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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /drivers/gpu/drm/tegra/mipi-phy.c | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/gpu/drm/tegra/mipi-phy.c')
-rw-r--r-- | drivers/gpu/drm/tegra/mipi-phy.c | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/drivers/gpu/drm/tegra/mipi-phy.c b/drivers/gpu/drm/tegra/mipi-phy.c new file mode 100644 index 0000000000..4fe05f2df6 --- /dev/null +++ b/drivers/gpu/drm/tegra/mipi-phy.c @@ -0,0 +1,134 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2013 NVIDIA Corporation + */ + +#include <linux/errno.h> +#include <linux/kernel.h> + +#include "mipi-phy.h" + +/* + * Default D-PHY timings based on MIPI D-PHY specification. Derived from the + * valid ranges specified in Section 6.9, Table 14, Page 40 of the D-PHY + * specification (v1.2) with minor adjustments. + */ +int mipi_dphy_timing_get_default(struct mipi_dphy_timing *timing, + unsigned long period) +{ + timing->clkmiss = 0; + timing->clkpost = 70 + 52 * period; + timing->clkpre = 8; + timing->clkprepare = 65; + timing->clksettle = 95; + timing->clktermen = 0; + timing->clktrail = 80; + timing->clkzero = 260; + timing->dtermen = 0; + timing->eot = 0; + timing->hsexit = 120; + timing->hsprepare = 65 + 5 * period; + timing->hszero = 145 + 5 * period; + timing->hssettle = 85 + 6 * period; + timing->hsskip = 40; + + /* + * The MIPI D-PHY specification (Section 6.9, v1.2, Table 14, Page 40) + * contains this formula as: + * + * T_HS-TRAIL = max(n * 8 * period, 60 + n * 4 * period) + * + * where n = 1 for forward-direction HS mode and n = 4 for reverse- + * direction HS mode. There's only one setting and this function does + * not parameterize on anything other that period, so this code will + * assumes that reverse-direction HS mode is supported and uses n = 4. + */ + timing->hstrail = max(4 * 8 * period, 60 + 4 * 4 * period); + + timing->init = 100000; + timing->lpx = 60; + timing->taget = 5 * timing->lpx; + timing->tago = 4 * timing->lpx; + timing->tasure = 2 * timing->lpx; + timing->wakeup = 1000000; + + return 0; +} + +/* + * Validate D-PHY timing according to MIPI D-PHY specification (v1.2, Section + * Section 6.9 "Global Operation Timing Parameters"). + */ +int mipi_dphy_timing_validate(struct mipi_dphy_timing *timing, + unsigned long period) +{ + if (timing->clkmiss > 60) + return -EINVAL; + + if (timing->clkpost < (60 + 52 * period)) + return -EINVAL; + + if (timing->clkpre < 8) + return -EINVAL; + + if (timing->clkprepare < 38 || timing->clkprepare > 95) + return -EINVAL; + + if (timing->clksettle < 95 || timing->clksettle > 300) + return -EINVAL; + + if (timing->clktermen > 38) + return -EINVAL; + + if (timing->clktrail < 60) + return -EINVAL; + + if (timing->clkprepare + timing->clkzero < 300) + return -EINVAL; + + if (timing->dtermen > 35 + 4 * period) + return -EINVAL; + + if (timing->eot > 105 + 12 * period) + return -EINVAL; + + if (timing->hsexit < 100) + return -EINVAL; + + if (timing->hsprepare < 40 + 4 * period || + timing->hsprepare > 85 + 6 * period) + return -EINVAL; + + if (timing->hsprepare + timing->hszero < 145 + 10 * period) + return -EINVAL; + + if ((timing->hssettle < 85 + 6 * period) || + (timing->hssettle > 145 + 10 * period)) + return -EINVAL; + + if (timing->hsskip < 40 || timing->hsskip > 55 + 4 * period) + return -EINVAL; + + if (timing->hstrail < max(8 * period, 60 + 4 * period)) + return -EINVAL; + + if (timing->init < 100000) + return -EINVAL; + + if (timing->lpx < 50) + return -EINVAL; + + if (timing->taget != 5 * timing->lpx) + return -EINVAL; + + if (timing->tago != 4 * timing->lpx) + return -EINVAL; + + if (timing->tasure < timing->lpx || timing->tasure > 2 * timing->lpx) + return -EINVAL; + + if (timing->wakeup < 1000000) + return -EINVAL; + + return 0; +} |