On Tue, Jun 07, 2016 at 06:04:11PM +0200, Neil Armstrong wrote:
> Add clocksource and clockevent driver from dual RPS timer.
> The HW provides a dual one-shot or periodic 24bit timers,
> the drivers set the first one as tick event source and the
> second as a continuous scheduler clock source.
> The timer can use 1, 16 or 256 as pre-dividers, thus the
> clocksource uses 16 by default.
>
> CC: Ma Haijun <mahaij...@gmail.com>
> Signed-off-by: Neil Armstrong <narmstr...@baylibre.com>
> ---
> drivers/clocksource/Kconfig | 6 +
> drivers/clocksource/Makefile | 1 +
> drivers/clocksource/timer-oxnas-rps.c | 270
> ++++++++++++++++++++++++++++++++++
> 3 files changed, 277 insertions(+)
> create mode 100644 drivers/clocksource/timer-oxnas-rps.c
>
> diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
> index 47352d2..7e382c5 100644
> --- a/drivers/clocksource/Kconfig
> +++ b/drivers/clocksource/Kconfig
> @@ -293,6 +293,12 @@ config VF_PIT_TIMER
> help
> Support for Period Interrupt Timer on Freescale Vybrid Family SoCs.
>
> +config OXNAS_RPS_TIMER
config OXNAS_RPS_TIMER "bla bla" if COMPILE_TEST
> + bool
> + select CLKSRC_MMIO
> + help
> + This enables support for the Oxford Semiconductor OXNAS RPS timers.
> +
> @@ -0,0 +1,270 @@
> +/*
> + * drivers/clocksource/timer-oxnas-rps.c
> + *
> + * Copyright (C) 2009 Oxford Semiconductor Ltd
> + * Copyright (C) 2013 Ma Haijun <mahaij...@gmail.com>
What are these two copyrights ?
[ ... ]
> +static void __init oxnas_rps_timer_init(struct device_node *np)
> +{
> + struct oxnas_rps_timer *rps;
> + void __iomem *base;
> + int ret;
> +
> + rps = kzalloc(sizeof(*rps), GFP_KERNEL);
> + if (WARN_ON(!rps))
It is pointless to add a WARN_ON, kzalloc already does that on failure.
> + return;
> +
> + rps->clk = of_clk_get(np, 0);
> + if (WARN_ON(IS_ERR(rps->clk)))
> + return;
> +
> + if (WARN_ON(clk_prepare_enable(rps->clk)))
> + goto err;
> +
> + base = of_iomap(np, 0);
> + if (WARN_ON(!base))
> + goto err;
> +
> +
> + rps->irq = irq_of_parse_and_map(np, 0);
> + if (WARN_ON(rps->irq < 0))
> + goto err;
> +
> + rps->clkevt_base = base + TIMER1_REG_OFFSET;
> + rps->clksrc_base = base + TIMER2_REG_OFFSET;
> +
> + /* Disable timers */
> + writel_relaxed(0, rps->clkevt_base + TIMER_CTRL_REG);
> + writel_relaxed(0, rps->clksrc_base + TIMER_CTRL_REG);
> + writel_relaxed(0, rps->clkevt_base + TIMER_LOAD_REG);
> + writel_relaxed(0, rps->clksrc_base + TIMER_LOAD_REG);
> + writel_relaxed(0, rps->clkevt_base + TIMER_CLRINT_REG);
> + writel_relaxed(0, rps->clksrc_base + TIMER_CLRINT_REG);
> +
> + ret = request_irq(rps->irq, oxnas_rps_timer_irq,
> + IRQF_TIMER | IRQF_IRQPOLL,
> + "rps-timer", rps);
> + if (WARN_ON(ret))
> + goto err;
> +
> + oxnas_rps_clockevent_init(rps);
> + oxnas_rps_clocksource_init(rps);
> +
> + return;
err_iounmap:
iounmap(base);
err_clk_unprepare:
clk_unprepare(rps->clk)
err_clk_put:
> + clk_put(rps->clk);
> + kfree(rps);
> +}
Regarding the current work I am doing to change the init function to return
an error in case of failure, can you do proper error handling in this
function and rollback ?
1. replace WARN_ON by a pr_err
2. make oxnas_rps_clockevent_init and oxnas_rps_clocksource_init to return
an error code
3. rollback clockevent or clocksource if one fails.
Thanks !
-- Daniel
> +
> +CLOCKSOURCE_OF_DECLARE(ox810se_rps,
> + "oxsemi,ox810se-rps-timer", oxnas_rps_timer_init);
> --
> 1.9.1
>
