diff options
Diffstat (limited to 'drivers/clk/at91/clk-utmi.c')
| -rw-r--r-- | drivers/clk/at91/clk-utmi.c | 95 |
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; |