Doug / smarc-fsl-linux-kernel

Download as
Browse Code ยป

Commit e75e657756554676f13070266bedbd75d404a0f8

Authored by Wim Van Sebroeck
1 parent 28401140a2
Exists in master and in 7 other branches imx_3.0.35_4.1.0, imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga, smarc-l5.0.0_1.0.0-ga

[WATCHDOG] at32ap700x_wdt.c - Add spinlock support 

Add spinlock support so that forked children can't
do different io stuff at the same time.

Signed-off-by: Hans-Christian Egtvedt <hcegtvedt@atmel.com>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Cc: Andrew Morton <akpm@linux-foundation.org>

Showing 1 changed file with 9 additions and 0 deletions Side-by-side Diff

drivers/char/watchdog/at32ap700x_wdt.c
Diff comments   View file @ e75e657
... ... @@ -18,6 +18,7 @@
18 18 #include <linux/watchdog.h>
19 19 #include <linux/uaccess.h>
20 20 #include <linux/io.h>
  21 +#include <linux/spinlock.h>
21 22  
22 23 #define TIMEOUT_MIN 1
23 24 #define TIMEOUT_MAX 2
... ... @@ -53,6 +54,7 @@
53 54  
54 55 struct wdt_at32ap700x {
55 56 void __iomem *regs;
  57 + spinlock_t io_lock;
56 58 int timeout;
57 59 int users;
58 60 struct miscdevice miscdev;
59 61  
... ... @@ -66,9 +68,11 @@
66 68 */
67 69 static inline void at32_wdt_stop(void)
68 70 {
  71 + spin_lock(&wdt->io_lock);
69 72 unsigned long psel = wdt_readl(wdt, CTRL) & WDT_BF(CTRL_PSEL, 0x0f);
70 73 wdt_writel(wdt, CTRL, psel | WDT_BF(CTRL_KEY, 0x55));
71 74 wdt_writel(wdt, CTRL, psel | WDT_BF(CTRL_KEY, 0xaa));
  75 + spin_unlock(&wdt->io_lock);
72 76 }
73 77  
74 78 /*
75 79  
... ... @@ -79,12 +83,14 @@
79 83 /* 0xf is 2^16 divider = 2 sec, 0xe is 2^15 divider = 1 sec */
80 84 unsigned long psel = (wdt->timeout > 1) ? 0xf : 0xe;
81 85  
  86 + spin_lock(&wdt->io_lock);
82 87 wdt_writel(wdt, CTRL, WDT_BIT(CTRL_EN)
83 88 | WDT_BF(CTRL_PSEL, psel)
84 89 | WDT_BF(CTRL_KEY, 0x55));
85 90 wdt_writel(wdt, CTRL, WDT_BIT(CTRL_EN)
86 91 | WDT_BF(CTRL_PSEL, psel)
87 92 | WDT_BF(CTRL_KEY, 0xaa));
  93 + spin_unlock(&wdt->io_lock);
88 94 }
89 95  
90 96 /*
91 97  
... ... @@ -92,7 +98,9 @@
92 98 */
93 99 static inline void at32_wdt_pat(void)
94 100 {
  101 + spin_lock(&wdt->io_lock);
95 102 wdt_writel(wdt, CLR, 0x42);
  103 + spin_unlock(&wdt->io_lock);
96 104 }
97 105  
98 106 /*
... ... @@ -272,6 +280,7 @@
272 280 dev_dbg(&pdev->dev, "could not map I/O memory\n");
273 281 goto err_free;
274 282 }
  283 + spin_lock_init(&wdt->io_lock);
275 284 wdt->users = 0;
276 285 wdt->miscdev.minor = WATCHDOG_MINOR;
277 286 wdt->miscdev.name = "watchdog";