Merge branch 'clk-at91' into clk-next

* clk-at91:
  clk: at91: utmi: set the mainck rate

1 files changed, 81 insertions, 14 deletions

diff --git a/drivers/clk/at91/clk-utmi.c b/drivers/clk/at91/clk-utmi.c
index aadabd9d1e2b..cd8d689138ff 100644
--- a/drivers/clk/at91/clk-utmi.c
+++ b/drivers/clk/at91/clk-utmi.c
@@ -14,14 +14,20 @@
 #include <linux/of.h>
 #include <linux/mfd/syscon.h>
 #include <linux/regmap.h>
+#include <soc/at91/atmel-sfr.h>
 
 #include "pmc.h"
 
-#define UTMI_FIXED_MUL		40
+/*
+ * The purpose of this clock is to generate a 480 MHz signal. A different
+ * rate can't be configured.
+ */
+#define UTMI_RATE	480000000
 
 struct clk_utmi {
 	struct clk_hw hw;
-	struct regmap *regmap;
+	struct regmap *regmap_pmc;
+	struct regmap *regmap_sfr;
 };
 
 #define to_clk_utmi(hw) container_of(hw, struct clk_utmi, hw)
@@ -37,13 +43,54 @@ static inline bool clk_utmi_ready(struct regmap *regmap)
 
 static int clk_utmi_prepare(struct clk_hw *hw)
 {
+	struct clk_hw *hw_parent;
 	struct clk_utmi *utmi = to_clk_utmi(hw);
 	unsigned int uckr = AT91_PMC_UPLLEN | AT91_PMC_UPLLCOUNT |
 			    AT91_PMC_BIASEN;
+	unsigned int utmi_ref_clk_freq;
+	unsigned long parent_rate;
+
+	/*
+	 * If mainck rate is different from 12 MHz, we have to configure the
+	 * FREQ field of the SFR_UTMICKTRIM register to generate properly
+	 * the utmi clock.
+	 */
+	hw_parent = clk_hw_get_parent(hw);
+	parent_rate = clk_hw_get_rate(hw_parent);
+
+	switch (parent_rate) {
+	case 12000000:
+		utmi_ref_clk_freq = 0;
+		break;
+	case 16000000:
+		utmi_ref_clk_freq = 1;
+		break;
+	case 24000000:
+		utmi_ref_clk_freq = 2;
+		break;
+	/*
+	 * Not supported on SAMA5D2 but it's not an issue since MAINCK
+	 * maximum value is 24 MHz.
+	 */
+	case 48000000:
+		utmi_ref_clk_freq = 3;
+		break;
+	default:
+		pr_err("UTMICK: unsupported mainck rate\n");
+		return -EINVAL;
+	}
 
-	regmap_update_bits(utmi->regmap, AT91_CKGR_UCKR, uckr, uckr);
+	if (utmi->regmap_sfr) {
+		regmap_update_bits(utmi->regmap_sfr, AT91_SFR_UTMICKTRIM,
+				   AT91_UTMICKTRIM_FREQ, utmi_ref_clk_freq);
+	} else if (utmi_ref_clk_freq) {
+		pr_err("UTMICK: sfr node required\n");
+		return -EINVAL;
+	}
 
-	while (!clk_utmi_ready(utmi->regmap))
+	regmap_update_bits(utmi->regmap_pmc, AT91_CKGR_UCKR, uckr, uckr);
+
+	while (!clk_utmi_ready(utmi->regmap_pmc))
 		cpu_relax();
 
 	return 0;
@@ -53,21 +100,22 @@ static int clk_utmi_is_prepared(struct clk_hw *hw)
 {
 	struct clk_utmi *utmi = to_clk_utmi(hw);
 
-	return clk_utmi_ready(utmi->regmap);
+	return clk_utmi_ready(utmi->regmap_pmc);
 }
 
 static void clk_utmi_unprepare(struct clk_hw *hw)
 {
 	struct clk_utmi *utmi = to_clk_utmi(hw);
 
-	regmap_update_bits(utmi->regmap, AT91_CKGR_UCKR, AT91_PMC_UPLLEN, 0);
+	regmap_update_bits(utmi->regmap_pmc, AT91_CKGR_UCKR,
+			   AT91_PMC_UPLLEN, 0);
 }
 
 static unsigned long clk_utmi_recalc_rate(struct clk_hw *hw,
 					  unsigned long parent_rate)
 {
-	/* UTMI clk is a fixed clk multiplier */
-	return parent_rate * UTMI_FIXED_MUL;
+	/* UTMI clk rate is fixed. */
+	return UTMI_RATE;
 }
 
 static const struct clk_ops utmi_ops = {
@@ -78,7 +126,7 @@ static const struct clk_ops utmi_ops = {
 };
 
 static struct clk_hw * __init
-at91_clk_register_utmi(struct regmap *regmap,
+at91_clk_register_utmi(struct regmap *regmap_pmc, struct regmap *regmap_sfr,
 		       const char *name, const char *parent_name)
 {
 	struct clk_utmi *utmi;
@@ -97,7 +145,8 @@ at91_clk_register_utmi(struct regmap *regmap,
 	init.flags = CLK_SET_RATE_GATE;
 
 	utmi->hw.init = &init;
-	utmi->regmap = regmap;
+	utmi->regmap_pmc = regmap_pmc;
+	utmi->regmap_sfr = regmap_sfr;
 
 	hw = &utmi->hw;
 	ret = clk_hw_register(NULL, &utmi->hw);
@@ -114,17 +163,35 @@ static void __init of_at91sam9x5_clk_utmi_setup(struct device_node *np)
 	struct clk_hw *hw;
 	const char *parent_name;
 	const char *name = np->name;
-	struct regmap *regmap;
+	struct regmap *regmap_pmc, *regmap_sfr;
 
 	parent_name = of_clk_get_parent_name(np, 0);
 
 	of_property_read_string(np, "clock-output-names", &name);
 
-	regmap = syscon_node_to_regmap(of_get_parent(np));
-	if (IS_ERR(regmap))
+	regmap_pmc = syscon_node_to_regmap(of_get_parent(np));
+	if (IS_ERR(regmap_pmc))
 		return;
 
-	hw = at91_clk_register_utmi(regmap, name, parent_name);
+	/*
+	 * If the device supports different mainck rates, this value has to be
+	 * set in the UTMI Clock Trimming register.
+	 * - 9x5: mainck supports several rates but it is indicated that a
+	 *   12 MHz is needed in case of USB.
+	 * - sama5d3 and sama5d2: mainck supports several rates. Configuring
+	 *   the FREQ field of the UTMI Clock Trimming register is mandatory.
+	 * - sama5d4: mainck is at 12 MHz.
+	 *
+	 * We only need to retrieve sama5d3 or sama5d2 sfr regmap.
+	 */
+	regmap_sfr = syscon_regmap_lookup_by_compatible("atmel,sama5d3-sfr");
+	if (IS_ERR(regmap_sfr)) {
+		regmap_sfr = syscon_regmap_lookup_by_compatible("atmel,sama5d2-sfr");
+		if (IS_ERR(regmap_sfr))
+			regmap_sfr = NULL;
+	}
+
+	hw = at91_clk_register_utmi(regmap_pmc, regmap_sfr, name, parent_name);
 	if (IS_ERR(hw))
 		return;