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: Frank Binns <frank.binns@imgtec.com>
Signed-off-by: Frank Binns <frank.binns@imgtec.com>
Co-developed-by: Matt Coster <matt.coster@imgtec.com>
Signed-off-by: Matt Coster <matt.coster@imgtec.com>
Signed-off-by: Sarah Walker <sarah.walker@imgtec.com>
Signed-off-by: Donald Robson <donald.robson@imgtec.com>
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Link: https://lore.kernel.org/r/579027bd5be4eb3218c9784050ded2326ecbc352.1700668843.git.donald.robson@imgtec.com
Signed-off-by: Maxime Ripard <mripard@kernel.org>
This commit is contained in:
Sarah Walker 2023-11-22 16:34:27 +00:00 committed by Maxime Ripard
parent 4babef0708
commit 1f88f017e6
No known key found for this signature in database
GPG Key ID: E3EF0D6F671851C5
4 changed files with 317 additions and 1 deletions

View File

@ -4,6 +4,7 @@
subdir-ccflags-y := -I$(srctree)/$(src)
powervr-y := \
pvr_device.o \
pvr_drv.o \
obj-$(CONFIG_DRM_POWERVR) += powervr.o

View File

@ -0,0 +1,147 @@
// 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().
*/
}

View File

@ -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
*

View File

@ -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;