Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / arch / arm / mach-bcm / board_bcm2835.c

diff --git a/kernel/arch/arm/mach-bcm/board_bcm2835.c b/kernel/arch/arm/mach-bcm/board_bcm2835.c
new file mode 100644 (file)
index 0000000..70f2f39
--- /dev/null
+++ b/kernel/arch/arm/mach-bcm/board_bcm2835.c
@@ -0,0 +1,137 @@
+/*
+ * Copyright (C) 2010 Broadcom
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/irqchip.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/clk/bcm2835.h>
+
+#include <asm/mach/arch.h>
+#include <asm/mach/map.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
+
+#define BCM2835_PERIPH_PHYS    0x20000000
+#define BCM2835_PERIPH_VIRT    0xf0000000
+#define BCM2835_PERIPH_SIZE    SZ_16M
+
+static void __iomem *wdt_regs;
+
+/*
+ * The machine restart method can be called from an atomic context so we won't
+ * be able to ioremap the regs then.
+ */
+static void bcm2835_setup_restart(void)
+{
+       struct device_node *np = of_find_compatible_node(NULL, NULL,
+                                               "brcm,bcm2835-pm-wdt");
+       if (WARN(!np, "unable to setup watchdog restart"))
+               return;
+
+       wdt_regs = of_iomap(np, 0);
+       WARN(!wdt_regs, "failed to remap watchdog regs");
+}
+
+static void bcm2835_restart(enum reboot_mode mode, const char *cmd)
+{
+       u32 val;
+
+       if (!wdt_regs)
+               return;
+
+       /* use a timeout of 10 ticks (~150us) */
+       writel_relaxed(10 | PM_PASSWORD, wdt_regs + PM_WDOG);
+       val = readl_relaxed(wdt_regs + PM_RSTC);
+       val &= ~PM_RSTC_WRCFG_MASK;
+       val |= PM_PASSWORD | PM_RSTC_WRCFG_FULL_RESET;
+       writel_relaxed(val, wdt_regs + PM_RSTC);
+
+       /* No sleeping, possibly atomic. */
+       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(REBOOT_HARD, "");
+}
+
+static struct map_desc io_map __initdata = {
+       .virtual = BCM2835_PERIPH_VIRT,
+       .pfn = __phys_to_pfn(BCM2835_PERIPH_PHYS),
+       .length = BCM2835_PERIPH_SIZE,
+       .type = MT_DEVICE
+};
+
+static void __init bcm2835_map_io(void)
+{
+       iotable_init(&io_map, 1);
+}
+
+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,
+                                  NULL);
+       if (ret) {
+               pr_err("of_platform_populate failed: %d\n", ret);
+               BUG();
+       }
+}
+
+static const char * const bcm2835_compat[] = {
+       "brcm,bcm2835",
+       NULL
+};
+
+DT_MACHINE_START(BCM2835, "BCM2835")
+       .map_io = bcm2835_map_io,
+       .init_irq = irqchip_init,
+       .init_machine = bcm2835_init,
+       .restart = bcm2835_restart,
+       .dt_compat = bcm2835_compat
+MACHINE_END