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path: root/drivers/soc/tegra/flowctrl.c
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Diffstat (limited to 'drivers/soc/tegra/flowctrl.c')
-rw-r--r--drivers/soc/tegra/flowctrl.c187
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);