[PATCH 18/19] clk: at91: clk-utmi: add utmi support for sama7g5

[Claudiu Beznea]

Add UTMI support for SAMA7G5. SAMA7G5's UTMI control is done via
XTALF register. Values written at bits 2..0 in this register
correspond to the on board crystal oscillator frequency.

Signed-off-by: Claudiu Beznea <claudiu.beznea at microchip.com>
---
 drivers/clk/at91/clk-utmi.c  | 103 ++++++++++++++++++++++++++++++++++++++++---
 drivers/clk/at91/pmc.h       |   4 ++
 include/linux/clk/at91_pmc.h |   2 +
 3 files changed, 104 insertions(+), 5 deletions(-)

diff --git a/drivers/clk/at91/clk-utmi.c b/drivers/clk/at91/clk-utmi.c
index f1ef4e1f41a9..df9f3fc3b6a6 100644
--- a/drivers/clk/at91/clk-utmi.c
+++ b/drivers/clk/at91/clk-utmi.c
@@ -120,9 +120,11 @@ static const struct clk_ops utmi_ops = {
 	.recalc_rate = clk_utmi_recalc_rate,
 };
 
-struct clk_hw * __init
-at91_clk_register_utmi(struct regmap *regmap_pmc, struct regmap *regmap_sfr,
-		       const char *name, const char *parent_name)
+static struct clk_hw * __init
+at91_clk_register_utmi_internal(struct regmap *regmap_pmc,
+				struct regmap *regmap_sfr,
+				const char *name, const char *parent_name,
+				const struct clk_ops *ops, unsigned long flags)
 {
 	struct clk_utmi *utmi;
 	struct clk_hw *hw;
@@ -134,10 +136,10 @@ at91_clk_register_utmi(struct regmap *regmap_pmc, struct regmap *regmap_sfr,
 		return ERR_PTR(-ENOMEM);
 
 	init.name = name;
-	init.ops = &utmi_ops;
+	init.ops = ops;
 	init.parent_names = parent_name ? &parent_name : NULL;
 	init.num_parents = parent_name ? 1 : 0;
-	init.flags = CLK_SET_RATE_GATE;
+	init.flags = flags;
 
 	utmi->hw.init = &init;
 	utmi->regmap_pmc = regmap_pmc;
@@ -152,3 +154,94 @@ at91_clk_register_utmi(struct regmap *regmap_pmc, struct regmap *regmap_sfr,
 
 	return hw;
 }
+
+struct clk_hw * __init
+at91_clk_register_utmi(struct regmap *regmap_pmc, struct regmap *regmap_sfr,
+		       const char *name, const char *parent_name)
+{
+	return at91_clk_register_utmi_internal(regmap_pmc, regmap_sfr, name,
+			parent_name, &utmi_ops, CLK_SET_RATE_GATE);
+}
+
+static int clk_utmi_sama7g5_prepare(struct clk_hw *hw)
+{
+	struct clk_utmi *utmi = to_clk_utmi(hw);
+	struct clk_hw *hw_parent;
+	unsigned long parent_rate;
+	unsigned int val;
+
+	hw_parent = clk_hw_get_parent(hw);
+	parent_rate = clk_hw_get_rate(hw_parent);
+
+	switch (parent_rate) {
+	case 16000000:
+		val = 0;
+		break;
+	case 20000000:
+		val = 2;
+		break;
+	case 24000000:
+		val = 3;
+		break;
+	case 32000000:
+		val = 5;
+		break;
+	default:
+		pr_err("UTMICK: unsupported main_xtal rate\n");
+		return -EINVAL;
+	}
+
+	regmap_write(utmi->regmap_pmc, AT91_PMC_XTALF, val);
+
+	return 0;
+
+}
+
+static int clk_utmi_sama7g5_is_prepared(struct clk_hw *hw)
+{
+	struct clk_utmi *utmi = to_clk_utmi(hw);
+	struct clk_hw *hw_parent;
+	unsigned long parent_rate;
+	unsigned int val;
+
+	hw_parent = clk_hw_get_parent(hw);
+	parent_rate = clk_hw_get_rate(hw_parent);
+
+	regmap_read(utmi->regmap_pmc, AT91_PMC_XTALF, &val);
+	switch (val & 0x7) {
+	case 0:
+		if (parent_rate == 16000000)
+			return 1;
+		break;
+	case 2:
+		if (parent_rate == 20000000)
+			return 1;
+		break;
+	case 3:
+		if (parent_rate == 24000000)
+			return 1;
+		break;
+	case 5:
+		if (parent_rate == 32000000)
+			return 1;
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static const struct clk_ops sama7g5_utmi_ops = {
+	.prepare = clk_utmi_sama7g5_prepare,
+	.is_prepared = clk_utmi_sama7g5_is_prepared,
+	.recalc_rate = clk_utmi_recalc_rate,
+};
+
+struct clk_hw * __init
+at91_clk_sama7g5_register_utmi(struct regmap *regmap_pmc, const char *name,
+			       const char *parent_name)
+{
+	return at91_clk_register_utmi_internal(regmap_pmc, NULL, name,
+			parent_name, &sama7g5_utmi_ops, 0);
+}
diff --git a/drivers/clk/at91/pmc.h b/drivers/clk/at91/pmc.h
index 6340b9be8205..7b86affc6d7c 100644
--- a/drivers/clk/at91/pmc.h
+++ b/drivers/clk/at91/pmc.h
@@ -236,6 +236,10 @@ struct clk_hw * __init
 at91_clk_register_utmi(struct regmap *regmap_pmc, struct regmap *regmap_sfr,
 		       const char *name, const char *parent_name);
 
+struct clk_hw * __init
+at91_clk_sama7g5_register_utmi(struct regmap *regmap, const char *name,
+			       const char *parent_name);
+
 #ifdef CONFIG_PM
 void pmc_register_id(u8 id);
 void pmc_register_pck(u8 pck);
diff --git a/include/linux/clk/at91_pmc.h b/include/linux/clk/at91_pmc.h
index dc5e85f124e0..a4f82e836a7c 100644
--- a/include/linux/clk/at91_pmc.h
+++ b/include/linux/clk/at91_pmc.h
@@ -137,6 +137,8 @@
 #define			AT91_PMC_PLLADIV2_ON		(1 << 12)
 #define		AT91_PMC_H32MXDIV	BIT(24)
 
+#define AT91_PMC_XTALF		0x34			/* Main XTAL Frequency Register [SAMA7G5 only] */
+
 #define	AT91_PMC_USB		0x38			/* USB Clock Register [some SAM9 only] */
 #define		AT91_PMC_USBS		(0x1 <<  0)		/* USB OHCI Input clock selection */
 #define			AT91_PMC_USBS_PLLA		(0 << 0)
-- 
2.7.4