From mboxrd@z Thu Jan  1 00:00:00 1970
From: philippe.cornu@st.com (Philippe CORNU)
Date: Mon, 3 Jul 2017 09:03:32 +0000
Subject: [PATCH v4 3/6] drm/bridge/synopsys: Add MIPI DSI host controller
 bridge
In-Reply-To: <606ab644-cf54-9e33-94a2-f7fdec2025cf@codeaurora.org>
References: <1497889685-27349-1-git-send-email-philippe.cornu@st.com>
 <1497889685-27349-4-git-send-email-philippe.cornu@st.com>
 <1aad8695-8527-574c-2b99-9efa88216aa8@codeaurora.org>
 <7ff83ef9-dfc1-6b05-ccf1-1637ed4f4bcc@st.com>
 <606ab644-cf54-9e33-94a2-f7fdec2025cf@codeaurora.org>
Message-ID: <bba0d804-f7b9-ddd8-8092-1cf213bdbe5e@st.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org



On 07/03/2017 08:31 AM, Archit Taneja wrote:
> 
> 
> On 06/29/2017 08:13 PM, Philippe CORNU wrote:
>>
>>
>> On 06/28/2017 08:44 AM, Archit Taneja wrote:
>>>
>>>
>>> On 06/19/2017 09:58 PM, Philippe CORNU wrote:
>>>> Add a Synopsys Designware MIPI DSI host DRM bridge driver, based on the
>>>> Rockchip version from rockchip/dw-mipi-dsi.c with phy & bridge APIs.
>>>>
>>>> Signed-off-by: Philippe CORNU <philippe.cornu@st.com>
>>>> ---
>>>>    drivers/gpu/drm/bridge/synopsys/Kconfig       |   6 +
>>>>    drivers/gpu/drm/bridge/synopsys/Makefile      |   2 +
>>>>    drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 976
>>>> ++++++++++++++++++++++++++
>>>>    include/drm/bridge/dw_mipi_dsi.h              |  39 +
>>>>    4 files changed, 1023 insertions(+)
>>>>    create mode 100644 drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
>>>>    create mode 100644 include/drm/bridge/dw_mipi_dsi.h
>>>>
>>>> diff --git a/drivers/gpu/drm/bridge/synopsys/Kconfig
>>>> b/drivers/gpu/drm/bridge/synopsys/Kconfig
>>>> index 40d2827..f00ee26 100644
>>>> --- a/drivers/gpu/drm/bridge/synopsys/Kconfig
>>>> +++ b/drivers/gpu/drm/bridge/synopsys/Kconfig
>>>> @@ -21,3 +21,9 @@ config DRM_DW_HDMI_I2S_AUDIO
>>>>        help
>>>>          Support the I2S Audio interface which is part of the Synopsys
>>>>          Designware HDMI block.
>>>> +
>>>> +config DRM_DW_MIPI_DSI
>>>> +    tristate
>>>> +    select DRM_KMS_HELPER
>>>> +    select DRM_MIPI_DSI
>>>> +    select DRM_PANEL_BRIDGE
>>>> diff --git a/drivers/gpu/drm/bridge/synopsys/Makefile
>>>> b/drivers/gpu/drm/bridge/synopsys/Makefile
>>>> index 17aa7a6..5f57d36 100644
>>>> --- a/drivers/gpu/drm/bridge/synopsys/Makefile
>>>> +++ b/drivers/gpu/drm/bridge/synopsys/Makefile
>>>> @@ -3,3 +3,5 @@
>>>>    obj-$(CONFIG_DRM_DW_HDMI) += dw-hdmi.o
>>>>    obj-$(CONFIG_DRM_DW_HDMI_AHB_AUDIO) += dw-hdmi-ahb-audio.o
>>>>    obj-$(CONFIG_DRM_DW_HDMI_I2S_AUDIO) += dw-hdmi-i2s-audio.o
>>>> +
>>>> +obj-$(CONFIG_DRM_DW_MIPI_DSI) += dw-mipi-dsi.o
>>>> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
>>>> b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
>>>> new file mode 100644
>>>> index 0000000..416ed7f
>>>> --- /dev/null
>>>> +++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
>>>> @@ -0,0 +1,976 @@
>>>> +/*
>>>> + * Copyright (c) 2016, Fuzhou Rockchip Electronics Co., Ltd
>>>> + * Copyright (C) STMicroelectronics SA 2017
>>>> + *
>>>> + * 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.
>>>> + *
>>>> + * Modified by Philippe Cornu <philippe.cornu@st.com>
>>>> + * This generic Synopsys DesignWare MIPI DSI host driver is based 
>>>> on the
>>>> + * Rockchip version from rockchip/dw-mipi-dsi.c with phy & bridge 
>>>> APIs.
>>>> + */
>>>> +
>>>> +#include <linux/clk.h>
>>>> +#include <linux/component.h>
>>>> +#include <linux/iopoll.h>
>>>> +#include <linux/module.h>
>>>> +#include <linux/of_device.h>
>>>> +#include <linux/pm_runtime.h>
>>>> +#include <linux/reset.h>
>>>> +#include <drm/drmP.h>
>>>> +#include <drm/drm_atomic_helper.h>
>>>> +#include <drm/drm_bridge.h>
>>>> +#include <drm/drm_crtc.h>
>>>> +#include <drm/drm_crtc_helper.h>
>>>> +#include <drm/drm_mipi_dsi.h>
>>>> +#include <drm/drm_of.h>
>>>> +#include <drm/bridge/dw_mipi_dsi.h>
>>>> +#include <video/mipi_display.h>
>>>> +
>>>> +#define DSI_VERSION            0x00
>>>> +#define DSI_PWR_UP            0x04
>>>> +#define RESET                0
>>>> +#define POWERUP                BIT(0)
>>>> +
>>>> +#define DSI_CLKMGR_CFG            0x08
>>>> +#define TO_CLK_DIVIDSION(div)        (((div) & 0xff) << 8)
>>>> +#define TX_ESC_CLK_DIVIDSION(div)    (((div) & 0xff) << 0)
>>>> +
>>>> +#define DSI_DPI_VCID            0x0c
>>>> +#define DPI_VID(vid)            (((vid) & 0x3) << 0)
>>>> +
>>>> +#define DSI_DPI_COLOR_CODING        0x10
>>>> +#define EN18_LOOSELY            BIT(8)
>>>> +#define DPI_COLOR_CODING_16BIT_1    0x0
>>>> +#define DPI_COLOR_CODING_16BIT_2    0x1
>>>> +#define DPI_COLOR_CODING_16BIT_3    0x2
>>>> +#define DPI_COLOR_CODING_18BIT_1    0x3
>>>> +#define DPI_COLOR_CODING_18BIT_2    0x4
>>>> +#define DPI_COLOR_CODING_24BIT        0x5
>>>> +
>>>> +#define DSI_DPI_CFG_POL            0x14
>>>> +#define COLORM_ACTIVE_LOW        BIT(4)
>>>> +#define SHUTD_ACTIVE_LOW        BIT(3)
>>>> +#define HSYNC_ACTIVE_LOW        BIT(2)
>>>> +#define VSYNC_ACTIVE_LOW        BIT(1)
>>>> +#define DATAEN_ACTIVE_LOW        BIT(0)
>>>> +
>>>> +#define DSI_DPI_LP_CMD_TIM        0x18
>>>> +#define OUTVACT_LPCMD_TIME(p)        (((p) & 0xff) << 16)
>>>> +#define INVACT_LPCMD_TIME(p)        ((p) & 0xff)
>>>> +
>>>> +#define DSI_DBI_CFG            0x20
>>>> +#define DSI_DBI_CMDSIZE            0x28
>>>> +
>>>> +#define DSI_PCKHDL_CFG            0x2c
>>>> +#define EN_CRC_RX            BIT(4)
>>>> +#define EN_ECC_RX            BIT(3)
>>>> +#define EN_BTA                BIT(2)
>>>> +#define EN_EOTP_RX            BIT(1)
>>>> +#define EN_EOTP_TX            BIT(0)
>>>> +
>>>> +#define DSI_MODE_CFG            0x34
>>>> +#define ENABLE_VIDEO_MODE        0
>>>> +#define ENABLE_CMD_MODE            BIT(0)
>>>> +
>>>> +#define DSI_VID_MODE_CFG        0x38
>>>> +#define FRAME_BTA_ACK            BIT(14)
>>>> +#define ENABLE_LOW_POWER        (0x3f << 8)
>>>> +#define ENABLE_LOW_POWER_MASK        (0x3f << 8)
>>>> +#define VID_MODE_TYPE_NON_BURST_SYNC_PULSES    0x0
>>>> +#define VID_MODE_TYPE_NON_BURST_SYNC_EVENTS    0x1
>>>> +#define VID_MODE_TYPE_BURST            0x2
>>>> +#define VID_MODE_TYPE_MASK            0x3
>>>> +
>>>> +#define DSI_VID_PKT_SIZE        0x3c
>>>> +#define VID_PKT_SIZE(p)            (((p) & 0x3fff) << 0)
>>>> +#define VID_PKT_MAX_SIZE        0x3fff
>>>> +
>>>> +#define DSI_VID_HSA_TIME        0x48
>>>> +#define DSI_VID_HBP_TIME        0x4c
>>>> +#define DSI_VID_HLINE_TIME        0x50
>>>> +#define DSI_VID_VSA_LINES        0x54
>>>> +#define DSI_VID_VBP_LINES        0x58
>>>> +#define DSI_VID_VFP_LINES        0x5c
>>>> +#define DSI_VID_VACTIVE_LINES        0x60
>>>> +#define DSI_CMD_MODE_CFG        0x68
>>>> +#define MAX_RD_PKT_SIZE_LP        BIT(24)
>>>> +#define DCS_LW_TX_LP            BIT(19)
>>>> +#define DCS_SR_0P_TX_LP            BIT(18)
>>>> +#define DCS_SW_1P_TX_LP            BIT(17)
>>>> +#define DCS_SW_0P_TX_LP            BIT(16)
>>>> +#define GEN_LW_TX_LP            BIT(14)
>>>> +#define GEN_SR_2P_TX_LP            BIT(13)
>>>> +#define GEN_SR_1P_TX_LP            BIT(12)
>>>> +#define GEN_SR_0P_TX_LP            BIT(11)
>>>> +#define GEN_SW_2P_TX_LP            BIT(10)
>>>> +#define GEN_SW_1P_TX_LP            BIT(9)
>>>> +#define GEN_SW_0P_TX_LP            BIT(8)
>>>> +#define EN_ACK_RQST            BIT(1)
>>>> +#define EN_TEAR_FX            BIT(0)
>>>> +
>>>> +#define CMD_MODE_ALL_LP            (MAX_RD_PKT_SIZE_LP | \
>>>> +                     DCS_LW_TX_LP | \
>>>> +                     DCS_SR_0P_TX_LP | \
>>>> +                     DCS_SW_1P_TX_LP | \
>>>> +                     DCS_SW_0P_TX_LP | \
>>>> +                     GEN_LW_TX_LP | \
>>>> +                     GEN_SR_2P_TX_LP | \
>>>> +                     GEN_SR_1P_TX_LP | \
>>>> +                     GEN_SR_0P_TX_LP | \
>>>> +                     GEN_SW_2P_TX_LP | \
>>>> +                     GEN_SW_1P_TX_LP | \
>>>> +                     GEN_SW_0P_TX_LP)
>>>> +
>>>> +#define DSI_GEN_HDR            0x6c
>>>> +#define GEN_HDATA(data)            (((data) & 0xffff) << 8)
>>>> +#define GEN_HDATA_MASK            (0xffff << 8)
>>>> +#define GEN_HTYPE(type)            (((type) & 0xff) << 0)
>>>> +#define GEN_HTYPE_MASK            0xff
>>>> +
>>>> +#define DSI_GEN_PLD_DATA        0x70
>>>> +
>>>> +#define DSI_CMD_PKT_STATUS        0x74
>>>> +#define GEN_CMD_EMPTY            BIT(0)
>>>> +#define GEN_CMD_FULL            BIT(1)
>>>> +#define GEN_PLD_W_EMPTY            BIT(2)
>>>> +#define GEN_PLD_W_FULL            BIT(3)
>>>> +#define GEN_PLD_R_EMPTY            BIT(4)
>>>> +#define GEN_PLD_R_FULL            BIT(5)
>>>> +#define GEN_RD_CMD_BUSY            BIT(6)
>>>> +
>>>> +#define DSI_TO_CNT_CFG            0x78
>>>> +#define HSTX_TO_CNT(p)            (((p) & 0xffff) << 16)
>>>> +#define LPRX_TO_CNT(p)            ((p) & 0xffff)
>>>> +
>>>> +#define DSI_BTA_TO_CNT            0x8c
>>>> +#define DSI_LPCLK_CTRL            0x94
>>>> +#define AUTO_CLKLANE_CTRL        BIT(1)
>>>> +#define PHY_TXREQUESTCLKHS        BIT(0)
>>>> +
>>>> +#define DSI_PHY_TMR_LPCLK_CFG        0x98
>>>> +#define PHY_CLKHS2LP_TIME(lbcc)        (((lbcc) & 0x3ff) << 16)
>>>> +#define PHY_CLKLP2HS_TIME(lbcc)        ((lbcc) & 0x3ff)
>>>> +
>>>> +#define DSI_PHY_TMR_CFG            0x9c
>>>> +#define PHY_HS2LP_TIME(lbcc)        (((lbcc) & 0xff) << 24)
>>>> +#define PHY_LP2HS_TIME(lbcc)        (((lbcc) & 0xff) << 16)
>>>> +#define MAX_RD_TIME(lbcc)        ((lbcc) & 0x7fff)
>>>> +
>>>> +#define DSI_PHY_RSTZ            0xa0
>>>> +#define PHY_DISFORCEPLL            0
>>>> +#define PHY_ENFORCEPLL            BIT(3)
>>>> +#define PHY_DISABLECLK            0
>>>> +#define PHY_ENABLECLK            BIT(2)
>>>> +#define PHY_RSTZ            0
>>>> +#define PHY_UNRSTZ            BIT(1)
>>>> +#define PHY_SHUTDOWNZ            0
>>>> +#define PHY_UNSHUTDOWNZ            BIT(0)
>>>> +
>>>> +#define DSI_PHY_IF_CFG            0xa4
>>>> +#define N_LANES(n)            ((((n) - 1) & 0x3) << 0)
>>>> +#define PHY_STOP_WAIT_TIME(cycle)    (((cycle) & 0xff) << 8)
>>>> +
>>>> +#define DSI_PHY_STATUS            0xb0
>>>> +#define LOCK                BIT(0)
>>>> +#define STOP_STATE_CLK_LANE        BIT(2)
>>>> +
>>>> +#define DSI_PHY_TST_CTRL0        0xb4
>>>> +#define PHY_TESTCLK            BIT(1)
>>>> +#define PHY_UNTESTCLK            0
>>>> +#define PHY_TESTCLR            BIT(0)
>>>> +#define PHY_UNTESTCLR            0
>>>> +
>>>> +#define DSI_PHY_TST_CTRL1        0xb8
>>>> +#define PHY_TESTEN            BIT(16)
>>>> +#define PHY_UNTESTEN            0
>>>> +#define PHY_TESTDOUT(n)            (((n) & 0xff) << 8)
>>>> +#define PHY_TESTDIN(n)            (((n) & 0xff) << 0)
>>>> +
>>>> +#define DSI_INT_ST0            0xbc
>>>> +#define DSI_INT_ST1            0xc0
>>>> +#define DSI_INT_MSK0            0xc4
>>>> +#define DSI_INT_MSK1            0xc8
>>>> +
>>>> +#define PHY_STATUS_TIMEOUT_US        10000
>>>> +#define CMD_PKT_STATUS_TIMEOUT_US    20000
>>>> +
>>>> +struct dw_mipi_dsi {
>>>> +    struct drm_bridge bridge;
>>>> +    struct mipi_dsi_host dsi_host;
>>>> +    struct drm_bridge *panel_bridge;
>>>> +    bool is_panel_bridge;
>>>> +    struct device *dev;
>>>> +    void __iomem *base;
>>>> +
>>>> +    struct clk *pclk;
>>>> +
>>>> +    unsigned int lane_mbps; /* per lane */
>>>> +    u32 channel;
>>>> +    u32 lanes;
>>>> +    u32 format;
>>>> +    unsigned long mode_flags;
>>>> +
>>>> +    const struct dw_mipi_dsi_plat_data *plat_data;
>>>> +};
>>>> +
>>>> +/*
>>>> + * The controller should generate 2 frames before
>>>> + * preparing the peripheral.
>>>> + */
>>>> +static void dw_mipi_dsi_wait_for_two_frames(struct drm_display_mode
>>>> *mode)
>>>> +{
>>>> +    int refresh, two_frames;
>>>> +
>>>> +    refresh = drm_mode_vrefresh(mode);
>>>> +    two_frames = DIV_ROUND_UP(MSEC_PER_SEC, refresh) * 2;
>>>> +    msleep(two_frames);
>>>> +}
>>>> +
>>>> +static inline struct dw_mipi_dsi *host_to_dsi(struct mipi_dsi_host
>>>> *host)
>>>> +{
>>>> +    return container_of(host, struct dw_mipi_dsi, dsi_host);
>>>> +}
>>>> +
>>>> +static inline struct dw_mipi_dsi *bridge_to_dsi(struct drm_bridge
>>>> *bridge)
>>>> +{
>>>> +    return container_of(bridge, struct dw_mipi_dsi, bridge);
>>>> +}
>>>> +
>>>> +static inline void dsi_write(struct dw_mipi_dsi *dsi, u32 reg, u32 
>>>> val)
>>>> +{
>>>> +    writel(val, dsi->base + reg);
>>>> +}
>>>> +
>>>> +static inline u32 dsi_read(struct dw_mipi_dsi *dsi, u32 reg)
>>>> +{
>>>> +    return readl(dsi->base + reg);
>>>> +}
>>>> +
>>>> +static int dw_mipi_dsi_host_attach(struct mipi_dsi_host *host,
>>>> +                   struct mipi_dsi_device *device)
>>>> +{
>>>> +    struct dw_mipi_dsi *dsi = host_to_dsi(host);
>>>> +    struct drm_bridge *bridge;
>>>> +    struct drm_panel *panel;
>>>> +    int ret;
>>>> +
>>>> +    if (device->lanes > dsi->plat_data->max_data_lanes) {
>>>> +        dev_err(dsi->dev, "the number of data lanes(%u) is too 
>>>> many\n",
>>>> +            device->lanes);
>>>> +        return -EINVAL;
>>>> +    }
>>>> +
>>>> +    dsi->lanes = device->lanes;
>>>> +    dsi->channel = device->channel;
>>>> +    dsi->format = device->format;
>>>> +    dsi->mode_flags = device->mode_flags;
>>>> +
>>>> +    ret = drm_of_find_panel_or_bridge(host->dev->of_node, 1, 0,
>>>> +                      &panel, &bridge);
>>>> +    if (ret)
>>>> +        return ret;
>>>> +
>>>> +    if (panel) {
>>>> +        bridge = drm_panel_bridge_add(panel, DRM_MODE_CONNECTOR_DSI);
>>>> +        if (IS_ERR(bridge))
>>>> +            return PTR_ERR(bridge);
>>>> +        dsi->is_panel_bridge = true;
>>>> +    }
>>>> +
>>>> +    dsi->panel_bridge = bridge;
>>>> +
>>>> +    return drm_bridge_add(&dsi->bridge);
>>>> +}
>>>> +
>>>> +static int dw_mipi_dsi_host_detach(struct mipi_dsi_host *host,
>>>> +                   struct mipi_dsi_device *device)
>>>> +{
>>>> +    struct dw_mipi_dsi *dsi = host_to_dsi(host);
>>>> +
>>>> +    if (dsi->is_panel_bridge)
>>>> +        drm_panel_bridge_remove(dsi->panel_bridge);
>>>> +
>>>> +    drm_bridge_remove(&dsi->bridge);
>>>> +
>>>> +    return 0;
>>>> +}
>>>> +
>>>> +static void dw_mipi_message_config(struct dw_mipi_dsi *dsi,
>>>> +                   const struct mipi_dsi_msg *msg)
>>>> +{
>>>> +    bool lpm = msg->flags & MIPI_DSI_MSG_USE_LPM;
>>>> +    u32 val = 0;
>>>> +
>>>> +    if (msg->flags & MIPI_DSI_MSG_REQ_ACK)
>>>> +        val |= EN_ACK_RQST;
>>>> +    if (lpm)
>>>> +        val |= CMD_MODE_ALL_LP;
>>>> +
>>>> +    dsi_write(dsi, DSI_LPCLK_CTRL, lpm ? 0 : PHY_TXREQUESTCLKHS);
>>>> +    dsi_write(dsi, DSI_CMD_MODE_CFG, val);
>>>> +}
>>>> +
>>>> +static int dw_mipi_dsi_gen_pkt_hdr_write(struct dw_mipi_dsi *dsi, u32
>>>> hdr_val)
>>>> +{
>>>> +    int ret;
>>>> +    u32 val, mask;
>>>> +
>>>> +    ret = readl_poll_timeout(dsi->base + DSI_CMD_PKT_STATUS,
>>>> +                 val, !(val & GEN_CMD_FULL), 1000,
>>>> +                 CMD_PKT_STATUS_TIMEOUT_US);
>>>> +    if (ret < 0) {
>>>> +        dev_err(dsi->dev, "failed to get available command FIFO\n");
>>>> +        return ret;
>>>> +    }
>>>> +
>>>> +    dsi_write(dsi, DSI_GEN_HDR, hdr_val);
>>>> +
>>>> +    mask = GEN_CMD_EMPTY | GEN_PLD_W_EMPTY;
>>>> +    ret = readl_poll_timeout(dsi->base + DSI_CMD_PKT_STATUS,
>>>> +                 val, (val & mask) == mask,
>>>> +                 1000, CMD_PKT_STATUS_TIMEOUT_US);
>>>> +    if (ret < 0) {
>>>> +        dev_err(dsi->dev, "failed to write command FIFO\n");
>>>> +        return ret;
>>>> +    }
>>>> +
>>>> +    return 0;
>>>> +}
>>>> +
>>>> +static int dw_mipi_dsi_dcs_short_write(struct dw_mipi_dsi *dsi,
>>>> +                       const struct mipi_dsi_msg *msg)
>>>> +{
>>>> +    const u8 *tx_buf = msg->tx_buf;
>>>> +    u16 data = 0;
>>>> +    u32 val;
>>>> +
>>>> +    if (msg->tx_len > 0)
>>>> +        data |= tx_buf[0];
>>>> +    if (msg->tx_len > 1)
>>>> +        data |= tx_buf[1] << 8;
>>>> +
>>>> +    if (msg->tx_len > 2) {
>>>> +        dev_err(dsi->dev, "too long tx buf length %zu for short
>>>> write\n",
>>>> +            msg->tx_len);
>>>> +        return -EINVAL;
>>>> +    }
>>>> +
>>>> +    val = GEN_HDATA(data) | GEN_HTYPE(msg->type);
>>>> +    return dw_mipi_dsi_gen_pkt_hdr_write(dsi, val);
>>>> +}
>>>> +
>>>> +static int dw_mipi_dsi_dcs_long_write(struct dw_mipi_dsi *dsi,
>>>> +                      const struct mipi_dsi_msg *msg)
>>>> +{
>>>> +    const u8 *tx_buf = msg->tx_buf;
>>>> +    int len = msg->tx_len, pld_data_bytes = sizeof(u32), ret;
>>>> +    u32 hdr_val = GEN_HDATA(msg->tx_len) | GEN_HTYPE(msg->type);
>>>> +    u32 remainder;
>>>> +    u32 val;
>>>> +
>>>> +    if (msg->tx_len < 3) {
>>>> +        dev_err(dsi->dev, "wrong tx buf length %zu for long write\n",
>>>> +            msg->tx_len);
>>>> +        return -EINVAL;
>>>> +    }
>>>> +
>>>> +    while (DIV_ROUND_UP(len, pld_data_bytes)) {
>>>> +        if (len < pld_data_bytes) {
>>>> +            remainder = 0;
>>>> +            memcpy(&remainder, tx_buf, len);
>>>> +            dsi_write(dsi, DSI_GEN_PLD_DATA, remainder);
>>>> +            len = 0;
>>>> +        } else {
>>>> +            memcpy(&remainder, tx_buf, pld_data_bytes);
>>>> +            dsi_write(dsi, DSI_GEN_PLD_DATA, remainder);
>>>> +            tx_buf += pld_data_bytes;
>>>> +            len -= pld_data_bytes;
>>>> +        }
>>>> +
>>>> +        ret = readl_poll_timeout(dsi->base + DSI_CMD_PKT_STATUS,
>>>> +                     val, !(val & GEN_PLD_W_FULL), 1000,
>>>> +                     CMD_PKT_STATUS_TIMEOUT_US);
>>>> +        if (ret < 0) {
>>>> +            dev_err(dsi->dev,
>>>> +                "failed to get available write payload FIFO\n");
>>>> +            return ret;
>>>> +        }
>>>> +    }
>>>> +
>>>> +    return dw_mipi_dsi_gen_pkt_hdr_write(dsi, hdr_val);
>>>> +}
>>>> +
>>>> +static ssize_t dw_mipi_dsi_host_transfer(struct mipi_dsi_host *host,
>>>> +                     const struct mipi_dsi_msg *msg)
>>>> +{
>>>> +    struct dw_mipi_dsi *dsi = host_to_dsi(host);
>>>> +    int ret;
>>>> +
>>>> +    /*
>>>> +     * TODO dw drv improvements
>>>> +     * use mipi_dsi_create_packet() instead of all following
>>>> +     * functions and code (no switch cases, no
>>>> +     * dw_mipi_dsi_dcs_short_write(), only the loop in long_write...)
>>>> +     * and use packet.header...
>>>> +     */
>>>> +    dw_mipi_message_config(dsi, msg);
>>>> +
>>>> +    switch (msg->type) {
>>>> +    case MIPI_DSI_DCS_SHORT_WRITE:
>>>> +    case MIPI_DSI_DCS_SHORT_WRITE_PARAM:
>>>> +    case MIPI_DSI_SET_MAXIMUM_RETURN_PACKET_SIZE:
>>>> +        ret = dw_mipi_dsi_dcs_short_write(dsi, msg);
>>>> +        break;
>>>> +    case MIPI_DSI_DCS_LONG_WRITE:
>>>> +        ret = dw_mipi_dsi_dcs_long_write(dsi, msg);
>>>> +        break;
>>>> +    default:
>>>> +        dev_err(dsi->dev, "unsupported message type 0x%02x\n",
>>>> +            msg->type);
>>>> +        ret = -EINVAL;
>>>> +    }
>>>> +
>>>> +    return ret;
>>>> +}
>>>> +
>>>> +static const struct mipi_dsi_host_ops dw_mipi_dsi_host_ops = {
>>>> +    .attach = dw_mipi_dsi_host_attach,
>>>> +    .detach = dw_mipi_dsi_host_detach,
>>>> +    .transfer = dw_mipi_dsi_host_transfer,
>>>> +};
>>>> +
>>>> +static void dw_mipi_dsi_video_mode_config(struct dw_mipi_dsi *dsi)
>>>> +{
>>>> +    u32 val;
>>>> +
>>>> +    /*
>>>> +     * TODO dw drv improvements
>>>> +     * enabling low power is panel-dependent, we should use the
>>>> +     * panel configuration here...
>>>> +     */
>>>> +    val = ENABLE_LOW_POWER;
>>>> +
>>>> +    if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO_BURST)
>>>> +        val |= VID_MODE_TYPE_BURST;
>>>> +    else if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE)
>>>> +        val |= VID_MODE_TYPE_NON_BURST_SYNC_PULSES;
>>>> +    else
>>>> +        val |= VID_MODE_TYPE_NON_BURST_SYNC_EVENTS;
>>>> +
>>>> +    dsi_write(dsi, DSI_VID_MODE_CFG, val);
>>>> +}
>>>> +
>>>> +static void dw_mipi_dsi_set_mode(struct dw_mipi_dsi *dsi,
>>>> +                 unsigned long mode_flags)
>>>> +{
>>>> +    dsi_write(dsi, DSI_PWR_UP, RESET);
>>>> +
>>>> +    if (mode_flags & MIPI_DSI_MODE_VIDEO) {
>>>> +        dsi_write(dsi, DSI_MODE_CFG, ENABLE_VIDEO_MODE);
>>>> +        dw_mipi_dsi_video_mode_config(dsi);
>>>> +        dsi_write(dsi, DSI_LPCLK_CTRL, PHY_TXREQUESTCLKHS);
>>>> +    } else {
>>>> +        dsi_write(dsi, DSI_MODE_CFG, ENABLE_CMD_MODE);
>>>> +    }
>>>> +
>>>> +    dsi_write(dsi, DSI_PWR_UP, POWERUP);
>>>> +}
>>>> +
>>>> +static void dw_mipi_dsi_disable(struct dw_mipi_dsi *dsi)
>>>> +{
>>>> +    dsi_write(dsi, DSI_PWR_UP, RESET);
>>>> +    dsi_write(dsi, DSI_PHY_RSTZ, PHY_RSTZ);
>>>> +}
>>>> +
>>>> +static void dw_mipi_dsi_init(struct dw_mipi_dsi *dsi)
>>>> +{
>>>> +    /*
>>>> +     * The maximum permitted escape clock is 20MHz and it is derived
>>>> from
>>>> +     * lanebyteclk, which is running at "lane_mbps / 8".  Thus we 
>>>> want:
>>>> +     *
>>>> +     *     (lane_mbps >> 3) / esc_clk_division < 20
>>>> +     * which is:
>>>> +     *     (lane_mbps >> 3) / 20 > esc_clk_division
>>>> +     */
>>>> +    u32 esc_clk_division = (dsi->lane_mbps >> 3) / 20 + 1;
>>>> +
>>>> +    dsi_write(dsi, DSI_PWR_UP, RESET);
>>>> +
>>>> +    /*
>>>> +     * TODO dw drv improvements
>>>> +     * timeout clock division should be computed with the
>>>> +     * high speed transmission counter timeout and byte lane...
>>>> +     */
>>>> +    dsi_write(dsi, DSI_CLKMGR_CFG, TO_CLK_DIVIDSION(10) |
>>>> +          TX_ESC_CLK_DIVIDSION(esc_clk_division));
>>>> +}
>>>> +
>>>> +static void dw_mipi_dsi_dpi_config(struct dw_mipi_dsi *dsi,
>>>> +                   struct drm_display_mode *mode)
>>>> +{
>>>> +    u32 val = 0, color = 0;
>>>> +
>>>> +    switch (dsi->format) {
>>>> +    case MIPI_DSI_FMT_RGB888:
>>>> +        color = DPI_COLOR_CODING_24BIT;
>>>> +        break;
>>>> +    case MIPI_DSI_FMT_RGB666:
>>>> +        color = DPI_COLOR_CODING_18BIT_2 | EN18_LOOSELY;
>>>> +        break;
>>>> +    case MIPI_DSI_FMT_RGB666_PACKED:
>>>> +        color = DPI_COLOR_CODING_18BIT_1;
>>>> +        break;
>>>> +    case MIPI_DSI_FMT_RGB565:
>>>> +        color = DPI_COLOR_CODING_16BIT_1;
>>>> +        break;
>>>> +    }
>>>> +
>>>> +    if (mode->flags & DRM_MODE_FLAG_NVSYNC)
>>>> +        val |= VSYNC_ACTIVE_LOW;
>>>> +    if (mode->flags & DRM_MODE_FLAG_NHSYNC)
>>>> +        val |= HSYNC_ACTIVE_LOW;
>>>> +
>>>> +    dsi_write(dsi, DSI_DPI_VCID, DPI_VID(dsi->channel));
>>>> +    dsi_write(dsi, DSI_DPI_COLOR_CODING, color);
>>>> +    dsi_write(dsi, DSI_DPI_CFG_POL, val);
>>>> +    /*
>>>> +     * TODO dw drv improvements
>>>> +     * largest packet sizes during hfp or during vsa/vpb/vfp
>>>> +     * should be computed according to byte lane, lane number and only
>>>> +     * if sending lp cmds in high speed is enable (PHY_TXREQUESTCLKHS)
>>>> +     */
>>>> +    dsi_write(dsi, DSI_DPI_LP_CMD_TIM, OUTVACT_LPCMD_TIME(4)
>>>> +          | INVACT_LPCMD_TIME(4));
>>>> +}
>>>> +
>>>> +static void dw_mipi_dsi_packet_handler_config(struct dw_mipi_dsi *dsi)
>>>> +{
>>>> +    dsi_write(dsi, DSI_PCKHDL_CFG, EN_CRC_RX | EN_ECC_RX | EN_BTA);
>>>> +}
>>>> +
>>>> +static void dw_mipi_dsi_video_packet_config(struct dw_mipi_dsi *dsi,
>>>> +                        struct drm_display_mode *mode)
>>>> +{
>>>> +    /*
>>>> +     * TODO dw drv improvements
>>>> +     * only burst mode is supported here. For non-burst video modes,
>>>> +     * we should compute DSI_VID_PKT_SIZE, DSI_VCCR.NUMC &
>>>> +     * DSI_VNPCR.NPSIZE... especially because this driver supports
>>>> +     * non-burst video modes, see dw_mipi_dsi_video_mode_config()...
>>>> +     */
>>>> +    dsi_write(dsi, DSI_VID_PKT_SIZE, VID_PKT_SIZE(mode->hdisplay));
>>>> +}
>>>> +
>>>> +static void dw_mipi_dsi_command_mode_config(struct dw_mipi_dsi *dsi)
>>>> +{
>>>> +    /*
>>>> +     * TODO dw drv improvements
>>>> +     * compute high speed transmission counter timeout according
>>>> +     * to the timeout clock division (TO_CLK_DIVIDSION) and byte 
>>>> lane...
>>>> +     */
>>>> +    dsi_write(dsi, DSI_TO_CNT_CFG, HSTX_TO_CNT(1000) |
>>>> LPRX_TO_CNT(1000));
>>>> +    /*
>>>> +     * TODO dw drv improvements
>>>> +     * the Bus-Turn-Around Timeout Counter should be computed
>>>> +     * according to byte lane...
>>>> +     */
>>>> +    dsi_write(dsi, DSI_BTA_TO_CNT, 0xd00);
>>>> +    dsi_write(dsi, DSI_MODE_CFG, ENABLE_CMD_MODE);
>>>> +}
>>>> +
>>>> +/* Get lane byte clock cycles. */
>>>> +static u32 dw_mipi_dsi_get_hcomponent_lbcc(struct dw_mipi_dsi *dsi,
>>>> +                       struct drm_display_mode *mode,
>>>> +                       u32 hcomponent)
>>>> +{
>>>> +    u32 frac, lbcc;
>>>> +
>>>> +    lbcc = hcomponent * dsi->lane_mbps * MSEC_PER_SEC / 8;
>>>> +
>>>> +    frac = lbcc % mode->clock;
>>>> +    lbcc = lbcc / mode->clock;
>>>> +    if (frac)
>>>> +        lbcc++;
>>>> +
>>>> +    return lbcc;
>>>> +}
>>>> +
>>>> +static void dw_mipi_dsi_line_timer_config(struct dw_mipi_dsi *dsi,
>>>> +                      struct drm_display_mode *mode)
>>>> +{
>>>> +    u32 htotal, hsa, hbp, lbcc;
>>>> +
>>>> +    htotal = mode->htotal;
>>>> +    hsa = mode->hsync_end - mode->hsync_start;
>>>> +    hbp = mode->htotal - mode->hsync_end;
>>>> +
>>>> +    /*
>>>> +     * TODO dw drv improvements
>>>> +     * computations below may be improved...
>>>> +     */
>>>> +    lbcc = dw_mipi_dsi_get_hcomponent_lbcc(dsi, mode, htotal);
>>>> +    dsi_write(dsi, DSI_VID_HLINE_TIME, lbcc);
>>>> +
>>>> +    lbcc = dw_mipi_dsi_get_hcomponent_lbcc(dsi, mode, hsa);
>>>> +    dsi_write(dsi, DSI_VID_HSA_TIME, lbcc);
>>>> +
>>>> +    lbcc = dw_mipi_dsi_get_hcomponent_lbcc(dsi, mode, hbp);
>>>> +    dsi_write(dsi, DSI_VID_HBP_TIME, lbcc);
>>>> +}
>>>> +
>>>> +static void dw_mipi_dsi_vertical_timing_config(struct dw_mipi_dsi 
>>>> *dsi,
>>>> +                           struct drm_display_mode *mode)
>>>> +{
>>>> +    u32 vactive, vsa, vfp, vbp;
>>>> +
>>>> +    vactive = mode->vdisplay;
>>>> +    vsa = mode->vsync_end - mode->vsync_start;
>>>> +    vfp = mode->vsync_start - mode->vdisplay;
>>>> +    vbp = mode->vtotal - mode->vsync_end;
>>>> +
>>>> +    dsi_write(dsi, DSI_VID_VACTIVE_LINES, vactive);
>>>> +    dsi_write(dsi, DSI_VID_VSA_LINES, vsa);
>>>> +    dsi_write(dsi, DSI_VID_VFP_LINES, vfp);
>>>> +    dsi_write(dsi, DSI_VID_VBP_LINES, vbp);
>>>> +}
>>>> +
>>>> +static void dw_mipi_dsi_dphy_timing_config(struct dw_mipi_dsi *dsi)
>>>> +{
>>>> +    /*
>>>> +     * TODO dw drv improvements
>>>> +     * data & clock lane timers should be computed according to panel
>>>> +     * blankings and to the automatic clock lane control mode...
>>>> +     * note: DSI_PHY_TMR_CFG.MAX_RD_TIME should be in line with
>>>> +     * DSI_CMD_MODE_CFG.MAX_RD_PKT_SIZE_LP (see CMD_MODE_ALL_LP)
>>>> +     */
>>>> +    dsi_write(dsi, DSI_PHY_TMR_CFG, PHY_HS2LP_TIME(0x40)
>>>> +          | PHY_LP2HS_TIME(0x40) | MAX_RD_TIME(10000));
>>>> +
>>>> +    dsi_write(dsi, DSI_PHY_TMR_LPCLK_CFG, PHY_CLKHS2LP_TIME(0x40)
>>>> +          | PHY_CLKLP2HS_TIME(0x40));
>>>> +}
>>>> +
>>>> +static void dw_mipi_dsi_dphy_interface_config(struct dw_mipi_dsi *dsi)
>>>> +{
>>>> +    /*
>>>> +     * TODO dw drv improvements
>>>> +     * stop wait time should be the maximum between host dsi
>>>> +     * and panel stop wait times
>>>> +     */
>>>> +    dsi_write(dsi, DSI_PHY_IF_CFG, PHY_STOP_WAIT_TIME(0x20) |
>>>> +          N_LANES(dsi->lanes));
>>>> +}
>>>> +
>>>> +static void dw_mipi_dsi_dphy_init(struct dw_mipi_dsi *dsi)
>>>> +{
>>>> +    /* Clear PHY state */
>>>> +    dsi_write(dsi, DSI_PHY_RSTZ, PHY_DISFORCEPLL | PHY_DISABLECLK
>>>> +          | PHY_RSTZ | PHY_SHUTDOWNZ);
>>>> +    dsi_write(dsi, DSI_PHY_TST_CTRL0, PHY_UNTESTCLR);
>>>> +    dsi_write(dsi, DSI_PHY_TST_CTRL0, PHY_TESTCLR);
>>>> +    dsi_write(dsi, DSI_PHY_TST_CTRL0, PHY_UNTESTCLR);
>>>> +}
>>>> +
>>>> +static void dw_mipi_dsi_dphy_enable(struct dw_mipi_dsi *dsi)
>>>> +{
>>>> +    u32 val;
>>>> +    int ret;
>>>> +
>>>> +    dsi_write(dsi, DSI_PHY_RSTZ, PHY_ENFORCEPLL | PHY_ENABLECLK |
>>>> +          PHY_UNRSTZ | PHY_UNSHUTDOWNZ);
>>>> +
>>>> +    ret = readl_poll_timeout(dsi->base + DSI_PHY_STATUS,
>>>> +                 val, val & LOCK, 1000, PHY_STATUS_TIMEOUT_US);
>>>> +    if (ret < 0)
>>>> +        DRM_DEBUG_DRIVER("failed to wait phy lock state\n");
>>>> +
>>>> +    ret = readl_poll_timeout(dsi->base + DSI_PHY_STATUS,
>>>> +                 val, val & STOP_STATE_CLK_LANE, 1000,
>>>> +                 PHY_STATUS_TIMEOUT_US);
>>>> +    if (ret < 0)
>>>> +        DRM_DEBUG_DRIVER("failed to wait phy clk lane stop state\n");
>>>> +}
>>>> +
>>>> +static void dw_mipi_dsi_clear_err(struct dw_mipi_dsi *dsi)
>>>> +{
>>>> +    dsi_read(dsi, DSI_INT_ST0);
>>>> +    dsi_read(dsi, DSI_INT_ST1);
>>>> +    dsi_write(dsi, DSI_INT_MSK0, 0);
>>>> +    dsi_write(dsi, DSI_INT_MSK1, 0);
>>>> +}
>>>> +
>>>> +static void dw_mipi_dsi_bridge_post_disable(struct drm_bridge *bridge)
>>>> +{
>>>> +    struct dw_mipi_dsi *dsi = bridge_to_dsi(bridge);
>>>> +
>>>> +    /*
>>>> +     * Switch to cmd mode before panel-bridge disable & panel 
>>>> unprepare.
>>>> +     * Note: panel-bridge disable & panel disable has been called
>>>> +     * before by the drm framework.
>>>
>>> I don't think that's exactly the case. I think the sequence should be as
>>> in the
>>> call chain below.
>>>
>>
>> Hi Archit,
>> And many thanks for your comments :-)
>> the word "post_" is missing in the above comment, sorry for that. I
>> should have written "Switch to cmd mode before panel-bridge post_disable
>> & ..." that is much more correct I think, I will update this comment for
>> v5 : )
>>
>>
>>>> +     */
>>>> +    dw_mipi_dsi_set_mode(dsi, 0);
>>>> +
>>>> +    /*
>>>> +     * TODO Only way found to call panel-bridge disable & panel
>>>> unprepare
>>>> +     * before the dsi "final" disable... can we do better?
>>>
>>> I agree, this is a problem. More below.
>>
>> Same remark here, I forgot "post_" in the above comment.
>>
>>>
>>>> +     */
>>>> +    drm_bridge_post_disable(dsi->panel_bridge);
>>>> +
>>>
>>> I'm guessing our display chain is something like:
>>>
>>> KMS_encoder -> DW_DSI_bridge -> Panel_bridge -> Panel
>>>
>>> The order in which the disable ops are called:
>>>
>>> drm_bridge_disable(Panel_bridge)
>>>     - drm_panel_disable(Panel)
>>> drm_bridge_disable(DW_DSI_bridge)
>>> encoder_funcs->prepare(KMS_encoder)
>>> drm_bridge_post_disable(DW_DSI_bridge)
>>> drm_bridge_post_disable(Panel_bridge)
>>>     - drm_panel_unprepare(Panel)
>>>
>>
>> 100%-perfect sequence, I do agree with you : )
>>
>>> Assuming that only drm_panel_unprepare() requires sending DSI commands,
>>
>> Well, it really depends on DSI panels. For instance, panel drivers can
>> send DCS/Generic DSI commands:
>> * in drm_panel_disable(): then these commands are sent during blankings,
>> many lcds allow that. This is the proper place for backlight through DSI
>> (dimming or off), for sleep mode DCS commands...
>>
>> or/and
>>
>> * in drm_panel_unprepare(): then these commands are sent during a
>> "command mode" phase. This is the proper place for many things, from
>> backlight off through DSI, sleep mode DCS commands... to a full power
>> off (voltage regulators are switched off).
>>
>>   From my pov, both drm_panel_disable() & drm_panel_unprepare() may send
>> DSI commands... but it is not a real problem in fact as DSI commands can
>> be sent through blankings in video mode or can be sent in "command 
>> mode"...
>>
>>> you could have
>>> switched to command mode in DW_DSI_bridge's disable() op, and do the
>>> "final" DSI disable
>>> in DW_DSI_bridge's post_disable(), but that would still result in
>>> drm_panel_unprepare()
>>> being called with the DSI host dead.
>>>
>>> The existing call chain of consecutive bridges is the most symmetric
>>> one, and the one
>>> expected to work in most cases, but it clearly doesn't work in your use
>>> case.
>>>
>>> We have a few options:
>>>
>>> - Undo the drm-panel-bridge stuff, and have the freedom of calling
>>> drm_panel ops in
>>> whatever order we want.
>>>
>>> - Put a big TODO/HACK comment here, saying that this needs to be fixed
>>> in the drm_bridge
>>> framework and the API needs to be updated to manage our own call chains.
>>> Also,
>>> instead of calling "drm_bridge_post_disable(dsi->panel_bridge);"
>>> explicitly, we
>>> can manually call panel_bridge->post_disable() op directly. This avoids
>>> us doing
>>> things recursively.
>>>
>>> We would implement the TODO task in drm_bridges only when there are more
>>> people
>>> desperately in the need to have customizable call chains of bridge ops
>>> for long
>>> display chains, so I don't see it being implemented in the near future,
>>> but I don't
>>> think there should be any problem keeping this hack in the dw dsi driver
>>> for now.
>>>
>>> What choice do you prefer?
>>
>> Well, not so easy to decide what could be the best solution...
>>
>> For the time being, I think I prefer keeping the panel bridge proposal
>> (the v4 one), for several reasons in fact:
>>
>> * It saves "many" lines of code, and supporting *both* panels & bridges
>> (homogeneous approach).
>>
>> * It helps reducing explicit calls like drm_panel_() or drm_bridge_()
>> letting the drm framework doing its job :-)
>>
>> * It is not an issue to have a TODO/HACK for the only remaining function
>> call (drm_bridge_post_disable() here). I mean many others drivers calls
>> directly these panel & bridge functions and this forces panel drivers to
>> have in many places in their code "if (enabled) return;" or "if
>> (prepared) return;" and we should work in the future to improve that
>> (ie. Let's drm framework doing its job).
>>
>> * It covers/offers the 3 important "hw disable" phases:
>>     - panel sends DCS/Generic DSI commands during its blankings in a 
>> video
>> mode phase (most of the times, these commands are short, for backlight
>> updates or sleep for instance...), it's correspond to panel_disable().
>>     - panel sends DCS/Generic DSI commands in a command mode phase 
>> (sleep,
>> power off...), it's correspond to panel_unprepare().
>>     - the dsi IP is stopped after the 2 previous phases.
>>
>> So, for all these reasons, I prefer the "Put a big TODO/HACK" option :)
> 
> Sure. For v5, could you consider calling
> panel_bridge->funcs->post_disable() op directly instead of calling
> "drm_bridge_post_disable(dsi->panel_bridge);"? The hack would be more 
> legible,
> and we'd avoid unnecessary recursive chains.
> 
> Thanks,
> Archit
> 

Hi Archit,
I sent the v5 taking into account your comments.
Many thanks : )
Philippe

>>
>> Thank you,
>> Philippe
>>
>>>
>>> Eric, Daniel,
>>>
>>> Fyi, this is another case where the panel-bridge stuff doesn't work so
>>> well. Not
>>> criticizing or anything, just pointing out :)
>>>
>>> Archit
>>>
>>>
>>>> +    dw_mipi_dsi_disable(dsi);
>>>> +    clk_disable_unprepare(dsi->pclk);
>>>> +    pm_runtime_put(dsi->dev);
>>>> +}
>>>> +
>>>> +void dw_mipi_dsi_bridge_mode_set(struct drm_bridge *bridge,
>>>> +                 struct drm_display_mode *mode,
>>>> +                 struct drm_display_mode *adjusted_mode)
>>>> +{
>>>> +    struct dw_mipi_dsi *dsi = bridge_to_dsi(bridge);
>>>> +    const struct dw_mipi_dsi_phy_ops *phy_ops = 
>>>> dsi->plat_data->phy_ops;
>>>> +    void *priv_data = dsi->plat_data->priv_data;
>>>> +    int ret;
>>>> +
>>>> +    clk_prepare_enable(dsi->pclk);
>>>> +
>>>> +    ret = phy_ops->get_lane_mbps(priv_data, mode, dsi->mode_flags,
>>>> +                     dsi->lanes, dsi->format, &dsi->lane_mbps);
>>>> +    if (ret)
>>>> +        DRM_DEBUG_DRIVER("Phy get_lane_mbps() failed\n");
>>>> +
>>>> +    pm_runtime_get_sync(dsi->dev);
>>>> +    dw_mipi_dsi_init(dsi);
>>>> +    dw_mipi_dsi_dpi_config(dsi, mode);
>>>> +    dw_mipi_dsi_packet_handler_config(dsi);
>>>> +    dw_mipi_dsi_video_mode_config(dsi);
>>>> +    dw_mipi_dsi_video_packet_config(dsi, mode);
>>>> +    dw_mipi_dsi_command_mode_config(dsi);
>>>> +    dw_mipi_dsi_line_timer_config(dsi, mode);
>>>> +    dw_mipi_dsi_vertical_timing_config(dsi, mode);
>>>> +
>>>> +    dw_mipi_dsi_dphy_init(dsi);
>>>> +    dw_mipi_dsi_dphy_timing_config(dsi);
>>>> +    dw_mipi_dsi_dphy_interface_config(dsi);
>>>> +
>>>> +    dw_mipi_dsi_clear_err(dsi);
>>>> +
>>>> +    ret = phy_ops->init(priv_data);
>>>> +    if (ret)
>>>> +        DRM_DEBUG_DRIVER("Phy init() failed\n");
>>>> +
>>>> +    dw_mipi_dsi_dphy_enable(dsi);
>>>> +
>>>> +    dw_mipi_dsi_wait_for_two_frames(mode);
>>>> +
>>>> +    /* Switch to cmd mode for panel-bridge pre_enable & panel 
>>>> prepare */
>>>> +    dw_mipi_dsi_set_mode(dsi, 0);
>>>> +}
>>>> +
>>>> +static void dw_mipi_dsi_bridge_enable(struct drm_bridge *bridge)
>>>> +{
>>>> +    struct dw_mipi_dsi *dsi = bridge_to_dsi(bridge);
>>>> +
>>>> +    /* Switch to video mode for panel-bridge enable & panel enable */
>>>> +    dw_mipi_dsi_set_mode(dsi, MIPI_DSI_MODE_VIDEO);
>>>> +}
>>>> +
>>>> +static enum drm_mode_status
>>>> +dw_mipi_dsi_bridge_mode_valid(struct drm_bridge *bridge,
>>>> +                  const struct drm_display_mode *mode)
>>>> +{
>>>> +    struct dw_mipi_dsi *dsi = bridge_to_dsi(bridge);
>>>> +    const struct dw_mipi_dsi_plat_data *pdata = dsi->plat_data;
>>>> +    enum drm_mode_status mode_status = MODE_OK;
>>>> +
>>>> +    if (pdata->mode_valid)
>>>> +        mode_status = pdata->mode_valid(pdata->priv_data, mode);
>>>> +
>>>> +    return mode_status;
>>>> +}
>>>> +
>>>> +static int dw_mipi_dsi_bridge_attach(struct drm_bridge *bridge)
>>>> +{
>>>> +    struct dw_mipi_dsi *dsi = bridge_to_dsi(bridge);
>>>> +
>>>> +    if (!bridge->encoder) {
>>>> +        DRM_ERROR("Parent encoder object not found\n");
>>>> +        return -ENODEV;
>>>> +    }
>>>> +
>>>> +    /* Set the encoder type as caller does not know it */
>>>> +    bridge->encoder->encoder_type = DRM_MODE_ENCODER_DSI;
>>>> +
>>>> +    /* Attach the panel-bridge to the dsi bridge */
>>>> +    return drm_bridge_attach(bridge->encoder, dsi->panel_bridge,
>>>> bridge);
>>>> +}
>>>> +
>>>> +static struct drm_bridge_funcs dw_mipi_dsi_bridge_funcs = {
>>>> +    .mode_set     = dw_mipi_dsi_bridge_mode_set,
>>>> +    .enable          = dw_mipi_dsi_bridge_enable,
>>>> +    .post_disable = dw_mipi_dsi_bridge_post_disable,
>>>> +    .mode_valid   = dw_mipi_dsi_bridge_mode_valid,
>>>> +    .attach          = dw_mipi_dsi_bridge_attach,
>>>> +};
>>>> +
>>>> +static struct dw_mipi_dsi *
>>>> +__dw_mipi_dsi_probe(struct platform_device *pdev,
>>>> +            const struct dw_mipi_dsi_plat_data *plat_data)
>>>> +{
>>>> +    struct device *dev = &pdev->dev;
>>>> +    struct reset_control *apb_rst;
>>>> +    struct dw_mipi_dsi *dsi;
>>>> +    struct resource *res;
>>>> +    int ret;
>>>> +
>>>> +    dsi = devm_kzalloc(dev, sizeof(*dsi), GFP_KERNEL);
>>>> +    if (!dsi)
>>>> +        return ERR_PTR(-ENOMEM);
>>>> +
>>>> +    dsi->dev = dev;
>>>> +    dsi->plat_data = plat_data;
>>>> +
>>>> +    if (!plat_data->phy_ops->init ||
>>>> !plat_data->phy_ops->get_lane_mbps) {
>>>> +        DRM_ERROR("Phy not properly configured\n");
>>>> +        return ERR_PTR(-ENODEV);
>>>> +    }
>>>> +
>>>> +    if (!plat_data->base) {
>>>> +        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>>> +        if (!res)
>>>> +            return ERR_PTR(-ENODEV);
>>>> +
>>>> +        dsi->base = devm_ioremap_resource(dev, res);
>>>> +        if (IS_ERR(dsi->base))
>>>> +            return ERR_PTR(-ENODEV);
>>>> +
>>>> +    } else {
>>>> +        dsi->base = plat_data->base;
>>>> +    }
>>>> +
>>>> +    dsi->pclk = devm_clk_get(dev, "pclk");
>>>> +    if (IS_ERR(dsi->pclk)) {
>>>> +        ret = PTR_ERR(dsi->pclk);
>>>> +        dev_err(dev, "Unable to get pclk: %d\n", ret);
>>>> +        return ERR_PTR(ret);
>>>> +    }
>>>> +
>>>> +    /*
>>>> +     * Note that the reset was not defined in the initial device
>>>> tree, so
>>>> +     * we have to be prepared for it not being found.
>>>> +     */
>>>> +    apb_rst = devm_reset_control_get(dev, "apb");
>>>> +    if (IS_ERR(apb_rst)) {
>>>> +        ret = PTR_ERR(apb_rst);
>>>> +        if (ret == -ENOENT) {
>>>> +            apb_rst = NULL;
>>>> +        } else {
>>>> +            dev_err(dev, "Unable to get reset control: %d\n", ret);
>>>> +            return ERR_PTR(ret);
>>>> +        }
>>>> +    }
>>>> +
>>>> +    if (apb_rst) {
>>>> +        ret = clk_prepare_enable(dsi->pclk);
>>>> +        if (ret) {
>>>> +            dev_err(dev, "%s: Failed to enable pclk\n", __func__);
>>>> +            return ERR_PTR(ret);
>>>> +        }
>>>> +
>>>> +        reset_control_assert(apb_rst);
>>>> +        usleep_range(10, 20);
>>>> +        reset_control_deassert(apb_rst);
>>>> +
>>>> +        clk_disable_unprepare(dsi->pclk);
>>>> +    }
>>>> +
>>>> +    pm_runtime_enable(dev);
>>>> +
>>>> +    dsi->dsi_host.ops = &dw_mipi_dsi_host_ops;
>>>> +    dsi->dsi_host.dev = dev;
>>>> +    ret = mipi_dsi_host_register(&dsi->dsi_host);
>>>> +    if (ret) {
>>>> +        dev_err(dev, "Failed to register MIPI host: %d\n", ret);
>>>> +        return ERR_PTR(ret);
>>>> +    }
>>>> +
>>>> +    dsi->bridge.driver_private = dsi;
>>>> +    dsi->bridge.funcs = &dw_mipi_dsi_bridge_funcs;
>>>> +#ifdef CONFIG_OF
>>>> +    dsi->bridge.of_node = pdev->dev.of_node;
>>>> +#endif
>>>> +
>>>> +    dev_set_drvdata(dev, dsi);
>>>> +
>>>> +    return dsi;
>>>> +}
>>>> +
>>>> +static void __dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi)
>>>> +{
>>>> +    pm_runtime_disable(dsi->dev);
>>>> +}
>>>> +
>>>> +/*
>>>> + * Probe/remove API, used from platforms based on the DRM bridge API.
>>>> + */
>>>> +int dw_mipi_dsi_probe(struct platform_device *pdev,
>>>> +              const struct dw_mipi_dsi_plat_data *plat_data)
>>>> +{
>>>> +    struct dw_mipi_dsi *dsi;
>>>> +
>>>> +    dsi = __dw_mipi_dsi_probe(pdev, plat_data);
>>>> +    if (IS_ERR(dsi))
>>>> +        return PTR_ERR(dsi);
>>>> +
>>>> +    return 0;
>>>> +}
>>>> +EXPORT_SYMBOL_GPL(dw_mipi_dsi_probe);
>>>> +
>>>> +void dw_mipi_dsi_remove(struct platform_device *pdev)
>>>> +{
>>>> +    struct dw_mipi_dsi *dsi = platform_get_drvdata(pdev);
>>>> +
>>>> +    mipi_dsi_host_unregister(&dsi->dsi_host);
>>>> +
>>>> +    __dw_mipi_dsi_remove(dsi);
>>>> +}
>>>> +EXPORT_SYMBOL_GPL(dw_mipi_dsi_remove);
>>>> +
>>>> +/*
>>>> + * Bind/unbind API, used from platforms based on the component
>>>> framework.
>>>> + */
>>>> +int dw_mipi_dsi_bind(struct platform_device *pdev, struct drm_encoder
>>>> *encoder,
>>>> +             const struct dw_mipi_dsi_plat_data *plat_data)
>>>> +{
>>>> +    struct dw_mipi_dsi *dsi;
>>>> +    int ret;
>>>> +
>>>> +    dsi = __dw_mipi_dsi_probe(pdev, plat_data);
>>>> +    if (IS_ERR(dsi))
>>>> +        return PTR_ERR(dsi);
>>>> +
>>>> +    ret = drm_bridge_attach(encoder, &dsi->bridge, NULL);
>>>> +    if (ret) {
>>>> +        dw_mipi_dsi_remove(pdev);
>>>> +        DRM_ERROR("Failed to initialize bridge with drm\n");
>>>> +        return ret;
>>>> +    }
>>>> +
>>>> +    return 0;
>>>> +}
>>>> +EXPORT_SYMBOL_GPL(dw_mipi_dsi_bind);
>>>> +
>>>> +void dw_mipi_dsi_unbind(struct device *dev)
>>>> +{
>>>> +    struct dw_mipi_dsi *dsi = dev_get_drvdata(dev);
>>>> +
>>>> +    __dw_mipi_dsi_remove(dsi);
>>>> +}
>>>> +EXPORT_SYMBOL_GPL(dw_mipi_dsi_unbind);
>>>> +
>>>> +MODULE_AUTHOR("Chris Zhong <zyw@rock-chips.com>");
>>>> +MODULE_AUTHOR("Philippe Cornu <philippe.cornu@st.com>");
>>>> +MODULE_DESCRIPTION("DW MIPI DSI host controller driver");
>>>> +MODULE_LICENSE("GPL");
>>>> +MODULE_ALIAS("platform:dw-mipi-dsi");
>>>> diff --git a/include/drm/bridge/dw_mipi_dsi.h
>>>> b/include/drm/bridge/dw_mipi_dsi.h
>>>> new file mode 100644
>>>> index 0000000..9b30fec
>>>> --- /dev/null
>>>> +++ b/include/drm/bridge/dw_mipi_dsi.h
>>>> @@ -0,0 +1,39 @@
>>>> +/*
>>>> + * Copyright (C) STMicroelectronics SA 2017
>>>> + *
>>>> + * Authors: Philippe Cornu <philippe.cornu@st.com>
>>>> + *          Yannick Fertre <yannick.fertre@st.com>
>>>> + *
>>>> + * License terms:  GNU General Public License (GPL), version 2
>>>> + */
>>>> +
>>>> +#ifndef __DW_MIPI_DSI__
>>>> +#define __DW_MIPI_DSI__
>>>> +
>>>> +struct dw_mipi_dsi_phy_ops {
>>>> +    int (*init)(void *priv_data);
>>>> +    int (*get_lane_mbps)(void *priv_data, struct drm_display_mode 
>>>> *mode,
>>>> +                 unsigned long mode_flags, u32 lanes, u32 format,
>>>> +                 unsigned int *lane_mbps);
>>>> +};
>>>> +
>>>> +struct dw_mipi_dsi_plat_data {
>>>> +    void __iomem *base;
>>>> +    unsigned int max_data_lanes;
>>>> +
>>>> +    enum drm_mode_status (*mode_valid)(void *priv_data,
>>>> +                       const struct drm_display_mode *mode);
>>>> +
>>>> +    const struct dw_mipi_dsi_phy_ops *phy_ops;
>>>> +
>>>> +    void *priv_data;
>>>> +};
>>>> +
>>>> +int dw_mipi_dsi_probe(struct platform_device *pdev,
>>>> +              const struct dw_mipi_dsi_plat_data *plat_data);
>>>> +void dw_mipi_dsi_remove(struct platform_device *pdev);
>>>> +int dw_mipi_dsi_bind(struct platform_device *pdev, struct drm_encoder
>>>> *encoder,
>>>> +             const struct dw_mipi_dsi_plat_data *plat_data);
>>>> +void dw_mipi_dsi_unbind(struct device *dev);
>>>> +
>>>> +#endif /* __DW_MIPI_DSI__ */
>>>>
>>>
>> _______________________________________________
>> linux-arm-kernel mailing list
>> linux-arm-kernel at lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>>
>