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>

1 files changed, 187 insertions, 0 deletions

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);