1 files changed, 224 insertions, 0 deletions

diff --git a/drivers/soc/tegra/flowctrl.c b/drivers/soc/tegra/flowctrl.c
new file mode 100644
index 000000000000..0e345c05fc65
--- /dev/null
+++ b/drivers/soc/tegra/flowctrl.c
@@ -0,0 +1,224 @@
+/*
+ * 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 <linux/platform_device.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(IS_ERR_OR_NULL(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(IS_ERR_OR_NULL(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 int tegra_flowctrl_probe(struct platform_device *pdev)
+{
+        void __iomem *base = tegra_flowctrl_base;
+        struct resource *res;
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        tegra_flowctrl_base = devm_ioremap_resource(&pdev->dev, res);
+        if (IS_ERR(tegra_flowctrl_base))
+                return PTR_ERR(base);
+
+        iounmap(base);
+
+        return 0;
+}
+
+static const struct of_device_id tegra_flowctrl_match[] = {
+        { .compatible = "nvidia,tegra210-flowctrl" },
+        { .compatible = "nvidia,tegra124-flowctrl" },
+        { .compatible = "nvidia,tegra114-flowctrl" },
+        { .compatible = "nvidia,tegra30-flowctrl" },
+        { .compatible = "nvidia,tegra20-flowctrl" },
+        { }
+};
+
+static struct platform_driver tegra_flowctrl_driver = {
+        .driver = {
+                .name = "tegra-flowctrl",
+                .suppress_bind_attrs = true,
+                .of_match_table = tegra_flowctrl_match,
+        },
+        .probe = tegra_flowctrl_probe,
+};
+builtin_platform_driver(tegra_flowctrl_driver);
+
+static int __init tegra_flowctrl_init(void)
+{
+        struct resource res;
+        struct device_node *np;
+
+        if (!soc_is_tegra())
+                return 0;
+
+        np = of_find_matching_node(NULL, tegra_flowctrl_match);
+        if (np) {
+                if (of_address_to_resource(np, 0, &res) < 0) {
+                        pr_err("failed to get flowctrl register\n");
+                        return -ENXIO;
+                }
+                of_node_put(np);
+        } else if (IS_ENABLED(CONFIG_ARM)) {
+                /*
+                 * Hardcoded fallback for 32-bit Tegra
+                 * devices if device tree node is missing.
+                 */
+                res.start = 0x60007000;
+                res.end = 0x60007fff;
+                res.flags = IORESOURCE_MEM;
+        } else {
+                /*
+                 * At this point we're running on a Tegra,
+                 * that doesn't support the flow controller
+                 * (eg. Tegra186), so just return.
+                 */
+                return 0;
+        }
+
+        tegra_flowctrl_base = ioremap_nocache(res.start, resource_size(&res));
+        if (!tegra_flowctrl_base)
+                return -ENXIO;
+
+        return 0;
+}
+early_initcall(tegra_flowctrl_init);