[PATCH OLK-5.10 2/3] drm/stm: ltdc: add support for CRC hashing feature

From: Raphael Gallais-Pou raphael.gallais-pou@foss.st.com

mainline inclusion from mainline-v5.16-rc3 commit 79b44684a14e363d24c299b772f037344ad8c8dc category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAYRAF

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

--------------------------------

This patch adds the CRC hashing feature supported by some recent hardware versions of the LTDC. This is useful for test suite such as IGT-GPU-tools [1] where a CRTC output frame can be compared to a test reference frame thanks to their respective CRC hash.

[1] https://cgit.freedesktop.org/drm/igt-gpu-tools

Signed-off-by: Raphael Gallais-Pou raphael.gallais-pou@foss.st.com Acked-by: Yannick Fertre yannick.fertre@foss.st.com Signed-off-by: Philippe Cornu philippe.cornu@foss.st.com Link: https://patchwork.freedesktop.org/patch/msgid/20220211104620.421177-1-raphae...

Conflicts: drivers/gpu/drm/stm/ltdc.c drivers/gpu/drm/stm/ltdc.h [ context conflicts ] Signed-off-by: Zhang Kunbo zhangkunbo@huawei.com --- drivers/gpu/drm/stm/ltdc.c | 104 +++++++++++++++++++++++++++++++++++-- drivers/gpu/drm/stm/ltdc.h | 3 ++ 2 files changed, 104 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c index cf27622e75ec..8bc86368069b 100644 --- a/drivers/gpu/drm/stm/ltdc.c +++ b/drivers/gpu/drm/stm/ltdc.c @@ -74,6 +74,7 @@ #define LTDC_LIPCR 0x0040 /* Line Interrupt Position Conf. */ #define LTDC_CPSR 0x0044 /* Current Position Status */ #define LTDC_CDSR 0x0048 /* Current Display Status */ +#define LTDC_CCRCR 0x007C /* Computed CRC value */ #define LTDC_FUT 0x0090 /* Fifo underrun Threshold */

/* Layer register offsets */ @@ -118,6 +119,7 @@

#define GCR_LTDCEN BIT(0) /* LTDC ENable */ #define GCR_DEN BIT(16) /* Dither ENable */ +#define GCR_CRCEN BIT(19) /* CRC ENable */ #define GCR_PCPOL BIT(28) /* Pixel Clock POLarity-Inverted */ #define GCR_DEPOL BIT(29) /* Data Enable POLarity-High */ #define GCR_VSPOL BIT(30) /* Vertical Synchro POLarity-High */ @@ -200,6 +202,13 @@

#define NB_PF 8 /* Max nb of HW pixel format */

+/* + * Skip the first value and the second in case CRC was enabled during + * the thread irq. This is to be sure CRC value is relevant for the + * frame. + */ +#define CRC_SKIP_FRAMES 2 + enum ltdc_pix_fmt { PF_NONE, /* RGB formats */ @@ -467,6 +476,26 @@ static inline u32 get_pixelformat_without_alpha(u32 drm) } }

+static inline void ltdc_irq_crc_handle(struct ltdc_device *ldev, + struct drm_crtc *crtc) +{ + u32 crc; + int ret; + + if (ldev->crc_skip_count < CRC_SKIP_FRAMES) { + ldev->crc_skip_count++; + return; + } + + /* Get the CRC of the frame */ + ret = regmap_read(ldev->regmap, LTDC_CCRCR, &crc); + if (ret) + return; + + /* Report to DRM the CRC (hw dependent feature) */ + drm_crtc_add_crc_entry(crtc, true, drm_crtc_accurate_vblank_count(crtc), &crc); +} + static irqreturn_t ltdc_irq_thread(int irq, void *arg) { struct drm_device *ddev = arg; @@ -474,9 +503,14 @@ static irqreturn_t ltdc_irq_thread(int irq, void *arg) struct drm_crtc *crtc = drm_crtc_from_index(ddev, 0);

/* Line IRQ : trigger the vblank event */ - if (ldev->irq_status & ISR_LIF) + if (ldev->irq_status & ISR_LIF) { drm_crtc_handle_vblank(crtc);

+ /* Early return if CRC is not active */ + if (ldev->crc_active) + ltdc_irq_crc_handle(ldev, crtc); + } + /* Save FIFO Underrun & Transfer Error status */ mutex_lock(&ldev->err_lock); if (ldev->irq_status & ISR_FUIF) @@ -840,6 +874,48 @@ static void ltdc_crtc_disable_vblank(struct drm_crtc *crtc) reg_clear(ldev->regs, LTDC_IER, IER_LIE); }

+static int ltdc_crtc_set_crc_source(struct drm_crtc *crtc, const char *source) +{ + struct ltdc_device *ldev = crtc_to_ltdc(crtc); + int ret; + + DRM_DEBUG_DRIVER("\n"); + + if (!crtc) + return -ENODEV; + + if (source && strcmp(source, "auto") == 0) { + ldev->crc_active = true; + ret = regmap_set_bits(ldev->regmap, LTDC_GCR, GCR_CRCEN); + } else if (!source) { + ldev->crc_active = false; + ret = regmap_clear_bits(ldev->regmap, LTDC_GCR, GCR_CRCEN); + } else { + ret = -EINVAL; + } + + ldev->crc_skip_count = 0; + return ret; +} + +static int ltdc_crtc_verify_crc_source(struct drm_crtc *crtc, + const char *source, size_t *values_cnt) +{ + DRM_DEBUG_DRIVER("\n"); + + if (!crtc) + return -ENODEV; + + if (source && strcmp(source, "auto") != 0) { + DRM_DEBUG_DRIVER("Unknown CRC source %s for %s\n", + source, crtc->name); + return -EINVAL; + } + + *values_cnt = 1; + return 0; +} + static const struct drm_crtc_funcs ltdc_crtc_funcs = { .destroy = drm_crtc_cleanup, .set_config = drm_atomic_helper_set_config, @@ -853,6 +929,20 @@ static const struct drm_crtc_funcs ltdc_crtc_funcs = { .gamma_set = drm_atomic_helper_legacy_gamma_set, };

+static const struct drm_crtc_funcs ltdc_crtc_with_crc_support_funcs = { + .destroy = drm_crtc_cleanup, + .set_config = drm_atomic_helper_set_config, + .page_flip = drm_atomic_helper_page_flip, + .reset = drm_atomic_helper_crtc_reset, + .atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state, + .atomic_destroy_state = drm_atomic_helper_crtc_destroy_state, + .enable_vblank = ltdc_crtc_enable_vblank, + .disable_vblank = ltdc_crtc_disable_vblank, + .get_vblank_timestamp = drm_crtc_vblank_helper_get_vblank_timestamp, + .set_crc_source = ltdc_crtc_set_crc_source, + .verify_crc_source = ltdc_crtc_verify_crc_source, +}; + /* * DRM_PLANE */ @@ -1127,8 +1217,13 @@ static int ltdc_crtc_init(struct drm_device *ddev, struct drm_crtc *crtc) return -EINVAL; }

- ret = drm_crtc_init_with_planes(ddev, crtc, primary, NULL, - &ltdc_crtc_funcs, NULL); + /* Init CRTC according to its hardware features */ + if (ldev->caps.crc) + ret = drm_crtc_init_with_planes(ddev, crtc, primary, NULL, + &ltdc_crtc_with_crc_support_funcs, NULL); + else + ret = drm_crtc_init_with_planes(ddev, crtc, primary, NULL, + &ltdc_crtc_funcs, NULL); if (ret) { DRM_ERROR("Can not initialize CRTC\n"); goto cleanup; @@ -1279,6 +1374,7 @@ static int ltdc_get_caps(struct drm_device *ddev) if (ldev->caps.hw_version == HWVER_10200) ldev->caps.pad_max_freq_hz = 65000000; ldev->caps.nb_irq = 2; + ldev->caps.crc = false; break; case HWVER_20101: ldev->caps.layer_ofs = LAY_OFS_0; @@ -1287,6 +1383,7 @@ static int ltdc_get_caps(struct drm_device *ddev) ldev->caps.non_alpha_only_l1 = false; ldev->caps.pad_max_freq_hz = 150000000; ldev->caps.nb_irq = 4; + ldev->caps.crc = false; break; case HWVER_40100: ldev->caps.layer_ofs = LAY_OFS_1; @@ -1295,6 +1392,7 @@ static int ltdc_get_caps(struct drm_device *ddev) ldev->caps.non_alpha_only_l1 = false; ldev->caps.pad_max_freq_hz = 90000000; ldev->caps.nb_irq = 2; + ldev->caps.crc = true; break; default: return -ENODEV; diff --git a/drivers/gpu/drm/stm/ltdc.h b/drivers/gpu/drm/stm/ltdc.h index 55a125f89af6..87a46253e444 100644 --- a/drivers/gpu/drm/stm/ltdc.h +++ b/drivers/gpu/drm/stm/ltdc.h @@ -21,6 +21,7 @@ struct ltdc_caps { bool non_alpha_only_l1; /* non-native no-alpha formats on layer 1 */ int pad_max_freq_hz; /* max frequency supported by pad */ int nb_irq; /* number of hardware interrupts */ + bool crc; /* cyclic redundancy check supported */ };

#define LTDC_MAX_LAYER 4 @@ -39,6 +40,8 @@ struct ltdc_device { u32 irq_status; struct fps_info plane_fpsi[LTDC_MAX_LAYER]; struct drm_atomic_state *suspend_state; + int crc_skip_count; + bool crc_active; };

int ltdc_load(struct drm_device *ddev);