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authorLinus Torvalds <torvalds@linux-foundation.org>2015-01-18 18:00:40 +1200
committerLinus Torvalds <torvalds@linux-foundation.org>2015-01-18 18:00:40 +1200
commitd0ac5d8e673aa7317c0d132ba3092935dac53298 (patch)
tree458afa365611acc689c63be1d7c6a7ac64c10d92 /arch/arm/mach-omap2/timer.c
parent12ba8571ab6b232f5facef6b1dd28c5ebc2b530a (diff)
parent966903a98fd80ae5f5c4a7ca121d36ea0ba23143 (diff)
Merge tag 'armsoc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC fixes from Olof Johansson: "We've been sitting on our fixes branch for a while, so this batch is unfortunately on the large side. A lot of these are tweaks and fixes to device trees, fixing various bugs around clocks, reg ranges, etc. There's also a few defconfig updates (which are on the late side, no more of those). All in all the diffstat is bigger than ideal at this time, but nothing in here seems particularly risky" * tag 'armsoc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (31 commits) reset: sunxi: fix spinlock initialization ARM: dts: disable CCI on exynos5420 based arndale-octa drivers: bus: check cci device tree node status ARM: rockchip: disable jtag/sdmmc autoswitching on rk3288 ARM: nomadik: fix up leftover device tree pins ARM: at91: board-dt-sama5: add phy_fixup to override NAND_Tree ARM: at91/dt: sam9263: Add missing clocks to lcdc node ARM: at91: sama5d3: dt: correct the sound route ARM: at91/dt: sama5d4: fix the timer reg length ARM: exynos_defconfig: Enable LM90 driver ARM: exynos_defconfig: Enable options for display panel support arm: dts: Use pmu_system_controller phandle for dp phy ARM: shmobile: sh73a0 legacy: Set .control_parent for all irqpin instances ARM: dts: berlin: correct BG2Q's SM GPIO location. ARM: dts: berlin: add broken-cd and set bus width for eMMC in Marvell DMP DT ARM: dts: berlin: fix io clk and add missing core clk for BG2Q sdhci2 host ARM: dts: Revert disabling of smc91x for n900 ARM: dts: imx51-babbage: Fix ULPI PHY reset modelling ARM: dts: dra7-evm: fix qspi device tree partition size ARM: omap2plus_defconfig: use CONFIG_CPUFREQ_DT ...
Diffstat (limited to 'arch/arm/mach-omap2/timer.c')
-rw-r--r--arch/arm/mach-omap2/timer.c44
1 files changed, 38 insertions, 6 deletions
diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c
index 4f61148ec168..7d45c84c69ba 100644
--- a/arch/arm/mach-omap2/timer.c
+++ b/arch/arm/mach-omap2/timer.c
@@ -54,6 +54,7 @@
#include "soc.h"
#include "common.h"
+#include "control.h"
#include "powerdomain.h"
#include "omap-secure.h"
@@ -496,7 +497,8 @@ static void __init realtime_counter_init(void)
void __iomem *base;
static struct clk *sys_clk;
unsigned long rate;
- unsigned int reg, num, den;
+ unsigned int reg;
+ unsigned long long num, den;
base = ioremap(REALTIME_COUNTER_BASE, SZ_32);
if (!base) {
@@ -511,13 +513,42 @@ static void __init realtime_counter_init(void)
}
rate = clk_get_rate(sys_clk);
+
+ if (soc_is_dra7xx()) {
+ /*
+ * Errata i856 says the 32.768KHz crystal does not start at
+ * power on, so the CPU falls back to an emulated 32KHz clock
+ * based on sysclk / 610 instead. This causes the master counter
+ * frequency to not be 6.144MHz but at sysclk / 610 * 375 / 2
+ * (OR sysclk * 75 / 244)
+ *
+ * This affects at least the DRA7/AM572x 1.0, 1.1 revisions.
+ * Of course any board built without a populated 32.768KHz
+ * crystal would also need this fix even if the CPU is fixed
+ * later.
+ *
+ * Either case can be detected by using the two speedselect bits
+ * If they are not 0, then the 32.768KHz clock driving the
+ * coarse counter that corrects the fine counter every time it
+ * ticks is actually rate/610 rather than 32.768KHz and we
+ * should compensate to avoid the 570ppm (at 20MHz, much worse
+ * at other rates) too fast system time.
+ */
+ reg = omap_ctrl_readl(DRA7_CTRL_CORE_BOOTSTRAP);
+ if (reg & DRA7_SPEEDSELECT_MASK) {
+ num = 75;
+ den = 244;
+ goto sysclk1_based;
+ }
+ }
+
/* Numerator/denumerator values refer TRM Realtime Counter section */
switch (rate) {
- case 1200000:
+ case 12000000:
num = 64;
den = 125;
break;
- case 1300000:
+ case 13000000:
num = 768;
den = 1625;
break;
@@ -529,11 +560,11 @@ static void __init realtime_counter_init(void)
num = 192;
den = 625;
break;
- case 2600000:
+ case 26000000:
num = 384;
den = 1625;
break;
- case 2700000:
+ case 27000000:
num = 256;
den = 1125;
break;
@@ -545,6 +576,7 @@ static void __init realtime_counter_init(void)
break;
}
+sysclk1_based:
/* Program numerator and denumerator registers */
reg = readl_relaxed(base + INCREMENTER_NUMERATOR_OFFSET) &
NUMERATOR_DENUMERATOR_MASK;
@@ -556,7 +588,7 @@ static void __init realtime_counter_init(void)
reg |= den;
writel_relaxed(reg, base + INCREMENTER_DENUMERATOR_RELOAD_OFFSET);
- arch_timer_freq = (rate / den) * num;
+ arch_timer_freq = DIV_ROUND_UP_ULL(rate * num, den);
set_cntfreq();
iounmap(base);