root/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c
/*
 * Copyright © 2016 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 *
 * Author: Deepak M <m.deepak at intel.com>
 */

#include <drm/drm_mipi_dsi.h>
#include <drm/drm_print.h>
#include <video/mipi_display.h>

#include "intel_display_core.h"
#include "intel_display_types.h"
#include "intel_dsi.h"
#include "intel_dsi_dcs_backlight.h"

#define CONTROL_DISPLAY_BCTRL           (1 << 5)
#define CONTROL_DISPLAY_DD              (1 << 3)
#define CONTROL_DISPLAY_BL              (1 << 2)

#define POWER_SAVE_OFF                  (0 << 0)
#define POWER_SAVE_LOW                  (1 << 0)
#define POWER_SAVE_MEDIUM               (2 << 0)
#define POWER_SAVE_HIGH                 (3 << 0)
#define POWER_SAVE_OUTDOOR_MODE         (4 << 0)

#define PANEL_PWM_MAX_VALUE             0xFF

static u32 dcs_get_backlight(struct intel_connector *connector, enum pipe unused)
{
        struct intel_encoder *encoder = intel_attached_encoder(connector);
        struct intel_dsi *intel_dsi = enc_to_intel_dsi(encoder);
        struct intel_panel *panel = &connector->panel;
        struct mipi_dsi_device *dsi_device;
        u8 data[2] = {};
        enum port port;
        size_t len = panel->backlight.max > U8_MAX ? 2 : 1;

        for_each_dsi_port(port, panel->vbt.dsi.bl_ports) {
                dsi_device = intel_dsi->dsi_hosts[port]->device;
                mipi_dsi_dcs_read(dsi_device, MIPI_DCS_GET_DISPLAY_BRIGHTNESS,
                                  &data, len);
                break;
        }

        return (data[1] << 8) | data[0];
}

static void dcs_set_backlight(const struct drm_connector_state *conn_state, u32 level)
{
        struct intel_dsi *intel_dsi = enc_to_intel_dsi(to_intel_encoder(conn_state->best_encoder));
        struct intel_panel *panel = &to_intel_connector(conn_state->connector)->panel;
        struct mipi_dsi_device *dsi_device;
        u8 data[2] = {};
        enum port port;
        size_t len = panel->backlight.max > U8_MAX ? 2 : 1;
        unsigned long mode_flags;

        if (len == 1) {
                data[0] = level;
        } else {
                data[0] = level >> 8;
                data[1] = level;
        }

        for_each_dsi_port(port, panel->vbt.dsi.bl_ports) {
                dsi_device = intel_dsi->dsi_hosts[port]->device;
                mode_flags = dsi_device->mode_flags;
                dsi_device->mode_flags &= ~MIPI_DSI_MODE_LPM;
                mipi_dsi_dcs_write(dsi_device, MIPI_DCS_SET_DISPLAY_BRIGHTNESS,
                                   &data, len);
                dsi_device->mode_flags = mode_flags;
        }
}

static void dcs_disable_backlight(const struct drm_connector_state *conn_state, u32 level)
{
        struct intel_dsi *intel_dsi = enc_to_intel_dsi(to_intel_encoder(conn_state->best_encoder));
        struct intel_panel *panel = &to_intel_connector(conn_state->connector)->panel;
        struct mipi_dsi_device *dsi_device;
        enum port port;

        dcs_set_backlight(conn_state, 0);

        for_each_dsi_port(port, panel->vbt.dsi.cabc_ports) {
                u8 cabc = POWER_SAVE_OFF;

                dsi_device = intel_dsi->dsi_hosts[port]->device;
                mipi_dsi_dcs_write(dsi_device, MIPI_DCS_WRITE_POWER_SAVE,
                                   &cabc, sizeof(cabc));
        }

        for_each_dsi_port(port, panel->vbt.dsi.bl_ports) {
                u8 ctrl = 0;

                dsi_device = intel_dsi->dsi_hosts[port]->device;

                mipi_dsi_dcs_read(dsi_device, MIPI_DCS_GET_CONTROL_DISPLAY,
                                  &ctrl, sizeof(ctrl));

                ctrl &= ~CONTROL_DISPLAY_BL;
                ctrl &= ~CONTROL_DISPLAY_DD;
                ctrl &= ~CONTROL_DISPLAY_BCTRL;

                mipi_dsi_dcs_write(dsi_device, MIPI_DCS_WRITE_CONTROL_DISPLAY,
                                   &ctrl, sizeof(ctrl));
        }
}

static void dcs_enable_backlight(const struct intel_crtc_state *crtc_state,
                                 const struct drm_connector_state *conn_state, u32 level)
{
        struct intel_dsi *intel_dsi = enc_to_intel_dsi(to_intel_encoder(conn_state->best_encoder));
        struct intel_panel *panel = &to_intel_connector(conn_state->connector)->panel;
        struct mipi_dsi_device *dsi_device;
        enum port port;

        for_each_dsi_port(port, panel->vbt.dsi.bl_ports) {
                u8 ctrl = 0;

                dsi_device = intel_dsi->dsi_hosts[port]->device;

                mipi_dsi_dcs_read(dsi_device, MIPI_DCS_GET_CONTROL_DISPLAY,
                                  &ctrl, sizeof(ctrl));

                ctrl |= CONTROL_DISPLAY_BL;
                ctrl |= CONTROL_DISPLAY_DD;
                ctrl |= CONTROL_DISPLAY_BCTRL;

                mipi_dsi_dcs_write(dsi_device, MIPI_DCS_WRITE_CONTROL_DISPLAY,
                                   &ctrl, sizeof(ctrl));
        }

        for_each_dsi_port(port, panel->vbt.dsi.cabc_ports) {
                u8 cabc = POWER_SAVE_MEDIUM;

                dsi_device = intel_dsi->dsi_hosts[port]->device;
                mipi_dsi_dcs_write(dsi_device, MIPI_DCS_WRITE_POWER_SAVE,
                                   &cabc, sizeof(cabc));
        }

        dcs_set_backlight(conn_state, level);
}

static int dcs_setup_backlight(struct intel_connector *connector,
                               enum pipe unused)
{
        struct intel_display *display = to_intel_display(connector);
        struct intel_panel *panel = &connector->panel;

        if (panel->vbt.backlight.brightness_precision_bits > 8)
                panel->backlight.max = (1 << panel->vbt.backlight.brightness_precision_bits) - 1;
        else
                panel->backlight.max = PANEL_PWM_MAX_VALUE;

        panel->backlight.level = panel->backlight.max;

        drm_dbg_kms(display->drm,
                    "[CONNECTOR:%d:%s] Using DCS for backlight control\n",
                    connector->base.base.id, connector->base.name);

        return 0;
}

static const struct intel_panel_bl_funcs dcs_bl_funcs = {
        .setup = dcs_setup_backlight,
        .enable = dcs_enable_backlight,
        .disable = dcs_disable_backlight,
        .set = dcs_set_backlight,
        .get = dcs_get_backlight,
};

int intel_dsi_dcs_init_backlight_funcs(struct intel_connector *intel_connector)
{
        struct drm_device *dev = intel_connector->base.dev;
        struct intel_encoder *encoder = intel_attached_encoder(intel_connector);
        struct intel_panel *panel = &intel_connector->panel;

        if (panel->vbt.backlight.type != INTEL_BACKLIGHT_DSI_DCS)
                return -ENODEV;

        if (drm_WARN_ON(dev, encoder->type != INTEL_OUTPUT_DSI))
                return -EINVAL;

        panel->backlight.funcs = &dcs_bl_funcs;

        return 0;
}