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Date: Sun, 18 Apr 2021 02:20:22 +0200
From: Alexandre Belloni <alexandre.belloni@...tlin.com>
To: Alessandro Zummo <a.zummo@...ertech.it>,
Alexandre Belloni <alexandre.belloni@...tlin.com>
Cc: linux-rtc@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH 2/3] rtc: pcf8523: add alarm support
Alarm support requires unconditionally disabling clock out because it is
using the int1 pin.
Signed-off-by: Alexandre Belloni <alexandre.belloni@...tlin.com>
---
drivers/rtc/rtc-pcf8523.c | 181 +++++++++++++++++++++++++++++++++++++-
1 file changed, 180 insertions(+), 1 deletion(-)
diff --git a/drivers/rtc/rtc-pcf8523.c b/drivers/rtc/rtc-pcf8523.c
index fe3ab41d8326..feadab8e3bd3 100644
--- a/drivers/rtc/rtc-pcf8523.c
+++ b/drivers/rtc/rtc-pcf8523.c
@@ -8,10 +8,15 @@
#include <linux/module.h>
#include <linux/rtc.h>
#include <linux/of.h>
+#include <linux/pm_wakeirq.h>
#define REG_CONTROL1 0x00
#define REG_CONTROL1_CAP_SEL BIT(7)
#define REG_CONTROL1_STOP BIT(5)
+#define REG_CONTROL1_AIE BIT(1)
+
+#define REG_CONTROL2 0x01
+#define REG_CONTROL2_AF BIT(3)
#define REG_CONTROL3 0x02
#define REG_CONTROL3_PM_BLD BIT(7) /* battery low detection disabled */
@@ -30,9 +35,22 @@
#define REG_MONTHS 0x08
#define REG_YEARS 0x09
+#define REG_MINUTE_ALARM 0x0a
+#define REG_HOUR_ALARM 0x0b
+#define REG_DAY_ALARM 0x0c
+#define REG_WEEKDAY_ALARM 0x0d
+#define ALARM_DIS BIT(7)
+
#define REG_OFFSET 0x0e
#define REG_OFFSET_MODE BIT(7)
+#define REG_TMR_CLKOUT_CTRL 0x0f
+
+struct pcf8523 {
+ struct rtc_device *rtc;
+ struct i2c_client *client;
+};
+
static int pcf8523_read(struct i2c_client *client, u8 reg, u8 *valuep)
{
struct i2c_msg msgs[2];
@@ -138,6 +156,27 @@ static int pcf8523_set_pm(struct i2c_client *client, u8 pm)
return 0;
}
+static irqreturn_t pcf8523_irq(int irq, void *dev_id)
+{
+ struct pcf8523 *pcf8523 = i2c_get_clientdata(dev_id);
+ u8 value;
+ int err;
+
+ err = pcf8523_read(pcf8523->client, REG_CONTROL2, &value);
+ if (err < 0)
+ return IRQ_HANDLED;
+
+ if (value & REG_CONTROL2_AF) {
+ value &= ~REG_CONTROL2_AF;
+ pcf8523_write(pcf8523->client, REG_CONTROL2, value);
+ rtc_update_irq(pcf8523->rtc, 1, RTC_IRQF | RTC_AF);
+
+ return IRQ_HANDLED;
+ }
+
+ return IRQ_NONE;
+}
+
static int pcf8523_stop_rtc(struct i2c_client *client)
{
u8 value;
@@ -257,6 +296,111 @@ static int pcf8523_rtc_set_time(struct device *dev, struct rtc_time *tm)
return pcf8523_start_rtc(client);
}
+static int pcf8523_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *tm)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ u8 start = REG_MINUTE_ALARM, regs[4];
+ struct i2c_msg msgs[2];
+ u8 value;
+ int err;
+
+ msgs[0].addr = client->addr;
+ msgs[0].flags = 0;
+ msgs[0].len = 1;
+ msgs[0].buf = &start;
+
+ msgs[1].addr = client->addr;
+ msgs[1].flags = I2C_M_RD;
+ msgs[1].len = sizeof(regs);
+ msgs[1].buf = regs;
+
+ err = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
+ if (err < 0)
+ return err;
+
+ tm->time.tm_sec = 0;
+ tm->time.tm_min = bcd2bin(regs[0] & 0x7F);
+ tm->time.tm_hour = bcd2bin(regs[1] & 0x3F);
+ tm->time.tm_mday = bcd2bin(regs[2] & 0x3F);
+ tm->time.tm_wday = bcd2bin(regs[3] & 0x7);
+
+ err = pcf8523_read(client, REG_CONTROL1, &value);
+ if (err < 0)
+ return err;
+ tm->enabled = !!(value & REG_CONTROL1_AIE);
+
+ err = pcf8523_read(client, REG_CONTROL2, &value);
+ if (err < 0)
+ return err;
+ tm->pending = !!(value & REG_CONTROL2_AF);
+
+ return 0;
+}
+
+static int pcf8523_irq_enable(struct device *dev, unsigned int enabled)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ u8 value;
+ int err;
+
+ err = pcf8523_read(client, REG_CONTROL1, &value);
+ if (err < 0)
+ return err;
+
+ value &= REG_CONTROL1_AIE;
+
+ if (enabled)
+ value |= REG_CONTROL1_AIE;
+
+ err = pcf8523_write(client, REG_CONTROL1, value);
+ if (err < 0)
+ return err;
+
+ return 0;
+}
+
+static int pcf8523_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *tm)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct i2c_msg msg;
+ u8 regs[5];
+ int err;
+
+ err = pcf8523_irq_enable(dev, 0);
+ if (err)
+ return err;
+
+ err = pcf8523_write(client, REG_CONTROL2, 0);
+ if (err < 0)
+ return err;
+
+ /* The alarm has no seconds, round up to nearest minute */
+ if (tm->time.tm_sec) {
+ time64_t alarm_time = rtc_tm_to_time64(&tm->time);
+
+ alarm_time += 60 - tm->time.tm_sec;
+ rtc_time64_to_tm(alarm_time, &tm->time);
+ }
+
+ regs[0] = REG_MINUTE_ALARM;
+ regs[1] = bin2bcd(tm->time.tm_min);
+ regs[2] = bin2bcd(tm->time.tm_hour);
+ regs[3] = bin2bcd(tm->time.tm_mday);
+ regs[4] = ALARM_DIS;
+ msg.addr = client->addr;
+ msg.flags = 0;
+ msg.len = sizeof(regs);
+ msg.buf = regs;
+ err = i2c_transfer(client->adapter, &msg, 1);
+ if (err < 0)
+ return err;
+
+ if (tm->enabled)
+ return pcf8523_irq_enable(dev, tm->enabled);
+
+ return 0;
+}
+
#ifdef CONFIG_RTC_INTF_DEV
static int pcf8523_rtc_ioctl(struct device *dev, unsigned int cmd,
unsigned long arg)
@@ -320,6 +464,9 @@ static int pcf8523_rtc_set_offset(struct device *dev, long offset)
static const struct rtc_class_ops pcf8523_rtc_ops = {
.read_time = pcf8523_rtc_read_time,
.set_time = pcf8523_rtc_set_time,
+ .read_alarm = pcf8523_rtc_read_alarm,
+ .set_alarm = pcf8523_rtc_set_alarm,
+ .alarm_irq_enable = pcf8523_irq_enable,
.ioctl = pcf8523_rtc_ioctl,
.read_offset = pcf8523_rtc_read_offset,
.set_offset = pcf8523_rtc_set_offset,
@@ -328,12 +475,21 @@ static const struct rtc_class_ops pcf8523_rtc_ops = {
static int pcf8523_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
+ struct pcf8523 *pcf8523;
struct rtc_device *rtc;
+ bool wakeup_source = false;
int err;
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
return -ENODEV;
+ pcf8523 = devm_kzalloc(&client->dev, sizeof(struct pcf8523), GFP_KERNEL);
+ if (!pcf8523)
+ return -ENOMEM;
+
+ i2c_set_clientdata(client, pcf8523);
+ pcf8523->client = client;
+
err = pcf8523_load_capacitance(client);
if (err < 0)
dev_warn(&client->dev, "failed to set xtal load capacitance: %d",
@@ -347,11 +503,34 @@ static int pcf8523_probe(struct i2c_client *client,
if (IS_ERR(rtc))
return PTR_ERR(rtc);
+ pcf8523->rtc = rtc;
rtc->ops = &pcf8523_rtc_ops;
rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
rtc->range_max = RTC_TIMESTAMP_END_2099;
+ rtc->uie_unsupported = 1;
+
+ if (client->irq > 0) {
+ err = pcf8523_write(client, REG_TMR_CLKOUT_CTRL, 0x38);
+ if (err < 0)
+ return err;
+
+ err = devm_request_threaded_irq(&client->dev, client->irq,
+ NULL, pcf8523_irq,
+ IRQF_SHARED | IRQF_ONESHOT | IRQF_TRIGGER_LOW,
+ dev_name(&rtc->dev), client);
+ if (err)
+ return err;
+
+ dev_pm_set_wake_irq(&client->dev, client->irq);
+ }
+
+#ifdef CONFIG_OF
+ wakeup_source = of_property_read_bool(client->dev.of_node, "wakeup-source");
+#endif
+ if (client->irq > 0 || wakeup_source)
+ device_init_wakeup(&client->dev, true);
- return devm_rtc_register_device(rtc);
+ return rtc_register_device(rtc);
}
static const struct i2c_device_id pcf8523_id[] = {
--
2.30.2
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