1 files changed, 15 insertions, 4 deletions

diff --git a/arch/arm/mach-at91/clock.c b/arch/arm/mach-at91/clock.c
index e8ce8f0f3eda..464bdbbf74df 100644
--- a/arch/arm/mach-at91/clock.c
+++ b/arch/arm/mach-at91/clock.c
@@ -515,14 +515,19 @@ static unsigned __init at91_pll_calc(unsigned main_freq, unsigned out_freq)
                 /*
                  * PLL input between 1MHz and 32MHz per spec, but lower
                  * frequences seem necessary in some cases so allow 100K.
+                 * Warning: some newer products need 2MHz min.
                  */
                 input = main_freq / i;
+                if (cpu_is_at91sam9g20() && input < 2000000)
+                        continue;
                 if (input < 100000)
                         continue;
                 if (input > 32000000)
                         continue;
 
                 mul1 = out_freq / input;
+                if (cpu_is_at91sam9g20() && mul > 63)
+                        continue;
                 if (mul1 > 2048)
                         continue;
                 if (mul1 < 2)
@@ -582,7 +587,8 @@ int __init at91_clock_init(unsigned long main_clock)
 
         /* report if PLLA is more than mildly overclocked */
         plla.rate_hz = at91_pll_rate(&plla, main_clock, at91_sys_read(AT91_CKGR_PLLAR));
-        if (plla.rate_hz > 209000000)
+        if ((!cpu_is_at91sam9g20() && plla.rate_hz > 209000000)
+           || (cpu_is_at91sam9g20() && plla.rate_hz > 800000000))
                 pr_info("Clocks: PLLA overclocked, %ld MHz\n", plla.rate_hz / 1000000);
 
         /*
@@ -597,7 +603,7 @@ int __init at91_clock_init(unsigned long main_clock)
                 uhpck.pmc_mask = AT91RM9200_PMC_UHP;
                 udpck.pmc_mask = AT91RM9200_PMC_UDP;
                 at91_sys_write(AT91_PMC_SCER, AT91RM9200_PMC_MCKUDP);
-        } else if (cpu_is_at91sam9260() || cpu_is_at91sam9261() || cpu_is_at91sam9263()) {
+        } else if (cpu_is_at91sam9260() || cpu_is_at91sam9261() || cpu_is_at91sam9263() || cpu_is_at91sam9g20()) {
                 uhpck.pmc_mask = AT91SAM926x_PMC_UHP;
                 udpck.pmc_mask = AT91SAM926x_PMC_UDP;
         } else if (cpu_is_at91cap9()) {
@@ -629,8 +635,13 @@ int __init at91_clock_init(unsigned long main_clock)
         freq /= (1 << ((mckr & AT91_PMC_PRES) >> 2));                           /* prescale */
         if (cpu_is_at91rm9200())
                 mck.rate_hz = freq / (1 + ((mckr & AT91_PMC_MDIV) >> 8));       /* mdiv */
-        else
-                mck.rate_hz = freq / (1 << ((mckr & AT91_PMC_MDIV) >> 8));      /* mdiv */
+        else if (cpu_is_at91sam9g20()) {
+                mck.rate_hz = (mckr & AT91_PMC_MDIV) ?
+                        freq / ((mckr & AT91_PMC_MDIV) >> 7) : freq;    /* mdiv ; (x >> 7) = ((x >> 8) * 2) */
+                if (mckr & AT91_PMC_PDIV)
+                        freq /= 2;              /* processor clock division */
+        } else
+                mck.rate_hz = freq / (1 << ((mckr & AT91_PMC_MDIV) >> 8));      /* mdiv */
 
         /* Register the PMC's standard clocks */
         for (i = 0; i < ARRAY_SIZE(standard_pmc_clocks); i++)