Re: [PATCH 09/46] watchdog: sa1100: use platform device registration

Guenter Roeck
2019-10-19T14:06:54Z

On 10/18/19 8:41 AM, Arnd Bergmann wrote:
> Rather than relying on machine specific headers to
> pass down the reboot status and the register locations,
> use resources and platform_data.
>
> Aside from this, keep the changes to a minimum.
>
> Cc: Wim Van Sebroeck <wim@linux-watchdog.org>
> Cc: Guenter Roeck <linux@roeck-us.net>
> Cc: linux-watchdog@vger.kernel.org
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
> arch/arm/mach-pxa/devices.c | 11 +++
> arch/arm/mach-pxa/include/mach/regs-ost.h | 2 +
> arch/arm/mach-pxa/include/mach/reset.h | 2 +-
> arch/arm/mach-pxa/pxa25x.c | 2 +-
> arch/arm/mach-pxa/pxa27x.c | 2 +-
> arch/arm/mach-pxa/pxa3xx.c | 2 +-
> arch/arm/mach-pxa/reset.c | 3 -
> arch/arm/mach-sa1100/generic.c | 6 +-
> arch/arm/mach-sa1100/include/mach/reset.h | 1 -
> drivers/watchdog/sa1100_wdt.c | 87 ++++++++++++++++-------
> 10 files changed, 83 insertions(+), 35 deletions(-)
>
> diff --git a/arch/arm/mach-pxa/devices.c b/arch/arm/mach-pxa/devices.c
> index 233035e6a2ff..fb9b4f6d32de 100644
> --- a/arch/arm/mach-pxa/devices.c
> +++ b/arch/arm/mach-pxa/devices.c
> @@ -23,6 +23,8 @@
> #include <linux/platform_data/mmp_dma.h>
> #include <linux/platform_data/mtd-nand-pxa3xx.h>
>
> +#include <mach/regs-ost.h>
> +#include <mach/reset.h>
> #include "devices.h"
> #include "generic.h"
>
> @@ -1110,3 +1112,12 @@ void __init pxa2xx_set_dmac_info(struct mmp_dma_platdata *dma_pdata)
> {
> pxa_register_device(&pxa2xx_pxa_dma, dma_pdata);
> }
> +
> +void __init pxa_register_wdt(unsigned int reset_status)
> +{
> + struct resource res = DEFINE_RES_MEM(OST_PHYS, OST_LEN);
> +
> + reset_status &= RESET_STATUS_WATCHDOG;
> + platform_device_register_resndata(NULL, "sa1100_wdt", -1, &res, 1,
> + &reset_status, sizeof(reset_status));
> +}
> diff --git a/arch/arm/mach-pxa/include/mach/regs-ost.h b/arch/arm/mach-pxa/include/mach/regs-ost.h
> index 109d0ed264df..c8001cfc8d6b 100644
> --- a/arch/arm/mach-pxa/include/mach/regs-ost.h
> +++ b/arch/arm/mach-pxa/include/mach/regs-ost.h
> @@ -7,6 +7,8 @@
> /*
> * OS Timer & Match Registers
> */
> +#define OST_PHYS 0x40A00000
> +#define OST_LEN 0x00000020
>
> #define OSMR0 io_p2v(0x40A00000) /* */
> #define OSMR1 io_p2v(0x40A00004) /* */
> diff --git a/arch/arm/mach-pxa/include/mach/reset.h b/arch/arm/mach-pxa/include/mach/reset.h
> index e1c4d100fd45..963dd190bc13 100644
> --- a/arch/arm/mach-pxa/include/mach/reset.h
> +++ b/arch/arm/mach-pxa/include/mach/reset.h
> @@ -8,8 +8,8 @@
> #define RESET_STATUS_GPIO (1 << 3) /* GPIO Reset */
> #define RESET_STATUS_ALL (0xf)
>
> -extern unsigned int reset_status;
> extern void clear_reset_status(unsigned int mask);
> +extern void pxa_register_wdt(unsigned int reset_status);
>
> /**
> * init_gpio_reset() - register GPIO as reset generator
> diff --git a/arch/arm/mach-pxa/pxa25x.c b/arch/arm/mach-pxa/pxa25x.c
> index 305047ebd2f1..dfc90b41fba3 100644
> --- a/arch/arm/mach-pxa/pxa25x.c
> +++ b/arch/arm/mach-pxa/pxa25x.c
> @@ -240,7 +240,7 @@ static int __init pxa25x_init(void)
>
> if (cpu_is_pxa25x()) {
>
> - reset_status = RCSR;
> + pxa_register_wdt(RCSR);
>
> pxa25x_init_pm();
>
> diff --git a/arch/arm/mach-pxa/pxa27x.c b/arch/arm/mach-pxa/pxa27x.c
> index a81ac88ecbfd..38fdd22c4dc5 100644
> --- a/arch/arm/mach-pxa/pxa27x.c
> +++ b/arch/arm/mach-pxa/pxa27x.c
> @@ -337,7 +337,7 @@ static int __init pxa27x_init(void)
>
> if (cpu_is_pxa27x()) {
>
> - reset_status = RCSR;
> + pxa_register_wdt(RCSR);
>
> pxa27x_init_pm();
>
> diff --git a/arch/arm/mach-pxa/pxa3xx.c b/arch/arm/mach-pxa/pxa3xx.c
> index fc84aed99481..7c569fa2a6da 100644
> --- a/arch/arm/mach-pxa/pxa3xx.c
> +++ b/arch/arm/mach-pxa/pxa3xx.c
> @@ -463,7 +463,7 @@ static int __init pxa3xx_init(void)
>
> if (cpu_is_pxa3xx()) {
>
> - reset_status = ARSR;
> + pxa_register_wdt(ARSR);
>
> /*
> * clear RDH bit every time after reset
> diff --git a/arch/arm/mach-pxa/reset.c b/arch/arm/mach-pxa/reset.c
> index af78405aa4e9..fcb791c5ae3e 100644
> --- a/arch/arm/mach-pxa/reset.c
> +++ b/arch/arm/mach-pxa/reset.c
> @@ -11,9 +11,6 @@
> #include <mach/reset.h>
> #include <mach/smemc.h>
>
> -unsigned int reset_status;
> -EXPORT_SYMBOL(reset_status);
> -
> static void do_hw_reset(void);
>
> static int reset_gpio = -1;
> diff --git a/arch/arm/mach-sa1100/generic.c b/arch/arm/mach-sa1100/generic.c
> index 4dfb7554649d..6c21f214cd60 100644
> --- a/arch/arm/mach-sa1100/generic.c
> +++ b/arch/arm/mach-sa1100/generic.c
> @@ -39,9 +39,6 @@
> #include "generic.h"
> #include <clocksource/pxa.h>
>
> -unsigned int reset_status;
> -EXPORT_SYMBOL(reset_status);
> -
> #define NR_FREQS 16
>
> /*
> @@ -319,10 +316,13 @@ static struct platform_device *sa11x0_devices[] __initdata = {
>
> static int __init sa1100_init(void)
> {
> + struct resource wdt_res = DEFINE_RES_MEM(0x90000000, 0x20);
> pm_power_off = sa1100_power_off;
>
> regulator_has_full_constraints();
>
> + platform_device_register_simple("sa1100_wdt", -1, &wdt_res, 1);
> +
> return platform_add_devices(sa11x0_devices, ARRAY_SIZE(sa11x0_devices));

Wouldn't it be better to add the watchdog device to sa11x0_devices ?

> }
>
> diff --git a/arch/arm/mach-sa1100/include/mach/reset.h b/arch/arm/mach-sa1100/include/mach/reset.h
> index 27695650a567..a6723d45ae2a 100644
> --- a/arch/arm/mach-sa1100/include/mach/reset.h
> +++ b/arch/arm/mach-sa1100/include/mach/reset.h
> @@ -10,7 +10,6 @@
> #define RESET_STATUS_GPIO (1 << 3) /* GPIO Reset */
> #define RESET_STATUS_ALL (0xf)
>
> -extern unsigned int reset_status;
> static inline void clear_reset_status(unsigned int mask)
> {
> RCSR = mask;
> diff --git a/drivers/watchdog/sa1100_wdt.c b/drivers/watchdog/sa1100_wdt.c
> index 0f6ffc1e7f4e..a24d6a07c7a7 100644
> --- a/drivers/watchdog/sa1100_wdt.c
> +++ b/drivers/watchdog/sa1100_wdt.c
> @@ -22,6 +22,7 @@
> #include <linux/types.h>
> #include <linux/kernel.h>
> #include <linux/fs.h>
> +#include <linux/platform_device.h>
> #include <linux/miscdevice.h>
> #include <linux/watchdog.h>
> #include <linux/init.h>
> @@ -30,16 +31,42 @@
> #include <linux/uaccess.h>
> #include <linux/timex.h>
>
> -#ifdef CONFIG_ARCH_PXA
> -#include <mach/regs-ost.h>
> -#endif
> +#define REG_OSMR0 0x0000 /* OS timer Match Reg. 0 */
> +#define REG_OSMR1 0x0004 /* OS timer Match Reg. 1 */
> +#define REG_OSMR2 0x0008 /* OS timer Match Reg. 2 */
> +#define REG_OSMR3 0x000c /* OS timer Match Reg. 3 */
> +#define REG_OSCR 0x0010 /* OS timer Counter Reg. */
> +#define REG_OSSR 0x0014 /* OS timer Status Reg. */
> +#define REG_OWER 0x0018 /* OS timer Watch-dog Enable Reg. */
> +#define REG_OIER 0x001C /* OS timer Interrupt Enable Reg. */
>
> -#include <mach/reset.h>
> +#define OSSR_M3 (1 << 3) /* Match status channel 3 */
> +#define OSSR_M2 (1 << 2) /* Match status channel 2 */
> +#define OSSR_M1 (1 << 1) /* Match status channel 1 */
> +#define OSSR_M0 (1 << 0) /* Match status channel 0 */
> +
> +#define OWER_WME (1 << 0) /* Watchdog Match Enable */
> +
> +#define OIER_E3 (1 << 3) /* Interrupt enable channel 3 */
> +#define OIER_E2 (1 << 2) /* Interrupt enable channel 2 */
> +#define OIER_E1 (1 << 1) /* Interrupt enable channel 1 */
> +#define OIER_E0 (1 << 0) /* Interrupt enable channel 0 */
>
> static unsigned long oscr_freq;
> static unsigned long sa1100wdt_users;
> static unsigned int pre_margin;
> static int boot_status;
> +static void __iomem *reg_base;
> +
> +static inline void sa1100_wr(u32 val, u32 offset)
> +{
> + writel_relaxed(val, reg_base + offset);
> +}
> +
> +static inline u32 sa1100_rd(u32 offset)
> +{
> + return readl_relaxed(reg_base + offset);
> +}
>
> /*
> * Allow only one person to hold it open
> @@ -50,10 +77,10 @@ static int sa1100dog_open(struct inode *inode, struct file *file)
> return -EBUSY;
>
> /* Activate SA1100 Watchdog timer */
> - writel_relaxed(readl_relaxed(OSCR) + pre_margin, OSMR3);
> - writel_relaxed(OSSR_M3, OSSR);
> - writel_relaxed(OWER_WME, OWER);
> - writel_relaxed(readl_relaxed(OIER) | OIER_E3, OIER);
> + sa1100_wr(sa1100_rd(REG_OSCR) + pre_margin, REG_OSMR3);
> + sa1100_wr(OSSR_M3, REG_OSSR);
> + sa1100_wr(OWER_WME, REG_OWER);
> + sa1100_wr(sa1100_rd(REG_OIER) | OIER_E3, REG_OIER);
> return stream_open(inode, file);
> }
>
> @@ -61,7 +88,7 @@ static int sa1100dog_open(struct inode *inode, struct file *file)
> * The watchdog cannot be disabled.
> *
> * Previous comments suggested that turning off the interrupt by
> - * clearing OIER[E3] would prevent the watchdog timing out but this
> + * clearing REG_OIER[E3] would prevent the watchdog timing out but this
> * does not appear to be true (at least on the PXA255).
> */
> static int sa1100dog_release(struct inode *inode, struct file *file)
> @@ -76,7 +103,7 @@ static ssize_t sa1100dog_write(struct file *file, const char __user *data,
> {
> if (len)
> /* Refresh OSMR3 timer. */
> - writel_relaxed(readl_relaxed(OSCR) + pre_margin, OSMR3);
> + sa1100_wr(sa1100_rd(REG_OSCR) + pre_margin, REG_OSMR3);
> return len;
> }
>
> @@ -110,7 +137,7 @@ static long sa1100dog_ioctl(struct file *file, unsigned int cmd,
> break;
>
> case WDIOC_KEEPALIVE:
> - writel_relaxed(readl_relaxed(OSCR) + pre_margin, OSMR3);
> + sa1100_wr(sa1100_rd(REG_OSCR) + pre_margin, REG_OSMR3);
> ret = 0;
> break;
>
> @@ -125,7 +152,7 @@ static long sa1100dog_ioctl(struct file *file, unsigned int cmd,
> }
>
> pre_margin = oscr_freq * time;
> - writel_relaxed(readl_relaxed(OSCR) + pre_margin, OSMR3);
> + sa1100_wr(sa1100_rd(REG_OSCR) + pre_margin, REG_OSMR3);
> /*fall through*/
>
> case WDIOC_GETTIMEOUT:
> @@ -150,12 +177,22 @@ static struct miscdevice sa1100dog_miscdev = {
> .fops = &sa1100dog_fops,
> };
>
> -static int margin __initdata = 60; /* (secs) Default is 1 minute */
> +static int margin = 60; /* (secs) Default is 1 minute */
> static struct clk *clk;
>
> -static int __init sa1100dog_init(void)
> +static int sa1100dog_probe(struct platform_device *pdev)
> {
> int ret;
> + int *platform_data;
> + struct resource *res;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!res)
> + return -ENXIO;
> + reg_base = devm_ioremap(&pdev->dev, res->start, resource_size(res));

reg_base = devm_platform_ioremap_resource(pdev, 0);

> + ret = PTR_ERR_OR_ZERO(reg_base);
> + if (ret)
> + return ret;
>
> clk = clk_get(NULL, "OSTIMER0");
> if (IS_ERR(clk)) {
> @@ -173,13 +210,9 @@ static int __init sa1100dog_init(void)
>
> oscr_freq = clk_get_rate(clk);
>
> - /*
> - * Read the reset status, and save it for later. If
> - * we suspend, RCSR will be cleared, and the watchdog
> - * reset reason will be lost.
> - */
> - boot_status = (reset_status & RESET_STATUS_WATCHDOG) ?
> - WDIOF_CARDRESET : 0;
> + platform_data = pdev->dev.platform_data;
> + if (platform_data && *platform_data)
> + boot_status = WDIOF_CARDRESET;
> pre_margin = oscr_freq * margin;
>
> ret = misc_register(&sa1100dog_miscdev);
> @@ -195,15 +228,21 @@ static int __init sa1100dog_init(void)
> return ret;
> }
>
> -static void __exit sa1100dog_exit(void)
> +static int sa1100dog_remove(struct platform_device *pdev)
> {
> misc_deregister(&sa1100dog_miscdev);
> clk_disable_unprepare(clk);
> clk_put(clk);
> +
> + return 0;
> }
>
> -module_init(sa1100dog_init);
> -module_exit(sa1100dog_exit);
> +struct platform_driver sa1100dog_driver = {
> + .driver.name = "sa1100_wdt",
> + .probe = sa1100dog_probe,
> + .remove = sa1100dog_remove,
> +};
> +module_platform_driver(sa1100dog_driver);
>
> MODULE_AUTHOR("Oleg Drokin <green@crimea.edu>");
> MODULE_DESCRIPTION("SA1100/PXA2xx Watchdog");
>