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soc: bcm: bcm2835-pm: Add support for power domains under a new binding.
authorEric Anholt <eric@anholt.net>
Wed, 12 Dec 2018 23:51:48 +0000 (15:51 -0800)
committerStefan Wahren <stefan.wahren@i2se.com>
Wed, 9 Jan 2019 15:55:09 +0000 (16:55 +0100)
This provides a free software alternative to raspberrypi-power.c's
firmware calls to manage power domains.  It also exposes a reset line,
where previously the vc4 driver had to try to force power off the
domain in order to trigger a reset.

Signed-off-by: Eric Anholt <eric@anholt.net>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
drivers/mfd/bcm2835-pm.c
drivers/soc/bcm/Kconfig
drivers/soc/bcm/Makefile
drivers/soc/bcm/bcm2835-power.c [new file with mode: 0644]
include/dt-bindings/soc/bcm2835-pm.h [new file with mode: 0644]
include/linux/mfd/bcm2835-pm.h

index 53839e6..42fe67f 100644 (file)
@@ -3,7 +3,7 @@
  * PM MFD driver for Broadcom BCM2835
  *
  * This driver binds to the PM block and creates the MFD device for
- * the WDT driver.
+ * the WDT and power drivers.
  */
 
 #include <linux/delay.h>
@@ -21,11 +21,16 @@ static const struct mfd_cell bcm2835_pm_devs[] = {
        { .name = "bcm2835-wdt" },
 };
 
+static const struct mfd_cell bcm2835_power_devs[] = {
+       { .name = "bcm2835-power" },
+};
+
 static int bcm2835_pm_probe(struct platform_device *pdev)
 {
        struct resource *res;
        struct device *dev = &pdev->dev;
        struct bcm2835_pm *pm;
+       int ret;
 
        pm = devm_kzalloc(dev, sizeof(*pm), GFP_KERNEL);
        if (!pm)
@@ -39,13 +44,36 @@ static int bcm2835_pm_probe(struct platform_device *pdev)
        if (IS_ERR(pm->base))
                return PTR_ERR(pm->base);
 
-       return devm_mfd_add_devices(dev, -1,
-                                   bcm2835_pm_devs, ARRAY_SIZE(bcm2835_pm_devs),
-                                   NULL, 0, NULL);
+       ret = devm_mfd_add_devices(dev, -1,
+                                  bcm2835_pm_devs, ARRAY_SIZE(bcm2835_pm_devs),
+                                  NULL, 0, NULL);
+       if (ret)
+               return ret;
+
+       /* We'll use the presence of the AXI ASB regs in the
+        * bcm2835-pm binding as the key for whether we can reference
+        * the full PM register range and support power domains.
+        */
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+       if (res) {
+               pm->asb = devm_ioremap_resource(dev, res);
+               if (IS_ERR(pm->asb))
+                       return PTR_ERR(pm->asb);
+
+               ret = devm_mfd_add_devices(dev, -1,
+                                          bcm2835_power_devs,
+                                          ARRAY_SIZE(bcm2835_power_devs),
+                                          NULL, 0, NULL);
+               if (ret)
+                       return ret;
+       }
+
+       return 0;
 }
 
 static const struct of_device_id bcm2835_pm_of_match[] = {
        { .compatible = "brcm,bcm2835-pm-wdt", },
+       { .compatible = "brcm,bcm2835-pm", },
        {},
 };
 MODULE_DEVICE_TABLE(of, bcm2835_pm_of_match);
index 055a845..fe1af29 100644 (file)
@@ -1,5 +1,16 @@
 menu "Broadcom SoC drivers"
 
+config BCM2835_POWER
+       bool "BCM2835 power domain driver"
+       depends on ARCH_BCM2835 || (COMPILE_TEST && OF)
+       select PM_GENERIC_DOMAINS if PM
+       select RESET_CONTROLLER
+       help
+         This enables support for the BCM2835 power domains and reset
+         controller.  Any usage of power domains by the Raspberry Pi
+         firmware means that Linux usage of the same power domain
+         must be accessed using the RASPBERRYPI_POWER driver
+
 config RASPBERRYPI_POWER
        bool "Raspberry Pi power domain driver"
        depends on ARCH_BCM2835 || (COMPILE_TEST && OF)
index dc4fced..c81df4b 100644 (file)
@@ -1,2 +1,3 @@
+obj-$(CONFIG_BCM2835_POWER)    += bcm2835-power.o
 obj-$(CONFIG_RASPBERRYPI_POWER)        += raspberrypi-power.o
 obj-$(CONFIG_SOC_BRCMSTB)      += brcmstb/
diff --git a/drivers/soc/bcm/bcm2835-power.c b/drivers/soc/bcm/bcm2835-power.c
new file mode 100644 (file)
index 0000000..4841295
--- /dev/null
@@ -0,0 +1,661 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Power domain driver for Broadcom BCM2835
+ *
+ * Copyright (C) 2018 Broadcom
+ */
+
+#include <dt-bindings/soc/bcm2835-pm.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/mfd/bcm2835-pm.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm_domain.h>
+#include <linux/reset-controller.h>
+#include <linux/types.h>
+
+#define PM_GNRIC                        0x00
+#define PM_AUDIO                        0x04
+#define PM_STATUS                       0x18
+#define PM_RSTC                                0x1c
+#define PM_RSTS                                0x20
+#define PM_WDOG                                0x24
+#define PM_PADS0                       0x28
+#define PM_PADS2                       0x2c
+#define PM_PADS3                       0x30
+#define PM_PADS4                       0x34
+#define PM_PADS5                       0x38
+#define PM_PADS6                       0x3c
+#define PM_CAM0                                0x44
+#define PM_CAM0_LDOHPEN                        BIT(2)
+#define PM_CAM0_LDOLPEN                        BIT(1)
+#define PM_CAM0_CTRLEN                 BIT(0)
+
+#define PM_CAM1                                0x48
+#define PM_CAM1_LDOHPEN                        BIT(2)
+#define PM_CAM1_LDOLPEN                        BIT(1)
+#define PM_CAM1_CTRLEN                 BIT(0)
+
+#define PM_CCP2TX                      0x4c
+#define PM_CCP2TX_LDOEN                        BIT(1)
+#define PM_CCP2TX_CTRLEN               BIT(0)
+
+#define PM_DSI0                                0x50
+#define PM_DSI0_LDOHPEN                        BIT(2)
+#define PM_DSI0_LDOLPEN                        BIT(1)
+#define PM_DSI0_CTRLEN                 BIT(0)
+
+#define PM_DSI1                                0x54
+#define PM_DSI1_LDOHPEN                        BIT(2)
+#define PM_DSI1_LDOLPEN                        BIT(1)
+#define PM_DSI1_CTRLEN                 BIT(0)
+
+#define PM_HDMI                                0x58
+#define PM_HDMI_RSTDR                  BIT(19)
+#define PM_HDMI_LDOPD                  BIT(1)
+#define PM_HDMI_CTRLEN                 BIT(0)
+
+#define PM_USB                         0x5c
+/* The power gates must be enabled with this bit before enabling the LDO in the
+ * USB block.
+ */
+#define PM_USB_CTRLEN                  BIT(0)
+
+#define PM_PXLDO                       0x60
+#define PM_PXBG                                0x64
+#define PM_DFT                         0x68
+#define PM_SMPS                                0x6c
+#define PM_XOSC                                0x70
+#define PM_SPAREW                      0x74
+#define PM_SPARER                      0x78
+#define PM_AVS_RSTDR                   0x7c
+#define PM_AVS_STAT                    0x80
+#define PM_AVS_EVENT                   0x84
+#define PM_AVS_INTEN                   0x88
+#define PM_DUMMY                       0xfc
+
+#define PM_IMAGE                       0x108
+#define PM_GRAFX                       0x10c
+#define PM_PROC                                0x110
+#define PM_ENAB                                BIT(12)
+#define PM_ISPRSTN                     BIT(8)
+#define PM_H264RSTN                    BIT(7)
+#define PM_PERIRSTN                    BIT(6)
+#define PM_V3DRSTN                     BIT(6)
+#define PM_ISFUNC                      BIT(5)
+#define PM_MRDONE                      BIT(4)
+#define PM_MEMREP                      BIT(3)
+#define PM_ISPOW                       BIT(2)
+#define PM_POWOK                       BIT(1)
+#define PM_POWUP                       BIT(0)
+#define PM_INRUSH_SHIFT                        13
+#define PM_INRUSH_3_5_MA               0
+#define PM_INRUSH_5_MA                 1
+#define PM_INRUSH_10_MA                        2
+#define PM_INRUSH_20_MA                        3
+#define PM_INRUSH_MASK                 (3 << PM_INRUSH_SHIFT)
+
+#define PM_PASSWORD                    0x5a000000
+
+#define PM_WDOG_TIME_SET               0x000fffff
+#define PM_RSTC_WRCFG_CLR              0xffffffcf
+#define PM_RSTS_HADWRH_SET             0x00000040
+#define PM_RSTC_WRCFG_SET              0x00000030
+#define PM_RSTC_WRCFG_FULL_RESET       0x00000020
+#define PM_RSTC_RESET                  0x00000102
+
+#define PM_READ(reg) readl(power->base + (reg))
+#define PM_WRITE(reg, val) writel(PM_PASSWORD | (val), power->base + (reg))
+
+#define ASB_BRDG_VERSION                0x00
+#define ASB_CPR_CTRL                    0x04
+
+#define ASB_V3D_S_CTRL                 0x08
+#define ASB_V3D_M_CTRL                 0x0c
+#define ASB_ISP_S_CTRL                 0x10
+#define ASB_ISP_M_CTRL                 0x14
+#define ASB_H264_S_CTRL                        0x18
+#define ASB_H264_M_CTRL                        0x1c
+
+#define ASB_REQ_STOP                    BIT(0)
+#define ASB_ACK                         BIT(1)
+#define ASB_EMPTY                       BIT(2)
+#define ASB_FULL                        BIT(3)
+
+#define ASB_AXI_BRDG_ID                        0x20
+
+#define ASB_READ(reg) readl(power->asb + (reg))
+#define ASB_WRITE(reg, val) writel(PM_PASSWORD | (val), power->asb + (reg))
+
+struct bcm2835_power_domain {
+       struct generic_pm_domain base;
+       struct bcm2835_power *power;
+       u32 domain;
+       struct clk *clk;
+};
+
+struct bcm2835_power {
+       struct device           *dev;
+       /* PM registers. */
+       void __iomem            *base;
+       /* AXI Async bridge registers. */
+       void __iomem            *asb;
+
+       struct genpd_onecell_data pd_xlate;
+       struct bcm2835_power_domain domains[BCM2835_POWER_DOMAIN_COUNT];
+       struct reset_controller_dev reset;
+};
+
+static int bcm2835_asb_enable(struct bcm2835_power *power, u32 reg)
+{
+       u64 start = ktime_get_ns();
+
+       /* Enable the module's async AXI bridges. */
+       ASB_WRITE(reg, ASB_READ(reg) & ~ASB_REQ_STOP);
+       while (ASB_READ(reg) & ASB_ACK) {
+               cpu_relax();
+               if (ktime_get_ns() - start >= 1000)
+                       return -ETIMEDOUT;
+       }
+
+       return 0;
+}
+
+static int bcm2835_asb_disable(struct bcm2835_power *power, u32 reg)
+{
+       u64 start = ktime_get_ns();
+
+       /* Enable the module's async AXI bridges. */
+       ASB_WRITE(reg, ASB_READ(reg) | ASB_REQ_STOP);
+       while (!(ASB_READ(reg) & ASB_ACK)) {
+               cpu_relax();
+               if (ktime_get_ns() - start >= 1000)
+                       return -ETIMEDOUT;
+       }
+
+       return 0;
+}
+
+static int bcm2835_power_power_off(struct bcm2835_power_domain *pd, u32 pm_reg)
+{
+       struct bcm2835_power *power = pd->power;
+
+       /* Enable functional isolation */
+       PM_WRITE(pm_reg, PM_READ(pm_reg) & ~PM_ISFUNC);
+
+       /* Enable electrical isolation */
+       PM_WRITE(pm_reg, PM_READ(pm_reg) & ~PM_ISPOW);
+
+       /* Open the power switches. */
+       PM_WRITE(pm_reg, PM_READ(pm_reg) & ~PM_POWUP);
+
+       return 0;
+}
+
+static int bcm2835_power_power_on(struct bcm2835_power_domain *pd, u32 pm_reg)
+{
+       struct bcm2835_power *power = pd->power;
+       struct device *dev = power->dev;
+       u64 start;
+       int ret;
+       int inrush;
+       bool powok;
+
+       /* If it was already powered on by the fw, leave it that way. */
+       if (PM_READ(pm_reg) & PM_POWUP)
+               return 0;
+
+       /* Enable power.  Allowing too much current at once may result
+        * in POWOK never getting set, so start low and ramp it up as
+        * necessary to succeed.
+        */
+       powok = false;
+       for (inrush = PM_INRUSH_3_5_MA; inrush <= PM_INRUSH_20_MA; inrush++) {
+               PM_WRITE(pm_reg,
+                        (PM_READ(pm_reg) & ~PM_INRUSH_MASK) |
+                        (inrush << PM_INRUSH_SHIFT) |
+                        PM_POWUP);
+
+               start = ktime_get_ns();
+               while (!(powok = !!(PM_READ(pm_reg) & PM_POWOK))) {
+                       cpu_relax();
+                       if (ktime_get_ns() - start >= 3000)
+                               break;
+               }
+       }
+       if (!powok) {
+               dev_err(dev, "Timeout waiting for %s power OK\n",
+                       pd->base.name);
+               ret = -ETIMEDOUT;
+               goto err_disable_powup;
+       }
+
+       /* Disable electrical isolation */
+       PM_WRITE(pm_reg, PM_READ(pm_reg) | PM_ISPOW);
+
+       /* Repair memory */
+       PM_WRITE(pm_reg, PM_READ(pm_reg) | PM_MEMREP);
+       start = ktime_get_ns();
+       while (!(PM_READ(pm_reg) & PM_MRDONE)) {
+               cpu_relax();
+               if (ktime_get_ns() - start >= 1000) {
+                       dev_err(dev, "Timeout waiting for %s memory repair\n",
+                               pd->base.name);
+                       ret = -ETIMEDOUT;
+                       goto err_disable_ispow;
+               }
+       }
+
+       /* Disable functional isolation */
+       PM_WRITE(pm_reg, PM_READ(pm_reg) | PM_ISFUNC);
+
+       return 0;
+
+err_disable_ispow:
+       PM_WRITE(pm_reg, PM_READ(pm_reg) & ~PM_ISPOW);
+err_disable_powup:
+       PM_WRITE(pm_reg, PM_READ(pm_reg) & ~(PM_POWUP | PM_INRUSH_MASK));
+       return ret;
+}
+
+static int bcm2835_asb_power_on(struct bcm2835_power_domain *pd,
+                               u32 pm_reg,
+                               u32 asb_m_reg,
+                               u32 asb_s_reg,
+                               u32 reset_flags)
+{
+       struct bcm2835_power *power = pd->power;
+       int ret;
+
+       ret = clk_prepare_enable(pd->clk);
+       if (ret) {
+               dev_err(power->dev, "Failed to enable clock for %s\n",
+                       pd->base.name);
+               return ret;
+       }
+
+       /* Wait 32 clocks for reset to propagate, 1 us will be enough */
+       udelay(1);
+
+       clk_disable_unprepare(pd->clk);
+
+       /* Deassert the resets. */
+       PM_WRITE(pm_reg, PM_READ(pm_reg) | reset_flags);
+
+       ret = clk_prepare_enable(pd->clk);
+       if (ret) {
+               dev_err(power->dev, "Failed to enable clock for %s\n",
+                       pd->base.name);
+               goto err_enable_resets;
+       }
+
+       ret = bcm2835_asb_enable(power, asb_m_reg);
+       if (ret) {
+               dev_err(power->dev, "Failed to enable ASB master for %s\n",
+                       pd->base.name);
+               goto err_disable_clk;
+       }
+       ret = bcm2835_asb_enable(power, asb_s_reg);
+       if (ret) {
+               dev_err(power->dev, "Failed to enable ASB slave for %s\n",
+                       pd->base.name);
+               goto err_disable_asb_master;
+       }
+
+       return 0;
+
+err_disable_asb_master:
+       bcm2835_asb_disable(power, asb_m_reg);
+err_disable_clk:
+       clk_disable_unprepare(pd->clk);
+err_enable_resets:
+       PM_WRITE(pm_reg, PM_READ(pm_reg) & ~reset_flags);
+       return ret;
+}
+
+static int bcm2835_asb_power_off(struct bcm2835_power_domain *pd,
+                                u32 pm_reg,
+                                u32 asb_m_reg,
+                                u32 asb_s_reg,
+                                u32 reset_flags)
+{
+       struct bcm2835_power *power = pd->power;
+       int ret;
+
+       ret = bcm2835_asb_disable(power, asb_s_reg);
+       if (ret) {
+               dev_warn(power->dev, "Failed to disable ASB slave for %s\n",
+                        pd->base.name);
+               return ret;
+       }
+       ret = bcm2835_asb_disable(power, asb_m_reg);
+       if (ret) {
+               dev_warn(power->dev, "Failed to disable ASB master for %s\n",
+                        pd->base.name);
+               bcm2835_asb_enable(power, asb_s_reg);
+               return ret;
+       }
+
+       clk_disable_unprepare(pd->clk);
+
+       /* Assert the resets. */
+       PM_WRITE(pm_reg, PM_READ(pm_reg) & ~reset_flags);
+
+       return 0;
+}
+
+static int bcm2835_power_pd_power_on(struct generic_pm_domain *domain)
+{
+       struct bcm2835_power_domain *pd =
+               container_of(domain, struct bcm2835_power_domain, base);
+       struct bcm2835_power *power = pd->power;
+
+       switch (pd->domain) {
+       case BCM2835_POWER_DOMAIN_GRAFX:
+               return bcm2835_power_power_on(pd, PM_GRAFX);
+
+       case BCM2835_POWER_DOMAIN_GRAFX_V3D:
+               return bcm2835_asb_power_on(pd, PM_GRAFX,
+                                           ASB_V3D_M_CTRL, ASB_V3D_S_CTRL,
+                                           PM_V3DRSTN);
+
+       case BCM2835_POWER_DOMAIN_IMAGE:
+               return bcm2835_power_power_on(pd, PM_IMAGE);
+
+       case BCM2835_POWER_DOMAIN_IMAGE_PERI:
+               return bcm2835_asb_power_on(pd, PM_IMAGE,
+                                           0, 0,
+                                           PM_PERIRSTN);
+
+       case BCM2835_POWER_DOMAIN_IMAGE_ISP:
+               return bcm2835_asb_power_on(pd, PM_IMAGE,
+                                           ASB_ISP_M_CTRL, ASB_ISP_S_CTRL,
+                                           PM_ISPRSTN);
+
+       case BCM2835_POWER_DOMAIN_IMAGE_H264:
+               return bcm2835_asb_power_on(pd, PM_IMAGE,
+                                           ASB_H264_M_CTRL, ASB_H264_S_CTRL,
+                                           PM_H264RSTN);
+
+       case BCM2835_POWER_DOMAIN_USB:
+               PM_WRITE(PM_USB, PM_USB_CTRLEN);
+               return 0;
+
+       case BCM2835_POWER_DOMAIN_DSI0:
+               PM_WRITE(PM_DSI0, PM_DSI0_CTRLEN);
+               PM_WRITE(PM_DSI0, PM_DSI0_CTRLEN | PM_DSI0_LDOHPEN);
+               return 0;
+
+       case BCM2835_POWER_DOMAIN_DSI1:
+               PM_WRITE(PM_DSI1, PM_DSI1_CTRLEN);
+               PM_WRITE(PM_DSI1, PM_DSI1_CTRLEN | PM_DSI1_LDOHPEN);
+               return 0;
+
+       case BCM2835_POWER_DOMAIN_CCP2TX:
+               PM_WRITE(PM_CCP2TX, PM_CCP2TX_CTRLEN);
+               PM_WRITE(PM_CCP2TX, PM_CCP2TX_CTRLEN | PM_CCP2TX_LDOEN);
+               return 0;
+
+       case BCM2835_POWER_DOMAIN_HDMI:
+               PM_WRITE(PM_HDMI, PM_READ(PM_HDMI) | PM_HDMI_RSTDR);
+               PM_WRITE(PM_HDMI, PM_READ(PM_HDMI) | PM_HDMI_CTRLEN);
+               PM_WRITE(PM_HDMI, PM_READ(PM_HDMI) & ~PM_HDMI_LDOPD);
+               usleep_range(100, 200);
+               PM_WRITE(PM_HDMI, PM_READ(PM_HDMI) & ~PM_HDMI_RSTDR);
+               return 0;
+
+       default:
+               dev_err(power->dev, "Invalid domain %d\n", pd->domain);
+               return -EINVAL;
+       }
+}
+
+static int bcm2835_power_pd_power_off(struct generic_pm_domain *domain)
+{
+       struct bcm2835_power_domain *pd =
+               container_of(domain, struct bcm2835_power_domain, base);
+       struct bcm2835_power *power = pd->power;
+
+       switch (pd->domain) {
+       case BCM2835_POWER_DOMAIN_GRAFX:
+               return bcm2835_power_power_off(pd, PM_GRAFX);
+
+       case BCM2835_POWER_DOMAIN_GRAFX_V3D:
+               return bcm2835_asb_power_off(pd, PM_GRAFX,
+                                            ASB_V3D_M_CTRL, ASB_V3D_S_CTRL,
+                                            PM_V3DRSTN);
+
+       case BCM2835_POWER_DOMAIN_IMAGE:
+               return bcm2835_power_power_off(pd, PM_IMAGE);
+
+       case BCM2835_POWER_DOMAIN_IMAGE_PERI:
+               return bcm2835_asb_power_off(pd, PM_IMAGE,
+                                            0, 0,
+                                            PM_PERIRSTN);
+
+       case BCM2835_POWER_DOMAIN_IMAGE_ISP:
+               return bcm2835_asb_power_off(pd, PM_IMAGE,
+                                            ASB_ISP_M_CTRL, ASB_ISP_S_CTRL,
+                                            PM_ISPRSTN);
+
+       case BCM2835_POWER_DOMAIN_IMAGE_H264:
+               return bcm2835_asb_power_off(pd, PM_IMAGE,
+                                            ASB_H264_M_CTRL, ASB_H264_S_CTRL,
+                                            PM_H264RSTN);
+
+       case BCM2835_POWER_DOMAIN_USB:
+               PM_WRITE(PM_USB, 0);
+               return 0;
+
+       case BCM2835_POWER_DOMAIN_DSI0:
+               PM_WRITE(PM_DSI0, PM_DSI0_CTRLEN);
+               PM_WRITE(PM_DSI0, 0);
+               return 0;
+
+       case BCM2835_POWER_DOMAIN_DSI1:
+               PM_WRITE(PM_DSI1, PM_DSI1_CTRLEN);
+               PM_WRITE(PM_DSI1, 0);
+               return 0;
+
+       case BCM2835_POWER_DOMAIN_CCP2TX:
+               PM_WRITE(PM_CCP2TX, PM_CCP2TX_CTRLEN);
+               PM_WRITE(PM_CCP2TX, 0);
+               return 0;
+
+       case BCM2835_POWER_DOMAIN_HDMI:
+               PM_WRITE(PM_HDMI, PM_READ(PM_HDMI) | PM_HDMI_LDOPD);
+               PM_WRITE(PM_HDMI, PM_READ(PM_HDMI) & ~PM_HDMI_CTRLEN);
+               return 0;
+
+       default:
+               dev_err(power->dev, "Invalid domain %d\n", pd->domain);
+               return -EINVAL;
+       }
+}
+
+static void
+bcm2835_init_power_domain(struct bcm2835_power *power,
+                         int pd_xlate_index, const char *name)
+{
+       struct device *dev = power->dev;
+       struct bcm2835_power_domain *dom = &power->domains[pd_xlate_index];
+
+       dom->clk = devm_clk_get(dev->parent, name);
+
+       dom->base.name = name;
+       dom->base.power_on = bcm2835_power_pd_power_on;
+       dom->base.power_off = bcm2835_power_pd_power_off;
+
+       dom->domain = pd_xlate_index;
+       dom->power = power;
+
+       /* XXX: on/off at boot? */
+       pm_genpd_init(&dom->base, NULL, true);
+
+       power->pd_xlate.domains[pd_xlate_index] = &dom->base;
+}
+
+/** bcm2835_reset_reset - Resets a block that has a reset line in the
+ * PM block.
+ *
+ * The consumer of the reset controller must have the power domain up
+ * -- there's no reset ability with the power domain down.  To reset
+ * the sub-block, we just disable its access to memory through the
+ * ASB, reset, and re-enable.
+ */
+static int bcm2835_reset_reset(struct reset_controller_dev *rcdev,
+                              unsigned long id)
+{
+       struct bcm2835_power *power = container_of(rcdev, struct bcm2835_power,
+                                                  reset);
+       struct bcm2835_power_domain *pd;
+       int ret;
+
+       switch (id) {
+       case BCM2835_RESET_V3D:
+               pd = &power->domains[BCM2835_POWER_DOMAIN_GRAFX_V3D];
+               break;
+       case BCM2835_RESET_H264:
+               pd = &power->domains[BCM2835_POWER_DOMAIN_IMAGE_H264];
+               break;
+       case BCM2835_RESET_ISP:
+               pd = &power->domains[BCM2835_POWER_DOMAIN_IMAGE_ISP];
+               break;
+       default:
+               dev_err(power->dev, "Bad reset id %ld\n", id);
+               return -EINVAL;
+       }
+
+       ret = bcm2835_power_pd_power_off(&pd->base);
+       if (ret)
+               return ret;
+
+       return bcm2835_power_pd_power_on(&pd->base);
+}
+
+static int bcm2835_reset_status(struct reset_controller_dev *rcdev,
+                               unsigned long id)
+{
+       struct bcm2835_power *power = container_of(rcdev, struct bcm2835_power,
+                                                  reset);
+
+       switch (id) {
+       case BCM2835_RESET_V3D:
+               return !PM_READ(PM_GRAFX & PM_V3DRSTN);
+       case BCM2835_RESET_H264:
+               return !PM_READ(PM_IMAGE & PM_H264RSTN);
+       case BCM2835_RESET_ISP:
+               return !PM_READ(PM_IMAGE & PM_ISPRSTN);
+       default:
+               return -EINVAL;
+       }
+}
+
+const struct reset_control_ops bcm2835_reset_ops = {
+       .reset = bcm2835_reset_reset,
+       .status = bcm2835_reset_status,
+};
+
+static const char *const power_domain_names[] = {
+       [BCM2835_POWER_DOMAIN_GRAFX] = "grafx",
+       [BCM2835_POWER_DOMAIN_GRAFX_V3D] = "v3d",
+
+       [BCM2835_POWER_DOMAIN_IMAGE] = "image",
+       [BCM2835_POWER_DOMAIN_IMAGE_PERI] = "peri_image",
+       [BCM2835_POWER_DOMAIN_IMAGE_H264] = "h264",
+       [BCM2835_POWER_DOMAIN_IMAGE_ISP] = "isp",
+
+       [BCM2835_POWER_DOMAIN_USB] = "usb",
+       [BCM2835_POWER_DOMAIN_DSI0] = "dsi0",
+       [BCM2835_POWER_DOMAIN_DSI1] = "dsi1",
+       [BCM2835_POWER_DOMAIN_CAM0] = "cam0",
+       [BCM2835_POWER_DOMAIN_CAM1] = "cam1",
+       [BCM2835_POWER_DOMAIN_CCP2TX] = "ccp2tx",
+       [BCM2835_POWER_DOMAIN_HDMI] = "hdmi",
+};
+
+static int bcm2835_power_probe(struct platform_device *pdev)
+{
+       struct bcm2835_pm *pm = dev_get_drvdata(pdev->dev.parent);
+       struct device *dev = &pdev->dev;
+       struct bcm2835_power *power;
+       static const struct {
+               int parent, child;
+       } domain_deps[] = {
+               { BCM2835_POWER_DOMAIN_GRAFX, BCM2835_POWER_DOMAIN_GRAFX_V3D },
+               { BCM2835_POWER_DOMAIN_IMAGE, BCM2835_POWER_DOMAIN_IMAGE_PERI },
+               { BCM2835_POWER_DOMAIN_IMAGE, BCM2835_POWER_DOMAIN_IMAGE_H264 },
+               { BCM2835_POWER_DOMAIN_IMAGE, BCM2835_POWER_DOMAIN_IMAGE_ISP },
+               { BCM2835_POWER_DOMAIN_IMAGE_PERI, BCM2835_POWER_DOMAIN_USB },
+               { BCM2835_POWER_DOMAIN_IMAGE_PERI, BCM2835_POWER_DOMAIN_CAM0 },
+               { BCM2835_POWER_DOMAIN_IMAGE_PERI, BCM2835_POWER_DOMAIN_CAM1 },
+       };
+       int ret, i;
+       u32 id;
+
+       power = devm_kzalloc(dev, sizeof(*power), GFP_KERNEL);
+       if (!power)
+               return -ENOMEM;
+       platform_set_drvdata(pdev, power);
+
+       power->dev = dev;
+       power->base = pm->base;
+       power->asb = pm->asb;
+
+       id = ASB_READ(ASB_AXI_BRDG_ID);
+       if (id != 0x62726467 /* "BRDG" */) {
+               dev_err(dev, "ASB register ID returned 0x%08x\n", id);
+               return -ENODEV;
+       }
+
+       power->pd_xlate.domains = devm_kcalloc(dev,
+                                              ARRAY_SIZE(power_domain_names),
+                                              sizeof(*power->pd_xlate.domains),
+                                              GFP_KERNEL);
+       if (!power->pd_xlate.domains)
+               return -ENOMEM;
+
+       power->pd_xlate.num_domains = ARRAY_SIZE(power_domain_names);
+
+       for (i = 0; i < ARRAY_SIZE(power_domain_names); i++)
+               bcm2835_init_power_domain(power, i, power_domain_names[i]);
+
+       for (i = 0; i < ARRAY_SIZE(domain_deps); i++) {
+               pm_genpd_add_subdomain(&power->domains[domain_deps[i].parent].base,
+                                      &power->domains[domain_deps[i].child].base);
+       }
+
+       power->reset.owner = THIS_MODULE;
+       power->reset.nr_resets = BCM2835_RESET_COUNT;
+       power->reset.ops = &bcm2835_reset_ops;
+       power->reset.of_node = dev->parent->of_node;
+
+       ret = devm_reset_controller_register(dev, &power->reset);
+       if (ret)
+               return ret;
+
+       of_genpd_add_provider_onecell(dev->parent->of_node, &power->pd_xlate);
+
+       dev_info(dev, "Broadcom BCM2835 power domains driver");
+       return 0;
+}
+
+static int bcm2835_power_remove(struct platform_device *pdev)
+{
+       return 0;
+}
+
+static struct platform_driver bcm2835_power_driver = {
+       .probe          = bcm2835_power_probe,
+       .remove         = bcm2835_power_remove,
+       .driver = {
+               .name = "bcm2835-power",
+       },
+};
+module_platform_driver(bcm2835_power_driver);
+
+MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
+MODULE_DESCRIPTION("Driver for Broadcom BCM2835 PM power domains and reset");
+MODULE_LICENSE("GPL");
diff --git a/include/dt-bindings/soc/bcm2835-pm.h b/include/dt-bindings/soc/bcm2835-pm.h
new file mode 100644 (file)
index 0000000..153d75b
--- /dev/null
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: (GPL-2.0+ OR MIT) */
+
+#ifndef _DT_BINDINGS_ARM_BCM2835_PM_H
+#define _DT_BINDINGS_ARM_BCM2835_PM_H
+
+#define BCM2835_POWER_DOMAIN_GRAFX             0
+#define BCM2835_POWER_DOMAIN_GRAFX_V3D         1
+#define BCM2835_POWER_DOMAIN_IMAGE             2
+#define BCM2835_POWER_DOMAIN_IMAGE_PERI                3
+#define BCM2835_POWER_DOMAIN_IMAGE_ISP         4
+#define BCM2835_POWER_DOMAIN_IMAGE_H264                5
+#define BCM2835_POWER_DOMAIN_USB               6
+#define BCM2835_POWER_DOMAIN_DSI0              7
+#define BCM2835_POWER_DOMAIN_DSI1              8
+#define BCM2835_POWER_DOMAIN_CAM0              9
+#define BCM2835_POWER_DOMAIN_CAM1              10
+#define BCM2835_POWER_DOMAIN_CCP2TX            11
+#define BCM2835_POWER_DOMAIN_HDMI              12
+
+#define BCM2835_POWER_DOMAIN_COUNT             13
+
+#define BCM2835_RESET_V3D                      0
+#define BCM2835_RESET_ISP                      1
+#define BCM2835_RESET_H264                     2
+
+#define BCM2835_RESET_COUNT                    3
+
+#endif /* _DT_BINDINGS_ARM_BCM2835_PM_H */
index b7d0ee1..ed37dc4 100644 (file)
@@ -8,6 +8,7 @@
 struct bcm2835_pm {
        struct device *dev;
        void __iomem *base;
+       void __iomem *asb;
 };
 
 #endif /* BCM2835_MFD_PM_H */