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SubjectRE: [PATCH] clocksource/drivers/timer-imx-tpm: convert the driver to timer-of
Date
Hi, Daniel

Best Regards!
Anson Huang

> -----Original Message-----
> From: Daniel Lezcano [mailto:daniel.lezcano@linaro.org]
> Sent: 2018年11月22日 21:21
> To: Anson Huang <anson.huang@nxp.com>; tglx@linutronix.de;
> linux-kernel@vger.kernel.org
> Cc: dl-linux-imx <linux-imx@nxp.com>
> Subject: Re: [PATCH] clocksource/drivers/timer-imx-tpm: convert the driver to
> timer-of
>
>
> Hi Anson,
>
>
> On 06/11/2018 06:15, Anson Huang wrote:
> > Convert the driver to use the timer_of helpers.
> > This allows to handle timer base, clock and irq using common timer_of
> > driver and it simplifies the code.
>
> Can you do an extra move by passing the timer_of structure around for:
> - tpm_timer_disable
> - tpm_timer_enable
> - tpm_irq_acknowledge
>
> and use to_timer_of(clkevt) to retrieve the timer_base value for other
> clockevent callbacks ?
>
> The clockevent code will be self-encapsulated.
>

I remove below inline function, and put the register operation in the clockevent callback using
to_timer_of(clkevt) and timer_of_base(), it make the code more simplified.
tpm_timer_disable
tpm_timer_enable
tpm_irq_acknowledge

For other functions like tpm_read_counter(), if using timer_of_base() to retrieve the timer base, it
needs to_tpm to be defined before this function, but to_tpm need to refer to some clockevent callbacks
which calls tpm_read_counter(), so the function definition sequence is conflict unless we add an function
statement, so I prefer to leave it as what it is now. Please help review V2 patch, thanks.

Anson.

>
>
> > Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
> > ---
> > drivers/clocksource/timer-imx-tpm.c | 136
> > +++++++++++++++---------------------
> > 1 file changed, 55 insertions(+), 81 deletions(-)
> >
> > diff --git a/drivers/clocksource/timer-imx-tpm.c
> > b/drivers/clocksource/timer-imx-tpm.c
> > index b7aa2b8..c3dd4d2 100644
> > --- a/drivers/clocksource/timer-imx-tpm.c
> > +++ b/drivers/clocksource/timer-imx-tpm.c
> > @@ -12,6 +12,8 @@
> > #include <linux/of_irq.h>
> > #include <linux/sched_clock.h>
> >
> > +#include "timer-of.h"
> > +
> > #define TPM_PARAM 0x4
> > #define TPM_PARAM_WIDTH_SHIFT 16
> > #define TPM_PARAM_WIDTH_MASK (0xff << 16)
> > @@ -33,9 +35,7 @@
> > #define TPM_C0V 0x24
> >
> > static int counter_width;
> > -static int rating;
> > static void __iomem *timer_base;
> > -static struct clock_event_device clockevent_tpm;
> >
> > static inline void tpm_timer_disable(void) { @@ -80,19 +80,6 @@
> > static u64 notrace tpm_read_sched_clock(void)
> > return tpm_read_counter();
> > }
> >
> > -static int __init tpm_clocksource_init(unsigned long rate) -{
> > - tpm_delay_timer.read_current_timer = &tpm_read_current_timer;
> > - tpm_delay_timer.freq = rate;
> > - register_current_timer_delay(&tpm_delay_timer);
> > -
> > - sched_clock_register(tpm_read_sched_clock, counter_width, rate);
> > -
> > - return clocksource_mmio_init(timer_base + TPM_CNT, "imx-tpm",
> > - rate, rating, counter_width,
> > - clocksource_mmio_readl_up);
> > -}
> > -
> > static int tpm_set_next_event(unsigned long delta,
> > struct clock_event_device *evt)
> > {
> > @@ -137,74 +124,77 @@ static irqreturn_t tpm_timer_interrupt(int irq,
> void *dev_id)
> > return IRQ_HANDLED;
> > }
> >
> > -static struct clock_event_device clockevent_tpm = {
> > - .name = "i.MX7ULP TPM Timer",
> > - .features = CLOCK_EVT_FEAT_ONESHOT,
> > - .set_state_oneshot = tpm_set_state_oneshot,
> > - .set_next_event = tpm_set_next_event,
> > - .set_state_shutdown = tpm_set_state_shutdown,
> > +static struct timer_of to_tpm = {
> > + .flags = TIMER_OF_IRQ | TIMER_OF_BASE | TIMER_OF_CLOCK,
> > + .clkevt = {
> > + .name = "i.MX7ULP TPM Timer",
> > + .rating = 200,
> > + .features = CLOCK_EVT_FEAT_ONESHOT,
> > + .set_state_shutdown = tpm_set_state_shutdown,
> > + .set_state_oneshot = tpm_set_state_oneshot,
> > + .set_next_event = tpm_set_next_event,
> > + .cpumask = cpu_possible_mask,
> > + },
> > + .of_irq = {
> > + .handler = tpm_timer_interrupt,
> > + .flags = IRQF_TIMER | IRQF_IRQPOLL,
> > + },
> > };
> >
> > -static int __init tpm_clockevent_init(unsigned long rate, int irq)
> > +static int __init tpm_clocksource_init(void)
> > {
> > - int ret;
> > + tpm_delay_timer.read_current_timer = &tpm_read_current_timer;
> > + tpm_delay_timer.freq = timer_of_rate(&to_tpm) >> 3;
> > + register_current_timer_delay(&tpm_delay_timer);
> >
> > - ret = request_irq(irq, tpm_timer_interrupt, IRQF_TIMER | IRQF_IRQPOLL,
> > - "i.MX7ULP TPM Timer", &clockevent_tpm);
> > + sched_clock_register(tpm_read_sched_clock, counter_width,
> > + timer_of_rate(&to_tpm) >> 3);
> >
> > - clockevent_tpm.rating = rating;
> > - clockevent_tpm.cpumask = cpumask_of(0);
> > - clockevent_tpm.irq = irq;
> > - clockevents_config_and_register(&clockevent_tpm, rate, 300,
> > - GENMASK(counter_width - 1, 1));
> > + return clocksource_mmio_init(timer_base + TPM_CNT,
> > + "imx-tpm",
> > + timer_of_rate(&to_tpm) >> 3,
> > + to_tpm.clkevt.rating,
> > + counter_width,
> > + clocksource_mmio_readl_up);
> > +}
> >
> > - return ret;
> > +static void __init tpm_clockevent_init(void) {
> > + clockevents_config_and_register(&to_tpm.clkevt,
> > + timer_of_rate(&to_tpm) >> 3,
> > + 300,
> > + GENMASK(counter_width - 1,
> > + 1));
> > }
> >
> > static int __init tpm_timer_init(struct device_node *np) {
> > - struct clk *ipg, *per;
> > - int irq, ret;
> > - u32 rate;
> > -
> > - timer_base = of_iomap(np, 0);
> > - if (!timer_base) {
> > - pr_err("tpm: failed to get base address\n");
> > - return -ENXIO;
> > - }
> > -
> > - irq = irq_of_parse_and_map(np, 0);
> > - if (!irq) {
> > - pr_err("tpm: failed to get irq\n");
> > - ret = -ENOENT;
> > - goto err_iomap;
> > - }
> > + struct clk *ipg;
> > + int ret;
> >
> > ipg = of_clk_get_by_name(np, "ipg");
> > - per = of_clk_get_by_name(np, "per");
> > - if (IS_ERR(ipg) || IS_ERR(per)) {
> > - pr_err("tpm: failed to get ipg or per clk\n");
> > - ret = -ENODEV;
> > - goto err_clk_get;
> > + if (IS_ERR(ipg)) {
> > + pr_err("tpm: failed to get ipg clk\n");
> > + return -ENODEV;
> > }
> > -
> > /* enable clk before accessing registers */
> > ret = clk_prepare_enable(ipg);
> > if (ret) {
> > pr_err("tpm: ipg clock enable failed (%d)\n", ret);
> > - goto err_clk_get;
> > + clk_put(ipg);
> > + return ret;
> > }
> >
> > - ret = clk_prepare_enable(per);
> > - if (ret) {
> > - pr_err("tpm: per clock enable failed (%d)\n", ret);
> > - goto err_per_clk_enable;
> > - }
> > + ret = timer_of_init(np, &to_tpm);
> > + if (ret)
> > + return ret;
> > +
> > + timer_base = timer_of_base(&to_tpm);
> >
> > - counter_width = (readl(timer_base + TPM_PARAM) &
> TPM_PARAM_WIDTH_MASK)
> > - >> TPM_PARAM_WIDTH_SHIFT;
> > + counter_width = (readl(timer_base + TPM_PARAM)
> > + & TPM_PARAM_WIDTH_MASK) >> TPM_PARAM_WIDTH_SHIFT;
> > /* use rating 200 for 32-bit counter and 150 for 16-bit counter */
> > - rating = counter_width == 0x20 ? 200 : 150;
> > + to_tpm.clkevt.rating = counter_width == 0x20 ? 200 : 150;
> >
> > /*
> > * Initialize tpm module to a known state @@ -229,29 +219,13 @@
> > static int __init tpm_timer_init(struct device_node *np)
> > writel(TPM_SC_CMOD_INC_PER_CNT |
> > (counter_width == 0x20 ?
> > TPM_SC_CMOD_DIV_DEFAULT : TPM_SC_CMOD_DIV_MAX),
> > - timer_base + TPM_SC);
> > + timer_base + TPM_SC);
> >
> > /* set MOD register to maximum for free running mode */
> > writel(GENMASK(counter_width - 1, 0), timer_base + TPM_MOD);
> >
> > - rate = clk_get_rate(per) >> 3;
> > - ret = tpm_clocksource_init(rate);
> > - if (ret)
> > - goto err_per_clk_enable;
> > -
> > - ret = tpm_clockevent_init(rate, irq);
> > - if (ret)
> > - goto err_per_clk_enable;
> > -
> > - return 0;
> > + tpm_clockevent_init();
> >
> > -err_per_clk_enable:
> > - clk_disable_unprepare(ipg);
> > -err_clk_get:
> > - clk_put(per);
> > - clk_put(ipg);
> > -err_iomap:
> > - iounmap(timer_base);
> > - return ret;
> > + return tpm_clocksource_init();
> > }
> > TIMER_OF_DECLARE(imx7ulp, "fsl,imx7ulp-tpm", tpm_timer_init);
> >
>
>
> --
>
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