[PATCH v2 1/2] clocksource: npcm: add NPCM7xx timer driver
Tomer Maimon
tmaimon77 at gmail.com
Mon Nov 6 21:23:14 AEDT 2017
On 4 November 2017 at 02:28, Brendan Higgins <brendanhiggins at google.com> wrote:
> Looks like you missed a couple of comments from Daniel:
> https://www.spinics.net/lists/devicetree/msg196683.html
>
> Also, I think the binding documentation is supposed to come before the driver.
>
> On Wed, Nov 1, 2017 at 5:16 AM, Tomer Maimon <tmaimon77 at gmail.com> wrote:
>> Add Nuvoton BMC NPCM7xx timer driver.
>>
>> the clocksource Enable 24-bit TIMER0 and TIMER1 counters,
>> while TIMER0 serves as clockevent and TIMER1 serves as clocksource.
>>
>> Signed-off-by: Tomer Maimon <tmaimon77 at gmail.com>
>> ---
>> drivers/clocksource/Kconfig | 8 ++
>> drivers/clocksource/Makefile | 1 +
>> drivers/clocksource/npcm7xx-timer.c | 224 ++++++++++++++++++++++++++++++++++++
>> 3 files changed, 233 insertions(+)
>> create mode 100644 drivers/clocksource/npcm7xx-timer.c
>
> Looks like you forgot to rename the driver.
I think Daniel asked to modify the driver name from npcm7xx_timer.c
to npcm7xx-timer.c and i did it.
>
>>
>> diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
>> index cc6062049170..46184af75d6c 100644
>> --- a/drivers/clocksource/Kconfig
>> +++ b/drivers/clocksource/Kconfig
>> @@ -140,6 +140,14 @@ config VT8500_TIMER
>> help
>> Enables support for the VT8500 driver.
>>
>> +config NPCM7XX_TIMER
>> + bool "NPCM7xx timer driver" if COMPILE_TEST
>> + depends on HAS_IOMEM
>> + select CLKSRC_MMIO
>> + help
>> + Enable 24-bit TIMER0 and TIMER1 counters in the NPCM7xx arcithcture,
>> + While TIMER0 serves as clockevent and TIMER1 serves as clocksource.
>> +
>> config CADENCE_TTC_TIMER
>> bool "Cadence TTC timer driver" if COMPILE_TEST
>> depends on COMMON_CLK
>> diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
>> index dbc1ad14515e..f2a9318a1eec 100644
>> --- a/drivers/clocksource/Makefile
>> +++ b/drivers/clocksource/Makefile
>> @@ -53,6 +53,7 @@ obj-$(CONFIG_CLKSRC_TI_32K) += timer-ti-32k.o
>> obj-$(CONFIG_CLKSRC_NPS) += timer-nps.o
>> obj-$(CONFIG_OXNAS_RPS_TIMER) += timer-oxnas-rps.o
>> obj-$(CONFIG_OWL_TIMER) += owl-timer.o
>> +obj-$(CONFIG_NPCM7XX_TIMER) += npcm7xx-timer.o
>>
>> obj-$(CONFIG_ARC_TIMERS) += arc_timer.o
>> obj-$(CONFIG_ARM_ARCH_TIMER) += arm_arch_timer.o
>> diff --git a/drivers/clocksource/npcm7xx-timer.c b/drivers/clocksource/npcm7xx-timer.c
>> new file mode 100644
>> index 000000000000..d1ea5c183a69
>> --- /dev/null
>> +++ b/drivers/clocksource/npcm7xx-timer.c
>> @@ -0,0 +1,224 @@
>> +
>> +/*
>> + * Copyright (c) 2017 Nuvoton Technology corporation.
>> + * Copyright 2017 Google, Inc.
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License as published by
>> + * the Free Software Foundation;version 2 of the License.
>> + */
>> +
>> +#include <linux/kernel.h>
>> +#include <linux/sched.h>
>> +#include <linux/init.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/err.h>
>> +#include <linux/clk.h>
>> +#include <linux/io.h>
>> +#include <linux/clockchips.h>
>> +#include <linux/of_irq.h>
>> +#include <linux/of_address.h>
>> +
>> +struct npcm7xx_clockevent_data {
>> + struct clock_event_device cvd;
>> + void __iomem *timer_base;
>> + unsigned int rate;
>> +};
>> +
>> +/* Timers registers */
>> +#define NPCM7XX_REG_TCSR0 0x0 /* Timer 0 Control and Status Register */
>> +#define NPCM7XX_REG_TICR0 0x8 /* Timer 0 Initial Count Register */
>> +#define NPCM7XX_REG_TCSR1 0x4 /* Timer 1 Control and Status Register */
>> +#define NPCM7XX_REG_TICR1 0xc /* Timer 1 Initial Count Register */
>> +#define NPCM7XX_REG_TDR1 0x14 /* Timer 1 Data Register */
>> +#define NPCM7XX_REG_TISR 0x18 /* Timer Interrupt Status Register */
>> +
>> +/* Timers control */
>> +#define NPCM7XX_Tx_RESETINT 0x1f
>> +#define NPCM7XX_Tx_PERIOD BIT(27)
>> +#define NPCM7XX_Tx_INTEN BIT(29)
>> +#define NPCM7XX_Tx_COUNTEN BIT(30)
>> +#define NPCM7XX_Tx_ONESHOT 0x0
>> +#define NPCM7XX_Tx_OPER GENMASK(3, 27)
>> +#define NPCM7XX_Tx_MIN_PRESCALE 0x1
>> +#define NPCM7XX_Tx_TDR_MASK_BITS 24
>> +#define NPCM7XX_Tx_MAX_CNT 0xFFFFFF
>> +#define NPCM7XX_T0_CLR_INT 0x1
>> +#define NPCM7XX_Tx_CLR_CSR 0x0
>> +
>> +/* Timers operating mode */
>> +#define NPCM7XX_START_PERIODIC_Tx (NPCM7XX_Tx_PERIOD | NPCM7XX_Tx_COUNTEN | \
>> + NPCM7XX_Tx_INTEN | \
>> + NPCM7XX_Tx_MIN_PRESCALE)
>> +
>> +#define NPCM7XX_START_ONESHOT_Tx (NPCM7XX_Tx_ONESHOT | NPCM7XX_Tx_COUNTEN | \
>> + NPCM7XX_Tx_INTEN | \
>> + NPCM7XX_Tx_MIN_PRESCALE)
>> +#define NPCM7XX_START_Tx (NPCM7XX_Tx_COUNTEN | NPCM7XX_Tx_PERIOD | \
>> + NPCM7XX_Tx_MIN_PRESCALE)
>> +
>> +static int npcm7xx_timer_oneshot(struct clock_event_device *evt)
>> +{
>> + u32 val;
>> + struct npcm7xx_clockevent_data *cevtd =
>> + container_of(evt, struct npcm7xx_clockevent_data, cvd);
>> +
>> + val = readl(cevtd->timer_base + NPCM7XX_REG_TCSR0);
>> + val &= ~NPCM7XX_Tx_OPER;
>> +
>> + val = readl(cevtd->timer_base + NPCM7XX_REG_TCSR0);
>> + val |= NPCM7XX_START_ONESHOT_Tx;
>> + writel(val, cevtd->timer_base + NPCM7XX_REG_TCSR0);
>> +
>> + return 0;
>> +}
>> +
>> +static int npcm7xx_timer_periodic(struct clock_event_device *evt)
>> +{
>> + struct npcm7xx_clockevent_data *cevtd =
>> + container_of(evt, struct npcm7xx_clockevent_data, cvd);
>> + u32 val;
>> +
>> + val = readl(cevtd->timer_base + NPCM7XX_REG_TCSR0);
>> + val &= ~NPCM7XX_Tx_OPER;
>> +
>> + writel((cevtd->rate / HZ), cevtd->timer_base + NPCM7XX_REG_TICR0);
>> + val |= NPCM7XX_START_PERIODIC_Tx;
>> +
>> + writel(val, cevtd->timer_base + NPCM7XX_REG_TCSR0);
>> +
>> + return 0;
>> +}
>> +
>> +static int npcm7xx_clockevent_setnextevent(unsigned long evt,
>> + struct clock_event_device *clk)
>> +{
>> + struct npcm7xx_clockevent_data *cevtd =
>> + container_of(clk, struct npcm7xx_clockevent_data, cvd);
>> + u32 val;
>> +
>> + writel(evt, cevtd->timer_base + NPCM7XX_REG_TICR0);
>> + val = readl(cevtd->timer_base + NPCM7XX_REG_TCSR0);
>> + val |= NPCM7XX_START_Tx;
>> + writel(val, cevtd->timer_base + NPCM7XX_REG_TCSR0);
>> +
>> + return 0;
>> +}
>> +
>> +static struct npcm7xx_clockevent_data npcm7xx_clockevent_data = {
>> + .cvd = {
>> + .name = "npcm7xx-timer0",
>> + .features = CLOCK_EVT_FEAT_PERIODIC |
>> + CLOCK_EVT_FEAT_ONESHOT,
>> + .set_next_event = npcm7xx_clockevent_setnextevent,
>> + .set_state_shutdown = npcm7xx_timer_oneshot,
>> + .set_state_periodic = npcm7xx_timer_periodic,
>> + .set_state_oneshot = npcm7xx_timer_oneshot,
>> + .tick_resume = npcm7xx_timer_oneshot,
>> + .rating = 300
>> + },
>> +};
>> +
>> +static irqreturn_t npcm7xx_timer0_interrupt(int irq, void *dev_id)
>> +{
>> + struct npcm7xx_clockevent_data *cevtd = dev_id;
>> + struct clock_event_device *evt = &cevtd->cvd;
>> +
>> + writel(NPCM7XX_T0_CLR_INT, cevtd->timer_base + NPCM7XX_REG_TISR);
>> +
>> + if (evt->event_handler) {
>
> I think Daniel was implying this is impossible or at least deserves a comment.
> I think I originally added this check to make the driver not crash when I was
> ripping out some of the HAL dependencies. I did not think about it too hard, so
> this might need some looking into.
I found the issue, calling incorrect procedure in set_state_shutdown().
will send a fix in V3.
>
>> + evt->event_handler(evt);
>> + return IRQ_HANDLED;
>> + }
>> +
>> + return IRQ_NONE;
>> +}
>> +
>> +static struct irqaction npcm7xx_timer0_irq = {
>> + .name = "npcm7xx-timer0",
>> + .flags = IRQF_TIMER | IRQF_IRQPOLL,
>> + .handler = npcm7xx_timer0_interrupt,
>> + .dev_id = &npcm7xx_clockevent_data,
>> +};
>> +
>> +static void __init npcm7xx_clockevents_init(int irq, u32 rate)
>> +{
>> + writel(NPCM7XX_Tx_CLR_CSR,
>> + npcm7xx_clockevent_data.timer_base + NPCM7XX_REG_TCSR0);
>> +
>> + writel(NPCM7XX_Tx_RESETINT,
>> + npcm7xx_clockevent_data.timer_base + NPCM7XX_REG_TISR);
>> + setup_irq(irq, &npcm7xx_timer0_irq);
>> + npcm7xx_clockevent_data.cvd.cpumask = cpumask_of(0);
>> +
>> + clockevents_config_and_register(&npcm7xx_clockevent_data.cvd, rate,
>> + 0x1, NPCM7XX_Tx_MAX_CNT);
>> +}
>> +
>> +static void __init npcm7xx_clocksource_init(u32 rate)
>> +{
>> + u32 val;
>> +
>> + writel(NPCM7XX_Tx_CLR_CSR,
>> + npcm7xx_clockevent_data.timer_base + NPCM7XX_REG_TCSR1);
>> + writel(NPCM7XX_Tx_MAX_CNT,
>> + npcm7xx_clockevent_data.timer_base + NPCM7XX_REG_TICR1);
>> +
>> + val = readl(npcm7xx_clockevent_data.timer_base + NPCM7XX_REG_TCSR1);
>> + val |= NPCM7XX_START_Tx;
>> + writel(val, npcm7xx_clockevent_data.timer_base + NPCM7XX_REG_TCSR1);
>> +
>> + clocksource_mmio_init(npcm7xx_clockevent_data.timer_base +
>> + NPCM7XX_REG_TDR1,
>> + "npcm7xx-timer1", rate,
>> + 300, (unsigned int)NPCM7XX_Tx_TDR_MASK_BITS,
>> + clocksource_mmio_readl_down);
>> +}
>> +
>> +static int __init npcm7xx_timer_init(struct device_node *np)
>> +{
>> + struct clk *clk;
>> + int irq, ret;
>> + u32 rate;
>> +
>> + irq = irq_of_parse_and_map(np, 0);
>
> Looks like this, the base addr, and possibly the clock is common with what
> timer_of_init does.
see above.
>
>> + if (!irq)
>> + return -EINVAL;
>> +
>> + npcm7xx_clockevent_data.timer_base = of_iomap(np, 0);
>> + if (!npcm7xx_clockevent_data.timer_base)
>> + return -ENXIO;
>> +
>> + clk = of_clk_get(np, 0);
>> +
>> + if (IS_ERR(clk)) {
>> + ret = of_property_read_u32(np, "clock-frequency", &rate);
>> + if (ret)
>> + goto err_iounmap;
>> + } else {
>> + clk_prepare_enable(clk);
>> + rate = clk_get_rate(clk);
>> + }
>> +
>> + /* Clock input is divided by PRESCALE + 1 before it is fed */
>> + /* to the counter */
>> + rate = rate / (NPCM7XX_Tx_MIN_PRESCALE + 1);
>> +
>> + npcm7xx_clockevent_data.rate = rate;
>> +
>> + npcm7xx_clocksource_init(rate);
>> + npcm7xx_clockevents_init(irq, rate);
>> +
>> + pr_info("Enabling NPCM7xx clocksource timer base: %p, IRQ: %u\n",
>> + npcm7xx_clockevent_data.timer_base, irq);
>> +
>> + return 0;
>> +
>> +err_iounmap:
>> + iounmap(npcm7xx_clockevent_data.timer_base);
>> + return ret;
>> +
>> +}
>> +
>> +TIMER_OF_DECLARE(npcm7xx, "nuvoton,npcm7xx-timer", npcm7xx_timer_init);
>> +
>> --
>> 2.14.1
>>
Thanks!
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