ rtc->ops = &rp5c01_rtc_ops;
+
+ priv->rtc = rtc;
+
+ nvmem_cfg.priv = priv;
+ error = devm_rtc_nvmem_register(rtc, &nvmem_cfg);
+ if (error)
+ return error;
+
+ return devm_rtc_register_device(rtc);
+}
+
+static struct platform_driver rp5c01_rtc_driver = {
+ .driver = {
+ .name = "rtc-rp5c01",
+ },
+};
+
+module_platform_driver_probe(rp5c01_rtc_driver, rp5c01_rtc_probe);
+
+MODULE_AUTHOR("Geert Uytterhoeven <geert@linux-m68k.org>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Ricoh RP5C01 RTC driver");
+MODULE_ALIAS("platform:rtc-rp5c01");