From 070ab1283a57d7bfff5cce9ce58be64b90173a8f Mon Sep 17 00:00:00 2001 From: Noralf Trønnes Date: Wed, 10 Jan 2018 19:59:37 +0100 Subject: drm/tinydrm/mipi-dbi: Add poweron-reset functions MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Split out common poweron-reset functionality. Signed-off-by: Noralf Trønnes Reviewed-by: David Lechner Tested-by: David Lechner Link: https://patchwork.freedesktop.org/patch/msgid/20180110185940.53841-5-noralf@tronnes.org --- drivers/gpu/drm/tinydrm/mipi-dbi.c | 73 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+) (limited to 'drivers/gpu/drm/tinydrm/mipi-dbi.c') diff --git a/drivers/gpu/drm/tinydrm/mipi-dbi.c b/drivers/gpu/drm/tinydrm/mipi-dbi.c index 1c8ef0c4d6d4..3e879d605ed3 100644 --- a/drivers/gpu/drm/tinydrm/mipi-dbi.c +++ b/drivers/gpu/drm/tinydrm/mipi-dbi.c @@ -463,6 +463,7 @@ bool mipi_dbi_display_is_on(struct mipi_dbi *mipi) val &= ~DCS_POWER_MODE_RESERVED_MASK; + /* The poweron/reset value is 08h DCS_POWER_MODE_DISPLAY_NORMAL_MODE */ if (val != (DCS_POWER_MODE_DISPLAY | DCS_POWER_MODE_DISPLAY_NORMAL_MODE | DCS_POWER_MODE_SLEEP_MODE)) return false; @@ -473,6 +474,78 @@ bool mipi_dbi_display_is_on(struct mipi_dbi *mipi) } EXPORT_SYMBOL(mipi_dbi_display_is_on); +static int mipi_dbi_poweron_reset_conditional(struct mipi_dbi *mipi, bool cond) +{ + struct device *dev = mipi->tinydrm.drm->dev; + int ret; + + if (mipi->regulator) { + ret = regulator_enable(mipi->regulator); + if (ret) { + DRM_DEV_ERROR(dev, "Failed to enable regulator (%d)\n", ret); + return ret; + } + } + + if (cond && mipi_dbi_display_is_on(mipi)) + return 1; + + mipi_dbi_hw_reset(mipi); + ret = mipi_dbi_command(mipi, MIPI_DCS_SOFT_RESET); + if (ret) { + DRM_DEV_ERROR(dev, "Failed to send reset command (%d)\n", ret); + if (mipi->regulator) + regulator_disable(mipi->regulator); + return ret; + } + + /* + * If we did a hw reset, we know the controller is in Sleep mode and + * per MIPI DSC spec should wait 5ms after soft reset. If we didn't, + * we assume worst case and wait 120ms. + */ + if (mipi->reset) + usleep_range(5000, 20000); + else + msleep(120); + + return 0; +} + +/** + * mipi_dbi_poweron_reset - MIPI DBI poweron and reset + * @mipi: MIPI DBI structure + * + * This function enables the regulator if used and does a hardware and software + * reset. + * + * Returns: + * Zero on success, or a negative error code. + */ +int mipi_dbi_poweron_reset(struct mipi_dbi *mipi) +{ + return mipi_dbi_poweron_reset_conditional(mipi, false); +} +EXPORT_SYMBOL(mipi_dbi_poweron_reset); + +/** + * mipi_dbi_poweron_conditional_reset - MIPI DBI poweron and conditional reset + * @mipi: MIPI DBI structure + * + * This function enables the regulator if used and if the display is off, it + * does a hardware and software reset. If mipi_dbi_display_is_on() determines + * that the display is on, no reset is performed. + * + * Returns: + * Zero if the controller was reset, 1 if the display was already on, or a + * negative error code. + */ +int mipi_dbi_poweron_conditional_reset(struct mipi_dbi *mipi) +{ + return mipi_dbi_poweron_reset_conditional(mipi, true); +} +EXPORT_SYMBOL(mipi_dbi_poweron_conditional_reset); + #if IS_ENABLED(CONFIG_SPI) /** -- cgit v1.2.3