arm: Xilinx Zynq cleanup patches for v3.18

- PM support
 - Fix L2 useless setting
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Merge tag 'zynq-cleanup-for-3.18' of git://git.xilinx.com/linux-xlnx into next/soc

Pull "arm: Xilinx Zynq cleanup patches for v3.18" from Michal Simek:

- PM support
- Fix L2 useless setting

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

* tag 'zynq-cleanup-for-3.18' of git://git.xilinx.com/linux-xlnx:
  ARM: zynq: Remove useless L2C AUX setting
  ARM: zynq: Rename 'zynq_platform_cpu_die'
  ARM: zynq: Remove hotplug.c
  ARM: zynq: Synchronise zynq_cpu_die/kill
  ARM: zynq: cpuidle: Remove pointless code
  ARM: zynq: Remove invalidate cache for cpu die
  ARM: zynq: PM: Enable DDR clock stop
  ARM: zynq: DT: Add DDRC node
  Documentation: devicetree: Add binding for Synopsys DDR controller
  ARM: zynq: PM: Enable A9 internal clock gating feature

Documentation/devicetree/bindings/memory-controllers/synopsys.txt

@@ -0,0 +1,11 @@
+Binding for Synopsys IntelliDDR Multi Protocol Memory Controller
+
+Required properties:
+ - compatible: Should be 'xlnx,zynq-ddrc-a05'
+ - reg: Base address and size of the controllers memory area
+
+Example:
+	memory-controller@f8006000 {
+		compatible = "xlnx,zynq-ddrc-a05";
+		reg = <0xf8006000 0x1000>;
+	};

arch/arm/boot/dts/zynq-7000.dtsi

@@ -146,6 +146,11 @@ L2: cache-controller {
 			cache-level = <2>;
 		};
 
+		memory-controller@f8006000 {
+			compatible = "xlnx,zynq-ddrc-a05";
+			reg = <0xf8006000 0x1000>;
+		} ;
+
 		uart0: serial@e0000000 {
 			compatible = "xlnx,xuartps", "cdns,uart-r1p8";
 			status = "disabled";

arch/arm/mach-zynq/Makefile

@@ -3,8 +3,7 @@
 #
 
 # Common support
-obj-y				:= common.o slcr.o
+obj-y				:= common.o slcr.o pm.o
 CFLAGS_REMOVE_hotplug.o		=-march=armv6k
 CFLAGS_hotplug.o 		=-Wa,-march=armv7-a -mcpu=cortex-a9
-obj-$(CONFIG_HOTPLUG_CPU)	+= hotplug.o
 obj-$(CONFIG_SMP)		+= headsmp.o platsmp.o

arch/arm/mach-zynq/common.c

@@ -98,6 +98,12 @@ static int __init zynq_get_revision(void)
 	return revision;
 }
 
+static void __init zynq_init_late(void)
+{
+	zynq_core_pm_init();
+	zynq_pm_late_init();
+}
+
 /**
  * zynq_init_machine - System specific initialization, intended to be
  *		       called from board specific initialization.
@@ -198,12 +204,13 @@ static const char * const zynq_dt_match[] = {
 
 DT_MACHINE_START(XILINX_EP107, "Xilinx Zynq Platform")
 	/* 64KB way size, 8-way associativity, parity disabled */
-	.l2c_aux_val	= 0x02000000,
-	.l2c_aux_mask	= 0xf0ffffff,
+	.l2c_aux_val	= 0x00000000,
+	.l2c_aux_mask	= 0xffffffff,
 	.smp		= smp_ops(zynq_smp_ops),
 	.map_io		= zynq_map_io,
 	.init_irq	= zynq_irq_init,
 	.init_machine	= zynq_init_machine,
+	.init_late	= zynq_init_late,
 	.init_time	= zynq_timer_init,
 	.dt_compat	= zynq_dt_match,
 	.reserve	= zynq_memory_init,

arch/arm/mach-zynq/common.h

@@ -24,6 +24,8 @@ extern int zynq_early_slcr_init(void);
 extern void zynq_slcr_system_reset(void);
 extern void zynq_slcr_cpu_stop(int cpu);
 extern void zynq_slcr_cpu_start(int cpu);
+extern bool zynq_slcr_cpu_state_read(int cpu);
+extern void zynq_slcr_cpu_state_write(int cpu, bool die);
 extern u32 zynq_slcr_get_device_id(void);
 
 #ifdef CONFIG_SMP
@@ -37,7 +39,17 @@ extern struct smp_operations zynq_smp_ops __initdata;
 
 extern void __iomem *zynq_scu_base;
 
-/* Hotplug */
-extern void zynq_platform_cpu_die(unsigned int cpu);
+void zynq_pm_late_init(void);
+
+static inline void zynq_core_pm_init(void)
+{
+	/* A9 clock gating */
+	asm volatile ("mrc  p15, 0, r12, c15, c0, 0\n"
+		      "orr  r12, r12, #1\n"
+		      "mcr  p15, 0, r12, c15, c0, 0\n"
+		      : /* no outputs */
+		      : /* no inputs */
+		      : "r12");
+}
 
 #endif

arch/arm/mach-zynq/hotplug.c

@@ -10,50 +10,5 @@
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  */
-#include <linux/kernel.h>
-#include <linux/errno.h>
-#include <linux/smp.h>
+#include <asm/proc-fns.h>
 
-#include <asm/cacheflush.h>
-#include <asm/cp15.h>
-#include "common.h"
-
-static inline void zynq_cpu_enter_lowpower(void)
-{
-	unsigned int v;
-
-	flush_cache_all();
-	asm volatile(
-	"	mcr	p15, 0, %1, c7, c5, 0\n"
-	"	dsb\n"
-	/*
-	 * Turn off coherency
-	 */
-	"	mrc	p15, 0, %0, c1, c0, 1\n"
-	"	bic	%0, %0, #0x40\n"
-	"	mcr	p15, 0, %0, c1, c0, 1\n"
-	"	mrc	p15, 0, %0, c1, c0, 0\n"
-	"	bic	%0, %0, %2\n"
-	"	mcr	p15, 0, %0, c1, c0, 0\n"
-	  : "=&r" (v)
-	  : "r" (0), "Ir" (CR_C)
-	  : "cc");
-}
-
-/*
- * platform-specific code to shutdown a CPU
- *
- * Called with IRQs disabled
- */
-void zynq_platform_cpu_die(unsigned int cpu)
-{
-	zynq_cpu_enter_lowpower();
-
-	/*
-	 * there is no power-control hardware on this platform, so all
-	 * we can do is put the core into WFI; this is safe as the calling
-	 * code will have already disabled interrupts
-	 */
-	for (;;)
-		cpu_do_idle();
-}

arch/arm/mach-zynq/platsmp.c

@@ -112,20 +112,59 @@ static void __init zynq_smp_prepare_cpus(unsigned int max_cpus)
 	scu_enable(zynq_scu_base);
 }
 
+/**
+ * zynq_secondary_init - Initialize secondary CPU cores
+ * @cpu:	CPU that is initialized
+ *
+ * This function is in the hotplug path. Don't move it into the
+ * init section!!
+ */
+static void zynq_secondary_init(unsigned int cpu)
+{
+	zynq_core_pm_init();
+}
+
 #ifdef CONFIG_HOTPLUG_CPU
 static int zynq_cpu_kill(unsigned cpu)
 {
+	unsigned long timeout = jiffies + msecs_to_jiffies(50);
+
+	while (zynq_slcr_cpu_state_read(cpu))
+		if (time_after(jiffies, timeout))
+			return 0;
+
 	zynq_slcr_cpu_stop(cpu);
 	return 1;
 }
+
+/**
+ * zynq_cpu_die - Let a CPU core die
+ * @cpu:	Dying CPU
+ *
+ * Platform-specific code to shutdown a CPU.
+ * Called with IRQs disabled on the dying CPU.
+ */
+static void zynq_cpu_die(unsigned int cpu)
+{
+	zynq_slcr_cpu_state_write(cpu, true);
+
+	/*
+	 * there is no power-control hardware on this platform, so all
+	 * we can do is put the core into WFI; this is safe as the calling
+	 * code will have already disabled interrupts
+	 */
+	for (;;)
+		cpu_do_idle();
+}
 #endif
 
 struct smp_operations zynq_smp_ops __initdata = {
 	.smp_init_cpus		= zynq_smp_init_cpus,
 	.smp_prepare_cpus	= zynq_smp_prepare_cpus,
 	.smp_boot_secondary	= zynq_boot_secondary,
+	.smp_secondary_init	= zynq_secondary_init,
 #ifdef CONFIG_HOTPLUG_CPU
-	.cpu_die		= zynq_platform_cpu_die,
+	.cpu_die		= zynq_cpu_die,
 	.cpu_kill		= zynq_cpu_kill,
 #endif
 };

arch/arm/mach-zynq/pm.c

@@ -0,0 +1,83 @@
+/*
+ * Zynq power management
+ *
+ *  Copyright (C) 2012 - 2014 Xilinx
+ *
+ *  Sören Brinkmann <soren.brinkmann@xilinx.com>
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/io.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include "common.h"
+
+/* register offsets */
+#define DDRC_CTRL_REG1_OFFS		0x60
+#define DDRC_DRAM_PARAM_REG3_OFFS	0x20
+
+/* bitfields */
+#define DDRC_CLOCKSTOP_MASK	BIT(23)
+#define DDRC_SELFREFRESH_MASK	BIT(12)
+
+static void __iomem *ddrc_base;
+
+/**
+ * zynq_pm_ioremap() - Create IO mappings
+ * @comp:	DT compatible string
+ * Return: Pointer to the mapped memory or NULL.
+ *
+ * Remap the memory region for a compatible DT node.
+ */
+static void __iomem *zynq_pm_ioremap(const char *comp)
+{
+	struct device_node *np;
+	void __iomem *base = NULL;
+
+	np = of_find_compatible_node(NULL, NULL, comp);
+	if (np) {
+		base = of_iomap(np, 0);
+		of_node_put(np);
+	} else {
+		pr_warn("%s: no compatible node found for '%s'\n", __func__,
+				comp);
+	}
+
+	return base;
+}
+
+/**
+ * zynq_pm_late_init() - Power management init
+ *
+ * Initialization of power management related featurs and infrastructure.
+ */
+void __init zynq_pm_late_init(void)
+{
+	u32 reg;
+
+	ddrc_base = zynq_pm_ioremap("xlnx,zynq-ddrc-a05");
+	if (!ddrc_base) {
+		pr_warn("%s: Unable to map DDRC IO memory.\n", __func__);
+	} else {
+		/*
+		 * Enable DDRC clock stop feature. The HW takes care of
+		 * entering/exiting the correct mode depending
+		 * on activity state.
+		 */
+		reg = readl(ddrc_base + DDRC_DRAM_PARAM_REG3_OFFS);
+		reg |= DDRC_CLOCKSTOP_MASK;
+		writel(reg, ddrc_base + DDRC_DRAM_PARAM_REG3_OFFS);
+	}
+}

arch/arm/mach-zynq/slcr.c

@@ -138,6 +138,8 @@ void zynq_slcr_cpu_start(int cpu)
 	zynq_slcr_write(reg, SLCR_A9_CPU_RST_CTRL_OFFSET);
 	reg &= ~(SLCR_A9_CPU_CLKSTOP << cpu);
 	zynq_slcr_write(reg, SLCR_A9_CPU_RST_CTRL_OFFSET);
+
+	zynq_slcr_cpu_state_write(cpu, false);
 }
 
 /**
@@ -154,8 +156,47 @@ void zynq_slcr_cpu_stop(int cpu)
 }
 
 /**
- * zynq_slcr_init - Regular slcr driver init
+ * zynq_slcr_cpu_state - Read/write cpu state
+ * @cpu:	cpu number
  *
+ * SLCR_REBOOT_STATUS save upper 2 bits (31/30 cpu states for cpu0 and cpu1)
+ * 0 means cpu is running, 1 cpu is going to die.
+ *
+ * Return: true if cpu is running, false if cpu is going to die
+ */
+bool zynq_slcr_cpu_state_read(int cpu)
+{
+	u32 state;
+
+	state = readl(zynq_slcr_base + SLCR_REBOOT_STATUS_OFFSET);
+	state &= 1 << (31 - cpu);
+
+	return !state;
+}
+
+/**
+ * zynq_slcr_cpu_state - Read/write cpu state
+ * @cpu:	cpu number
+ * @die:	cpu state - true if cpu is going to die
+ *
+ * SLCR_REBOOT_STATUS save upper 2 bits (31/30 cpu states for cpu0 and cpu1)
+ * 0 means cpu is running, 1 cpu is going to die.
+ */
+void zynq_slcr_cpu_state_write(int cpu, bool die)
+{
+	u32 state, mask;
+
+	state = readl(zynq_slcr_base + SLCR_REBOOT_STATUS_OFFSET);
+	mask = 1 << (31 - cpu);
+	if (die)
+		state |= mask;
+	else
+		state &= ~mask;
+	writel(state, zynq_slcr_base + SLCR_REBOOT_STATUS_OFFSET);
+}
+
+/**
+ * zynq_slcr_init - Regular slcr driver init
  * Return:	0 on success, negative errno otherwise.
  *
  * Called early during boot from platform code to remap SLCR area.

drivers/cpuidle/cpuidle-zynq.c

@@ -26,7 +26,6 @@
  */
 
 #include <linux/init.h>
-#include <linux/cpu_pm.h>
 #include <linux/cpuidle.h>
 #include <linux/platform_device.h>
 #include <asm/proc-fns.h>
@@ -38,15 +37,9 @@
 static int zynq_enter_idle(struct cpuidle_device *dev,
 			   struct cpuidle_driver *drv, int index)
 {
-	/* Devices must be stopped here */
-	cpu_pm_enter();
-
 	/* Add code for DDR self refresh start */
 	cpu_do_idle();
 
-	/* Add code for DDR self refresh stop */
-	cpu_pm_exit();
-
 	return index;
 }
 
@@ -59,8 +52,7 @@ static struct cpuidle_driver zynq_idle_driver = {
 			.enter			= zynq_enter_idle,
 			.exit_latency		= 10,
 			.target_residency	= 10000,
-			.flags			= CPUIDLE_FLAG_TIME_VALID |
-						  CPUIDLE_FLAG_TIMER_STOP,
+			.flags			= CPUIDLE_FLAG_TIME_VALID,
 			.name			= "RAM_SR",
 			.desc			= "WFI and RAM Self Refresh",
 		},