diff options
| -rw-r--r-- | drivers/gpu/drm/imagination/pvr_device.c | 21 | ||||
| -rw-r--r-- | drivers/gpu/drm/imagination/pvr_device.h | 9 | ||||
| -rw-r--r-- | drivers/gpu/drm/imagination/pvr_power.c | 22 |
3 files changed, 51 insertions, 1 deletions
diff --git a/drivers/gpu/drm/imagination/pvr_device.c b/drivers/gpu/drm/imagination/pvr_device.c index 1e488a30c784..8b9ba4983c4c 100644 --- a/drivers/gpu/drm/imagination/pvr_device.c +++ b/drivers/gpu/drm/imagination/pvr_device.c @@ -25,6 +25,7 @@ #include <linux/interrupt.h> #include <linux/platform_device.h> #include <linux/pm_runtime.h> +#include <linux/reset.h> #include <linux/slab.h> #include <linux/stddef.h> #include <linux/types.h> @@ -120,6 +121,21 @@ static int pvr_device_clk_init(struct pvr_device *pvr_dev) return 0; } +static int pvr_device_reset_init(struct pvr_device *pvr_dev) +{ + struct drm_device *drm_dev = from_pvr_device(pvr_dev); + struct reset_control *reset; + + reset = devm_reset_control_get_optional_exclusive(drm_dev->dev, NULL); + if (IS_ERR(reset)) + return dev_err_probe(drm_dev->dev, PTR_ERR(reset), + "failed to get gpu reset line\n"); + + pvr_dev->reset = reset; + + return 0; +} + /** * pvr_device_process_active_queues() - Process all queue related events. * @pvr_dev: PowerVR device to check @@ -615,6 +631,11 @@ pvr_device_init(struct pvr_device *pvr_dev) if (err) return err; + /* Get the reset line for the GPU */ + err = pvr_device_reset_init(pvr_dev); + if (err) + return err; + /* Explicitly power the GPU so we can access control registers before the FW is booted. */ err = pm_runtime_resume_and_get(dev); if (err) diff --git a/drivers/gpu/drm/imagination/pvr_device.h b/drivers/gpu/drm/imagination/pvr_device.h index eb5da8c7040f..7cb01c38d2a9 100644 --- a/drivers/gpu/drm/imagination/pvr_device.h +++ b/drivers/gpu/drm/imagination/pvr_device.h @@ -139,6 +139,15 @@ struct pvr_device { u32 domain_count; } power; + /** + * @reset: Optional reset line. + * + * This may be used on some platforms to provide a reset line that needs to be de-asserted + * after power-up procedure. It would also need to be asserted after the power-down + * procedure. + */ + struct reset_control *reset; + /** @irq: IRQ number. */ int irq; diff --git a/drivers/gpu/drm/imagination/pvr_power.c b/drivers/gpu/drm/imagination/pvr_power.c index 19b079b357df..41f5d89e78b8 100644 --- a/drivers/gpu/drm/imagination/pvr_power.c +++ b/drivers/gpu/drm/imagination/pvr_power.c @@ -18,6 +18,7 @@ #include <linux/platform_device.h> #include <linux/pm_domain.h> #include <linux/pm_runtime.h> +#include <linux/reset.h> #include <linux/timer.h> #include <linux/types.h> #include <linux/workqueue.h> @@ -255,6 +256,8 @@ pvr_power_device_suspend(struct device *dev) clk_disable_unprepare(pvr_dev->sys_clk); clk_disable_unprepare(pvr_dev->core_clk); + err = reset_control_assert(pvr_dev->reset); + err_drm_dev_exit: drm_dev_exit(idx); @@ -285,16 +288,33 @@ pvr_power_device_resume(struct device *dev) if (err) goto err_sys_clk_disable; + /* + * According to the hardware manual, a delay of at least 32 clock + * cycles is required between de-asserting the clkgen reset and + * de-asserting the GPU reset. Assuming a worst-case scenario with + * a very high GPU clock frequency, a delay of 1 microsecond is + * sufficient to ensure this requirement is met across all + * feasible GPU clock speeds. + */ + udelay(1); + + err = reset_control_deassert(pvr_dev->reset); + if (err) + goto err_mem_clk_disable; + if (pvr_dev->fw_dev.booted) { err = pvr_power_fw_enable(pvr_dev); if (err) - goto err_mem_clk_disable; + goto err_reset_assert; } drm_dev_exit(idx); return 0; +err_reset_assert: + reset_control_assert(pvr_dev->reset); + err_mem_clk_disable: clk_disable_unprepare(pvr_dev->mem_clk); |