[PATCH 0/5] AT91: sckc improvements

[PATCH 0/5] AT91: sckc improvements

[Alexandre Belloni]

Hi,

This patch set improves the slow clock controller driver.

The first patch simply moves some code around to avoid having extern
functions declared.

The second patch adds support for the SCKC found on sama5d4 and later.
It is notably missing the OSC32EN bit.
The third and fourth patches make use of this new driver (DT ABI is not
broken \o/)

Finally, there is an optimization. Trying to find wether the slow
oscillator is already stable to avoid waiting 1.2s twice in the boot
process.


Alexandre Belloni (5):
  clk: at91: move slow clock controller clocks to sckc.c
  clk: at91: Add sama5d4 sckc support
  ARM: dts: at91: sama5d4: use proper sckc compatible
  ARM: dts: at91: sama5d2: use correct sckc compatible
  clk: at91: sckc: optimize boot time

 .../devicetree/bindings/clock/at91-clock.txt       |   3 +-
 arch/arm/boot/dts/sama5d2.dtsi                     |  26 +-
 arch/arm/boot/dts/sama5d4.dtsi                     |  27 +-
 drivers/clk/at91/clk-slow.c                        | 353 ----------------
 drivers/clk/at91/sckc.c                            | 447 ++++++++++++++++++++-
 drivers/clk/at91/sckc.h                            |  22 -
 6 files changed, 456 insertions(+), 422 deletions(-)
 delete mode 100644 drivers/clk/at91/sckc.h

-- 
2.9.3

[PATCH 1/5] clk: at91: move slow clock controller clocks to sckc.c

[Alexandre Belloni]

Move all clocks related to the slow clock controller to sckc.c. This avoids
extern definitions and allows to remove sckc.h

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
 drivers/clk/at91/clk-slow.c | 353 --------------------------------------------
 drivers/clk/at91/sckc.c     | 352 ++++++++++++++++++++++++++++++++++++++++++-
 drivers/clk/at91/sckc.h     |  22 ---
 3 files changed, 351 insertions(+), 376 deletions(-)
 delete mode 100644 drivers/clk/at91/sckc.h

diff --git a/drivers/clk/at91/clk-slow.c b/drivers/clk/at91/clk-slow.c
index 61090b1146cf..31908331e883 100644
--- a/drivers/clk/at91/clk-slow.c
+++ b/drivers/clk/at91/clk-slow.c
@@ -13,42 +13,11 @@
 #include <linux/clk-provider.h>
 #include <linux/clkdev.h>
 #include <linux/clk/at91_pmc.h>
-#include <linux/delay.h>
 #include <linux/of.h>
 #include <linux/mfd/syscon.h>
 #include <linux/regmap.h>
 
 #include "pmc.h"
-#include "sckc.h"
-
-#define SLOW_CLOCK_FREQ		32768
-#define SLOWCK_SW_CYCLES	5
-#define SLOWCK_SW_TIME_USEC	((SLOWCK_SW_CYCLES * USEC_PER_SEC) / \
-				 SLOW_CLOCK_FREQ)
-
-#define	AT91_SCKC_CR			0x00
-#define		AT91_SCKC_RCEN		(1 << 0)
-#define		AT91_SCKC_OSC32EN	(1 << 1)
-#define		AT91_SCKC_OSC32BYP	(1 << 2)
-#define		AT91_SCKC_OSCSEL	(1 << 3)
-
-struct clk_slow_osc {
-	struct clk_hw hw;
-	void __iomem *sckcr;
-	unsigned long startup_usec;
-};
-
-#define to_clk_slow_osc(hw) container_of(hw, struct clk_slow_osc, hw)
-
-struct clk_slow_rc_osc {
-	struct clk_hw hw;
-	void __iomem *sckcr;
-	unsigned long frequency;
-	unsigned long accuracy;
-	unsigned long startup_usec;
-};
-
-#define to_clk_slow_rc_osc(hw) container_of(hw, struct clk_slow_rc_osc, hw)
 
 struct clk_sam9260_slow {
 	struct clk_hw hw;
@@ -57,328 +26,6 @@ struct clk_sam9260_slow {
 
 #define to_clk_sam9260_slow(hw) container_of(hw, struct clk_sam9260_slow, hw)
 
-struct clk_sam9x5_slow {
-	struct clk_hw hw;
-	void __iomem *sckcr;
-	u8 parent;
-};
-
-#define to_clk_sam9x5_slow(hw) container_of(hw, struct clk_sam9x5_slow, hw)
-
-static int clk_slow_osc_prepare(struct clk_hw *hw)
-{
-	struct clk_slow_osc *osc = to_clk_slow_osc(hw);
-	void __iomem *sckcr = osc->sckcr;
-	u32 tmp = readl(sckcr);
-
-	if (tmp & AT91_SCKC_OSC32BYP)
-		return 0;
-
-	writel(tmp | AT91_SCKC_OSC32EN, sckcr);
-
-	usleep_range(osc->startup_usec, osc->startup_usec + 1);
-
-	return 0;
-}
-
-static void clk_slow_osc_unprepare(struct clk_hw *hw)
-{
-	struct clk_slow_osc *osc = to_clk_slow_osc(hw);
-	void __iomem *sckcr = osc->sckcr;
-	u32 tmp = readl(sckcr);
-
-	if (tmp & AT91_SCKC_OSC32BYP)
-		return;
-
-	writel(tmp & ~AT91_SCKC_OSC32EN, sckcr);
-}
-
-static int clk_slow_osc_is_prepared(struct clk_hw *hw)
-{
-	struct clk_slow_osc *osc = to_clk_slow_osc(hw);
-	void __iomem *sckcr = osc->sckcr;
-	u32 tmp = readl(sckcr);
-
-	if (tmp & AT91_SCKC_OSC32BYP)
-		return 1;
-
-	return !!(tmp & AT91_SCKC_OSC32EN);
-}
-
-static const struct clk_ops slow_osc_ops = {
-	.prepare = clk_slow_osc_prepare,
-	.unprepare = clk_slow_osc_unprepare,
-	.is_prepared = clk_slow_osc_is_prepared,
-};
-
-static struct clk * __init
-at91_clk_register_slow_osc(void __iomem *sckcr,
-			   const char *name,
-			   const char *parent_name,
-			   unsigned long startup,
-			   bool bypass)
-{
-	struct clk_slow_osc *osc;
-	struct clk *clk = NULL;
-	struct clk_init_data init;
-
-	if (!sckcr || !name || !parent_name)
-		return ERR_PTR(-EINVAL);
-
-	osc = kzalloc(sizeof(*osc), GFP_KERNEL);
-	if (!osc)
-		return ERR_PTR(-ENOMEM);
-
-	init.name = name;
-	init.ops = &slow_osc_ops;
-	init.parent_names = &parent_name;
-	init.num_parents = 1;
-	init.flags = CLK_IGNORE_UNUSED;
-
-	osc->hw.init = &init;
-	osc->sckcr = sckcr;
-	osc->startup_usec = startup;
-
-	if (bypass)
-		writel((readl(sckcr) & ~AT91_SCKC_OSC32EN) | AT91_SCKC_OSC32BYP,
-		       sckcr);
-
-	clk = clk_register(NULL, &osc->hw);
-	if (IS_ERR(clk))
-		kfree(osc);
-
-	return clk;
-}
-
-void __init of_at91sam9x5_clk_slow_osc_setup(struct device_node *np,
-					     void __iomem *sckcr)
-{
-	struct clk *clk;
-	const char *parent_name;
-	const char *name = np->name;
-	u32 startup;
-	bool bypass;
-
-	parent_name = of_clk_get_parent_name(np, 0);
-	of_property_read_string(np, "clock-output-names", &name);
-	of_property_read_u32(np, "atmel,startup-time-usec", &startup);
-	bypass = of_property_read_bool(np, "atmel,osc-bypass");
-
-	clk = at91_clk_register_slow_osc(sckcr, name, parent_name, startup,
-					 bypass);
-	if (IS_ERR(clk))
-		return;
-
-	of_clk_add_provider(np, of_clk_src_simple_get, clk);
-}
-
-static unsigned long clk_slow_rc_osc_recalc_rate(struct clk_hw *hw,
-						 unsigned long parent_rate)
-{
-	struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
-
-	return osc->frequency;
-}
-
-static unsigned long clk_slow_rc_osc_recalc_accuracy(struct clk_hw *hw,
-						     unsigned long parent_acc)
-{
-	struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
-
-	return osc->accuracy;
-}
-
-static int clk_slow_rc_osc_prepare(struct clk_hw *hw)
-{
-	struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
-	void __iomem *sckcr = osc->sckcr;
-
-	writel(readl(sckcr) | AT91_SCKC_RCEN, sckcr);
-
-	usleep_range(osc->startup_usec, osc->startup_usec + 1);
-
-	return 0;
-}
-
-static void clk_slow_rc_osc_unprepare(struct clk_hw *hw)
-{
-	struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
-	void __iomem *sckcr = osc->sckcr;
-
-	writel(readl(sckcr) & ~AT91_SCKC_RCEN, sckcr);
-}
-
-static int clk_slow_rc_osc_is_prepared(struct clk_hw *hw)
-{
-	struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
-
-	return !!(readl(osc->sckcr) & AT91_SCKC_RCEN);
-}
-
-static const struct clk_ops slow_rc_osc_ops = {
-	.prepare = clk_slow_rc_osc_prepare,
-	.unprepare = clk_slow_rc_osc_unprepare,
-	.is_prepared = clk_slow_rc_osc_is_prepared,
-	.recalc_rate = clk_slow_rc_osc_recalc_rate,
-	.recalc_accuracy = clk_slow_rc_osc_recalc_accuracy,
-};
-
-static struct clk * __init
-at91_clk_register_slow_rc_osc(void __iomem *sckcr,
-			      const char *name,
-			      unsigned long frequency,
-			      unsigned long accuracy,
-			      unsigned long startup)
-{
-	struct clk_slow_rc_osc *osc;
-	struct clk *clk = NULL;
-	struct clk_init_data init;
-
-	if (!sckcr || !name)
-		return ERR_PTR(-EINVAL);
-
-	osc = kzalloc(sizeof(*osc), GFP_KERNEL);
-	if (!osc)
-		return ERR_PTR(-ENOMEM);
-
-	init.name = name;
-	init.ops = &slow_rc_osc_ops;
-	init.parent_names = NULL;
-	init.num_parents = 0;
-	init.flags = CLK_IGNORE_UNUSED;
-
-	osc->hw.init = &init;
-	osc->sckcr = sckcr;
-	osc->frequency = frequency;
-	osc->accuracy = accuracy;
-	osc->startup_usec = startup;
-
-	clk = clk_register(NULL, &osc->hw);
-	if (IS_ERR(clk))
-		kfree(osc);
-
-	return clk;
-}
-
-void __init of_at91sam9x5_clk_slow_rc_osc_setup(struct device_node *np,
-						void __iomem *sckcr)
-{
-	struct clk *clk;
-	u32 frequency = 0;
-	u32 accuracy = 0;
-	u32 startup = 0;
-	const char *name = np->name;
-
-	of_property_read_string(np, "clock-output-names", &name);
-	of_property_read_u32(np, "clock-frequency", &frequency);
-	of_property_read_u32(np, "clock-accuracy", &accuracy);
-	of_property_read_u32(np, "atmel,startup-time-usec", &startup);
-
-	clk = at91_clk_register_slow_rc_osc(sckcr, name, frequency, accuracy,
-					    startup);
-	if (IS_ERR(clk))
-		return;
-
-	of_clk_add_provider(np, of_clk_src_simple_get, clk);
-}
-
-static int clk_sam9x5_slow_set_parent(struct clk_hw *hw, u8 index)
-{
-	struct clk_sam9x5_slow *slowck = to_clk_sam9x5_slow(hw);
-	void __iomem *sckcr = slowck->sckcr;
-	u32 tmp;
-
-	if (index > 1)
-		return -EINVAL;
-
-	tmp = readl(sckcr);
-
-	if ((!index && !(tmp & AT91_SCKC_OSCSEL)) ||
-	    (index && (tmp & AT91_SCKC_OSCSEL)))
-		return 0;
-
-	if (index)
-		tmp |= AT91_SCKC_OSCSEL;
-	else
-		tmp &= ~AT91_SCKC_OSCSEL;
-
-	writel(tmp, sckcr);
-
-	usleep_range(SLOWCK_SW_TIME_USEC, SLOWCK_SW_TIME_USEC + 1);
-
-	return 0;
-}
-
-static u8 clk_sam9x5_slow_get_parent(struct clk_hw *hw)
-{
-	struct clk_sam9x5_slow *slowck = to_clk_sam9x5_slow(hw);
-
-	return !!(readl(slowck->sckcr) & AT91_SCKC_OSCSEL);
-}
-
-static const struct clk_ops sam9x5_slow_ops = {
-	.set_parent = clk_sam9x5_slow_set_parent,
-	.get_parent = clk_sam9x5_slow_get_parent,
-};
-
-static struct clk * __init
-at91_clk_register_sam9x5_slow(void __iomem *sckcr,
-			      const char *name,
-			      const char **parent_names,
-			      int num_parents)
-{
-	struct clk_sam9x5_slow *slowck;
-	struct clk *clk = NULL;
-	struct clk_init_data init;
-
-	if (!sckcr || !name || !parent_names || !num_parents)
-		return ERR_PTR(-EINVAL);
-
-	slowck = kzalloc(sizeof(*slowck), GFP_KERNEL);
-	if (!slowck)
-		return ERR_PTR(-ENOMEM);
-
-	init.name = name;
-	init.ops = &sam9x5_slow_ops;
-	init.parent_names = parent_names;
-	init.num_parents = num_parents;
-	init.flags = 0;
-
-	slowck->hw.init = &init;
-	slowck->sckcr = sckcr;
-	slowck->parent = !!(readl(sckcr) & AT91_SCKC_OSCSEL);
-
-	clk = clk_register(NULL, &slowck->hw);
-	if (IS_ERR(clk))
-		kfree(slowck);
-
-	return clk;
-}
-
-void __init of_at91sam9x5_clk_slow_setup(struct device_node *np,
-					 void __iomem *sckcr)
-{
-	struct clk *clk;
-	const char *parent_names[2];
-	unsigned int num_parents;
-	const char *name = np->name;
-
-	num_parents = of_clk_get_parent_count(np);
-	if (num_parents == 0 || num_parents > 2)
-		return;
-
-	of_clk_parent_fill(np, parent_names, num_parents);
-
-	of_property_read_string(np, "clock-output-names", &name);
-
-	clk = at91_clk_register_sam9x5_slow(sckcr, name, parent_names,
-					    num_parents);
-	if (IS_ERR(clk))
-		return;
-
-	of_clk_add_provider(np, of_clk_src_simple_get, clk);
-}
-
 static u8 clk_sam9260_slow_get_parent(struct clk_hw *hw)
 {
 	struct clk_sam9260_slow *slowck = to_clk_sam9260_slow(hw);
diff --git a/drivers/clk/at91/sckc.c b/drivers/clk/at91/sckc.c
index 1184d76a7ab7..f1b00b1d7132 100644
--- a/drivers/clk/at91/sckc.c
+++ b/drivers/clk/at91/sckc.c
@@ -12,11 +12,361 @@
 
 #include <linux/clk-provider.h>
 #include <linux/clkdev.h>
+#include <linux/delay.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/io.h>
 
-#include "sckc.h"
+#define SLOW_CLOCK_FREQ		32768
+#define SLOWCK_SW_CYCLES	5
+#define SLOWCK_SW_TIME_USEC	((SLOWCK_SW_CYCLES * USEC_PER_SEC) / \
+				 SLOW_CLOCK_FREQ)
+
+#define	AT91_SCKC_CR			0x00
+#define		AT91_SCKC_RCEN		(1 << 0)
+#define		AT91_SCKC_OSC32EN	(1 << 1)
+#define		AT91_SCKC_OSC32BYP	(1 << 2)
+#define		AT91_SCKC_OSCSEL	(1 << 3)
+
+struct clk_slow_osc {
+	struct clk_hw hw;
+	void __iomem *sckcr;
+	unsigned long startup_usec;
+};
+
+#define to_clk_slow_osc(hw) container_of(hw, struct clk_slow_osc, hw)
+
+struct clk_slow_rc_osc {
+	struct clk_hw hw;
+	void __iomem *sckcr;
+	unsigned long frequency;
+	unsigned long accuracy;
+	unsigned long startup_usec;
+};
+
+#define to_clk_slow_rc_osc(hw) container_of(hw, struct clk_slow_rc_osc, hw)
+
+struct clk_sam9x5_slow {
+	struct clk_hw hw;
+	void __iomem *sckcr;
+	u8 parent;
+};
+
+#define to_clk_sam9x5_slow(hw) container_of(hw, struct clk_sam9x5_slow, hw)
+
+static int clk_slow_osc_prepare(struct clk_hw *hw)
+{
+	struct clk_slow_osc *osc = to_clk_slow_osc(hw);
+	void __iomem *sckcr = osc->sckcr;
+	u32 tmp = readl(sckcr);
+
+	if (tmp & AT91_SCKC_OSC32BYP)
+		return 0;
+
+	writel(tmp | AT91_SCKC_OSC32EN, sckcr);
+
+	usleep_range(osc->startup_usec, osc->startup_usec + 1);
+
+	return 0;
+}
+
+static void clk_slow_osc_unprepare(struct clk_hw *hw)
+{
+	struct clk_slow_osc *osc = to_clk_slow_osc(hw);
+	void __iomem *sckcr = osc->sckcr;
+	u32 tmp = readl(sckcr);
+
+	if (tmp & AT91_SCKC_OSC32BYP)
+		return;
+
+	writel(tmp & ~AT91_SCKC_OSC32EN, sckcr);
+}
+
+static int clk_slow_osc_is_prepared(struct clk_hw *hw)
+{
+	struct clk_slow_osc *osc = to_clk_slow_osc(hw);
+	void __iomem *sckcr = osc->sckcr;
+	u32 tmp = readl(sckcr);
+
+	if (tmp & AT91_SCKC_OSC32BYP)
+		return 1;
+
+	return !!(tmp & AT91_SCKC_OSC32EN);
+}
+
+static const struct clk_ops slow_osc_ops = {
+	.prepare = clk_slow_osc_prepare,
+	.unprepare = clk_slow_osc_unprepare,
+	.is_prepared = clk_slow_osc_is_prepared,
+};
+
+static struct clk * __init
+at91_clk_register_slow_osc(void __iomem *sckcr,
+			   const char *name,
+			   const char *parent_name,
+			   unsigned long startup,
+			   bool bypass)
+{
+	struct clk_slow_osc *osc;
+	struct clk *clk = NULL;
+	struct clk_init_data init;
+
+	if (!sckcr || !name || !parent_name)
+		return ERR_PTR(-EINVAL);
+
+	osc = kzalloc(sizeof(*osc), GFP_KERNEL);
+	if (!osc)
+		return ERR_PTR(-ENOMEM);
+
+	init.name = name;
+	init.ops = &slow_osc_ops;
+	init.parent_names = &parent_name;
+	init.num_parents = 1;
+	init.flags = CLK_IGNORE_UNUSED;
+
+	osc->hw.init = &init;
+	osc->sckcr = sckcr;
+	osc->startup_usec = startup;
+
+	if (bypass)
+		writel((readl(sckcr) & ~AT91_SCKC_OSC32EN) | AT91_SCKC_OSC32BYP,
+		       sckcr);
+
+	clk = clk_register(NULL, &osc->hw);
+	if (IS_ERR(clk))
+		kfree(osc);
+
+	return clk;
+}
+
+void __init of_at91sam9x5_clk_slow_osc_setup(struct device_node *np,
+					     void __iomem *sckcr)
+{
+	struct clk *clk;
+	const char *parent_name;
+	const char *name = np->name;
+	u32 startup;
+	bool bypass;
+
+	parent_name = of_clk_get_parent_name(np, 0);
+	of_property_read_string(np, "clock-output-names", &name);
+	of_property_read_u32(np, "atmel,startup-time-usec", &startup);
+	bypass = of_property_read_bool(np, "atmel,osc-bypass");
+
+	clk = at91_clk_register_slow_osc(sckcr, name, parent_name, startup,
+					 bypass);
+	if (IS_ERR(clk))
+		return;
+
+	of_clk_add_provider(np, of_clk_src_simple_get, clk);
+}
+
+static unsigned long clk_slow_rc_osc_recalc_rate(struct clk_hw *hw,
+						 unsigned long parent_rate)
+{
+	struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
+
+	return osc->frequency;
+}
+
+static unsigned long clk_slow_rc_osc_recalc_accuracy(struct clk_hw *hw,
+						     unsigned long parent_acc)
+{
+	struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
+
+	return osc->accuracy;
+}
+
+static int clk_slow_rc_osc_prepare(struct clk_hw *hw)
+{
+	struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
+	void __iomem *sckcr = osc->sckcr;
+
+	writel(readl(sckcr) | AT91_SCKC_RCEN, sckcr);
+
+	usleep_range(osc->startup_usec, osc->startup_usec + 1);
+
+	return 0;
+}
+
+static void clk_slow_rc_osc_unprepare(struct clk_hw *hw)
+{
+	struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
+	void __iomem *sckcr = osc->sckcr;
+
+	writel(readl(sckcr) & ~AT91_SCKC_RCEN, sckcr);
+}
+
+static int clk_slow_rc_osc_is_prepared(struct clk_hw *hw)
+{
+	struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
+
+	return !!(readl(osc->sckcr) & AT91_SCKC_RCEN);
+}
+
+static const struct clk_ops slow_rc_osc_ops = {
+	.prepare = clk_slow_rc_osc_prepare,
+	.unprepare = clk_slow_rc_osc_unprepare,
+	.is_prepared = clk_slow_rc_osc_is_prepared,
+	.recalc_rate = clk_slow_rc_osc_recalc_rate,
+	.recalc_accuracy = clk_slow_rc_osc_recalc_accuracy,
+};
+
+static struct clk * __init
+at91_clk_register_slow_rc_osc(void __iomem *sckcr,
+			      const char *name,
+			      unsigned long frequency,
+			      unsigned long accuracy,
+			      unsigned long startup)
+{
+	struct clk_slow_rc_osc *osc;
+	struct clk *clk = NULL;
+	struct clk_init_data init;
+
+	if (!sckcr || !name)
+		return ERR_PTR(-EINVAL);
+
+	osc = kzalloc(sizeof(*osc), GFP_KERNEL);
+	if (!osc)
+		return ERR_PTR(-ENOMEM);
+
+	init.name = name;
+	init.ops = &slow_rc_osc_ops;
+	init.parent_names = NULL;
+	init.num_parents = 0;
+	init.flags = CLK_IGNORE_UNUSED;
+
+	osc->hw.init = &init;
+	osc->sckcr = sckcr;
+	osc->frequency = frequency;
+	osc->accuracy = accuracy;
+	osc->startup_usec = startup;
+
+	clk = clk_register(NULL, &osc->hw);
+	if (IS_ERR(clk))
+		kfree(osc);
+
+	return clk;
+}
+
+void __init of_at91sam9x5_clk_slow_rc_osc_setup(struct device_node *np,
+						void __iomem *sckcr)
+{
+	struct clk *clk;
+	u32 frequency = 0;
+	u32 accuracy = 0;
+	u32 startup = 0;
+	const char *name = np->name;
+
+	of_property_read_string(np, "clock-output-names", &name);
+	of_property_read_u32(np, "clock-frequency", &frequency);
+	of_property_read_u32(np, "clock-accuracy", &accuracy);
+	of_property_read_u32(np, "atmel,startup-time-usec", &startup);
+
+	clk = at91_clk_register_slow_rc_osc(sckcr, name, frequency, accuracy,
+					    startup);
+	if (IS_ERR(clk))
+		return;
+
+	of_clk_add_provider(np, of_clk_src_simple_get, clk);
+}
+
+static int clk_sam9x5_slow_set_parent(struct clk_hw *hw, u8 index)
+{
+	struct clk_sam9x5_slow *slowck = to_clk_sam9x5_slow(hw);
+	void __iomem *sckcr = slowck->sckcr;
+	u32 tmp;
+
+	if (index > 1)
+		return -EINVAL;
+
+	tmp = readl(sckcr);
+
+	if ((!index && !(tmp & AT91_SCKC_OSCSEL)) ||
+	    (index && (tmp & AT91_SCKC_OSCSEL)))
+		return 0;
+
+	if (index)
+		tmp |= AT91_SCKC_OSCSEL;
+	else
+		tmp &= ~AT91_SCKC_OSCSEL;
+
+	writel(tmp, sckcr);
+
+	usleep_range(SLOWCK_SW_TIME_USEC, SLOWCK_SW_TIME_USEC + 1);
+
+	return 0;
+}
+
+static u8 clk_sam9x5_slow_get_parent(struct clk_hw *hw)
+{
+	struct clk_sam9x5_slow *slowck = to_clk_sam9x5_slow(hw);
+
+	return !!(readl(slowck->sckcr) & AT91_SCKC_OSCSEL);
+}
+
+static const struct clk_ops sam9x5_slow_ops = {
+	.set_parent = clk_sam9x5_slow_set_parent,
+	.get_parent = clk_sam9x5_slow_get_parent,
+};
+
+static struct clk * __init
+at91_clk_register_sam9x5_slow(void __iomem *sckcr,
+			      const char *name,
+			      const char **parent_names,
+			      int num_parents)
+{
+	struct clk_sam9x5_slow *slowck;
+	struct clk *clk = NULL;
+	struct clk_init_data init;
+
+	if (!sckcr || !name || !parent_names || !num_parents)
+		return ERR_PTR(-EINVAL);
+
+	slowck = kzalloc(sizeof(*slowck), GFP_KERNEL);
+	if (!slowck)
+		return ERR_PTR(-ENOMEM);
+
+	init.name = name;
+	init.ops = &sam9x5_slow_ops;
+	init.parent_names = parent_names;
+	init.num_parents = num_parents;
+	init.flags = 0;
+
+	slowck->hw.init = &init;
+	slowck->sckcr = sckcr;
+	slowck->parent = !!(readl(sckcr) & AT91_SCKC_OSCSEL);
+
+	clk = clk_register(NULL, &slowck->hw);
+	if (IS_ERR(clk))
+		kfree(slowck);
+
+	return clk;
+}
+
+void __init of_at91sam9x5_clk_slow_setup(struct device_node *np,
+					 void __iomem *sckcr)
+{
+	struct clk *clk;
+	const char *parent_names[2];
+	unsigned int num_parents;
+	const char *name = np->name;
+
+	num_parents = of_clk_get_parent_count(np);
+	if (num_parents == 0 || num_parents > 2)
+		return;
+
+	of_clk_parent_fill(np, parent_names, num_parents);
+
+	of_property_read_string(np, "clock-output-names", &name);
+
+	clk = at91_clk_register_sam9x5_slow(sckcr, name, parent_names,
+					    num_parents);
+	if (IS_ERR(clk))
+		return;
+
+	of_clk_add_provider(np, of_clk_src_simple_get, clk);
+}
 
 static const struct of_device_id sckc_clk_ids[] __initconst = {
 	/* Slow clock */
diff --git a/drivers/clk/at91/sckc.h b/drivers/clk/at91/sckc.h
deleted file mode 100644
index 836fcf59820f..000000000000
--- a/drivers/clk/at91/sckc.h
+++ /dev/null
@@ -1,22 +0,0 @@
-/*
- * drivers/clk/at91/sckc.h
- *
- *  Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- */
-
-#ifndef __AT91_SCKC_H_
-#define __AT91_SCKC_H_
-
-extern void __init of_at91sam9x5_clk_slow_osc_setup(struct device_node *np,
-						    void __iomem *sckcr);
-extern void __init of_at91sam9x5_clk_slow_rc_osc_setup(struct device_node *np,
-						       void __iomem *sckcr);
-extern void __init of_at91sam9x5_clk_slow_setup(struct device_node *np,
-						void __iomem *sckcr);
-
-#endif /* __AT91_SCKC_H_ */
-- 
2.9.3

[PATCH 2/5] clk: at91: Add sama5d4 sckc support

[Alexandre Belloni]

Starting with sama5d4, the crystal oscillator is always enabled at startup
and the SCKC doesn't have an OSC32EN bit anymore.

Add support for that new controller.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
 .../devicetree/bindings/clock/at91-clock.txt       |  3 +-
 drivers/clk/at91/sckc.c                            | 95 ++++++++++++++++++++++
 2 files changed, 97 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/clock/at91-clock.txt b/Documentation/devicetree/bindings/clock/at91-clock.txt
index 181bc8ac4e3a..5f3ad65daf69 100644
--- a/Documentation/devicetree/bindings/clock/at91-clock.txt
+++ b/Documentation/devicetree/bindings/clock/at91-clock.txt
@@ -6,7 +6,8 @@ This binding uses the common clock binding[1].
 
 Required properties:
 - compatible : shall be one of the following:
-	"atmel,at91sam9x5-sckc":
+	"atmel,at91sam9x5-sckc" or
+	"atmel,sama5d4-sckc":
 		at91 SCKC (Slow Clock Controller)
 		This node contains the slow clock definitions.
 
diff --git a/drivers/clk/at91/sckc.c b/drivers/clk/at91/sckc.c
index f1b00b1d7132..88907c48092b 100644
--- a/drivers/clk/at91/sckc.c
+++ b/drivers/clk/at91/sckc.c
@@ -36,6 +36,15 @@ struct clk_slow_osc {
 
 #define to_clk_slow_osc(hw) container_of(hw, struct clk_slow_osc, hw)
 
+struct clk_sama5d4_slow_osc {
+	struct clk_hw hw;
+	void __iomem *sckcr;
+	unsigned long startup_usec;
+	bool prepared;
+};
+
+#define to_clk_sama5d4_slow_osc(hw) container_of(hw, struct clk_sama5d4_slow_osc, hw)
+
 struct clk_slow_rc_osc {
 	struct clk_hw hw;
 	void __iomem *sckcr;
@@ -405,3 +414,89 @@ static void __init of_at91sam9x5_sckc_setup(struct device_node *np)
 }
 CLK_OF_DECLARE(at91sam9x5_clk_sckc, "atmel,at91sam9x5-sckc",
 	       of_at91sam9x5_sckc_setup);
+
+static int clk_sama5d4_slow_osc_prepare(struct clk_hw *hw)
+{
+	struct clk_sama5d4_slow_osc *osc = to_clk_sama5d4_slow_osc(hw);
+
+	if (osc->prepared)
+		return 0;
+
+	/*
+	 * Assume that if it has already been selected (for example by the
+	 * bootloader), enough time has aready passed.
+	 */
+	if ((readl(osc->sckcr) | AT91_SCKC_OSCSEL)) {
+		osc->prepared = true;
+		return 0;
+	}
+
+	usleep_range(osc->startup_usec, osc->startup_usec + 1);
+	osc->prepared = true;
+
+	return 0;
+}
+
+static int clk_sama5d4_slow_osc_is_prepared(struct clk_hw *hw)
+{
+	struct clk_sama5d4_slow_osc *osc = to_clk_sama5d4_slow_osc(hw);
+
+	return osc->prepared;
+}
+
+static const struct clk_ops sama5d4_slow_osc_ops = {
+	.prepare = clk_sama5d4_slow_osc_prepare,
+	.is_prepared = clk_sama5d4_slow_osc_is_prepared,
+};
+
+static void __init of_sama5d4_sckc_setup(struct device_node *np)
+{
+	void __iomem *regbase = of_iomap(np, 0);
+	struct clk *clk = NULL;
+	struct clk_sama5d4_slow_osc *osc;
+	struct clk_init_data init;
+	const char *xtal_name;
+	const char *parent_names[2] = { "slow_rc_osc", "slow_osc" };
+	bool bypass;
+
+	if (!regbase)
+		return;
+
+	xtal_name = of_clk_get_parent_name(np, 0);
+
+	bypass = of_property_read_bool(np, "atmel,osc-bypass");
+
+	osc = kzalloc(sizeof(*osc), GFP_KERNEL);
+	if (!osc)
+		return;
+
+	init.name = parent_names[1];
+	init.ops = &sama5d4_slow_osc_ops;
+	init.parent_names = &xtal_name;
+	init.num_parents = 1;
+	init.flags = CLK_IGNORE_UNUSED;
+
+	osc->hw.init = &init;
+	osc->sckcr = regbase;
+	osc->startup_usec = 1200000;
+
+	if (bypass)
+		writel((readl(regbase) | AT91_SCKC_OSC32BYP), regbase);
+
+	clk = clk_register(NULL, &osc->hw);
+	if (IS_ERR(clk))
+		kfree(osc);
+
+	clk = at91_clk_register_slow_rc_osc(regbase, parent_names[0], 32768,
+					    250000000, 75);
+	if (IS_ERR(clk))
+		return;
+
+	clk = at91_clk_register_sam9x5_slow(regbase, "slowck", parent_names, 2);
+	if (IS_ERR(clk))
+		return;
+
+	of_clk_add_provider(np, of_clk_src_simple_get, clk);
+}
+CLK_OF_DECLARE(sama5d4_clk_sckc, "atmel,sama5d4-sckc",
+	       of_sama5d4_sckc_setup);
-- 
2.9.3

[PATCH 3/5] ARM: dts: at91: sama5d4: use proper sckc compatible

[Alexandre Belloni]

Now that there is support for the sama5d4 slow clock controller, use its
driver.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
 arch/arm/boot/dts/sama5d4.dtsi | 27 ++++-----------------------
 1 file changed, 4 insertions(+), 23 deletions(-)

diff --git a/arch/arm/boot/dts/sama5d4.dtsi b/arch/arm/boot/dts/sama5d4.dtsi
index 65e725fb5679..fe094263595c 100644
--- a/arch/arm/boot/dts/sama5d4.dtsi
+++ b/arch/arm/boot/dts/sama5d4.dtsi
@@ -1314,30 +1314,11 @@
 				status = "disabled";
 			};
 
-			sckc@fc068650 {
-				compatible = "atmel,at91sam9x5-sckc";
+			clk32k: sckc@fc068650 {
+				compatible = "atmel,sama5d4-sckc";
 				reg = <0xfc068650 0x4>;
-
-				slow_rc_osc: slow_rc_osc {
-					compatible = "atmel,at91sam9x5-clk-slow-rc-osc";
-					#clock-cells = <0>;
-					clock-frequency = <32768>;
-					clock-accuracy = <250000000>;
-					atmel,startup-time-usec = <75>;
-				};
-
-				slow_osc: slow_osc {
-					compatible = "atmel,at91sam9x5-clk-slow-osc";
-					#clock-cells = <0>;
-					clocks = <&slow_xtal>;
-					atmel,startup-time-usec = <1200000>;
-				};
-
-				clk32k: slowck {
-					compatible = "atmel,at91sam9x5-clk-slow";
-					#clock-cells = <0>;
-					clocks = <&slow_rc_osc &slow_osc>;
-				};
+				#clock-cells = <0>;
+				clocks = <&slow_xtal>;
 			};
 
 			rtc@fc0686b0 {
-- 
2.9.3

[PATCH 4/5] ARM: dts: at91: sama5d2: use correct sckc compatible

[Alexandre Belloni]

the sama5d2 sckc is actually sama5d4 compatible

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
 arch/arm/boot/dts/sama5d2.dtsi | 26 ++++----------------------
 1 file changed, 4 insertions(+), 22 deletions(-)

diff --git a/arch/arm/boot/dts/sama5d2.dtsi b/arch/arm/boot/dts/sama5d2.dtsi
index 353d0e5ec83b..2e49f10f93fa 100644
--- a/arch/arm/boot/dts/sama5d2.dtsi
+++ b/arch/arm/boot/dts/sama5d2.dtsi
@@ -1059,30 +1059,12 @@
 				status = "disabled";
 			};
 
-			sckc@f8048050 {
-				compatible = "atmel,at91sam9x5-sckc";
+			clk32k: sckc@f8048050 {
+				compatible = "atmel,sama5d4-sckc";
 				reg = <0xf8048050 0x4>;
 
-				slow_rc_osc: slow_rc_osc {
-					compatible = "atmel,at91sam9x5-clk-slow-rc-osc";
-					#clock-cells = <0>;
-					clock-frequency = <32768>;
-					clock-accuracy = <250000000>;
-					atmel,startup-time-usec = <75>;
-				};
-
-				slow_osc: slow_osc {
-					compatible = "atmel,at91sam9x5-clk-slow-osc";
-					#clock-cells = <0>;
-					clocks = <&slow_xtal>;
-					atmel,startup-time-usec = <1200000>;
-				};
-
-				clk32k: slowck {
-					compatible = "atmel,at91sam9x5-clk-slow";
-					#clock-cells = <0>;
-					clocks = <&slow_rc_osc &slow_osc>;
-				};
+				clocks = <&slow_xtal>;
+				#clock-cells = <0>;
 			};
 
 			rtc@f80480b0 {
-- 
2.9.3

[PATCH 5/5] clk: at91: sckc: optimize boot time

[Alexandre Belloni]

Assume that if the oscillator is enabled (OSC32EN bit is present), the
delay has already elapsed as the bootloader probably waited for the
oscillator to settle. This could waste up to 1.2s.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
 drivers/clk/at91/sckc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clk/at91/sckc.c b/drivers/clk/at91/sckc.c
index 88907c48092b..b0a41170309f 100644
--- a/drivers/clk/at91/sckc.c
+++ b/drivers/clk/at91/sckc.c
@@ -69,7 +69,7 @@ static int clk_slow_osc_prepare(struct clk_hw *hw)
 	void __iomem *sckcr = osc->sckcr;
 	u32 tmp = readl(sckcr);
 
-	if (tmp & AT91_SCKC_OSC32BYP)
+	if (tmp & (AT91_SCKC_OSC32BYP | AT91_SCKC_OSC32EN))
 		return 0;
 
 	writel(tmp | AT91_SCKC_OSC32EN, sckcr);
-- 
2.9.3