[PATCH v14 7/9] clocksource/drivers/arm_arch_timer: Refactor the timer init code to prepare for GTDT
Mark Rutland
mark.rutland at arm.com
Fri Oct 21 04:32:13 PDT 2016
On Thu, Sep 29, 2016 at 02:17:15AM +0800, fu.wei at linaro.org wrote:
> From: Fu Wei <fu.wei at linaro.org>
>
> The patch refactor original memory-mapped timer init code:
> (1) extract some subfunction for reusing some common code
> a. get_cnttidr
> b. is_best_frame
> (2) move base address and irq code for arch_timer_mem to
> arch_timer_mem_register
>
> Signed-off-by: Fu Wei <fu.wei at linaro.org>
> ---
> drivers/clocksource/arm_arch_timer.c | 159 +++++++++++++++++++++--------------
> 1 file changed, 96 insertions(+), 63 deletions(-)
>
> diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
> index c7b0040..e78095f 100644
> --- a/drivers/clocksource/arm_arch_timer.c
> +++ b/drivers/clocksource/arm_arch_timer.c
> @@ -57,6 +57,7 @@
> static unsigned arch_timers_present __initdata;
>
> static void __iomem *arch_counter_base;
> +static void __iomem *cntctlbase __initdata;
>
> struct arch_timer {
> void __iomem *base;
> @@ -656,15 +657,49 @@ out:
> return err;
> }
>
> -static int __init arch_timer_mem_register(void __iomem *base, unsigned int irq)
> +static int __init arch_timer_mem_register(struct device_node *np, void *frame)
> {
> - int ret;
> - irq_handler_t func;
> + struct device_node *frame_node = NULL;
> struct arch_timer *t;
> + void __iomem *base;
> + irq_handler_t func;
> + unsigned int irq;
> + int ret;
> +
> + if (!frame)
> + return -EINVAL;
Why would we call this without a frame?
> +
> + if (np) {
... or without a node?
> + frame_node = (struct device_node *)frame;
> + base = of_iomap(frame_node, 0);
> + arch_timer_detect_rate(base, np);
... BANG! (we check base too late, below).
Please as Marc requested several versions ago: split the FW parsing
(ACPI and DT) so that happens first, *then* once we have the data in a
common format, use that to drive poking the HW, requesting IRQs, etc,
completely independent of the source.
In patches, do this by:
(1) adding the data structures
(2) splitting the existing DT probing to use them
(3) Adding ACPI functionality atop
> -static int __init arch_timer_mem_init(struct device_node *np)
> +static int __init get_cnttidr(struct device_node *np, u32 *cnttidr)
> {
> - struct device_node *frame, *best_frame = NULL;
> - void __iomem *cntctlbase, *base;
> - unsigned int irq, ret = -EINVAL;
> - u32 cnttidr;
> + if (!cnttidr)
> + return -EINVAL;
> +
> + if (np)
> + cntctlbase = of_iomap(np, 0);
> + else
> + return -EINVAL;
We want to check this for ACPI too, no?
Thanks,
Mark.
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