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

From: Guenter Roeck
Date: Sat Oct 19 2019 - 10:07:29 EST


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@xxxxxxxxxxxxxxxxxx>
Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
Cc: linux-watchdog@xxxxxxxxxxxxxxx
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
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@xxxxxxxxxx>");
MODULE_DESCRIPTION("SA1100/PXA2xx Watchdog");