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path: root/drivers/clk/at91/clk-utmi.c
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Diffstat (limited to 'drivers/clk/at91/clk-utmi.c')
-rw-r--r--drivers/clk/at91/clk-utmi.c95
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;