rtc: add support for EPSON TOYOCOM RTC-7301SF/DG
authorAkinobu Mita <akinobu.mita@gmail.com>
Sun, 4 Dec 2016 14:04:39 +0000 (23:04 +0900)
committerAlexandre Belloni <alexandre.belloni@free-electrons.com>
Sun, 18 Dec 2016 23:59:21 +0000 (00:59 +0100)
This adds support for EPSON TOYOCOM RTC-7301SF/DG which has parallel
interface compatible with SRAM.

This driver supports basic clock, calendar and alarm functionality.

Tested with Microblaze linux running on Artix7 FPGA board with my own
custom IP for RTC-7301.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Documentation/devicetree/bindings/rtc/epson,rtc7301.txt [new file with mode: 0644]
drivers/rtc/Kconfig
drivers/rtc/Makefile
drivers/rtc/rtc-r7301.c [new file with mode: 0644]

diff --git a/Documentation/devicetree/bindings/rtc/epson,rtc7301.txt b/Documentation/devicetree/bindings/rtc/epson,rtc7301.txt
new file mode 100644 (file)
index 0000000..5f9df3f
--- /dev/null
@@ -0,0 +1,16 @@
+EPSON TOYOCOM RTC-7301SF/DG
+
+Required properties:
+
+- compatible: Should be "epson,rtc7301sf" or "epson,rtc7301dg"
+- reg: Specifies base physical address and size of the registers.
+- interrupts: A single interrupt specifier.
+
+Example:
+
+rtc: rtc@44a00000 {
+       compatible = "epson,rtc7301dg";
+       reg = <0x44a00000 0x10000>;
+       interrupt-parent = <&axi_intc_0>;
+       interrupts = <3 2>;
+};
index a44f1f27ecfa4b033b4547fc146eff9fba5d3911..c93c5a8fba32925584dbc28c60610786328d09ff 100644 (file)
@@ -1705,6 +1705,17 @@ config RTC_DRV_PIC32
           This driver can also be built as a module. If so, the module
           will be called rtc-pic32
 
+config RTC_DRV_R7301
+       tristate "EPSON TOYOCOM RTC-7301SF/DG"
+       select REGMAP_MMIO
+       depends on OF && HAS_IOMEM
+       help
+          If you say yes here you get support for the EPSON TOYOCOM
+          RTC-7301SF/DG chips.
+
+          This driver can also be built as a module. If so, the module
+          will be called rtc-r7301.
+
 comment "HID Sensor RTC drivers"
 
 config RTC_DRV_HID_SENSOR_TIME
index 1ac694a330c8dadc0cbe78a4f6cd8d7359de2ecc..f13ab1c5c222c269e711786e74f5a99a258150a5 100644 (file)
@@ -120,6 +120,7 @@ obj-$(CONFIG_RTC_DRV_PM8XXX)        += rtc-pm8xxx.o
 obj-$(CONFIG_RTC_DRV_PS3)      += rtc-ps3.o
 obj-$(CONFIG_RTC_DRV_PUV3)     += rtc-puv3.o
 obj-$(CONFIG_RTC_DRV_PXA)      += rtc-pxa.o
+obj-$(CONFIG_RTC_DRV_R7301)    += rtc-r7301.o
 obj-$(CONFIG_RTC_DRV_R9701)    += rtc-r9701.o
 obj-$(CONFIG_RTC_DRV_RC5T583)  += rtc-rc5t583.o
 obj-$(CONFIG_RTC_DRV_RK808)    += rtc-rk808.o
diff --git a/drivers/rtc/rtc-r7301.c b/drivers/rtc/rtc-r7301.c
new file mode 100644 (file)
index 0000000..28d5408
--- /dev/null
@@ -0,0 +1,453 @@
+/*
+ * EPSON TOYOCOM RTC-7301SF/DG Driver
+ *
+ * Copyright (c) 2016 Akinobu Mita <akinobu.mita@gmail.com>
+ *
+ * Based on rtc-rp5c01.c
+ *
+ * Datasheet: http://www5.epsondevice.com/en/products/parallel/rtc7301sf.html
+ */
+
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/regmap.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+
+#define DRV_NAME "rtc-r7301"
+
+#define RTC7301_1_SEC          0x0     /* Bank 0 and Band 1 */
+#define RTC7301_10_SEC         0x1     /* Bank 0 and Band 1 */
+#define RTC7301_AE             BIT(3)
+#define RTC7301_1_MIN          0x2     /* Bank 0 and Band 1 */
+#define RTC7301_10_MIN         0x3     /* Bank 0 and Band 1 */
+#define RTC7301_1_HOUR         0x4     /* Bank 0 and Band 1 */
+#define RTC7301_10_HOUR                0x5     /* Bank 0 and Band 1 */
+#define RTC7301_DAY_OF_WEEK    0x6     /* Bank 0 and Band 1 */
+#define RTC7301_1_DAY          0x7     /* Bank 0 and Band 1 */
+#define RTC7301_10_DAY         0x8     /* Bank 0 and Band 1 */
+#define RTC7301_1_MONTH                0x9     /* Bank 0 */
+#define RTC7301_10_MONTH       0xa     /* Bank 0 */
+#define RTC7301_1_YEAR         0xb     /* Bank 0 */
+#define RTC7301_10_YEAR                0xc     /* Bank 0 */
+#define RTC7301_100_YEAR       0xd     /* Bank 0 */
+#define RTC7301_1000_YEAR      0xe     /* Bank 0 */
+#define RTC7301_ALARM_CONTROL  0xe     /* Bank 1 */
+#define RTC7301_ALARM_CONTROL_AIE      BIT(0)
+#define RTC7301_ALARM_CONTROL_AF       BIT(1)
+#define RTC7301_TIMER_CONTROL  0xe     /* Bank 2 */
+#define RTC7301_TIMER_CONTROL_TIE      BIT(0)
+#define RTC7301_TIMER_CONTROL_TF       BIT(1)
+#define RTC7301_CONTROL                0xf     /* All banks */
+#define RTC7301_CONTROL_BUSY           BIT(0)
+#define RTC7301_CONTROL_STOP           BIT(1)
+#define RTC7301_CONTROL_BANK_SEL_0     BIT(2)
+#define RTC7301_CONTROL_BANK_SEL_1     BIT(3)
+
+struct rtc7301_priv {
+       struct regmap *regmap;
+       int irq;
+       spinlock_t lock;
+       u8 bank;
+};
+
+static const struct regmap_config rtc7301_regmap_config = {
+       .reg_bits = 32,
+       .val_bits = 8,
+       .reg_stride = 4,
+};
+
+static u8 rtc7301_read(struct rtc7301_priv *priv, unsigned int reg)
+{
+       int reg_stride = regmap_get_reg_stride(priv->regmap);
+       unsigned int val;
+
+       regmap_read(priv->regmap, reg_stride * reg, &val);
+
+       return val & 0xf;
+}
+
+static void rtc7301_write(struct rtc7301_priv *priv, u8 val, unsigned int reg)
+{
+       int reg_stride = regmap_get_reg_stride(priv->regmap);
+
+       regmap_write(priv->regmap, reg_stride * reg, val);
+}
+
+static void rtc7301_update_bits(struct rtc7301_priv *priv, unsigned int reg,
+                               u8 mask, u8 val)
+{
+       int reg_stride = regmap_get_reg_stride(priv->regmap);
+
+       regmap_update_bits(priv->regmap, reg_stride * reg, mask, val);
+}
+
+static int rtc7301_wait_while_busy(struct rtc7301_priv *priv)
+{
+       int retries = 100;
+
+       while (retries-- > 0) {
+               u8 val;
+
+               val = rtc7301_read(priv, RTC7301_CONTROL);
+               if (!(val & RTC7301_CONTROL_BUSY))
+                       return 0;
+
+               usleep_range(200, 300);
+       }
+
+       return -ETIMEDOUT;
+}
+
+static void rtc7301_stop(struct rtc7301_priv *priv)
+{
+       rtc7301_update_bits(priv, RTC7301_CONTROL, RTC7301_CONTROL_STOP,
+                           RTC7301_CONTROL_STOP);
+}
+
+static void rtc7301_start(struct rtc7301_priv *priv)
+{
+       rtc7301_update_bits(priv, RTC7301_CONTROL, RTC7301_CONTROL_STOP, 0);
+}
+
+static void rtc7301_select_bank(struct rtc7301_priv *priv, u8 bank)
+{
+       u8 val = 0;
+
+       if (bank == priv->bank)
+               return;
+
+       if (bank & BIT(0))
+               val |= RTC7301_CONTROL_BANK_SEL_0;
+       if (bank & BIT(1))
+               val |= RTC7301_CONTROL_BANK_SEL_1;
+
+       rtc7301_update_bits(priv, RTC7301_CONTROL,
+                           RTC7301_CONTROL_BANK_SEL_0 |
+                           RTC7301_CONTROL_BANK_SEL_1, val);
+
+       priv->bank = bank;
+}
+
+static void rtc7301_get_time(struct rtc7301_priv *priv, struct rtc_time *tm,
+                            bool alarm)
+{
+       int year;
+
+       tm->tm_sec = rtc7301_read(priv, RTC7301_1_SEC);
+       tm->tm_sec += (rtc7301_read(priv, RTC7301_10_SEC) & ~RTC7301_AE) * 10;
+       tm->tm_min = rtc7301_read(priv, RTC7301_1_MIN);
+       tm->tm_min += (rtc7301_read(priv, RTC7301_10_MIN) & ~RTC7301_AE) * 10;
+       tm->tm_hour = rtc7301_read(priv, RTC7301_1_HOUR);
+       tm->tm_hour += (rtc7301_read(priv, RTC7301_10_HOUR) & ~RTC7301_AE) * 10;
+       tm->tm_mday = rtc7301_read(priv, RTC7301_1_DAY);
+       tm->tm_mday += (rtc7301_read(priv, RTC7301_10_DAY) & ~RTC7301_AE) * 10;
+
+       if (alarm) {
+               tm->tm_wday = -1;
+               tm->tm_mon = -1;
+               tm->tm_year = -1;
+               tm->tm_yday = -1;
+               tm->tm_isdst = -1;
+               return;
+       }
+
+       tm->tm_wday = (rtc7301_read(priv, RTC7301_DAY_OF_WEEK) & ~RTC7301_AE);
+       tm->tm_mon = rtc7301_read(priv, RTC7301_10_MONTH) * 10 +
+                    rtc7301_read(priv, RTC7301_1_MONTH) - 1;
+       year = rtc7301_read(priv, RTC7301_1000_YEAR) * 1000 +
+              rtc7301_read(priv, RTC7301_100_YEAR) * 100 +
+              rtc7301_read(priv, RTC7301_10_YEAR) * 10 +
+              rtc7301_read(priv, RTC7301_1_YEAR);
+
+       tm->tm_year = year - 1900;
+}
+
+static void rtc7301_write_time(struct rtc7301_priv *priv, struct rtc_time *tm,
+                              bool alarm)
+{
+       int year;
+
+       rtc7301_write(priv, tm->tm_sec % 10, RTC7301_1_SEC);
+       rtc7301_write(priv, tm->tm_sec / 10, RTC7301_10_SEC);
+
+       rtc7301_write(priv, tm->tm_min % 10, RTC7301_1_MIN);
+       rtc7301_write(priv, tm->tm_min / 10, RTC7301_10_MIN);
+
+       rtc7301_write(priv, tm->tm_hour % 10, RTC7301_1_HOUR);
+       rtc7301_write(priv, tm->tm_hour / 10, RTC7301_10_HOUR);
+
+       rtc7301_write(priv, tm->tm_mday % 10, RTC7301_1_DAY);
+       rtc7301_write(priv, tm->tm_mday / 10, RTC7301_10_DAY);
+
+       /* Don't care for alarm register */
+       rtc7301_write(priv, alarm ? RTC7301_AE : tm->tm_wday,
+                     RTC7301_DAY_OF_WEEK);
+
+       if (alarm)
+               return;
+
+       rtc7301_write(priv, (tm->tm_mon + 1) % 10, RTC7301_1_MONTH);
+       rtc7301_write(priv, (tm->tm_mon + 1) / 10, RTC7301_10_MONTH);
+
+       year = tm->tm_year + 1900;
+
+       rtc7301_write(priv, year % 10, RTC7301_1_YEAR);
+       rtc7301_write(priv, (year / 10) % 10, RTC7301_10_YEAR);
+       rtc7301_write(priv, (year / 100) % 10, RTC7301_100_YEAR);
+       rtc7301_write(priv, year / 1000, RTC7301_1000_YEAR);
+}
+
+static void rtc7301_alarm_irq(struct rtc7301_priv *priv, unsigned int enabled)
+{
+       rtc7301_update_bits(priv, RTC7301_ALARM_CONTROL,
+                           RTC7301_ALARM_CONTROL_AF |
+                           RTC7301_ALARM_CONTROL_AIE,
+                           enabled ? RTC7301_ALARM_CONTROL_AIE : 0);
+}
+
+static int rtc7301_read_time(struct device *dev, struct rtc_time *tm)
+{
+       struct rtc7301_priv *priv = dev_get_drvdata(dev);
+       unsigned long flags;
+       int err;
+
+       spin_lock_irqsave(&priv->lock, flags);
+
+       rtc7301_select_bank(priv, 0);
+
+       err = rtc7301_wait_while_busy(priv);
+       if (!err)
+               rtc7301_get_time(priv, tm, false);
+
+       spin_unlock_irqrestore(&priv->lock, flags);
+
+       return err ? err : rtc_valid_tm(tm);
+}
+
+static int rtc7301_set_time(struct device *dev, struct rtc_time *tm)
+{
+       struct rtc7301_priv *priv = dev_get_drvdata(dev);
+       unsigned long flags;
+
+       spin_lock_irqsave(&priv->lock, flags);
+
+       rtc7301_stop(priv);
+       usleep_range(200, 300);
+       rtc7301_select_bank(priv, 0);
+       rtc7301_write_time(priv, tm, false);
+       rtc7301_start(priv);
+
+       spin_unlock_irqrestore(&priv->lock, flags);
+
+       return 0;
+}
+
+static int rtc7301_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+       struct rtc7301_priv *priv = dev_get_drvdata(dev);
+       unsigned long flags;
+       u8 alrm_ctrl;
+
+       if (priv->irq <= 0)
+               return -EINVAL;
+
+       spin_lock_irqsave(&priv->lock, flags);
+
+       rtc7301_select_bank(priv, 1);
+       rtc7301_get_time(priv, &alarm->time, true);
+
+       alrm_ctrl = rtc7301_read(priv, RTC7301_ALARM_CONTROL);
+
+       alarm->enabled = !!(alrm_ctrl & RTC7301_ALARM_CONTROL_AIE);
+       alarm->pending = !!(alrm_ctrl & RTC7301_ALARM_CONTROL_AF);
+
+       spin_unlock_irqrestore(&priv->lock, flags);
+
+       return 0;
+}
+
+static int rtc7301_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+       struct rtc7301_priv *priv = dev_get_drvdata(dev);
+       unsigned long flags;
+
+       if (priv->irq <= 0)
+               return -EINVAL;
+
+       spin_lock_irqsave(&priv->lock, flags);
+
+       rtc7301_select_bank(priv, 1);
+       rtc7301_write_time(priv, &alarm->time, true);
+       rtc7301_alarm_irq(priv, alarm->enabled);
+
+       spin_unlock_irqrestore(&priv->lock, flags);
+
+       return 0;
+}
+
+static int rtc7301_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+       struct rtc7301_priv *priv = dev_get_drvdata(dev);
+       unsigned long flags;
+
+       if (priv->irq <= 0)
+               return -EINVAL;
+
+       spin_lock_irqsave(&priv->lock, flags);
+
+       rtc7301_select_bank(priv, 1);
+       rtc7301_alarm_irq(priv, enabled);
+
+       spin_unlock_irqrestore(&priv->lock, flags);
+
+       return 0;
+}
+
+static const struct rtc_class_ops rtc7301_rtc_ops = {
+       .read_time      = rtc7301_read_time,
+       .set_time       = rtc7301_set_time,
+       .read_alarm     = rtc7301_read_alarm,
+       .set_alarm      = rtc7301_set_alarm,
+       .alarm_irq_enable = rtc7301_alarm_irq_enable,
+};
+
+static irqreturn_t rtc7301_irq_handler(int irq, void *dev_id)
+{
+       struct rtc_device *rtc = dev_id;
+       struct rtc7301_priv *priv = dev_get_drvdata(rtc->dev.parent);
+       unsigned long flags;
+       irqreturn_t ret = IRQ_NONE;
+       u8 alrm_ctrl;
+
+       spin_lock_irqsave(&priv->lock, flags);
+
+       rtc7301_select_bank(priv, 1);
+
+       alrm_ctrl = rtc7301_read(priv, RTC7301_ALARM_CONTROL);
+       if (alrm_ctrl & RTC7301_ALARM_CONTROL_AF) {
+               ret = IRQ_HANDLED;
+               rtc7301_alarm_irq(priv, false);
+               rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF);
+       }
+
+       spin_unlock_irqrestore(&priv->lock, flags);
+
+       return ret;
+}
+
+static void rtc7301_init(struct rtc7301_priv *priv)
+{
+       unsigned long flags;
+
+       spin_lock_irqsave(&priv->lock, flags);
+
+       rtc7301_select_bank(priv, 2);
+       rtc7301_write(priv, 0, RTC7301_TIMER_CONTROL);
+
+       spin_unlock_irqrestore(&priv->lock, flags);
+}
+
+static int __init rtc7301_rtc_probe(struct platform_device *dev)
+{
+       struct resource *res;
+       void __iomem *regs;
+       struct rtc7301_priv *priv;
+       struct rtc_device *rtc;
+       int ret;
+
+       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;
+
+       regs = devm_ioremap_resource(&dev->dev, res);
+       if (IS_ERR(regs))
+               return PTR_ERR(regs);
+
+       priv->regmap = devm_regmap_init_mmio(&dev->dev, regs,
+                                            &rtc7301_regmap_config);
+       if (IS_ERR(priv->regmap))
+               return PTR_ERR(priv->regmap);
+
+       priv->irq = platform_get_irq(dev, 0);
+
+       spin_lock_init(&priv->lock);
+       priv->bank = -1;
+
+       rtc7301_init(priv);
+
+       platform_set_drvdata(dev, priv);
+
+       rtc = devm_rtc_device_register(&dev->dev, DRV_NAME, &rtc7301_rtc_ops,
+                                      THIS_MODULE);
+       if (IS_ERR(rtc))
+               return PTR_ERR(rtc);
+
+       if (priv->irq > 0) {
+               ret = devm_request_irq(&dev->dev, priv->irq,
+                                      rtc7301_irq_handler, IRQF_SHARED,
+                                      dev_name(&dev->dev), rtc);
+               if (ret) {
+                       priv->irq = 0;
+                       dev_err(&dev->dev, "unable to request IRQ\n");
+               } else {
+                       device_set_wakeup_capable(&dev->dev, true);
+               }
+       }
+
+       return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+
+static int rtc7301_suspend(struct device *dev)
+{
+       struct rtc7301_priv *priv = dev_get_drvdata(dev);
+
+       if (device_may_wakeup(dev))
+               enable_irq_wake(priv->irq);
+
+       return 0;
+}
+
+static int rtc7301_resume(struct device *dev)
+{
+       struct rtc7301_priv *priv = dev_get_drvdata(dev);
+
+       if (device_may_wakeup(dev))
+               disable_irq_wake(priv->irq);
+
+       return 0;
+}
+
+#endif
+
+static SIMPLE_DEV_PM_OPS(rtc7301_pm_ops, rtc7301_suspend, rtc7301_resume);
+
+static const struct of_device_id rtc7301_dt_match[] = {
+       { .compatible = "epson,rtc7301sf" },
+       { .compatible = "epson,rtc7301dg" },
+       {}
+};
+MODULE_DEVICE_TABLE(of, rtc7301_dt_match);
+
+static struct platform_driver rtc7301_rtc_driver = {
+       .driver = {
+               .name = DRV_NAME,
+               .of_match_table = rtc7301_dt_match,
+               .pm = &rtc7301_pm_ops,
+       },
+};
+
+module_platform_driver_probe(rtc7301_rtc_driver, rtc7301_rtc_probe);
+
+MODULE_AUTHOR("Akinobu Mita <akinobu.mita@gmail.com>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("EPSON TOYOCOM RTC-7301SF/DG Driver");
+MODULE_ALIAS("platform:rtc-r7301");