diff options
| author | Eric Anholt <eric@anholt.net> | 2015-12-27 00:47:21 +0300 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2015-12-29 13:40:45 +0300 |
| commit | 401667bb8a2e0825090c5e6c15b899c1c36a4773 (patch) | |
| tree | 36645c6c460e7fe1fc76804917626aa1c1e1a870 /drivers | |
| parent | 5c4acd97e812de908cda97e2da02dead261915fa (diff) | |
| download | linux-401667bb8a2e0825090c5e6c15b899c1c36a4773.tar.xz | |
irqchip/bcm2836: Fix initialization of the LOCAL_IRQ_CNT timers
The irqchip's register area includes the the setup for the timer's
scaling factors, and for the platform we want a fixed configuration of
these registers.
Signed-off-by: Eric Anholt <eric@anholt.net>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Lee Jones <lee@kernel.org>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: linux-rpi-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1451166444-11044-2-git-send-email-eric@anholt.net
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/irqchip/irq-bcm2836.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-bcm2836.c b/drivers/irqchip/irq-bcm2836.c index f68708281fcf..6ec125ef3607 100644 --- a/drivers/irqchip/irq-bcm2836.c +++ b/drivers/irqchip/irq-bcm2836.c @@ -21,6 +21,9 @@ #include <linux/irqdomain.h> #include <asm/exception.h> +#define LOCAL_CONTROL 0x000 +#define LOCAL_PRESCALER 0x008 + /* * The low 2 bits identify the CPU that the GPU IRQ goes to, and the * next 2 bits identify the CPU that the GPU FIQ goes to. @@ -237,6 +240,27 @@ bcm2836_arm_irqchip_smp_init(void) #endif } +/* + * The LOCAL_IRQ_CNT* timer firings are based off of the external + * oscillator with some scaling. The firmware sets up CNTFRQ to + * report 19.2Mhz, but doesn't set up the scaling registers. + */ +static void bcm2835_init_local_timer_frequency(void) +{ + /* + * Set the timer to source from the 19.2Mhz crystal clock (bit + * 8 unset), and only increment by 1 instead of 2 (bit 9 + * unset). + */ + writel(0, intc.base + LOCAL_CONTROL); + + /* + * Set the timer prescaler to 1:1 (timer freq = input freq * + * 2**31 / prescaler) + */ + writel(0x80000000, intc.base + LOCAL_PRESCALER); +} + static int __init bcm2836_arm_irqchip_l1_intc_of_init(struct device_node *node, struct device_node *parent) { @@ -246,6 +270,8 @@ static int __init bcm2836_arm_irqchip_l1_intc_of_init(struct device_node *node, node->full_name); } + bcm2835_init_local_timer_frequency(); + intc.domain = irq_domain_add_linear(node, LAST_IRQ + 1, &bcm2836_arm_irqchip_intc_ops, NULL); |