soc/tegra: Move Tegra flowctrl driver

The flowctrl driver is required for both ARM and ARM64 Tegra devices
and in order to enable support for it for ARM64, move the Tegra flowctrl
driver into drivers/soc/tegra.

By moving the flowctrl driver, tegra_flowctrl_init() is now called by
via an early initcall and to prevent this function from attempting to
mapping IO space for a non-Tegra device, a test for 'soc_is_tegra()'
is also added.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

3 files changed, 195 insertions, 0 deletions

diff --git a/drivers/soc/tegra/Kconfig b/drivers/soc/tegra/Kconfig
index 208d6edb3fdb..c7e8ddfb574e 100644
--- a/drivers/soc/tegra/Kconfig
+++ b/drivers/soc/tegra/Kconfig
@@ -12,6 +12,7 @@ config ARCH_TEGRA_2x_SOC
 	select PINCTRL_TEGRA20
 	select PL310_ERRATA_727915 if CACHE_L2X0
 	select PL310_ERRATA_769419 if CACHE_L2X0
+	select SOC_TEGRA_FLOWCTRL
 	select SOC_TEGRA_PMC
 	select TEGRA_TIMER
 	help
@@ -24,6 +25,7 @@ config ARCH_TEGRA_3x_SOC
 	select ARM_ERRATA_764369 if SMP
 	select PINCTRL_TEGRA30
 	select PL310_ERRATA_769419 if CACHE_L2X0
+	select SOC_TEGRA_FLOWCTRL
 	select SOC_TEGRA_PMC
 	select TEGRA_TIMER
 	help
@@ -35,6 +37,7 @@ config ARCH_TEGRA_114_SOC
 	select ARM_ERRATA_798181 if SMP
 	select HAVE_ARM_ARCH_TIMER
 	select PINCTRL_TEGRA114
+	select SOC_TEGRA_FLOWCTRL
 	select SOC_TEGRA_PMC
 	select TEGRA_TIMER
 	help
@@ -45,6 +48,7 @@ config ARCH_TEGRA_124_SOC
 	bool "Enable support for Tegra124 family"
 	select HAVE_ARM_ARCH_TIMER
 	select PINCTRL_TEGRA124
+	select SOC_TEGRA_FLOWCTRL
 	select SOC_TEGRA_PMC
 	select TEGRA_TIMER
 	help
@@ -101,6 +105,9 @@ config ARCH_TEGRA_186_SOC
 endif
 endif
 
+config SOC_TEGRA_FLOWCTRL
+	bool
+
 config SOC_TEGRA_PMC
 	bool
 
diff --git a/drivers/soc/tegra/Makefile b/drivers/soc/tegra/Makefile
index b4425e4319ff..4f81dd55e5d1 100644
--- a/drivers/soc/tegra/Makefile
+++ b/drivers/soc/tegra/Makefile
@@ -1,5 +1,6 @@
 obj-y += fuse/
 
 obj-y += common.o
+obj-$(CONFIG_SOC_TEGRA_FLOWCTRL) += flowctrl.o
 obj-$(CONFIG_SOC_TEGRA_PMC) += pmc.o
 obj-$(CONFIG_SOC_TEGRA_PMC_TEGRA186) += pmc-tegra186.o
diff --git a/drivers/soc/tegra/flowctrl.c b/drivers/soc/tegra/flowctrl.c
new file mode 100644
index 000000000000..3a5a1cb9ae90
--- /dev/null
+++ b/drivers/soc/tegra/flowctrl.c
@@ -0,0 +1,187 @@
+/*
+ * drivers/soc/tegra/flowctrl.c
+ *
+ * Functions and macros to control the flowcontroller
+ *
+ * Copyright (c) 2010-2012, NVIDIA Corporation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * 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/cpumask.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+
+#include <soc/tegra/common.h>
+#include <soc/tegra/flowctrl.h>
+#include <soc/tegra/fuse.h>
+
+static u8 flowctrl_offset_halt_cpu[] = {
+	FLOW_CTRL_HALT_CPU0_EVENTS,
+	FLOW_CTRL_HALT_CPU1_EVENTS,
+	FLOW_CTRL_HALT_CPU1_EVENTS + 8,
+	FLOW_CTRL_HALT_CPU1_EVENTS + 16,
+};
+
+static u8 flowctrl_offset_cpu_csr[] = {
+	FLOW_CTRL_CPU0_CSR,
+	FLOW_CTRL_CPU1_CSR,
+	FLOW_CTRL_CPU1_CSR + 8,
+	FLOW_CTRL_CPU1_CSR + 16,
+};
+
+static void __iomem *tegra_flowctrl_base;
+
+static void flowctrl_update(u8 offset, u32 value)
+{
+	if (WARN_ONCE(!tegra_flowctrl_base,
+		      "Tegra flowctrl not initialised!\n"))
+		return;
+
+	writel(value, tegra_flowctrl_base + offset);
+
+	/* ensure the update has reached the flow controller */
+	wmb();
+	readl_relaxed(tegra_flowctrl_base + offset);
+}
+
+u32 flowctrl_read_cpu_csr(unsigned int cpuid)
+{
+	u8 offset = flowctrl_offset_cpu_csr[cpuid];
+
+	if (WARN_ONCE(!tegra_flowctrl_base,
+		      "Tegra flowctrl not initialised!\n"))
+		return 0;
+
+	return readl(tegra_flowctrl_base + offset);
+}
+
+void flowctrl_write_cpu_csr(unsigned int cpuid, u32 value)
+{
+	return flowctrl_update(flowctrl_offset_cpu_csr[cpuid], value);
+}
+
+void flowctrl_write_cpu_halt(unsigned int cpuid, u32 value)
+{
+	return flowctrl_update(flowctrl_offset_halt_cpu[cpuid], value);
+}
+
+void flowctrl_cpu_suspend_enter(unsigned int cpuid)
+{
+	unsigned int reg;
+	int i;
+
+	reg = flowctrl_read_cpu_csr(cpuid);
+	switch (tegra_get_chip_id()) {
+	case TEGRA20:
+		/* clear wfe bitmap */
+		reg &= ~TEGRA20_FLOW_CTRL_CSR_WFE_BITMAP;
+		/* clear wfi bitmap */
+		reg &= ~TEGRA20_FLOW_CTRL_CSR_WFI_BITMAP;
+		/* pwr gating on wfe */
+		reg |= TEGRA20_FLOW_CTRL_CSR_WFE_CPU0 << cpuid;
+		break;
+	case TEGRA30:
+	case TEGRA114:
+	case TEGRA124:
+		/* clear wfe bitmap */
+		reg &= ~TEGRA30_FLOW_CTRL_CSR_WFE_BITMAP;
+		/* clear wfi bitmap */
+		reg &= ~TEGRA30_FLOW_CTRL_CSR_WFI_BITMAP;
+		/* pwr gating on wfi */
+		reg |= TEGRA30_FLOW_CTRL_CSR_WFI_CPU0 << cpuid;
+		break;
+	}
+	reg |= FLOW_CTRL_CSR_INTR_FLAG;			/* clear intr flag */
+	reg |= FLOW_CTRL_CSR_EVENT_FLAG;		/* clear event flag */
+	reg |= FLOW_CTRL_CSR_ENABLE;			/* pwr gating */
+	flowctrl_write_cpu_csr(cpuid, reg);
+
+	for (i = 0; i < num_possible_cpus(); i++) {
+		if (i == cpuid)
+			continue;
+		reg = flowctrl_read_cpu_csr(i);
+		reg |= FLOW_CTRL_CSR_EVENT_FLAG;
+		reg |= FLOW_CTRL_CSR_INTR_FLAG;
+		flowctrl_write_cpu_csr(i, reg);
+	}
+}
+
+void flowctrl_cpu_suspend_exit(unsigned int cpuid)
+{
+	unsigned int reg;
+
+	/* Disable powergating via flow controller for CPU0 */
+	reg = flowctrl_read_cpu_csr(cpuid);
+	switch (tegra_get_chip_id()) {
+	case TEGRA20:
+		/* clear wfe bitmap */
+		reg &= ~TEGRA20_FLOW_CTRL_CSR_WFE_BITMAP;
+		/* clear wfi bitmap */
+		reg &= ~TEGRA20_FLOW_CTRL_CSR_WFI_BITMAP;
+		break;
+	case TEGRA30:
+	case TEGRA114:
+	case TEGRA124:
+		/* clear wfe bitmap */
+		reg &= ~TEGRA30_FLOW_CTRL_CSR_WFE_BITMAP;
+		/* clear wfi bitmap */
+		reg &= ~TEGRA30_FLOW_CTRL_CSR_WFI_BITMAP;
+		break;
+	}
+	reg &= ~FLOW_CTRL_CSR_ENABLE;			/* clear enable */
+	reg |= FLOW_CTRL_CSR_INTR_FLAG;			/* clear intr */
+	reg |= FLOW_CTRL_CSR_EVENT_FLAG;		/* clear event */
+	flowctrl_write_cpu_csr(cpuid, reg);
+}
+
+static const struct of_device_id matches[] __initconst = {
+	{ .compatible = "nvidia,tegra124-flowctrl" },
+	{ .compatible = "nvidia,tegra114-flowctrl" },
+	{ .compatible = "nvidia,tegra30-flowctrl" },
+	{ .compatible = "nvidia,tegra20-flowctrl" },
+	{ }
+};
+
+static int __init tegra_flowctrl_init(void)
+{
+	/* hardcoded fallback if device tree node is missing */
+	unsigned long base = 0x60007000;
+	unsigned long size = SZ_4K;
+	struct device_node *np;
+
+	if (!soc_is_tegra())
+		return 0;
+
+	np = of_find_matching_node(NULL, matches);
+	if (np) {
+		struct resource res;
+
+		if (of_address_to_resource(np, 0, &res) == 0) {
+			size = resource_size(&res);
+			base = res.start;
+		}
+
+		of_node_put(np);
+	}
+
+	tegra_flowctrl_base = ioremap_nocache(base, size);
+	if (!tegra_flowctrl_base)
+		return -ENXIO;
+
+	return 0;
+}
+early_initcall(tegra_flowctrl_init);