Merge tag 'v4.13-rc1' into fixes

The fixes branch is based off a random pre-rc1 commit, because we had
some fixes that needed to go in before rc1 was released.

However we now need to fix some code that went in after that point, but
before rc1, so merge rc1 to get that code into fixes so we can fix it!

1 files changed, 175 insertions, 76 deletions

diff --git a/drivers/rtc/rtc-m41t80.c b/drivers/rtc/rtc-m41t80.c
index 5ec4653022ff..8940e9e43ea0 100644
--- a/drivers/rtc/rtc-m41t80.c
+++ b/drivers/rtc/rtc-m41t80.c
@@ -16,6 +16,7 @@
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/bcd.h>
+#include <linux/clk-provider.h>
 #include <linux/i2c.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
@@ -53,6 +54,8 @@
 #define M41T80_ALARM_REG_SIZE	\
 	(M41T80_REG_ALARM_SEC + 1 - M41T80_REG_ALARM_MON)
 
+#define M41T80_SQW_MAX_FREQ	32768
+
 #define M41T80_SEC_ST		BIT(7)	/* ST: Stop Bit */
 #define M41T80_ALMON_AFE	BIT(7)	/* AFE: AF Enable Bit */
 #define M41T80_ALMON_SQWE	BIT(6)	/* SQWE: SQW Enable Bit */
@@ -147,7 +150,11 @@ MODULE_DEVICE_TABLE(of, m41t80_of_match);
 
 struct m41t80_data {
 	unsigned long features;
+	struct i2c_client *client;
 	struct rtc_device *rtc;
+#ifdef CONFIG_COMMON_CLK
+	struct clk_hw sqw;
+#endif
 };
 
 static irqreturn_t m41t80_handle_irq(int irq, void *dev_id)
@@ -227,6 +234,7 @@ static int m41t80_get_datetime(struct i2c_client *client,
 /* Sets the given date and time to the real time clock. */
 static int m41t80_set_datetime(struct i2c_client *client, struct rtc_time *tm)
 {
+	struct m41t80_data *clientdata = i2c_get_clientdata(client);
 	unsigned char buf[8];
 	int err, flags;
 
@@ -242,6 +250,17 @@ static int m41t80_set_datetime(struct i2c_client *client, struct rtc_time *tm)
 	buf[M41T80_REG_YEAR] = bin2bcd(tm->tm_year - 100);
 	buf[M41T80_REG_WDAY] = tm->tm_wday;
 
+	/* If the square wave output is controlled in the weekday register */
+	if (clientdata->features & M41T80_FEATURE_SQ_ALT) {
+		int val;
+
+		val = i2c_smbus_read_byte_data(client, M41T80_REG_WDAY);
+		if (val < 0)
+			return val;
+
+		buf[M41T80_REG_WDAY] |= (val & 0xf0);
+	}
+
 	err = i2c_smbus_write_i2c_block_data(client, M41T80_REG_SSEC,
 					     sizeof(buf), buf);
 	if (err < 0) {
@@ -332,6 +351,9 @@ static int m41t80_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 		return err;
 	}
 
+	/* Keep SQWE bit value */
+	alarmvals[0] |= (ret & M41T80_ALMON_SQWE);
+
 	ret = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
 	if (ret < 0)
 		return ret;
@@ -431,103 +453,175 @@ static ssize_t flags_show(struct device *dev,
 }
 static DEVICE_ATTR_RO(flags);
 
-static ssize_t sqwfreq_show(struct device *dev,
-			    struct device_attribute *attr, char *buf)
+static struct attribute *attrs[] = {
+	&dev_attr_flags.attr,
+	NULL,
+};
+
+static struct attribute_group attr_group = {
+	.attrs = attrs,
+};
+
+#ifdef CONFIG_COMMON_CLK
+#define sqw_to_m41t80_data(_hw) container_of(_hw, struct m41t80_data, sqw)
+
+static unsigned long m41t80_sqw_recalc_rate(struct clk_hw *hw,
+					    unsigned long parent_rate)
 {
-	struct i2c_client *client = to_i2c_client(dev);
-	struct m41t80_data *clientdata = i2c_get_clientdata(client);
-	int val, reg_sqw;
+	struct m41t80_data *m41t80 = sqw_to_m41t80_data(hw);
+	struct i2c_client *client = m41t80->client;
+	int reg_sqw = (m41t80->features & M41T80_FEATURE_SQ_ALT) ?
+		M41T80_REG_WDAY : M41T80_REG_SQW;
+	int ret = i2c_smbus_read_byte_data(client, reg_sqw);
+	unsigned long val = M41T80_SQW_MAX_FREQ;
 
-	if (!(clientdata->features & M41T80_FEATURE_SQ))
-		return -EINVAL;
+	if (ret < 0)
+		return 0;
 
-	reg_sqw = M41T80_REG_SQW;
-	if (clientdata->features & M41T80_FEATURE_SQ_ALT)
-		reg_sqw = M41T80_REG_WDAY;
-	val = i2c_smbus_read_byte_data(client, reg_sqw);
-	if (val < 0)
-		return val;
-	val = (val >> 4) & 0xf;
-	switch (val) {
-	case 0:
-		break;
-	case 1:
-		val = 32768;
-		break;
-	default:
-		val = 32768 >> val;
-	}
-	return sprintf(buf, "%d\n", val);
+	ret >>= 4;
+	if (ret == 0)
+		val = 0;
+	else if (ret > 1)
+		val = val / (1 << ret);
+
+	return val;
 }
 
-static ssize_t sqwfreq_store(struct device *dev,
-			     struct device_attribute *attr,
-			     const char *buf, size_t count)
+static long m41t80_sqw_round_rate(struct clk_hw *hw, unsigned long rate,
+				  unsigned long *prate)
 {
-	struct i2c_client *client = to_i2c_client(dev);
-	struct m41t80_data *clientdata = i2c_get_clientdata(client);
-	int almon, sqw, reg_sqw, rc;
-	unsigned long val;
+	int i, freq = M41T80_SQW_MAX_FREQ;
 
-	rc = kstrtoul(buf, 0, &val);
-	if (rc < 0)
-		return rc;
+	if (freq <= rate)
+		return freq;
 
-	if (!(clientdata->features & M41T80_FEATURE_SQ))
-		return -EINVAL;
+	for (i = 2; i <= ilog2(M41T80_SQW_MAX_FREQ); i++) {
+		freq /= 1 << i;
+		if (freq <= rate)
+			return freq;
+	}
 
-	if (val) {
-		if (!is_power_of_2(val))
+	return 0;
+}
+
+static int m41t80_sqw_set_rate(struct clk_hw *hw, unsigned long rate,
+			       unsigned long parent_rate)
+{
+	struct m41t80_data *m41t80 = sqw_to_m41t80_data(hw);
+	struct i2c_client *client = m41t80->client;
+	int reg_sqw = (m41t80->features & M41T80_FEATURE_SQ_ALT) ?
+		M41T80_REG_WDAY : M41T80_REG_SQW;
+	int reg, ret, val = 0;
+
+	if (rate) {
+		if (!is_power_of_2(rate))
 			return -EINVAL;
-		val = ilog2(val);
-		if (val == 15)
+		val = ilog2(rate);
+		if (val == ilog2(M41T80_SQW_MAX_FREQ))
 			val = 1;
-		else if (val < 14)
-			val = 15 - val;
+		else if (val < (ilog2(M41T80_SQW_MAX_FREQ) - 1))
+			val = ilog2(M41T80_SQW_MAX_FREQ) - val;
 		else
 			return -EINVAL;
 	}
-	/* disable SQW, set SQW frequency & re-enable */
-	almon = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
-	if (almon < 0)
-		return almon;
-	reg_sqw = M41T80_REG_SQW;
-	if (clientdata->features & M41T80_FEATURE_SQ_ALT)
-		reg_sqw = M41T80_REG_WDAY;
-	sqw = i2c_smbus_read_byte_data(client, reg_sqw);
-	if (sqw < 0)
-		return sqw;
-	sqw = (sqw & 0x0f) | (val << 4);
-
-	rc = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
-				       almon & ~M41T80_ALMON_SQWE);
-	if (rc < 0)
-		return rc;
 
-	if (val) {
-		rc = i2c_smbus_write_byte_data(client, reg_sqw, sqw);
-		if (rc < 0)
-			return rc;
+	reg = i2c_smbus_read_byte_data(client, reg_sqw);
+	if (reg < 0)
+		return reg;
 
-		rc = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
-					       almon | M41T80_ALMON_SQWE);
-		if (rc < 0)
-			return rc;
-	}
-	return count;
+	reg = (reg & 0x0f) | (val << 4);
+
+	ret = i2c_smbus_write_byte_data(client, reg_sqw, reg);
+	if (ret < 0)
+		return ret;
+
+	return -EINVAL;
 }
-static DEVICE_ATTR_RW(sqwfreq);
 
-static struct attribute *attrs[] = {
-	&dev_attr_flags.attr,
-	&dev_attr_sqwfreq.attr,
-	NULL,
-};
+static int m41t80_sqw_control(struct clk_hw *hw, bool enable)
+{
+	struct m41t80_data *m41t80 = sqw_to_m41t80_data(hw);
+	struct i2c_client *client = m41t80->client;
+	int ret = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
 
-static struct attribute_group attr_group = {
-	.attrs = attrs,
+	if (ret < 0)
+		return ret;
+
+	if (enable)
+		ret |= M41T80_ALMON_SQWE;
+	else
+		ret &= ~M41T80_ALMON_SQWE;
+
+	return i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, ret);
+}
+
+static int m41t80_sqw_prepare(struct clk_hw *hw)
+{
+	return m41t80_sqw_control(hw, 1);
+}
+
+static void m41t80_sqw_unprepare(struct clk_hw *hw)
+{
+	m41t80_sqw_control(hw, 0);
+}
+
+static int m41t80_sqw_is_prepared(struct clk_hw *hw)
+{
+	struct m41t80_data *m41t80 = sqw_to_m41t80_data(hw);
+	struct i2c_client *client = m41t80->client;
+	int ret = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
+
+	if (ret < 0)
+		return ret;
+
+	return !!(ret & M41T80_ALMON_SQWE);
+}
+
+static const struct clk_ops m41t80_sqw_ops = {
+	.prepare = m41t80_sqw_prepare,
+	.unprepare = m41t80_sqw_unprepare,
+	.is_prepared = m41t80_sqw_is_prepared,
+	.recalc_rate = m41t80_sqw_recalc_rate,
+	.round_rate = m41t80_sqw_round_rate,
+	.set_rate = m41t80_sqw_set_rate,
 };
 
+static struct clk *m41t80_sqw_register_clk(struct m41t80_data *m41t80)
+{
+	struct i2c_client *client = m41t80->client;
+	struct device_node *node = client->dev.of_node;
+	struct clk *clk;
+	struct clk_init_data init;
+	int ret;
+
+	/* First disable the clock */
+	ret = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
+	if (ret < 0)
+		return ERR_PTR(ret);
+	ret = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
+					ret & ~(M41T80_ALMON_SQWE));
+	if (ret < 0)
+		return ERR_PTR(ret);
+
+	init.name = "m41t80-sqw";
+	init.ops = &m41t80_sqw_ops;
+	init.flags = 0;
+	init.parent_names = NULL;
+	init.num_parents = 0;
+	m41t80->sqw.init = &init;
+
+	/* optional override of the clockname */
+	of_property_read_string(node, "clock-output-names", &init.name);
+
+	/* register the clock */
+	clk = clk_register(&client->dev, &m41t80->sqw);
+	if (!IS_ERR(clk))
+		of_clk_add_provider(node, of_clk_src_simple_get, clk);
+
+	return clk;
+}
+#endif
+
 #ifdef CONFIG_RTC_DRV_M41T80_WDT
 /*
  *****************************************************************************
@@ -845,6 +939,7 @@ static int m41t80_probe(struct i2c_client *client,
 	if (!m41t80_data)
 		return -ENOMEM;
 
+	m41t80_data->client = client;
 	if (client->dev.of_node)
 		m41t80_data->features = (unsigned long)
 			of_device_get_match_data(&client->dev);
@@ -937,6 +1032,10 @@ static int m41t80_probe(struct i2c_client *client,
 		}
 	}
 #endif
+#ifdef CONFIG_COMMON_CLK
+	if (m41t80_data->features & M41T80_FEATURE_SQ)
+		m41t80_sqw_register_clk(m41t80_data);
+#endif
 	return 0;
 }