Unverified Commit 1f88f017 authored by Sarah Walker's avatar Sarah Walker Committed by Maxime Ripard
Browse files

drm/imagination: Get GPU resources 



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

Changes since v8:
- Corrected license identifiers

Changes since v3:
- Remove regulator resource (not used on supported platform)
- Use devm helpers
- Use devm_clk_get_optional() for optional clocks
- Don't prepare clocks on resource acquisition
- Drop pvr_device_clk_core_get_freq() helper
- Drop pvr_device_reg_fini()
- Drop NULLing of clocks in pvr_device_clk_init()
- Use dev_err_probe() on clock acquisition failure
- Remove PVR_CR_READ/WRITE helper macros
- Improve documentation for GPU clocks
- Remove regs resource (not used in this commit)

Co-developed-by: default avatarFrank Binns <frank.binns@imgtec.com>
Signed-off-by: default avatarFrank Binns <frank.binns@imgtec.com>
Co-developed-by: default avatarMatt Coster <matt.coster@imgtec.com>
Signed-off-by: default avatarMatt Coster <matt.coster@imgtec.com>
Signed-off-by: default avatarSarah Walker <sarah.walker@imgtec.com>
Signed-off-by: default avatarDonald Robson <donald.robson@imgtec.com>
Reviewed-by: default avatarMaxime Ripard <mripard@kernel.org>
Link: https://lore.kernel.org/r/579027bd5be4eb3218c9784050ded2326ecbc352.1700668843.git.donald.robson@imgtec.com


Signed-off-by: default avatarMaxime Ripard <mripard@kernel.org>
parent 4babef07

drivers/gpu/drm/imagination/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ 
subdir-ccflags-y := -I$(srctree)/$(src)



powervr-y := \

	pvr_device.o \

	pvr_drv.o \



obj-$(CONFIG_DRM_POWERVR) += powervr.o

drivers/gpu/drm/imagination/pvr_device.c

0 → 100644
+147 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only OR MIT

/* Copyright (c) 2023 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/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);

	void __iomem *regs;



	pvr_dev->regs = NULL;



	regs = devm_platform_ioremap_resource(plat_dev, 0);

	if (IS_ERR(regs))

		return dev_err_probe(drm_dev->dev, PTR_ERR(regs),

				     "failed to ioremap gpu registers\n");



	pvr_dev->regs = regs;



	return 0;

}



/**

 * 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 devm_clk_get_optional().

 */

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;



	core_clk = devm_clk_get(drm_dev->dev, "core");

	if (IS_ERR(core_clk))

		return dev_err_probe(drm_dev->dev, PTR_ERR(core_clk),

				     "failed to get core clock\n");



	sys_clk = devm_clk_get_optional(drm_dev->dev, "sys");

	if (IS_ERR(sys_clk))

		return dev_err_probe(drm_dev->dev, PTR_ERR(core_clk),

				     "failed to get sys clock\n");



	mem_clk = devm_clk_get_optional(drm_dev->dev, "mem");

	if (IS_ERR(mem_clk))

		return dev_err_probe(drm_dev->dev, PTR_ERR(core_clk),

				     "failed to get mem clock\n");



	pvr_dev->core_clk = core_clk;

	pvr_dev->sys_clk = sys_clk;

	pvr_dev->mem_clk = mem_clk;



	return 0;

}



/**

 * 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)

		return err;



	/* Map the control registers into memory. */

	return pvr_device_reg_init(pvr_dev);

}



/**

 * 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().

	 */

}

drivers/gpu/drm/imagination/pvr_device.h

+152 −0
Original line number Diff line number Diff line
@@ -11,9 +11,22 @@ 
#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;



/**

 * struct pvr_device - powervr-specific wrapper for &struct drm_device
@@ -26,6 +39,37 @@ struct pvr_device { 
	 * from_pvr_device().

	 */

	struct drm_device base;



	/**

	 * @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.

	 *

	 * This is the primary clock used by the entire GPU core.

	 */

	struct clk *core_clk;



	/**

	 * @sys_clk: Optional system bus clock.

	 *

	 * This may be used on some platforms to provide an independent clock to the SoC Interface

	 * (SOCIF). If present, this needs to be enabled/disabled together with @core_clk.

	 */

	struct clk *sys_clk;



	/**

	 * @mem_clk: Optional memory clock.

	 *

	 * This may be used on some platforms to provide an independent clock to the Memory

	 * Interface (MEMIF). If present, this needs to be enabled/disabled together with @core_clk.

	 */

	struct clk *mem_clk;

};



/**
@@ -56,6 +100,114 @@ struct pvr_file { 


#define to_pvr_file(file) ((file)->driver_priv)



int pvr_device_init(struct pvr_device *pvr_dev);

void pvr_device_fini(struct pvr_device *pvr_dev);



/**

 * 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.

 *

 * 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.

 *

 * 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.

 */

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.

 */

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

 *

drivers/gpu/drm/imagination/pvr_drv.c

+17 −1
Original line number Diff line number Diff line
@@ -464,6 +464,7 @@ pvr_probe(struct platform_device *plat_dev) 
{

	struct pvr_device *pvr_dev;

	struct drm_device *drm_dev;

	int err;



	pvr_dev = devm_drm_dev_alloc(&plat_dev->dev, &pvr_drm_driver,

				     struct pvr_device, base);
@@ -474,14 +475,29 @@ pvr_probe(struct platform_device *plat_dev) 


	platform_set_drvdata(plat_dev, drm_dev);



	return drm_dev_register(drm_dev, 0);

	err = pvr_device_init(pvr_dev);

	if (err)

		return err;



	err = drm_dev_register(drm_dev, 0);

	if (err)

		goto err_device_fini;



	return 0;



err_device_fini:

	pvr_device_fini(pvr_dev);



	return err;

}



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);



	pvr_device_fini(pvr_dev);

	drm_dev_unplug(drm_dev);



	return 0;