[PATCH v3 05/17] drm/imagination: Get GPU resources

[Sarah Walker <sarah.walker@imgtec.com>]

Acquire clock, regulator and register resources, and enable/map as
appropriate.

Signed-off-by: Sarah Walker <sarah.walker@imgtec.com>
---
 drivers/gpu/drm/imagination/Makefile     |   1 +
 drivers/gpu/drm/imagination/pvr_device.c | 271 +++++++++++++++++++++++
 drivers/gpu/drm/imagination/pvr_device.h | 214 ++++++++++++++++++
 drivers/gpu/drm/imagination/pvr_drv.c    |  11 +-
 4 files changed, 496 insertions(+), 1 deletion(-)
 create mode 100644 drivers/gpu/drm/imagination/pvr_device.c

diff --git a/drivers/gpu/drm/imagination/Makefile b/drivers/gpu/drm/imagination/Makefile
index 62ccf0ccbd51..186f920d615b 100644
--- a/drivers/gpu/drm/imagination/Makefile
+++ b/drivers/gpu/drm/imagination/Makefile
@@ -4,6 +4,7 @@
 subdir-ccflags-y := -I$(srctree)/$(src)
 
 powervr-y := \
+	pvr_device.o \
 	pvr_drv.o \
 
 obj-$(CONFIG_DRM_POWERVR) += powervr.o
diff --git a/drivers/gpu/drm/imagination/pvr_device.c b/drivers/gpu/drm/imagination/pvr_device.c
new file mode 100644
index 000000000000..790c36cebec1
--- /dev/null
+++ b/drivers/gpu/drm/imagination/pvr_device.c
@@ -0,0 +1,271 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+/* Copyright (c) 2022 Imagination Technologies Ltd. */
+
+#include "pvr_device.h"
+
+#include <drm/drm_print.h>
+
+#include <linux/clk.h>
+#include <linux/compiler_attributes.h>
+#include <linux/compiler_types.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/gfp.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+#include <linux/stddef.h>
+#include <linux/types.h>
+
+/**
+ * pvr_device_reg_init() - Initialize kernel access to a PowerVR device's
+ * control registers.
+ * @pvr_dev: Target PowerVR device.
+ *
+ * Sets struct pvr_device->regs.
+ *
+ * This method of mapping the device control registers into memory ensures that
+ * they are unmapped when the driver is detached (i.e. no explicit cleanup is
+ * required).
+ *
+ * Return:
+ *  * 0 on success, or
+ *  * Any error returned by devm_platform_ioremap_resource().
+ */
+static int
+pvr_device_reg_init(struct pvr_device *pvr_dev)
+{
+	struct drm_device *drm_dev = from_pvr_device(pvr_dev);
+	struct platform_device *plat_dev = to_platform_device(drm_dev->dev);
+	struct resource *regs_resource;
+	void __iomem *regs;
+	int err;
+
+	pvr_dev->regs_resource = NULL;
+	pvr_dev->regs = NULL;
+
+	regs = devm_platform_get_and_ioremap_resource(plat_dev, 0, &regs_resource);
+	if (IS_ERR(regs)) {
+		err = PTR_ERR(regs);
+		drm_err(drm_dev, "failed to ioremap gpu registers (err=%d)\n",
+			err);
+		return err;
+	}
+
+	pvr_dev->regs = regs;
+	pvr_dev->regs_resource = regs_resource;
+
+	return 0;
+}
+
+/**
+ * pvr_device_reg_fini() - Deinitialize kernel access to a PowerVR device's
+ * control registers.
+ * @pvr_dev: Target PowerVR device.
+ *
+ * This is essentially a no-op, since pvr_device_reg_init() already ensures that
+ * struct pvr_device->regs is unmapped when the device is detached. This
+ * function just sets struct pvr_device->regs to %NULL.
+ */
+static __always_inline void
+pvr_device_reg_fini(struct pvr_device *pvr_dev)
+{
+	pvr_dev->regs = NULL;
+}
+
+/**
+ * pvr_device_clk_init() - Initialize clocks required by a PowerVR device
+ * @pvr_dev: Target PowerVR device.
+ *
+ * Sets struct pvr_device->core_clk, struct pvr_device->sys_clk and
+ * struct pvr_device->mem_clk.
+ *
+ * Three clocks are required by the PowerVR device: core, sys and mem. On
+ * return, this function guarantees that the clocks are in one of the following
+ * states:
+ *
+ *  * All successfully initialized,
+ *  * Core errored, sys and mem uninitialized,
+ *  * Core deinitialized, sys errored, mem uninitialized, or
+ *  * Core and sys deinitialized, mem errored.
+ *
+ * Return:
+ *  * 0 on success,
+ *  * Any error returned by devm_clk_get(), or
+ *  * Any error returned by clk_prepare_enable().
+ */
+static int pvr_device_clk_init(struct pvr_device *pvr_dev)
+{
+	struct drm_device *drm_dev = from_pvr_device(pvr_dev);
+	struct clk *core_clk;
+	struct clk *sys_clk;
+	struct clk *mem_clk;
+	int err;
+
+	pvr_dev->core_clk = NULL;
+	pvr_dev->sys_clk = NULL;
+	pvr_dev->mem_clk = NULL;
+
+	core_clk = devm_clk_get(drm_dev->dev, "core");
+	if (IS_ERR(core_clk)) {
+		err = PTR_ERR(core_clk);
+		drm_err(drm_dev, "failed to get core clock (err=%d)\n", err);
+		goto err_out;
+	}
+
+	sys_clk = devm_clk_get(drm_dev->dev, "sys");
+	if (IS_ERR(sys_clk))
+		sys_clk = NULL;
+
+	mem_clk = devm_clk_get(drm_dev->dev, "mem");
+	if (IS_ERR(mem_clk))
+		mem_clk = NULL;
+
+	err = clk_prepare(core_clk);
+	if (err)
+		goto err_out;
+
+	if (sys_clk) {
+		err = clk_prepare(sys_clk);
+		if (err)
+			goto err_deinit_core_clk;
+	}
+
+	if (mem_clk) {
+		err = clk_prepare(mem_clk);
+		if (err)
+			goto err_deinit_sys_clk;
+	}
+
+	pvr_dev->core_clk = core_clk;
+	pvr_dev->sys_clk = sys_clk;
+	pvr_dev->mem_clk = mem_clk;
+
+	return 0;
+
+err_deinit_sys_clk:
+	if (sys_clk)
+		clk_disable_unprepare(sys_clk);
+err_deinit_core_clk:
+	clk_disable_unprepare(core_clk);
+err_out:
+	return err;
+}
+
+/**
+ * pvr_device_clk_fini() - Deinitialize clocks required by a PowerVR device
+ * @pvr_dev: Target PowerVR device.
+ */
+static void
+pvr_device_clk_fini(struct pvr_device *pvr_dev)
+{
+	if (pvr_dev->mem_clk)
+		clk_unprepare(pvr_dev->mem_clk);
+	if (pvr_dev->sys_clk)
+		clk_unprepare(pvr_dev->sys_clk);
+	clk_unprepare(pvr_dev->core_clk);
+
+	pvr_dev->core_clk = NULL;
+	pvr_dev->sys_clk = NULL;
+	pvr_dev->mem_clk = NULL;
+}
+
+/**
+ * pvr_device_regulator_init() - Initialise regulator required by a PowerVR device
+ * @pvr_dev: Target PowerVR device.
+ *
+ * The regulator is not a required devicetree property. If it is not present then this function will
+ * succeed, but &pvr_device->regulator will be %NULL.
+ *
+ * Returns:
+ *  * 0 on success, or
+ *  * Any error returned by devm_regulator_get().
+ */
+static int
+pvr_device_regulator_init(struct pvr_device *pvr_dev)
+{
+	struct drm_device *drm_dev = from_pvr_device(pvr_dev);
+	struct regulator *regulator;
+	int err;
+
+	regulator = devm_regulator_get(drm_dev->dev, "power");
+	if (IS_ERR(regulator)) {
+		err = PTR_ERR(regulator);
+		/* Regulator is not required, so ENODEV is allowed here. */
+		if (err != -ENODEV)
+			goto err_out;
+		regulator = NULL;
+	}
+
+	pvr_dev->regulator = regulator;
+
+	return 0;
+
+err_out:
+	return err;
+}
+
+/**
+ * pvr_device_init() - Initialize a PowerVR device
+ * @pvr_dev: Target PowerVR device.
+ *
+ * If this function returns successfully, the device will have been fully
+ * initialized. Otherwise, any parts of the device initialized before an error
+ * occurs will be de-initialized before returning.
+ *
+ * NOTE: The initialization steps currently taken are the bare minimum required
+ *       to read from the control registers. The device is unlikely to function
+ *       until further initialization steps are added. [This note should be
+ *       removed when that happens.]
+ *
+ * Return:
+ *  * 0 on success,
+ *  * Any error returned by pvr_device_reg_init(),
+ *  * Any error returned by pvr_device_clk_init(), or
+ *  * Any error returned by pvr_device_gpu_init().
+ */
+int
+pvr_device_init(struct pvr_device *pvr_dev)
+{
+	int err;
+
+	/* Enable and initialize clocks required for the device to operate. */
+	err = pvr_device_clk_init(pvr_dev);
+	if (err)
+		goto err_out;
+
+	err = pvr_device_regulator_init(pvr_dev);
+	if (err)
+		goto err_device_clk_fini;
+
+	/* Map the control registers into memory. */
+	err = pvr_device_reg_init(pvr_dev);
+	if (err)
+		goto err_device_reg_fini;
+
+	return 0;
+
+err_device_reg_fini:
+	pvr_device_reg_fini(pvr_dev);
+
+err_device_clk_fini:
+	pvr_device_clk_fini(pvr_dev);
+
+err_out:
+	return err;
+}
+
+/**
+ * pvr_device_fini() - Deinitialize a PowerVR device
+ * @pvr_dev: Target PowerVR device.
+ */
+void
+pvr_device_fini(struct pvr_device *pvr_dev)
+{
+	/*
+	 * Deinitialization stages are performed in reverse order compared to
+	 * the initialization stages in pvr_device_init().
+	 */
+	pvr_device_reg_fini(pvr_dev);
+	pvr_device_clk_fini(pvr_dev);
+}
diff --git a/drivers/gpu/drm/imagination/pvr_device.h b/drivers/gpu/drm/imagination/pvr_device.h
index 3d2865d726b8..c0dd0562844c 100644
--- a/drivers/gpu/drm/imagination/pvr_device.h
+++ b/drivers/gpu/drm/imagination/pvr_device.h
@@ -11,9 +11,25 @@
 #include <linux/bits.h>
 #include <linux/compiler_attributes.h>
 #include <linux/compiler_types.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
 #include <linux/kernel.h>
+#include <linux/math.h>
+#include <linux/mutex.h>
+#include <linux/timer.h>
 #include <linux/types.h>
 #include <linux/wait.h>
+#include <linux/workqueue.h>
+#include <linux/xarray.h>
+
+/* Forward declaration from <linux/clk.h>. */
+struct clk;
+
+/* Forward declaration from <linux/firmware.h>. */
+struct firmware;
+
+/* Forward declaration from <linux/regulator/consumer.h>. */
+struct regulator;
 
 /**
  * struct pvr_device - powervr-specific wrapper for &struct drm_device
@@ -26,6 +42,29 @@ struct pvr_device {
 	 * from_pvr_device().
 	 */
 	struct drm_device base;
+
+	/** @regs_resource: Resource representing device control registers. */
+	struct resource *regs_resource;
+
+	/**
+	 * @regs: Device control registers.
+	 *
+	 * These are mapped into memory when the device is initialized; that
+	 * location is where this pointer points.
+	 */
+	void __iomem *regs;
+
+	/** @core_clk: General core clock. */
+	struct clk *core_clk;
+
+	/** @sys_clk: System bus clock. */
+	struct clk *sys_clk;
+
+	/** @mem_clk: Memory clock. */
+	struct clk *mem_clk;
+
+	/** @regulator: Power regulator. */
+	struct regulator *regulator;
 };
 
 /**
@@ -72,6 +111,181 @@ to_pvr_file(struct drm_file *file)
 	return file->driver_priv;
 }
 
+int pvr_device_init(struct pvr_device *pvr_dev);
+void pvr_device_fini(struct pvr_device *pvr_dev);
+
+int
+pvr_device_clk_core_get_freq(struct pvr_device *pvr_dev, u32 *freq_out);
+
+/**
+ * PVR_CR_READ32() - Read a 32-bit register from a PowerVR device
+ * @pvr_dev: Target PowerVR device.
+ * @reg: Target register.
+ *
+ * This macro is a wrapper around pvr_cr_read32(). It applies ROGUE_CR_ prefix
+ * to the provided @reg name, making it behave comparably to the
+ * PVR_CR_FIELD_GET() macro.
+ *
+ * Return: The value of the requested register.
+ */
+#define PVR_CR_READ32(pvr_dev, reg) pvr_cr_read32(pvr_dev, ROGUE_CR_##reg)
+
+/**
+ * PVR_CR_READ64() - Read a 64-bit register from a PowerVR device
+ * @pvr_dev: Target PowerVR device.
+ * @reg: Target register.
+ *
+ * This macro is a wrapper around pvr_cr_read64(). It applies ROGUE_CR_ prefix
+ * to the provided @reg name, making it behave comparably to the
+ * PVR_CR_FIELD_GET() macro.
+ *
+ * Return: The value of the requested register.
+ */
+#define PVR_CR_READ64(pvr_dev, reg) pvr_cr_read64(pvr_dev, ROGUE_CR_##reg)
+
+/**
+ * PVR_CR_WRITE32() - Write to a 32-bit register in a PowerVR device
+ * @pvr_dev: Target PowerVR device.
+ * @reg: Target register.
+ * @val: Value to write.
+ *
+ * This macro is a wrapper around pvr_cr_write32(). It applies ROGUE_CR_
+ * prefix to the provided @reg name, making it behave comparably to the
+ * PVR_CR_FIELD_GET() macro.
+ */
+#define PVR_CR_WRITE32(pvr_dev, reg, val) \
+	pvr_cr_write32(pvr_dev, ROGUE_CR_##reg, val)
+
+/**
+ * PVR_CR_WRITE64() - Write to a 64-bit register in a PowerVR device
+ * @pvr_dev: Target PowerVR device.
+ * @reg: Target register.
+ * @val: Value to write.
+ *
+ * This macro is a wrapper around pvr_cr_write64(). It applies ROGUE_CR_
+ * prefix to the provided @reg name, making it behave comparably to the
+ * PVR_CR_FIELD_GET() macro.
+ */
+#define PVR_CR_WRITE64(pvr_dev, reg, val) \
+	pvr_cr_write64(pvr_dev, ROGUE_CR_##reg, val)
+
+/**
+ * PVR_CR_FIELD_GET() - Extract a single field from a PowerVR control register
+ * @val: Value of the target register.
+ * @field: Field specifier, as defined in "pvr_rogue_cr_defs.h".
+ *
+ * Return: The extracted field.
+ */
+#define PVR_CR_FIELD_GET(val, field) FIELD_GET(~ROGUE_CR_##field##_CLRMSK, val)
+
+/**
+ * pvr_cr_read32() - Read a 32-bit register from a PowerVR device
+ * @pvr_dev: Target PowerVR device.
+ * @reg: Target register.
+ *
+ * The wrapper macro PVR_CR_READ32() may be used instead to simplify the
+ * selection of @reg.
+ *
+ * Return: The value of the requested register.
+ */
+static __always_inline u32
+pvr_cr_read32(struct pvr_device *pvr_dev, u32 reg)
+{
+	return ioread32(pvr_dev->regs + reg);
+}
+
+/**
+ * pvr_cr_read64() - Read a 64-bit register from a PowerVR device
+ * @pvr_dev: Target PowerVR device.
+ * @reg: Target register.
+ *
+ * The wrapper macro PVR_CR_READ64() may be used instead to simplify the
+ * selection of @reg.
+ *
+ * Return: The value of the requested register.
+ */
+static __always_inline u64
+pvr_cr_read64(struct pvr_device *pvr_dev, u32 reg)
+{
+	return ioread64(pvr_dev->regs + reg);
+}
+
+/**
+ * pvr_cr_write32() - Write to a 32-bit register in a PowerVR device
+ * @pvr_dev: Target PowerVR device.
+ * @reg: Target register.
+ * @val: Value to write.
+ *
+ * The wrapper macro PVR_CR_WRITE32() may be used instead to simplify the
+ * selection of @reg.
+ */
+static __always_inline void
+pvr_cr_write32(struct pvr_device *pvr_dev, u32 reg, u32 val)
+{
+	iowrite32(val, pvr_dev->regs + reg);
+}
+
+/**
+ * pvr_cr_write64() - Write to a 64-bit register in a PowerVR device
+ * @pvr_dev: Target PowerVR device.
+ * @reg: Target register.
+ * @val: Value to write.
+ *
+ * The wrapper macro PVR_CR_WRITE64() may be used instead to simplify the
+ * selection of @reg.
+ */
+static __always_inline void
+pvr_cr_write64(struct pvr_device *pvr_dev, u32 reg, u64 val)
+{
+	iowrite64(val, pvr_dev->regs + reg);
+}
+
+/**
+ * pvr_cr_poll_reg32() - Wait for a 32-bit register to match a given value by
+ *                       polling
+ * @pvr_dev: Target PowerVR device.
+ * @reg_addr: Address of register.
+ * @reg_value: Expected register value (after masking).
+ * @reg_mask: Mask of bits valid for comparison with @reg_value.
+ * @timeout_usec: Timeout length, in us.
+ *
+ * Returns:
+ *  * 0 on success, or
+ *  * -%ETIMEDOUT on timeout.
+ */
+static __always_inline int
+pvr_cr_poll_reg32(struct pvr_device *pvr_dev, u32 reg_addr, u32 reg_value,
+		  u32 reg_mask, u64 timeout_usec)
+{
+	u32 value;
+
+	return readl_poll_timeout(pvr_dev->regs + reg_addr, value,
+		(value & reg_mask) == reg_value, 0, timeout_usec);
+}
+
+/**
+ * pvr_cr_poll_reg64() - Wait for a 64-bit register to match a given value by
+ *                       polling
+ * @pvr_dev: Target PowerVR device.
+ * @reg_addr: Address of register.
+ * @reg_value: Expected register value (after masking).
+ * @reg_mask: Mask of bits valid for comparison with @reg_value.
+ * @timeout_usec: Timeout length, in us.
+ *
+ * Returns:
+ *  * 0 on success, or
+ *  * -%ETIMEDOUT on timeout.
+ */
+static __always_inline int
+pvr_cr_poll_reg64(struct pvr_device *pvr_dev, u32 reg_addr, u64 reg_value,
+		  u64 reg_mask, u64 timeout_usec)
+{
+	u64 value;
+
+	return readq_poll_timeout(pvr_dev->regs + reg_addr, value,
+		(value & reg_mask) == reg_value, 0, timeout_usec);
+}
+
 /**
  * DOC: IOCTL validation helpers
  *
diff --git a/drivers/gpu/drm/imagination/pvr_drv.c b/drivers/gpu/drm/imagination/pvr_drv.c
index e203a2370f55..48a870715426 100644
--- a/drivers/gpu/drm/imagination/pvr_drv.c
+++ b/drivers/gpu/drm/imagination/pvr_drv.c
@@ -485,12 +485,19 @@ pvr_probe(struct platform_device *plat_dev)
 
 	platform_set_drvdata(plat_dev, drm_dev);
 
-	err = drm_dev_register(drm_dev, 0);
+	err = pvr_device_init(pvr_dev);
 	if (err)
 		goto err_out;
 
+	err = drm_dev_register(drm_dev, 0);
+	if (err)
+		goto err_device_fini;
+
 	return 0;
 
+err_device_fini:
+	pvr_device_fini(pvr_dev);
+
 err_out:
 	return err;
 }
@@ -499,8 +506,10 @@ static int
 pvr_remove(struct platform_device *plat_dev)
 {
 	struct drm_device *drm_dev = platform_get_drvdata(plat_dev);
+	struct pvr_device *pvr_dev = to_pvr_device(drm_dev);
 
 	drm_dev_unregister(drm_dev);
+	pvr_device_fini(pvr_dev);
 
 	return 0;
 }
-- 
2.40.1