[PATCH 3/6] ARM: at91/at91sam9x5: clock management for at91sam9x5 chip family
Nicolas Ferre
nicolas.ferre at atmel.com
Thu Jan 26 12:12:34 EST 2012
Several changes to PMC have to be managed for adding this support:
- alternate prescaler location for both MCKR and PCKR
- alternate CSS length for PCKR
- added cpu_is_at91sam9x5() to functional switches
- manage UTMI bias like sam9g45 chip family
Signed-off-by: Nicolas Ferre <nicolas.ferre at atmel.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>
---
arch/arm/mach-at91/clock.c | 83 ++++++++++++++++++++++++++++++++++----------
1 files changed, 64 insertions(+), 19 deletions(-)
diff --git a/arch/arm/mach-at91/clock.c b/arch/arm/mach-at91/clock.c
index aa04e22..a5291e0 100644
--- a/arch/arm/mach-at91/clock.c
+++ b/arch/arm/mach-at91/clock.c
@@ -48,24 +48,37 @@
* Chips have some kind of clocks : group them by functionality
*/
#define cpu_has_utmi() ( cpu_is_at91sam9rl() \
- || cpu_is_at91sam9g45())
+ || cpu_is_at91sam9g45() \
+ || cpu_is_at91sam9x5())
#define cpu_has_800M_plla() ( cpu_is_at91sam9g20() \
- || cpu_is_at91sam9g45())
+ || cpu_is_at91sam9g45() \
+ || cpu_is_at91sam9x5())
#define cpu_has_300M_plla() (cpu_is_at91sam9g10())
#define cpu_has_pllb() (!(cpu_is_at91sam9rl() \
- || cpu_is_at91sam9g45()))
+ || cpu_is_at91sam9g45() \
+ || cpu_is_at91sam9x5()))
-#define cpu_has_upll() (cpu_is_at91sam9g45())
+#define cpu_has_upll() (cpu_is_at91sam9g45() \
+ || cpu_is_at91sam9x5())
/* USB host HS & FS */
#define cpu_has_uhp() (!cpu_is_at91sam9rl())
/* USB device FS only */
#define cpu_has_udpfs() (!(cpu_is_at91sam9rl() \
- || cpu_is_at91sam9g45()))
+ || cpu_is_at91sam9g45() \
+ || cpu_is_at91sam9x5()))
+
+#define cpu_has_plladiv2() (cpu_is_at91sam9g45() \
+ || cpu_is_at91sam9x5())
+
+#define cpu_has_mdiv3() (cpu_is_at91sam9g45() \
+ || cpu_is_at91sam9x5())
+
+#define cpu_has_alt_prescaler() (cpu_is_at91sam9x5())
static LIST_HEAD(clocks);
static DEFINE_SPINLOCK(clk_lock);
@@ -138,13 +151,6 @@ static void pmc_uckr_mode(struct clk *clk, int is_on)
{
unsigned int uckr = at91_sys_read(AT91_CKGR_UCKR);
- if (cpu_is_at91sam9g45()) {
- if (is_on)
- uckr |= AT91_PMC_BIASEN;
- else
- uckr &= ~AT91_PMC_BIASEN;
- }
-
if (is_on) {
is_on = AT91_PMC_LOCKU;
at91_sys_write(AT91_CKGR_UCKR, uckr | clk->pmc_mask);
@@ -209,11 +215,24 @@ static struct clk __init *at91_css_to_clk(unsigned long css)
return &utmi_clk;
else if (cpu_has_pllb())
return &pllb;
+ break;
+ /* alternate PMC: can use master clock */
+ case AT91_PMC_CSS_MASTER:
+ return &mck;
}
return NULL;
}
+static int pmc_prescaler_divider(u32 reg)
+{
+ if (cpu_has_alt_prescaler()) {
+ return 1 << ((reg & AT91_PMC_ALT_PRES) >> PMC_ALT_PRES_OFFSET);
+ } else {
+ return 1 << ((reg & AT91_PMC_PRES) >> PMC_PRES_OFFSET);
+ }
+}
+
static void __clk_enable(struct clk *clk)
{
if (clk->parent)
@@ -315,12 +334,22 @@ int clk_set_rate(struct clk *clk, unsigned long rate)
{
unsigned long flags;
unsigned prescale;
+ unsigned long prescale_offset, css_mask;
unsigned long actual;
if (!clk_is_programmable(clk))
return -EINVAL;
if (clk->users)
return -EBUSY;
+
+ if (cpu_has_alt_prescaler()) {
+ prescale_offset = PMC_ALT_PRES_OFFSET;
+ css_mask = AT91_PMC_ALT_PCKR_CSS;
+ } else {
+ prescale_offset = PMC_PRES_OFFSET;
+ css_mask = AT91_PMC_CSS;
+ }
+
spin_lock_irqsave(&clk_lock, flags);
actual = clk->parent->rate_hz;
@@ -329,8 +358,8 @@ int clk_set_rate(struct clk *clk, unsigned long rate)
u32 pckr;
pckr = at91_sys_read(AT91_PMC_PCKR(clk->id));
- pckr &= AT91_PMC_CSS; /* clock selection */
- pckr |= prescale << 2;
+ pckr &= css_mask; /* keep clock selection */
+ pckr |= prescale << prescale_offset;
at91_sys_write(AT91_PMC_PCKR(clk->id), pckr);
clk->rate_hz = actual;
break;
@@ -377,11 +406,17 @@ static void __init init_programmable_clock(struct clk *clk)
{
struct clk *parent;
u32 pckr;
+ unsigned int css_mask;
+
+ if (cpu_has_alt_prescaler())
+ css_mask = AT91_PMC_ALT_PCKR_CSS;
+ else
+ css_mask = AT91_PMC_CSS;
pckr = at91_sys_read(AT91_PMC_PCKR(clk->id));
- parent = at91_css_to_clk(pckr & AT91_PMC_CSS);
+ parent = at91_css_to_clk(pckr & css_mask);
clk->parent = parent;
- clk->rate_hz = parent->rate_hz / (1 << ((pckr & AT91_PMC_PRES) >> 2));
+ clk->rate_hz = parent->rate_hz / pmc_prescaler_divider(pckr);
}
#endif /* CONFIG_AT91_PROGRAMMABLE_CLOCKS */
@@ -663,7 +698,7 @@ int __init at91_clock_init(unsigned long main_clock)
if (pll_overclock)
pr_info("Clocks: PLLA overclocked, %ld MHz\n", plla.rate_hz / 1000000);
- if (cpu_is_at91sam9g45()) {
+ if (cpu_has_plladiv2()) {
mckr = at91_sys_read(AT91_PMC_MCKR);
plla.rate_hz /= (1 << ((mckr & AT91_PMC_PLLADIV2) >> 12)); /* plla divisor by 2 */
}
@@ -685,6 +720,10 @@ int __init at91_clock_init(unsigned long main_clock)
* (obtain the USB High Speed 480 MHz when input is 12 MHz)
*/
utmi_clk.rate_hz = 40 * utmi_clk.parent->rate_hz;
+
+ /* UTMI bias and PLL are managed at the same time */
+ if (cpu_has_upll())
+ utmi_clk.pmc_mask |= AT91_PMC_BIASEN;
}
/*
@@ -703,7 +742,7 @@ int __init at91_clock_init(unsigned long main_clock)
mckr = at91_sys_read(AT91_PMC_MCKR);
mck.parent = at91_css_to_clk(mckr & AT91_PMC_CSS);
freq = mck.parent->rate_hz;
- freq /= (1 << ((mckr & AT91_PMC_PRES) >> 2)); /* prescale */
+ freq /= pmc_prescaler_divider(mckr); /* prescale */
if (cpu_is_at91rm9200()) {
mck.rate_hz = freq / (1 + ((mckr & AT91_PMC_MDIV) >> 8)); /* mdiv */
} else if (cpu_is_at91sam9g20()) {
@@ -711,13 +750,19 @@ int __init at91_clock_init(unsigned long main_clock)
freq / ((mckr & AT91_PMC_MDIV) >> 7) : freq; /* mdiv ; (x >> 7) = ((x >> 8) * 2) */
if (mckr & AT91_PMC_PDIV)
freq /= 2; /* processor clock division */
- } else if (cpu_is_at91sam9g45()) {
+ } else if (cpu_has_mdiv3()) {
mck.rate_hz = (mckr & AT91_PMC_MDIV) == AT91SAM9_PMC_MDIV_3 ?
freq / 3 : freq / (1 << ((mckr & AT91_PMC_MDIV) >> 8)); /* mdiv */
} else {
mck.rate_hz = freq / (1 << ((mckr & AT91_PMC_MDIV) >> 8)); /* mdiv */
}
+ if (cpu_has_alt_prescaler()) {
+ /* Programmable clocks can use MCK */
+ mck.type |= CLK_TYPE_PRIMARY;
+ mck.id = 4;
+ }
+
/* Register the PMC's standard clocks */
for (i = 0; i < ARRAY_SIZE(standard_pmc_clocks); i++)
at91_clk_add(standard_pmc_clocks[i]);
--
1.7.5.4
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