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Merge tag 'bcm2835-for-3.9-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/swarren/linux-rpi into next/soc

From Stephen Warren:
ARM: bcm2835: SoC driver updates

The bcm2835 clock driver is enhanced to allow fixed clocks to be probed
from device tree.

A system power-off implementation is added.

This branch is based on v3.8-rc3.

* tag 'bcm2835-for-3.9-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/swarren/linux-rpi:
  ARM: bcm2835: add a pm_power_off implementation
  clk: bcm2835: probe for fixed-clock in device tree

Signed-off-by: Olof Johansson <olof@lixom.net>
Olof Johansson 12 years ago
parent
commit
6ed05a2aab
2 changed files with 37 additions and 0 deletions
  1. 28 0
      arch/arm/mach-bcm2835/bcm2835.c
  2. 9 0
      drivers/clk/clk-bcm2835.c

+ 28 - 0
arch/arm/mach-bcm2835/bcm2835.c

@@ -26,11 +26,13 @@
 #include <mach/bcm2835_soc.h>
 
 #define PM_RSTC				0x1c
+#define PM_RSTS				0x20
 #define PM_WDOG				0x24
 
 #define PM_PASSWORD			0x5a000000
 #define PM_RSTC_WRCFG_MASK		0x00000030
 #define PM_RSTC_WRCFG_FULL_RESET	0x00000020
+#define PM_RSTS_HADWRH_SET		0x00000040
 
 static void __iomem *wdt_regs;
 
@@ -67,6 +69,29 @@ static void bcm2835_restart(char mode, const char *cmd)
 	mdelay(1);
 }
 
+/*
+ * We can't really power off, but if we do the normal reset scheme, and
+ * indicate to bootcode.bin not to reboot, then most of the chip will be
+ * powered off.
+ */
+static void bcm2835_power_off(void)
+{
+	u32 val;
+
+	/*
+	 * We set the watchdog hard reset bit here to distinguish this reset
+	 * from the normal (full) reset. bootcode.bin will not reboot after a
+	 * hard reset.
+	 */
+	val = readl_relaxed(wdt_regs + PM_RSTS);
+	val &= ~PM_RSTC_WRCFG_MASK;
+	val |= PM_PASSWORD | PM_RSTS_HADWRH_SET;
+	writel_relaxed(val, wdt_regs + PM_RSTS);
+
+	/* Continue with normal reset mechanism */
+	bcm2835_restart(0, "");
+}
+
 static struct map_desc io_map __initdata = {
 	.virtual = BCM2835_PERIPH_VIRT,
 	.pfn = __phys_to_pfn(BCM2835_PERIPH_PHYS),
@@ -84,6 +109,9 @@ static void __init bcm2835_init(void)
 	int ret;
 
 	bcm2835_setup_restart();
+	if (wdt_regs)
+		pm_power_off = bcm2835_power_off;
+
 	bcm2835_init_clocks();
 
 	ret = of_platform_populate(NULL, of_default_bus_match_table, NULL,

+ 9 - 0
drivers/clk/clk-bcm2835.c

@@ -20,6 +20,13 @@
 #include <linux/clk-provider.h>
 #include <linux/clkdev.h>
 #include <linux/clk/bcm2835.h>
+#include <linux/clk-provider.h>
+#include <linux/of.h>
+
+static const __initconst struct of_device_id clk_match[] = {
+	{ .compatible = "fixed-clock", .data = of_fixed_clk_setup, },
+	{ }
+};
 
 /*
  * These are fixed clocks. They're probably not all root clocks and it may
@@ -56,4 +63,6 @@ void __init bcm2835_init_clocks(void)
 	ret = clk_register_clkdev(clk, NULL, "20215000.uart");
 	if (ret)
 		pr_err("uart1_pclk alias not registered\n");
+
+	of_clk_init(clk_match);
 }