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Date: Thu, 7 Nov 2019 12:51:15 +0000
From: <Eugen.Hristev@...rochip.com>
To: <linux@...ck-us.net>
CC: <wim@...ux-watchdog.org>, <robh+dt@...nel.org>,
<Nicolas.Ferre@...rochip.com>, <alexandre.belloni@...tlin.com>,
<linux-watchdog@...r.kernel.org>, <devicetree@...r.kernel.org>,
<linux-arm-kernel@...ts.infradead.org>,
<linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2 2/2] watchdog: sama5d4_wdt: addition of sam9x60
compatible watchdog
On 29.10.2019 15:28, Guenter Roeck wrote:
>
> On Mon, Oct 21, 2019 at 09:14:09AM +0000, Eugen.Hristev@...rochip.com wrote:
>> From: Eugen Hristev <eugen.hristev@...rochip.com>
>>
>> Add support for SAM9X60 WDT into sama5d4_wdt.
>> This means that this driver will have a platform data that will
>> hold differences.
>> Added definitions of different bits.
>> The ops functions will differentiate between the two hardware blocks.
>>
>> Signed-off-by: Eugen Hristev <eugen.hristev@...rochip.com>
>> ---
>>
>> Hello,
>>
>> This is a rework of the separate sam9x60 watchdog driver into a single driver
>> that supports both hardware blocks (sam9x60 and sama5d4)
>> This was done as suggested on the original patches on the mailing list.
>>
>> Thanks,
>> Eugen
>>
>> drivers/watchdog/at91sam9_wdt.h | 14 +++++
>> drivers/watchdog/sama5d4_wdt.c | 127 +++++++++++++++++++++++++++++++---------
>> 2 files changed, 112 insertions(+), 29 deletions(-)
>>
>> diff --git a/drivers/watchdog/at91sam9_wdt.h b/drivers/watchdog/at91sam9_wdt.h
>> index 390941c..7a053fd 100644
>> --- a/drivers/watchdog/at91sam9_wdt.h
>> +++ b/drivers/watchdog/at91sam9_wdt.h
>> @@ -20,7 +20,10 @@
>> #define AT91_WDT_MR 0x04 /* Watchdog Mode Register */
>> #define AT91_WDT_WDV (0xfff << 0) /* Counter Value */
>> #define AT91_WDT_SET_WDV(x) ((x) & AT91_WDT_WDV)
>> +#define AT91_SAM9X60_PERIODRST BIT(4) /* Period Reset */
>> +#define AT91_SAM9X60_RPTHRST BIT(5) /* Minimum Restart Period */
>> #define AT91_WDT_WDFIEN (1 << 12) /* Fault Interrupt Enable */
>> +#define AT91_SAM9X60_WDDIS BIT(12) /* Disable */
>> #define AT91_WDT_WDRSTEN (1 << 13) /* Reset Processor */
>> #define AT91_WDT_WDRPROC (1 << 14) /* Timer Restart */
>> #define AT91_WDT_WDDIS (1 << 15) /* Watchdog Disable */
>> @@ -33,4 +36,15 @@
>> #define AT91_WDT_WDUNF (1 << 0) /* Watchdog Underflow */
>> #define AT91_WDT_WDERR (1 << 1) /* Watchdog Error */
>>
>> +#define AT91_SAM9X60_VR 0x08 /* Watchdog Timer Value Register */
>> +
>> +#define AT91_SAM9X60_WLR 0x0c
>> +#define AT91_SAM9X60_COUNTER (0xfff << 0) /* Watchdog Period Value */
>> +#define AT91_SAM9X60_SET_COUNTER(x) ((x) & AT91_SAM9X60_COUNTER)
>> +
>> +#define AT91_SAM9X60_IER 0x14 /* Interrupt Enable Register */
>> +#define AT91_SAM9X60_PERINT BIT(0) /* Period Interrupt Enable */
>> +#define AT91_SAM9X60_IDR 0x18 /* Interrupt Disable Register */
>> +#define AT91_SAM9X60_ISR 0x1c /* Interrupt Status Register */
>> +
>
> Those tabs are getting messy, and the mix of BIT() and shift is messy too.
> Mind cleaning it up a bit ? Especially, two tabs after #define doesn't really
> add value (use two spaces), and use BIT() throughout or not at all.
>
>> #endif
>> diff --git a/drivers/watchdog/sama5d4_wdt.c b/drivers/watchdog/sama5d4_wdt.c
>> index d193a60..b92afd7 100644
>> --- a/drivers/watchdog/sama5d4_wdt.c
>> +++ b/drivers/watchdog/sama5d4_wdt.c
>> @@ -2,7 +2,7 @@
>> /*
>> * Driver for Atmel SAMA5D4 Watchdog Timer
>> *
>> - * Copyright (C) 2015 Atmel Corporation
>> + * Copyright (C) 2015-2019 Microchip Technology Inc. and its subsidiaries
>> */
>>
>> #include <linux/delay.h>
>> @@ -11,6 +11,7 @@
>> #include <linux/kernel.h>
>> #include <linux/module.h>
>> #include <linux/of.h>
>> +#include <linux/of_device.h>
>> #include <linux/of_irq.h>
>> #include <linux/platform_device.h>
>> #include <linux/reboot.h>
>> @@ -25,11 +26,18 @@
>>
>> #define WDT_SEC2TICKS(s) ((s) ? (((s) << 8) - 1) : 0)
>>
>> +struct sama5d4_wdt_data {
>> + const unsigned int sam9x60_support;
>> +};
>> +
>> struct sama5d4_wdt {
>> - struct watchdog_device wdd;
>> - void __iomem *reg_base;
>> - u32 mr;
>> - unsigned long last_ping;
>> + struct watchdog_device wdd;
>> + const struct sama5d4_wdt_data *data;
>> + void __iomem *reg_base;
>> + u32 mr;
>> + u32 ir;
>> + unsigned long last_ping;
>> + unsigned int need_irq:1;
>
> This can be a bool. Making it a bit just adds complexity to the code.
>
>> };
>>
>> static int wdt_timeout;
>> @@ -78,7 +86,12 @@ static int sama5d4_wdt_start(struct watchdog_device *wdd)
>> {
>> struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd);
>>
>> - wdt->mr &= ~AT91_WDT_WDDIS;
>> + if (wdt->data->sam9x60_support) {
>> + writel_relaxed(wdt->ir, wdt->reg_base + AT91_SAM9X60_IER);
>> + wdt->mr &= ~AT91_SAM9X60_WDDIS;
>> + } else {
>> + wdt->mr &= ~AT91_WDT_WDDIS;
>> + }
>> wdt_write(wdt, AT91_WDT_MR, wdt->mr);
>>
>> return 0;
>> @@ -88,7 +101,12 @@ static int sama5d4_wdt_stop(struct watchdog_device *wdd)
>> {
>> struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd);
>>
>> - wdt->mr |= AT91_WDT_WDDIS;
>> + if (wdt->data->sam9x60_support) {
>> + writel_relaxed(wdt->ir, wdt->reg_base + AT91_SAM9X60_IDR);
>> + wdt->mr |= AT91_SAM9X60_WDDIS;
>> + } else {
>> + wdt->mr |= AT91_WDT_WDDIS;
>> + }
>> wdt_write(wdt, AT91_WDT_MR, wdt->mr);
>>
>> return 0;
>> @@ -109,6 +127,14 @@ static int sama5d4_wdt_set_timeout(struct watchdog_device *wdd,
>> struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd);
>> u32 value = WDT_SEC2TICKS(timeout);
>>
>> + if (wdt->data->sam9x60_support) {
>> + wdt_write(wdt, AT91_SAM9X60_WLR,
>> + AT91_SAM9X60_SET_COUNTER(value));
>> +
>> + wdd->timeout = timeout;
>> + return 0;
>> + }
>> +
>> wdt->mr &= ~AT91_WDT_WDV;
>> wdt->mr |= AT91_WDT_SET_WDV(value);
>>
>> @@ -143,8 +169,14 @@ static const struct watchdog_ops sama5d4_wdt_ops = {
>> static irqreturn_t sama5d4_wdt_irq_handler(int irq, void *dev_id)
>> {
>> struct sama5d4_wdt *wdt = platform_get_drvdata(dev_id);
>> + u32 reg;
>>
>> - if (wdt_read(wdt, AT91_WDT_SR)) {
>> + if (wdt->data->sam9x60_support)
>> + reg = wdt_read(wdt, AT91_SAM9X60_ISR);
>> + else
>> + reg = wdt_read(wdt, AT91_WDT_SR);
>> +
>> + if (reg) {
>> pr_crit("Atmel Watchdog Software Reset\n");
>> emergency_restart();
>> pr_crit("Reboot didn't succeed\n");
>> @@ -157,13 +189,14 @@ static int of_sama5d4_wdt_init(struct device_node *np, struct sama5d4_wdt *wdt)
>> {
>> const char *tmp;
>>
>> - wdt->mr = AT91_WDT_WDDIS;
>> + if (wdt->data->sam9x60_support)
>> + wdt->mr = AT91_SAM9X60_WDDIS;
>> + else
>> + wdt->mr = AT91_WDT_WDDIS;
>>
>> if (!of_property_read_string(np, "atmel,watchdog-type", &tmp) &&
>> !strcmp(tmp, "software"))
>> - wdt->mr |= AT91_WDT_WDFIEN;
>> - else
>> - wdt->mr |= AT91_WDT_WDRSTEN;
>> + wdt->need_irq = 1;
>>
>> if (of_property_read_bool(np, "atmel,idle-halt"))
>> wdt->mr |= AT91_WDT_WDIDLEHLT;
>> @@ -176,21 +209,46 @@ static int of_sama5d4_wdt_init(struct device_node *np, struct sama5d4_wdt *wdt)
>>
>> static int sama5d4_wdt_init(struct sama5d4_wdt *wdt)
>> {
>> - u32 reg;
>> + u32 reg, val;
>> +
>> + val = WDT_SEC2TICKS(WDT_DEFAULT_TIMEOUT);
>> /*
>> * When booting and resuming, the bootloader may have changed the
>> * watchdog configuration.
>> * If the watchdog is already running, we can safely update it.
>> * Else, we have to disable it properly.
>> */
>> - if (wdt_enabled) {
>> - wdt_write_nosleep(wdt, AT91_WDT_MR, wdt->mr);
>> - } else {
>> + if (!wdt_enabled) {
>> reg = wdt_read(wdt, AT91_WDT_MR);
>> - if (!(reg & AT91_WDT_WDDIS))
>> + if (wdt->data->sam9x60_support && (!(reg & AT91_SAM9X60_WDDIS)))
>> + wdt_write_nosleep(wdt, AT91_WDT_MR,
>> + reg | AT91_SAM9X60_WDDIS);
>> + else if (!wdt->data->sam9x60_support &&
>> + (!(reg & AT91_WDT_WDDIS)))
>> wdt_write_nosleep(wdt, AT91_WDT_MR,
>> reg | AT91_WDT_WDDIS);
>> }
>> +
>> + if (wdt->data->sam9x60_support) {
>> + if (wdt->need_irq)
>> + wdt->ir = AT91_SAM9X60_PERINT;
>> + else
>> + wdt->mr |= AT91_SAM9X60_PERIODRST;
>> +
>> + wdt_write(wdt, AT91_SAM9X60_IER, wdt->ir);
>> + wdt_write(wdt, AT91_SAM9X60_WLR, AT91_SAM9X60_SET_COUNTER(val));
>> + } else {
>> + wdt->mr |= AT91_WDT_SET_WDD(WDT_SEC2TICKS(MAX_WDT_TIMEOUT));
>> + wdt->mr |= AT91_WDT_SET_WDV(val);
>> +
>> + if (wdt->need_irq)
>> + wdt->mr |= AT91_WDT_WDFIEN;
>> + else
>> + wdt->mr |= AT91_WDT_WDRSTEN;
>> + }
>> +
>> + wdt_write_nosleep(wdt, AT91_WDT_MR, wdt->mr);
>> +
>> return 0;
>> }
>>
>> @@ -201,13 +259,14 @@ static int sama5d4_wdt_probe(struct platform_device *pdev)
>> struct sama5d4_wdt *wdt;
>> void __iomem *regs;
>> u32 irq = 0;
>> - u32 timeout;
>> int ret;
>>
>> wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
>> if (!wdt)
>> return -ENOMEM;
>>
>> + wdt->data = of_device_get_match_data(&pdev->dev);
>> +
>> wdd = &wdt->wdd;
>> wdd->timeout = WDT_DEFAULT_TIMEOUT;
>> wdd->info = &sama5d4_wdt_info;
>> @@ -224,15 +283,17 @@ static int sama5d4_wdt_probe(struct platform_device *pdev)
>>
>> wdt->reg_base = regs;
>>
>> - irq = irq_of_parse_and_map(dev->of_node, 0);
>> - if (!irq)
>> - dev_warn(dev, "failed to get IRQ from DT\n");
>> -
>> ret = of_sama5d4_wdt_init(dev->of_node, wdt);
>> if (ret)
>> return ret;
>>
>> - if ((wdt->mr & AT91_WDT_WDFIEN) && irq) {
>> + irq = irq_of_parse_and_map(dev->of_node, 0);
>> + if (!irq) {
>> + dev_warn(dev, "failed to get IRQ from DT\n");
>> + wdt->need_irq = 0;
>
> Does it make sense to ignore that ?
Hi Guenter,
Can you detail what exactly is ignored ?
>
>> + }
>> +
>> + if (wdt->need_irq) {
>> ret = devm_request_irq(dev, irq, sama5d4_wdt_irq_handler,
>> IRQF_SHARED | IRQF_IRQPOLL |
>> IRQF_NO_SUSPEND, pdev->name, pdev);
>> @@ -244,11 +305,6 @@ static int sama5d4_wdt_probe(struct platform_device *pdev)
>>
>> watchdog_init_timeout(wdd, wdt_timeout, dev);
>>
>> - timeout = WDT_SEC2TICKS(wdd->timeout);
>> -
>> - wdt->mr |= AT91_WDT_SET_WDD(WDT_SEC2TICKS(MAX_WDT_TIMEOUT));
>> - wdt->mr |= AT91_WDT_SET_WDV(timeout);
>> -
>> ret = sama5d4_wdt_init(wdt);
>> if (ret)
>> return ret;
>> @@ -268,8 +324,21 @@ static int sama5d4_wdt_probe(struct platform_device *pdev)
>> return 0;
>> }
>>
>> +static struct sama5d4_wdt_data sama5d4_config;
>> +
>> +static struct sama5d4_wdt_data sam9x60_config = {
>> + .sam9x60_support = 1,
>> +};
>
> Unless there is reason to believe that there will be other
> configuration data, please just assign the flag value directly
> to .data and add a variable to struct sama5d4_wdt to access it.
> Please make that variable a bool.
There will be more configuration data for future products, but not at
this moment. Do the change or keep it this way ?
I will do the other changes as requested.
Thanks for reviewing,
Eugen
>
>> +
>> static const struct of_device_id sama5d4_wdt_of_match[] = {
>> - { .compatible = "atmel,sama5d4-wdt", },
>> + {
>> + .compatible = "atmel,sama5d4-wdt",
>> + .data = &sama5d4_config,
>> + },
>> + {
>> + .compatible = "microchip,sam9x60-wdt",
>> + .data = &sam9x60_config,
>> + },
>> { }
>> };
>> MODULE_DEVICE_TABLE(of, sama5d4_wdt_of_match);
>
>
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