From fa201ac2c61f51d9abdaffdf994d5780dcb51703 Mon Sep 17 00:00:00 2001 From: Noralf Trønnes Date: Sun, 22 Jan 2017 00:15:00 +0100 Subject: drm: Add DRM support for tiny LCD displays MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit tinydrm provides helpers for very simple displays that can use CMA backed framebuffers and need flushing on changes. Signed-off-by: Noralf Trønnes Acked-by: Daniel Vetter Acked-by: Thierry Reding --- drivers/gpu/drm/tinydrm/core/tinydrm-core.c | 376 ++++++++++++++++++++++++++++ 1 file changed, 376 insertions(+) create mode 100644 drivers/gpu/drm/tinydrm/core/tinydrm-core.c (limited to 'drivers/gpu/drm/tinydrm/core/tinydrm-core.c') diff --git a/drivers/gpu/drm/tinydrm/core/tinydrm-core.c b/drivers/gpu/drm/tinydrm/core/tinydrm-core.c new file mode 100644 index 000000000000..6a257dd08ee0 --- /dev/null +++ b/drivers/gpu/drm/tinydrm/core/tinydrm-core.c @@ -0,0 +1,376 @@ +/* + * Copyright (C) 2016 Noralf Trønnes + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#include +#include +#include +#include +#include +#include + +/** + * DOC: overview + * + * This library provides driver helpers for very simple display hardware. + * + * It is based on &drm_simple_display_pipe coupled with a &drm_connector which + * has only one fixed &drm_display_mode. The framebuffers are backed by the + * cma helper and have support for framebuffer flushing (dirty). + * fbdev support is also included. + * + */ + +/** + * DOC: core + * + * The driver allocates &tinydrm_device, initializes it using + * devm_tinydrm_init(), sets up the pipeline using tinydrm_display_pipe_init() + * and registers the DRM device using devm_tinydrm_register(). + */ + +/** + * tinydrm_lastclose - DRM lastclose helper + * @drm: DRM device + * + * This function ensures that fbdev is restored when drm_lastclose() is called + * on the last drm_release(). Drivers can use this as their + * &drm_driver->lastclose callback. + */ +void tinydrm_lastclose(struct drm_device *drm) +{ + struct tinydrm_device *tdev = drm->dev_private; + + DRM_DEBUG_KMS("\n"); + drm_fbdev_cma_restore_mode(tdev->fbdev_cma); +} +EXPORT_SYMBOL(tinydrm_lastclose); + +/** + * tinydrm_gem_cma_prime_import_sg_table - Produce a CMA GEM object from + * another driver's scatter/gather table of pinned pages + * @drm: DRM device to import into + * @attach: DMA-BUF attachment + * @sgt: Scatter/gather table of pinned pages + * + * This function imports a scatter/gather table exported via DMA-BUF by + * another driver using drm_gem_cma_prime_import_sg_table(). It sets the + * kernel virtual address on the CMA object. Drivers should use this as their + * &drm_driver->gem_prime_import_sg_table callback if they need the virtual + * address. tinydrm_gem_cma_free_object() should be used in combination with + * this function. + * + * Returns: + * A pointer to a newly created GEM object or an ERR_PTR-encoded negative + * error code on failure. + */ +struct drm_gem_object * +tinydrm_gem_cma_prime_import_sg_table(struct drm_device *drm, + struct dma_buf_attachment *attach, + struct sg_table *sgt) +{ + struct drm_gem_cma_object *cma_obj; + struct drm_gem_object *obj; + void *vaddr; + + vaddr = dma_buf_vmap(attach->dmabuf); + if (!vaddr) { + DRM_ERROR("Failed to vmap PRIME buffer\n"); + return ERR_PTR(-ENOMEM); + } + + obj = drm_gem_cma_prime_import_sg_table(drm, attach, sgt); + if (IS_ERR(obj)) { + dma_buf_vunmap(attach->dmabuf, vaddr); + return obj; + } + + cma_obj = to_drm_gem_cma_obj(obj); + cma_obj->vaddr = vaddr; + + return obj; +} +EXPORT_SYMBOL(tinydrm_gem_cma_prime_import_sg_table); + +/** + * tinydrm_gem_cma_free_object - Free resources associated with a CMA GEM + * object + * @gem_obj: GEM object to free + * + * This function frees the backing memory of the CMA GEM object, cleans up the + * GEM object state and frees the memory used to store the object itself using + * drm_gem_cma_free_object(). It also handles PRIME buffers which has the kernel + * virtual address set by tinydrm_gem_cma_prime_import_sg_table(). Drivers + * can use this as their &drm_driver->gem_free_object callback. + */ +void tinydrm_gem_cma_free_object(struct drm_gem_object *gem_obj) +{ + if (gem_obj->import_attach) { + struct drm_gem_cma_object *cma_obj; + + cma_obj = to_drm_gem_cma_obj(gem_obj); + dma_buf_vunmap(gem_obj->import_attach->dmabuf, cma_obj->vaddr); + cma_obj->vaddr = NULL; + } + + drm_gem_cma_free_object(gem_obj); +} +EXPORT_SYMBOL_GPL(tinydrm_gem_cma_free_object); + +const struct file_operations tinydrm_fops = { + .owner = THIS_MODULE, + .open = drm_open, + .release = drm_release, + .unlocked_ioctl = drm_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = drm_compat_ioctl, +#endif + .poll = drm_poll, + .read = drm_read, + .llseek = no_llseek, + .mmap = drm_gem_cma_mmap, +}; +EXPORT_SYMBOL(tinydrm_fops); + +static struct drm_framebuffer * +tinydrm_fb_create(struct drm_device *drm, struct drm_file *file_priv, + const struct drm_mode_fb_cmd2 *mode_cmd) +{ + struct tinydrm_device *tdev = drm->dev_private; + + return drm_fb_cma_create_with_funcs(drm, file_priv, mode_cmd, + tdev->fb_funcs); +} + +static const struct drm_mode_config_funcs tinydrm_mode_config_funcs = { + .fb_create = tinydrm_fb_create, + .atomic_check = drm_atomic_helper_check, + .atomic_commit = drm_atomic_helper_commit, +}; + +static int tinydrm_init(struct device *parent, struct tinydrm_device *tdev, + const struct drm_framebuffer_funcs *fb_funcs, + struct drm_driver *driver) +{ + struct drm_device *drm; + + mutex_init(&tdev->dirty_lock); + tdev->fb_funcs = fb_funcs; + + /* + * We don't embed drm_device, because that prevent us from using + * devm_kzalloc() to allocate tinydrm_device in the driver since + * drm_dev_unref() frees the structure. The devm_ functions provide + * for easy error handling. + */ + drm = drm_dev_alloc(driver, parent); + if (IS_ERR(drm)) + return PTR_ERR(drm); + + tdev->drm = drm; + drm->dev_private = tdev; + drm_mode_config_init(drm); + drm->mode_config.funcs = &tinydrm_mode_config_funcs; + + return 0; +} + +static void tinydrm_fini(struct tinydrm_device *tdev) +{ + drm_mode_config_cleanup(tdev->drm); + mutex_destroy(&tdev->dirty_lock); + tdev->drm->dev_private = NULL; + drm_dev_unref(tdev->drm); +} + +static void devm_tinydrm_release(void *data) +{ + tinydrm_fini(data); +} + +/** + * devm_tinydrm_init - Initialize tinydrm device + * @parent: Parent device object + * @tdev: tinydrm device + * @fb_funcs: Framebuffer functions + * @driver: DRM driver + * + * This function initializes @tdev, the underlying DRM device and it's + * mode_config. Resources will be automatically freed on driver detach (devres) + * using drm_mode_config_cleanup() and drm_dev_unref(). + * + * Returns: + * Zero on success, negative error code on failure. + */ +int devm_tinydrm_init(struct device *parent, struct tinydrm_device *tdev, + const struct drm_framebuffer_funcs *fb_funcs, + struct drm_driver *driver) +{ + int ret; + + ret = tinydrm_init(parent, tdev, fb_funcs, driver); + if (ret) + return ret; + + ret = devm_add_action(parent, devm_tinydrm_release, tdev); + if (ret) + tinydrm_fini(tdev); + + return ret; +} +EXPORT_SYMBOL(devm_tinydrm_init); + +static int tinydrm_register(struct tinydrm_device *tdev) +{ + struct drm_device *drm = tdev->drm; + int bpp = drm->mode_config.preferred_depth; + struct drm_fbdev_cma *fbdev; + int ret; + + ret = drm_dev_register(tdev->drm, 0); + if (ret) + return ret; + + fbdev = drm_fbdev_cma_init_with_funcs(drm, bpp ? bpp : 32, + drm->mode_config.num_connector, + tdev->fb_funcs); + if (IS_ERR(fbdev)) + DRM_ERROR("Failed to initialize fbdev: %ld\n", PTR_ERR(fbdev)); + else + tdev->fbdev_cma = fbdev; + + return 0; +} + +static void tinydrm_unregister(struct tinydrm_device *tdev) +{ + struct drm_fbdev_cma *fbdev_cma = tdev->fbdev_cma; + + drm_crtc_force_disable_all(tdev->drm); + /* don't restore fbdev in lastclose, keep pipeline disabled */ + tdev->fbdev_cma = NULL; + drm_dev_unregister(tdev->drm); + if (fbdev_cma) + drm_fbdev_cma_fini(fbdev_cma); +} + +static void devm_tinydrm_register_release(void *data) +{ + tinydrm_unregister(data); +} + +/** + * devm_tinydrm_register - Register tinydrm device + * @tdev: tinydrm device + * + * This function registers the underlying DRM device and fbdev. + * These resources will be automatically unregistered on driver detach (devres) + * and the display pipeline will be disabled. + * + * Returns: + * Zero on success, negative error code on failure. + */ +int devm_tinydrm_register(struct tinydrm_device *tdev) +{ + struct device *dev = tdev->drm->dev; + int ret; + + ret = tinydrm_register(tdev); + if (ret) + return ret; + + ret = devm_add_action(dev, devm_tinydrm_register_release, tdev); + if (ret) + tinydrm_unregister(tdev); + + return ret; +} +EXPORT_SYMBOL(devm_tinydrm_register); + +/** + * tinydrm_shutdown - Shutdown tinydrm + * @tdev: tinydrm device + * + * This function makes sure that the display pipeline is disabled. + * Used by drivers in their shutdown callback to turn off the display + * on machine shutdown and reboot. + */ +void tinydrm_shutdown(struct tinydrm_device *tdev) +{ + drm_crtc_force_disable_all(tdev->drm); +} +EXPORT_SYMBOL(tinydrm_shutdown); + +/** + * tinydrm_suspend - Suspend tinydrm + * @tdev: tinydrm device + * + * Used in driver PM operations to suspend tinydrm. + * Suspends fbdev and DRM. + * Resume with tinydrm_resume(). + * + * Returns: + * Zero on success, negative error code on failure. + */ +int tinydrm_suspend(struct tinydrm_device *tdev) +{ + struct drm_atomic_state *state; + + if (tdev->suspend_state) { + DRM_ERROR("Failed to suspend: state already set\n"); + return -EINVAL; + } + + drm_fbdev_cma_set_suspend_unlocked(tdev->fbdev_cma, 1); + state = drm_atomic_helper_suspend(tdev->drm); + if (IS_ERR(state)) { + drm_fbdev_cma_set_suspend_unlocked(tdev->fbdev_cma, 0); + return PTR_ERR(state); + } + + tdev->suspend_state = state; + + return 0; +} +EXPORT_SYMBOL(tinydrm_suspend); + +/** + * tinydrm_resume - Resume tinydrm + * @tdev: tinydrm device + * + * Used in driver PM operations to resume tinydrm. + * Suspend with tinydrm_suspend(). + * + * Returns: + * Zero on success, negative error code on failure. + */ +int tinydrm_resume(struct tinydrm_device *tdev) +{ + struct drm_atomic_state *state = tdev->suspend_state; + int ret; + + if (!state) { + DRM_ERROR("Failed to resume: state is not set\n"); + return -EINVAL; + } + + tdev->suspend_state = NULL; + + ret = drm_atomic_helper_resume(tdev->drm, state); + if (ret) { + DRM_ERROR("Error resuming state: %d\n", ret); + return ret; + } + + drm_fbdev_cma_set_suspend_unlocked(tdev->fbdev_cma, 0); + + return 0; +} +EXPORT_SYMBOL(tinydrm_resume); + +MODULE_LICENSE("GPL"); -- cgit v1.2.3