* http://www.gnu.org/copyleft/gpl.html
  */
 
+#include <linux/clk.h>
+#include <linux/delay.h>
 #include <linux/io.h>
 #include <linux/irq.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/pm_domain.h>
+#include <linux/regulator/consumer.h>
 #include <linux/irqchip/arm-gic.h>
 #include "common.h"
+#include "hardware.h"
 
+#define GPC_CNTR               0x000
 #define GPC_IMR1               0x008
+#define GPC_PGC_GPU_PDN                0x260
+#define GPC_PGC_GPU_PUPSCR     0x264
+#define GPC_PGC_GPU_PDNSCR     0x268
 #define GPC_PGC_CPU_PDN                0x2a0
 #define GPC_PGC_CPU_PUPSCR     0x2a4
 #define GPC_PGC_CPU_PDNSCR     0x2a8
 
 #define IMR_NUM                        4
 
+#define GPU_VPU_PUP_REQ                BIT(1)
+#define GPU_VPU_PDN_REQ                BIT(0)
+
+#define GPC_CLK_MAX            6
+
+struct pu_domain {
+       struct generic_pm_domain base;
+       struct regulator *reg;
+       struct clk *clk[GPC_CLK_MAX];
+       int num_clks;
+};
+
 static void __iomem *gpc_base;
 static u32 gpc_wake_irqs[IMR_NUM];
 static u32 gpc_saved_imrs[IMR_NUM];
        gic_arch_extn.irq_unmask = imx_gpc_irq_unmask;
        gic_arch_extn.irq_set_wake = imx_gpc_irq_set_wake;
 }
+
+#ifdef CONFIG_PM_GENERIC_DOMAINS
+
+static void _imx6q_pm_pu_power_off(struct generic_pm_domain *genpd)
+{
+       int iso, iso2sw;
+       u32 val;
+
+       /* Read ISO and ISO2SW power down delays */
+       val = readl_relaxed(gpc_base + GPC_PGC_GPU_PDNSCR);
+       iso = val & 0x3f;
+       iso2sw = (val >> 8) & 0x3f;
+
+       /* Gate off PU domain when GPU/VPU when powered down */
+       writel_relaxed(0x1, gpc_base + GPC_PGC_GPU_PDN);
+
+       /* Request GPC to power down GPU/VPU */
+       val = readl_relaxed(gpc_base + GPC_CNTR);
+       val |= GPU_VPU_PDN_REQ;
+       writel_relaxed(val, gpc_base + GPC_CNTR);
+
+       /* Wait ISO + ISO2SW IPG clock cycles */
+       ndelay((iso + iso2sw) * 1000 / 66);
+}
+
+static int imx6q_pm_pu_power_off(struct generic_pm_domain *genpd)
+{
+       struct pu_domain *pu = container_of(genpd, struct pu_domain, base);
+
+       _imx6q_pm_pu_power_off(genpd);
+
+       if (pu->reg)
+               regulator_disable(pu->reg);
+
+       return 0;
+}
+
+static int imx6q_pm_pu_power_on(struct generic_pm_domain *genpd)
+{
+       struct pu_domain *pu = container_of(genpd, struct pu_domain, base);
+       int i, ret, sw, sw2iso;
+       u32 val;
+
+       if (pu->reg)
+               ret = regulator_enable(pu->reg);
+       if (pu->reg && ret) {
+               pr_err("%s: failed to enable regulator: %d\n", __func__, ret);
+               return ret;
+       }
+
+       /* Enable reset clocks for all devices in the PU domain */
+       for (i = 0; i < pu->num_clks; i++)
+               clk_prepare_enable(pu->clk[i]);
+
+       /* Gate off PU domain when GPU/VPU when powered down */
+       writel_relaxed(0x1, gpc_base + GPC_PGC_GPU_PDN);
+
+       /* Read ISO and ISO2SW power down delays */
+       val = readl_relaxed(gpc_base + GPC_PGC_GPU_PUPSCR);
+       sw = val & 0x3f;
+       sw2iso = (val >> 8) & 0x3f;
+
+       /* Request GPC to power up GPU/VPU */
+       val = readl_relaxed(gpc_base + GPC_CNTR);
+       val |= GPU_VPU_PUP_REQ;
+       writel_relaxed(val, gpc_base + GPC_CNTR);
+
+       /* Wait ISO + ISO2SW IPG clock cycles */
+       ndelay((sw + sw2iso) * 1000 / 66);
+
+       /* Disable reset clocks for all devices in the PU domain */
+       for (i = 0; i < pu->num_clks; i++)
+               clk_disable_unprepare(pu->clk[i]);
+
+       return 0;
+}
+
+static struct generic_pm_domain imx6q_arm_domain = {
+       .name = "ARM",
+};
+
+static struct pu_domain imx6q_pu_domain = {
+       .base = {
+               .name = "PU",
+               .power_off = imx6q_pm_pu_power_off,
+               .power_on = imx6q_pm_pu_power_on,
+               .power_off_latency_ns = 25000,
+               .power_on_latency_ns = 2000000,
+       },
+};
+
+static struct generic_pm_domain imx6sl_display_domain = {
+       .name = "DISPLAY",
+};
+
+static struct generic_pm_domain *imx_gpc_domains[] = {
+       &imx6q_arm_domain,
+       &imx6q_pu_domain.base,
+       &imx6sl_display_domain,
+};
+
+static struct genpd_onecell_data imx_gpc_onecell_data = {
+       .domains = imx_gpc_domains,
+       .num_domains = ARRAY_SIZE(imx_gpc_domains),
+};
+
+static int imx_gpc_genpd_init(struct device *dev, struct regulator *pu_reg)
+{
+       struct clk *clk;
+       bool is_off;
+       int i;
+
+       imx6q_pu_domain.reg = pu_reg;
+
+       for (i = 0; ; i++) {
+               clk = of_clk_get(dev->of_node, i);
+               if (IS_ERR(clk))
+                       break;
+               if (i >= GPC_CLK_MAX) {
+                       dev_err(dev, "more than %d clocks\n", GPC_CLK_MAX);
+                       goto clk_err;
+               }
+               imx6q_pu_domain.clk[i] = clk;
+       }
+       imx6q_pu_domain.num_clks = i;
+
+       is_off = IS_ENABLED(CONFIG_PM);
+       if (is_off) {
+               _imx6q_pm_pu_power_off(&imx6q_pu_domain.base);
+       } else {
+               /*
+                * Enable power if compiled without CONFIG_PM in case the
+                * bootloader disabled it.
+                */
+               imx6q_pm_pu_power_on(&imx6q_pu_domain.base);
+       }
+
+       pm_genpd_init(&imx6q_pu_domain.base, NULL, is_off);
+       return of_genpd_add_provider_onecell(dev->of_node,
+                                            &imx_gpc_onecell_data);
+
+clk_err:
+       while (i--)
+               clk_put(imx6q_pu_domain.clk[i]);
+       return -EINVAL;
+}
+
+#else
+static inline int imx_gpc_genpd_init(struct device *dev, struct regulator *reg)
+{
+       return 0;
+}
+#endif /* CONFIG_PM_GENERIC_DOMAINS */
+
+static int imx_gpc_probe(struct platform_device *pdev)
+{
+       struct regulator *pu_reg;
+       int ret;
+
+       pu_reg = devm_regulator_get_optional(&pdev->dev, "pu");
+       if (PTR_ERR(pu_reg) == -ENODEV)
+               pu_reg = NULL;
+       if (IS_ERR(pu_reg)) {
+               ret = PTR_ERR(pu_reg);
+               dev_err(&pdev->dev, "failed to get pu regulator: %d\n", ret);
+               return ret;
+       }
+
+       return imx_gpc_genpd_init(&pdev->dev, pu_reg);
+}
+
+static const struct of_device_id imx_gpc_dt_ids[] = {
+       { .compatible = "fsl,imx6q-gpc" },
+       { .compatible = "fsl,imx6sl-gpc" },
+       { }
+};
+
+static struct platform_driver imx_gpc_driver = {
+       .driver = {
+               .name = "imx-gpc",
+               .owner = THIS_MODULE,
+               .of_match_table = imx_gpc_dt_ids,
+       },
+       .probe = imx_gpc_probe,
+};
+
+static int __init imx_pgc_init(void)
+{
+       return platform_driver_register(&imx_gpc_driver);
+}
+subsys_initcall(imx_pgc_init);