[PATCH v8 06/20] drm/imagination: Get GPU resources
Sarah Walker
sarah.walker at imgtec.com
Tue Oct 31 15:12:43 UTC 2023
Acquire clock and register resources, and enable/map as appropriate.
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 at imgtec.com>
Signed-off-by: Frank Binns <frank.binns at imgtec.com>
Co-developed-by: Matt Coster <matt.coster at imgtec.com>
Signed-off-by: Matt Coster <matt.coster at imgtec.com>
Signed-off-by: Sarah Walker <sarah.walker at imgtec.com>
Reviewed-by: Maxime Ripard <mripard at kernel.org>
---
drivers/gpu/drm/imagination/Makefile | 1 +
drivers/gpu/drm/imagination/pvr_device.c | 147 ++++++++++++++++++++++
drivers/gpu/drm/imagination/pvr_device.h | 152 +++++++++++++++++++++++
drivers/gpu/drm/imagination/pvr_drv.c | 18 ++-
4 files changed, 317 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 19b40c2d7356..b4aa190c9d4a 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..cef3511c0c42
--- /dev/null
+++ b/drivers/gpu/drm/imagination/pvr_device.c
@@ -0,0 +1,147 @@
+// SPDX-License-Identifier: GPL-2.0 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().
+ */
+}
diff --git a/drivers/gpu/drm/imagination/pvr_device.h b/drivers/gpu/drm/imagination/pvr_device.h
index 53b1cdb5a6a6..d61b3615b49f 100644
--- a/drivers/gpu/drm/imagination/pvr_device.h
+++ b/drivers/gpu/drm/imagination/pvr_device.h
@@ -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
*
diff --git a/drivers/gpu/drm/imagination/pvr_drv.c b/drivers/gpu/drm/imagination/pvr_drv.c
index a23bef62b52b..a4c871f58fa4 100644
--- a/drivers/gpu/drm/imagination/pvr_drv.c
+++ b/drivers/gpu/drm/imagination/pvr_drv.c
@@ -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;
--
2.42.0
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