Re: [PATCH v2 2/2] drm/bridge: Add tc358768 driver
From: Andrzej Hajda
Date: Fri Jan 24 2020 - 09:27:54 EST
On 24.01.2020 11:55, Peter Ujfalusi wrote:
> Add basic support for the Toshiba TC358768 RGB to DSI bridge.
> Not all the features of the TC358768 is implemented by the initial driver:
> MIPI_DSI_MODE_VIDEO and MIPI_DSI_FMT_RGB888 is only supported and tested.
>
> Only write is implemented for mipi_dsi_host_ops.transfer.
>
> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx>
> ---
> drivers/gpu/drm/bridge/Kconfig | 10 +
> drivers/gpu/drm/bridge/Makefile | 1 +
> drivers/gpu/drm/bridge/tc358768.c | 992 ++++++++++++++++++++++++++++++
> 3 files changed, 1003 insertions(+)
> create mode 100644 drivers/gpu/drm/bridge/tc358768.c
>
> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
> index 0b9ca5862455..3fef3513bdd0 100644
> --- a/drivers/gpu/drm/bridge/Kconfig
> +++ b/drivers/gpu/drm/bridge/Kconfig
> @@ -122,6 +122,16 @@ config DRM_TOSHIBA_TC358767
> ---help---
> Toshiba TC358767 eDP bridge chip driver.
>
> +config DRM_TOSHIBA_TC358768
> + tristate "Toshiba TC358768 MIPI DSI bridge"
> + depends on OF
> + select DRM_KMS_HELPER
> + select REGMAP_I2C
> + select DRM_PANEL
> + select DRM_MIPI_DSI
> + help
> + Toshiba TC358768AXBG/TC358778XBG DSI bridge chip driver.
> +
> config DRM_TI_TFP410
> tristate "TI TFP410 DVI/HDMI bridge"
> depends on OF
> diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
> index cd16ce830270..06fc265de0ef 100644
> --- a/drivers/gpu/drm/bridge/Makefile
> +++ b/drivers/gpu/drm/bridge/Makefile
> @@ -11,6 +11,7 @@ obj-$(CONFIG_DRM_SII9234) += sii9234.o
> obj-$(CONFIG_DRM_THINE_THC63LVD1024) += thc63lvd1024.o
> obj-$(CONFIG_DRM_TOSHIBA_TC358764) += tc358764.o
> obj-$(CONFIG_DRM_TOSHIBA_TC358767) += tc358767.o
> +obj-$(CONFIG_DRM_TOSHIBA_TC358768) += tc358768.o
> obj-$(CONFIG_DRM_I2C_ADV7511) += adv7511/
> obj-$(CONFIG_DRM_TI_SN65DSI86) += ti-sn65dsi86.o
> obj-$(CONFIG_DRM_TI_TFP410) += ti-tfp410.o
> diff --git a/drivers/gpu/drm/bridge/tc358768.c b/drivers/gpu/drm/bridge/tc358768.c
> new file mode 100644
> index 000000000000..5e12b1390254
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/tc358768.c
> @@ -0,0 +1,992 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2020 Texas Instruments Incorporated - http://www.ti.com
> + * Author: Peter Ujfalusi <peter.ujfalusi@xxxxxx>
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/device.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/i2c.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/regmap.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/slab.h>
> +
> +#include <drm/drm_atomic_helper.h>
> +#include <drm/drm_crtc_helper.h>
> +#include <drm/drm_drv.h>
> +#include <drm/drm_mipi_dsi.h>
> +#include <drm/drm_of.h>
> +#include <drm/drm_panel.h>
> +#include <video/mipi_display.h>
> +#include <video/videomode.h>
> +
> +/* Global (16-bit addressable) */
> +#define TC358768_CHIPID 0x0000
> +#define TC358768_SYSCTL 0x0002
> +#define TC358768_CONFCTL 0x0004
> +#define TC358768_VSDLY 0x0006
> +#define TC358768_DATAFMT 0x0008
> +#define TC358768_GPIOEN 0x000E
> +#define TC358768_GPIODIR 0x0010
> +#define TC358768_GPIOIN 0x0012
> +#define TC358768_GPIOOUT 0x0014
> +#define TC358768_PLLCTL0 0x0016
> +#define TC358768_PLLCTL1 0x0018
> +#define TC358768_CMDBYTE 0x0022
> +#define TC358768_PP_MISC 0x0032
> +#define TC358768_DSITX_DT 0x0050
> +#define TC358768_FIFOSTATUS 0x00F8
> +
> +/* Debug (16-bit addressable) */
> +#define TC358768_VBUFCTRL 0x00E0
> +#define TC358768_DBG_WIDTH 0x00E2
> +#define TC358768_DBG_VBLANK 0x00E4
> +#define TC358768_DBG_DATA 0x00E8
> +
> +/* TX PHY (32-bit addressable) */
> +#define TC358768_CLW_DPHYCONTTX 0x0100
> +#define TC358768_D0W_DPHYCONTTX 0x0104
> +#define TC358768_D1W_DPHYCONTTX 0x0108
> +#define TC358768_D2W_DPHYCONTTX 0x010C
> +#define TC358768_D3W_DPHYCONTTX 0x0110
> +#define TC358768_CLW_CNTRL 0x0140
> +#define TC358768_D0W_CNTRL 0x0144
> +#define TC358768_D1W_CNTRL 0x0148
> +#define TC358768_D2W_CNTRL 0x014C
> +#define TC358768_D3W_CNTRL 0x0150
> +
> +/* TX PPI (32-bit addressable) */
> +#define TC358768_STARTCNTRL 0x0204
> +#define TC358768_DSITXSTATUS 0x0208
> +#define TC358768_LINEINITCNT 0x0210
> +#define TC358768_LPTXTIMECNT 0x0214
> +#define TC358768_TCLK_HEADERCNT 0x0218
> +#define TC358768_TCLK_TRAILCNT 0x021C
> +#define TC358768_THS_HEADERCNT 0x0220
> +#define TC358768_TWAKEUP 0x0224
> +#define TC358768_TCLK_POSTCNT 0x0228
> +#define TC358768_THS_TRAILCNT 0x022C
> +#define TC358768_HSTXVREGCNT 0x0230
> +#define TC358768_HSTXVREGEN 0x0234
> +#define TC358768_TXOPTIONCNTRL 0x0238
> +#define TC358768_BTACNTRL1 0x023C
> +
> +/* TX CTRL (32-bit addressable) */
> +#define TC358768_DSI_CONTROL 0x040C
> +#define TC358768_DSI_STATUS 0x0410
> +#define TC358768_DSI_INT 0x0414
> +#define TC358768_DSI_INT_ENA 0x0418
> +#define TC358768_DSICMD_RDFIFO 0x0430
> +#define TC358768_DSI_ACKERR 0x0434
> +#define TC358768_DSI_ACKERR_INTENA 0x0438
> +#define TC358768_DSI_ACKERR_HALT 0x043c
> +#define TC358768_DSI_RXERR 0x0440
> +#define TC358768_DSI_RXERR_INTENA 0x0444
> +#define TC358768_DSI_RXERR_HALT 0x0448
> +#define TC358768_DSI_ERR 0x044C
> +#define TC358768_DSI_ERR_INTENA 0x0450
> +#define TC358768_DSI_ERR_HALT 0x0454
> +#define TC358768_DSI_CONFW 0x0500
> +#define TC358768_DSI_LPCMD 0x0500
> +#define TC358768_DSI_RESET 0x0504
> +#define TC358768_DSI_INT_CLR 0x050C
> +#define TC358768_DSI_START 0x0518
> +
> +/* DSITX CTRL (16-bit addressable) */
> +#define TC358768_DSICMD_TX 0x0600
> +#define TC358768_DSICMD_TYPE 0x0602
> +#define TC358768_DSICMD_WC 0x0604
> +#define TC358768_DSICMD_WD0 0x0610
> +#define TC358768_DSICMD_WD1 0x0612
> +#define TC358768_DSICMD_WD2 0x0614
> +#define TC358768_DSICMD_WD3 0x0616
> +#define TC358768_DSI_EVENT 0x0620
> +#define TC358768_DSI_VSW 0x0622
> +#define TC358768_DSI_VBPR 0x0624
> +#define TC358768_DSI_VACT 0x0626
> +#define TC358768_DSI_HSW 0x0628
> +#define TC358768_DSI_HBPR 0x062A
> +#define TC358768_DSI_HACT 0x062C
> +
> +static const char * const tc358768_supplies[] = {
> + "vddc", "vddmipi", "vddio"
> +};
> +
> +struct tc358768_dsi_output {
> + struct mipi_dsi_device *dev;
> + struct drm_panel *panel;
> + struct drm_bridge *bridge;
> +};
> +
> +struct tc358768_priv {
> + struct device *dev;
> + struct regmap *regmap;
> + struct gpio_desc *reset_gpio;
> + struct regulator_bulk_data supplies[ARRAY_SIZE(tc358768_supplies)];
> + struct clk *refclk;
> + int enabled;
> + int error;
> +
> + struct mipi_dsi_host dsi_host;
> + struct drm_bridge bridge;
> + struct tc358768_dsi_output output;
> +
> + u32 pd_lines; /* number of Parallel Port Input Data Lines */
> + u32 dsi_lanes; /* number of DSI Lanes */
> +
> + /* Parameters for PLL programming */
> + u32 fbd; /* PLL feedback divider */
> + u32 prd; /* PLL input divider */
> + u32 frs; /* PLL Freqency range for HSCK (post divider) */
> +
> + u32 dsiclk; /* pll_clk / 2 */
> +};
> +
> +static inline struct tc358768_priv *dsi_host_to_tc358768(struct mipi_dsi_host
> + *host)
> +{
> + return container_of(host, struct tc358768_priv, dsi_host);
> +}
> +
> +static inline struct tc358768_priv *bridge_to_tc358768(struct drm_bridge
> + *bridge)
> +{
> + return container_of(bridge, struct tc358768_priv, bridge);
> +}
> +
> +static int tc358768_clear_error(struct tc358768_priv *priv)
> +{
> + int ret = priv->error;
> +
> + priv->error = 0;
> + return ret;
> +}
> +
> +static void tc358768_write(struct tc358768_priv *priv, u32 reg, u32 val)
> +{
> + size_t count = 2;
> +
> + if (priv->error)
> + return;
> +
> + /* 16-bit register? */
> + if (reg < 0x100 || reg >= 0x600)
> + count = 1;
> +
> + priv->error = regmap_bulk_write(priv->regmap, reg, &val, count);
Maybe it would be good to log possible error here and after regmap*read,
to have more precise info, unless such log is provided already by
regmap, up to you.
> +}
> +
> +static void tc358768_read(struct tc358768_priv *priv, u32 reg, u32 *val)
> +{
> + size_t count = 2;
> +
> + if (priv->error)
> + return;
> +
> + /* 16-bit register? */
> + if (reg < 0x100 || reg >= 0x600) {
> + *val = 0;
> + count = 1;
> + }
> +
> + priv->error = regmap_bulk_read(priv->regmap, reg, val, count);
> +}
> +
> +static void tc358768_update_bits(struct tc358768_priv *priv, u32 reg, u32 mask,
> + u32 val)
> +{
> + u32 tmp, orig;
> +
> + tc358768_read(priv, reg, &orig);
> + tmp = orig & ~mask;
> + tmp |= val & mask;
> + if (tmp != orig)
> + tc358768_write(priv, reg, tmp);
> +}
> +
> +static int tc358768_sw_reset(struct tc358768_priv *priv)
> +{
> + /* Assert Reset */
> + tc358768_write(priv, TC358768_SYSCTL, 1);
> + /* Release Reset, Exit Sleep */
> + tc358768_write(priv, TC358768_SYSCTL, 0);
> +
> + return tc358768_clear_error(priv);
> +}
> +
> +static void tc358768_hw_enable(struct tc358768_priv *priv)
> +{
> + int ret;
> +
> + if (priv->enabled++ > 0)
> + return;
> +
> + ret = regulator_bulk_enable(ARRAY_SIZE(priv->supplies), priv->supplies);
> + if (ret < 0)
> + dev_err(priv->dev, "error enabling regulators (%d)\n", ret);
> +
> + if (priv->reset_gpio)
> + usleep_range(200, 300);
> +
> + /*
> + * The RESX is active low (GPIO_ACTIVE_LOW).
> + * DEASSERT (value = 0) the reset_gpio to enable the chip
> + */
> + gpiod_set_value_cansleep(priv->reset_gpio, 0);
> +
> + /* wait for encoder clocks to stabilize */
> + usleep_range(1000, 2000);
> +}
> +
> +static void tc358768_hw_disable(struct tc358768_priv *priv)
> +{
> + int ret;
> +
> + if (--priv->enabled != 0)
> + return;
> +
> + /*
> + * The RESX is active low (GPIO_ACTIVE_LOW).
> + * ASSERT (value = 1) the reset_gpio to disable the chip
> + */
> + gpiod_set_value_cansleep(priv->reset_gpio, 1);
> +
> + ret = regulator_bulk_disable(ARRAY_SIZE(priv->supplies),
> + priv->supplies);
> + if (ret < 0)
> + dev_err(priv->dev, "error disabling regulators (%d)\n", ret);
> +}
> +
> +static u32 tc358768_pll_to_pclk(struct tc358768_priv *priv, u32 pll_clk)
> +{
> + return (u32)div_u64((u64)pll_clk * priv->dsi_lanes, priv->pd_lines);
> +}
> +
> +static u32 tc358768_pclk_to_pll(struct tc358768_priv *priv, u32 pclk)
> +{
> + return (u32)div_u64((u64)pclk * priv->pd_lines, priv->dsi_lanes);
> +}
> +
> +static int tc358768_calc_pll(struct tc358768_priv *priv,
> + const struct drm_display_mode *mode,
> + bool verify_only)
> +{
> + const u32 frs_limits[] = {
> + 1000000000,
> + 500000000,
> + 250000000,
> + 125000000,
> + 62500000
> + };
> + unsigned long refclk;
> + u32 prd, target_pll, i, max_pll, min_pll;
> + u32 frs, best_diff, best_pll, best_prd, best_fbd;
> +
> + target_pll = tc358768_pclk_to_pll(priv, mode->clock * 1000);
> +
> + /* pll_clk = RefClk * [(FBD + 1)/ (PRD + 1)] * [1 / (2^FRS)] */
> +
> + for (i = 0; i < ARRAY_SIZE(frs_limits); i++)
> + if (target_pll >= frs_limits[i])
> + break;
> +
> + if (i == ARRAY_SIZE(frs_limits) || i == 0)
> + return -EINVAL;
> +
> + frs = i - 1;
> + max_pll = frs_limits[i - 1];
> + min_pll = frs_limits[i];
> +
> + refclk = clk_get_rate(priv->refclk);
> +
> + best_diff = UINT_MAX;
> + best_pll = 0;
> + best_prd = 0;
> + best_fbd = 0;
> +
> + for (prd = 0; prd < 16; ++prd) {
> + u32 divisor = (prd + 1) * (1 << frs);
> + u32 fbd;
> +
> + for (fbd = 0; fbd < 512; ++fbd) {
> + u32 pll, diff;
> +
> + pll = (u32)div_u64((u64)refclk * (fbd + 1), divisor);
> +
> + if (pll >= max_pll || pll < min_pll)
> + continue;
> +
> + diff = max(pll, target_pll) - min(pll, target_pll);
> +
> + if (diff < best_diff) {
> + best_diff = diff;
> + best_pll = pll;
> + best_prd = prd;
> + best_fbd = fbd;
> + }
> +
> + if (best_diff == 0)
> + goto found;
More optimal would be put above check inside block few lines above, at
the cost of another indent, up to you.
> + }
> + }
> +
> +found:
> + if (best_diff == UINT_MAX) {
> + dev_err(priv->dev, "could not find suitable PLL setup\n");
> + return -EINVAL;
> + }
> +
> + if (verify_only)
> + return 0;
> +
> + priv->fbd = best_fbd;
> + priv->prd = best_prd;
> + priv->frs = frs;
> + priv->dsiclk = best_pll / 2;
> +
> + return 0;
> +}
> +
> +static int tc358768_dsi_host_attach(struct mipi_dsi_host *host,
> + struct mipi_dsi_device *dev)
> +{
> + struct tc358768_priv *priv = dsi_host_to_tc358768(host);
> + struct drm_bridge *bridge;
> + struct drm_panel *panel;
> + struct device_node *ep;
> + int ret;
> +
> + if (dev->lanes > 4) {
> + dev_err(priv->dev, "unsupported number of data lanes(%u)\n",
> + dev->lanes);
> + return -EINVAL;
> + }
> +
> + /*
> + * tc358768 supports both Video and Pulse mode, but the driver only
> + * implements Video (event) mode currently
> + */
> + if (!(dev->mode_flags & MIPI_DSI_MODE_VIDEO)) {
> + dev_err(priv->dev, "Only MIPI_DSI_MODE_VIDEO is supported\n");
> + return -ENOTSUPP;
> + }
> +
> + /*
> + * tc358768 supports RGB888, RGB666, RGB666_PACKED and RGB565, but only
> + * RGB888 is verified.
> + */
> + if (dev->format != MIPI_DSI_FMT_RGB888) {
> + dev_warn(priv->dev, "Only MIPI_DSI_FMT_RGB888 tested!\n");
> + return -ENOTSUPP;
> + }
> +
> + 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_typed(panel,
> + DRM_MODE_CONNECTOR_DSI);
> + if (IS_ERR(bridge))
> + return PTR_ERR(bridge);
> + }
> +
> + priv->output.dev = dev;
> + priv->output.bridge = bridge;
> + priv->output.panel = panel;
> +
> + priv->dsi_lanes = dev->lanes;
> +
> + /* get input ep (port0/endpoint0) */
> + ret = -EINVAL;
> + ep = of_graph_get_endpoint_by_regs(host->dev->of_node, 0, 0);
> + if (ep) {
> + ret = of_property_read_u32(ep, "data-lines", &priv->pd_lines);
> +
> + of_node_put(ep);
> + }
> +
> + if (ret)
> + priv->pd_lines = mipi_dsi_pixel_format_to_bpp(dev->format);
> +
> + drm_bridge_add(&priv->bridge);
> +
> + return 0;
> +}
> +
> +static int tc358768_dsi_host_detach(struct mipi_dsi_host *host,
> + struct mipi_dsi_device *dev)
> +{
> + struct tc358768_priv *priv = dsi_host_to_tc358768(host);
> +
> + drm_bridge_remove(&priv->bridge);
> + if (priv->output.panel)
> + drm_panel_bridge_remove(priv->output.bridge);
> +
> + return 0;
> +}
> +
> +static ssize_t tc358768_dsi_host_transfer(struct mipi_dsi_host *host,
> + const struct mipi_dsi_msg *msg)
> +{
> + struct tc358768_priv *priv = dsi_host_to_tc358768(host);
> + struct mipi_dsi_packet packet;
> + int ret;
> +
> + if (msg->rx_len) {
> + dev_warn(priv->dev, "MIPI rx is not supported\n");
> + return -ENOTSUPP;
> + }
> +
> + if (msg->tx_len > 8) {
> + dev_warn(priv->dev, "Maximum 8 byte MIPI tx is supported\n");
> + return -ENOTSUPP;
> + }
> +
> + ret = mipi_dsi_create_packet(&packet, msg);
> + if (ret)
> + return ret;
> +
> + tc358768_hw_enable(priv);
This looks suspicious, if you put tc358768_hw_enable here it means you
are assuming hw can be disabled when transfer is requested, it means
that after transfer the hardware will be disabled again, I do not think
it is good thing - DSI bus is not designed for short transfers
interleaved with hw enable/disable cycle, I guess it can be even harmful
for downstream devices.
If this is workaround to allow downstream devices initialization in
.pre_enable/.prepare callbacks I guess it can be solved properly by
avoiding bridge->next callback chain, and calling downstream device
opses directly, or we should think about more convenient solution.
> +
> + if (mipi_dsi_packet_format_is_short(msg->type)) {
> + tc358768_write(priv, TC358768_DSICMD_TYPE,
> + (0x10 << 8) | (packet.header[0] & 0x3f));
> + tc358768_write(priv, TC358768_DSICMD_WC, 0);
> + tc358768_write(priv, TC358768_DSICMD_WD0,
> + (packet.header[2] << 8) | packet.header[1]);
> + } else {
> + int i;
> +
> + tc358768_write(priv, TC358768_DSICMD_TYPE,
> + (0x40 << 8) | (packet.header[0] & 0x3f));
> + tc358768_write(priv, TC358768_DSICMD_WC, packet.payload_length);
> + for (i = 0; i < packet.payload_length; i += 2) {
> + u16 val = packet.payload[i];
> +
> + if (i + 1 < packet.payload_length)
> + val |= packet.payload[i + 1] << 8;
> +
> + tc358768_write(priv, TC358768_DSICMD_WD0 + i, val);
> + }
> + }
> +
> + /* start transfer */
> + tc358768_write(priv, TC358768_DSICMD_TX, 1);
> +
> + tc358768_hw_disable(priv);
> +
> + return tc358768_clear_error(priv);
> +}
> +
> +static const struct mipi_dsi_host_ops tc358768_dsi_host_ops = {
> + .attach = tc358768_dsi_host_attach,
> + .detach = tc358768_dsi_host_detach,
> + .transfer = tc358768_dsi_host_transfer,
> +};
> +
> +static int tc358768_bridge_attach(struct drm_bridge *bridge)
> +{
> + struct tc358768_priv *priv = bridge_to_tc358768(bridge);
> +
> + if (!drm_core_check_feature(bridge->dev, DRIVER_ATOMIC)) {
> + dev_err(priv->dev, "needs atomic updates support\n");
> + return -ENOTSUPP;
> + }
> +
> + return drm_bridge_attach(bridge->encoder, priv->output.bridge, bridge);
> +}
> +
> +static enum drm_mode_status
> +tc358768_bridge_mode_valid(struct drm_bridge *bridge,
> + const struct drm_display_mode *mode)
> +{
> + struct tc358768_priv *priv = bridge_to_tc358768(bridge);
> +
> + if (tc358768_calc_pll(priv, mode, true))
> + return MODE_CLOCK_RANGE;
> +
> + return MODE_OK;
> +}
> +
> +static void tc358768_bridge_disable(struct drm_bridge *bridge)
> +{
> + struct tc358768_priv *priv = bridge_to_tc358768(bridge);
> + int ret;
> +
> + /* set FrmStop */
> + tc358768_update_bits(priv, TC358768_PP_MISC, BIT(15), BIT(15));
> +
> + /* wait at least for one frame */
> + msleep(50);
> +
> + /* clear PP_en */
> + tc358768_update_bits(priv, TC358768_CONFCTL, BIT(6), 0);
> +
> + /* set RstPtr */
> + tc358768_update_bits(priv, TC358768_PP_MISC, BIT(14), BIT(14));
> +
> + ret = tc358768_clear_error(priv);
> + if (ret)
> + dev_warn(priv->dev, "Software disable failed: %d\n", ret);
> +
> + tc358768_hw_disable(priv);
> +}
> +
> +static int tc358768_setup_pll(struct tc358768_priv *priv,
> + const struct drm_display_mode *mode)
> +{
> + u32 fbd, prd, frs;
> + int ret;
> +
> + ret = tc358768_calc_pll(priv, mode, false);
> + if (ret) {
> + dev_err(priv->dev, "PLL calculation failed: %d\n", ret);
> + return ret;
> + }
> +
> + fbd = priv->fbd;
> + prd = priv->prd;
> + frs = priv->frs;
> +
> + dev_dbg(priv->dev, "PLL: refclk %lu, fbd %u, prd %u, frs %u\n",
> + clk_get_rate(priv->refclk), fbd, prd, frs);
> + dev_dbg(priv->dev, "PLL: pll_clk: %u, DSIClk %u, DSIByteClk %u\n",
> + priv->dsiclk * 2, priv->dsiclk, priv->dsiclk / 4);
> + dev_dbg(priv->dev, "PLL: pclk %u (panel: %u)\n",
> + tc358768_pll_to_pclk(priv, priv->dsiclk * 2),
> + mode->clock * 1000);
> +
> + /* PRD[15:12] FBD[8:0] */
> + tc358768_write(priv, TC358768_PLLCTL0, (prd << 12) | fbd);
> +
> + /* FRS[11:10] LBWS[9:8] CKEN[4] RESETB[1] EN[0] */
> + tc358768_write(priv, TC358768_PLLCTL1,
> + (frs << 10) | (0x2 << 8) | BIT(1) | BIT(0));
> +
> + /* wait for lock */
> + usleep_range(1000, 2000);
> +
> + /* FRS[11:10] LBWS[9:8] CKEN[4] PLL_CKEN[4] RESETB[1] EN[0] */
> + tc358768_write(priv, TC358768_PLLCTL1,
> + (frs << 10) | (0x2 << 8) | BIT(4) | BIT(1) | BIT(0));
> +
> + return tc358768_clear_error(priv);
> +}
> +
> +#define TC358768_PRECISION 1000
> +static u32 tc358768_ns_to_cnt(u32 ns, u32 period_nsk)
> +{
> + return (ns * TC358768_PRECISION + period_nsk) / period_nsk;
> +}
> +
> +static u32 tc358768_to_ns(u32 nsk)
> +{
> + return (nsk / TC358768_PRECISION);
> +}
> +
> +static void tc358768_bridge_enable(struct drm_bridge *bridge)
> +{
> + struct tc358768_priv *priv = bridge_to_tc358768(bridge);
> + struct mipi_dsi_device *dsi_dev = priv->output.dev;
> + u32 val, val2, lptxcnt, hact, data_type;
> + const struct drm_display_mode *mode;
> + u32 dsibclk_nsk, dsiclk_nsk, ui_nsk, phy_delay_nsk;
> + u32 dsiclk, dsibclk;
> + int ret, i;
> +
> + tc358768_hw_enable(priv);
> +
> + ret = tc358768_sw_reset(priv);
> + if (ret) {
> + dev_err(priv->dev, "Software reset failed: %d\n", ret);
> + return;
> + }
I think above code (maybe more) should go to pre_enable, bridges should
follow quite well established practices for panels [1], ie
bridge.pre_enable should do similar things as panel.prepare, etc,
this can be separated if user requiring it appears.
https://dri.freedesktop.org/docs/drm/gpu/drm-kms-helpers.html?highlight=drm_panel_funcs#c.drm_panel_funcs
> +
> + mode = &bridge->encoder->crtc->state->adjusted_mode;
> + ret = tc358768_setup_pll(priv, mode);
> + if (ret) {
> + dev_err(priv->dev, "PLL setup failed: %d\n", ret);
> + return;
> + }
> +
> + dsiclk = priv->dsiclk;
> + dsibclk = dsiclk / 4;
> +
> + /* Data Format Control Register */
> + val = BIT(2) | BIT(1) | BIT(0); /* rdswap_en | dsitx_en | txdt_en */
> + switch (dsi_dev->format) {
> + case MIPI_DSI_FMT_RGB888:
> + val |= (0x3 << 4);
> + hact = mode->hdisplay * 3;
> + data_type = MIPI_DSI_PACKED_PIXEL_STREAM_24;
> + break;
> + case MIPI_DSI_FMT_RGB666:
> + val |= (0x4 << 4);
> + hact = mode->hdisplay * 3;
> + data_type = MIPI_DSI_PACKED_PIXEL_STREAM_18;
> + break;
> +
> + case MIPI_DSI_FMT_RGB666_PACKED:
> + val |= (0x4 << 4) | BIT(3);
> + hact = mode->hdisplay * 18 / 8;
> + data_type = MIPI_DSI_PIXEL_STREAM_3BYTE_18;
> + break;
> +
> + case MIPI_DSI_FMT_RGB565:
> + val |= (0x5 << 4);
> + hact = mode->hdisplay * 2;
> + data_type = MIPI_DSI_PACKED_PIXEL_STREAM_16;
> + break;
> + default:
> + dev_err(priv->dev, "Invalid data format (%u)\n",
> + dsi_dev->format);
> + return;
> + }
> +
> + /* VSDly[9:0] */
> + tc358768_write(priv, TC358768_VSDLY, 1);
> +
> + tc358768_write(priv, TC358768_DATAFMT, val);
> + tc358768_write(priv, TC358768_DSITX_DT, data_type);
> +
> + /* Enable D-PHY (HiZ->LP11) */
> + tc358768_write(priv, TC358768_CLW_CNTRL, 0x0000);
> + /* Enable lanes */
> + for (i = 0; i < dsi_dev->lanes; i++)
> + tc358768_write(priv, TC358768_D0W_CNTRL + i * 4, 0x0000);
> +
> + /* DSI Timings */
> + dsibclk_nsk = (u32)div_u64((u64)1000000000 * TC358768_PRECISION,
> + dsibclk);
> + dsiclk_nsk = (u32)div_u64((u64)1000000000 * TC358768_PRECISION, dsiclk);
> + ui_nsk = dsiclk_nsk / 2;
> + phy_delay_nsk = dsibclk_nsk + 2 * dsiclk_nsk;
> + dev_dbg(priv->dev, "dsiclk_nsk: %u\n", dsiclk_nsk);
> + dev_dbg(priv->dev, "ui_nsk: %u\n", ui_nsk);
> + dev_dbg(priv->dev, "dsibclk_nsk: %u\n", dsibclk_nsk);
> + dev_dbg(priv->dev, "phy_delay_nsk: %u\n", phy_delay_nsk);
> +
> + /* LP11 > 100us for D-PHY Rx Init */
> + val = tc358768_ns_to_cnt(100 * 1000, dsibclk_nsk) - 1;
> + dev_dbg(priv->dev, "LINEINITCNT: 0x%x\n", val);
> + tc358768_write(priv, TC358768_LINEINITCNT, val);
> +
> + /* LPTimeCnt > 50ns */
> + val = tc358768_ns_to_cnt(50, dsibclk_nsk) - 1;
> + lptxcnt = val;
> + dev_dbg(priv->dev, "LPTXTIMECNT: 0x%x\n", val);
> + tc358768_write(priv, TC358768_LPTXTIMECNT, val);
> +
> + /* 38ns < TCLK_PREPARE < 95ns */
> + val = tc358768_ns_to_cnt(65, dsibclk_nsk) - 1;
> + /* TCLK_PREPARE > 300ns */
> + val2 = tc358768_ns_to_cnt(300 + tc358768_to_ns(3 * ui_nsk),
> + dsibclk_nsk);
> + val |= (val2 - tc358768_to_ns(phy_delay_nsk - dsibclk_nsk)) << 8;
> + dev_dbg(priv->dev, "TCLK_HEADERCNT: 0x%x\n", val);
> + tc358768_write(priv, TC358768_TCLK_HEADERCNT, val);
> +
> + /* TCLK_TRAIL > 60ns + 3*UI */
> + val = 60 + tc358768_to_ns(3 * ui_nsk);
> + val = tc358768_ns_to_cnt(val, dsibclk_nsk) - 5;
> + dev_dbg(priv->dev, "TCLK_TRAILCNT: 0x%x\n", val);
> + tc358768_write(priv, TC358768_TCLK_TRAILCNT, val);
> +
> + /* 40ns + 4*UI < THS_PREPARE < 85ns + 6*UI */
> + val = 50 + tc358768_to_ns(4 * ui_nsk);
> + val = tc358768_ns_to_cnt(val, dsibclk_nsk) - 1;
> + /* THS_ZERO > 145ns + 10*UI */
> + val2 = tc358768_ns_to_cnt(145 - tc358768_to_ns(ui_nsk), dsibclk_nsk);
> + val |= (val2 - tc358768_to_ns(phy_delay_nsk)) << 8;
> + dev_dbg(priv->dev, "THS_HEADERCNT: 0x%x\n", val);
> + tc358768_write(priv, TC358768_THS_HEADERCNT, val);
> +
> + /* TWAKEUP > 1ms in lptxcnt steps */
> + val = tc358768_ns_to_cnt(1020000, dsibclk_nsk);
> + val = val / (lptxcnt + 1) - 1;
> + dev_dbg(priv->dev, "TWAKEUP: 0x%x\n", val);
> + tc358768_write(priv, TC358768_TWAKEUP, val);
> +
> + /* TCLK_POSTCNT > 60ns + 52*UI */
> + val = tc358768_ns_to_cnt(60 + tc358768_to_ns(52 * ui_nsk),
> + dsibclk_nsk) - 3;
> + dev_dbg(priv->dev, "TCLK_POSTCNT: 0x%x\n", val);
> + tc358768_write(priv, TC358768_TCLK_POSTCNT, val);
> +
> + /* 60ns + 4*UI < THS_PREPARE < 105ns + 12*UI */
> + val = tc358768_ns_to_cnt(60 + tc358768_to_ns(15 * ui_nsk),
> + dsibclk_nsk) - 5;
> + dev_dbg(priv->dev, "THS_TRAILCNT: 0x%x\n", val);
> + tc358768_write(priv, TC358768_THS_TRAILCNT, val);
> +
> + val = BIT(0);
> + for (i = 0; i < dsi_dev->lanes; i++)
> + val |= BIT(i + 1);
> + tc358768_write(priv, TC358768_HSTXVREGEN, val);
> +
> + if (!(dsi_dev->mode_flags & MIPI_DSI_CLOCK_NON_CONTINUOUS))
> + tc358768_write(priv, TC358768_TXOPTIONCNTRL, 0x1);
> +
> + /* TXTAGOCNT[26:16] RXTASURECNT[10:0] */
> + val = tc358768_to_ns((lptxcnt + 1) * dsibclk_nsk * 4);
> + val = tc358768_ns_to_cnt(val, dsibclk_nsk) - 1;
> + val2 = tc358768_ns_to_cnt(tc358768_to_ns((lptxcnt + 1) * dsibclk_nsk),
> + dsibclk_nsk) - 2;
> + val |= val2 << 16;
> + dev_dbg(priv->dev, "BTACNTRL1: 0x%x\n", val);
> + tc358768_write(priv, TC358768_BTACNTRL1, val);
> +
> + /* START[0] */
> + tc358768_write(priv, TC358768_STARTCNTRL, 1);
> +
> + /* Set event mode */
> + tc358768_write(priv, TC358768_DSI_EVENT, 1);
> +
> + /* vsw (+ vbp) */
> + tc358768_write(priv, TC358768_DSI_VSW,
> + mode->vtotal - mode->vsync_start);
> + /* vbp (not used in event mode) */
> + tc358768_write(priv, TC358768_DSI_VBPR, 0);
> + /* vact */
> + tc358768_write(priv, TC358768_DSI_VACT, mode->vdisplay);
> +
> + /* (hsw + hbp) * byteclk * ndl / pclk */
> + val = (u32)div_u64((mode->htotal - mode->hsync_start) *
> + ((u64)priv->dsiclk / 4) * priv->dsi_lanes,
> + mode->clock * 1000);
> + tc358768_write(priv, TC358768_DSI_HSW, val);
> + /* hbp (not used in event mode) */
> + tc358768_write(priv, TC358768_DSI_HBPR, 0);
> + /* hact (bytes) */
> + tc358768_write(priv, TC358768_DSI_HACT, hact);
> +
> + /* VSYNC polarity */
> + if (!(mode->flags & DRM_MODE_FLAG_NVSYNC))
> + tc358768_update_bits(priv, TC358768_CONFCTL, BIT(5), BIT(5));
> + /* HSYNC polarity */
> + if (mode->flags & DRM_MODE_FLAG_PHSYNC)
> + tc358768_update_bits(priv, TC358768_PP_MISC, BIT(0), BIT(0));
> +
> + /* Start DSI Tx */
> + tc358768_write(priv, TC358768_DSI_START, 0x1);
> +
> + /* Configure DSI_Control register */
> + val = (6 << 29) | (0x3 << 24); /* CLEAR, DSI_Control */
> + val |= BIT(7) | BIT(5) | 0x3 << 1 | BIT(0);
> + tc358768_write(priv, TC358768_DSI_CONFW, val);
> +
> + val = (5 << 29) | (0x3 << 24); /* SET, DSI_Control */
> + if (!(dsi_dev->mode_flags & MIPI_DSI_MODE_LPM))
> + val |= BIT(7);
> + if (!(dsi_dev->mode_flags & MIPI_DSI_CLOCK_NON_CONTINUOUS))
> + val |= BIT(5);
> + val |= (dsi_dev->lanes - 1) << 1;
> + if (dsi_dev->mode_flags & MIPI_DSI_MODE_EOT_PACKET)
> + val |= BIT(0);
> + tc358768_write(priv, TC358768_DSI_CONFW, val);
> +
> + val = (6 << 29) | (0x3 << 24); /* CLEAR, DSI_Control */
> + val |= 0x8000; /* DSI mode */
> + tc358768_write(priv, TC358768_DSI_CONFW, val);
> +
> + /* clear FrmStop and RstPtr */
> + tc358768_update_bits(priv, TC358768_PP_MISC, 0x3 << 14, 0);
> +
> + /* set PP_en */
> + tc358768_update_bits(priv, TC358768_CONFCTL, BIT(6), BIT(6));
> +
> + ret = tc358768_clear_error(priv);
> + if (ret) {
> + dev_err(priv->dev, "Bridge enable failed: %d\n", ret);
> + tc358768_bridge_disable(bridge);
> + }
> +}
> +
> +static const struct drm_bridge_funcs tc358768_bridge_funcs = {
> + .attach = tc358768_bridge_attach,
> + .mode_valid = tc358768_bridge_mode_valid,
> + .disable = tc358768_bridge_disable,
> + .enable = tc358768_bridge_enable,
> +};
> +
> +static const struct drm_bridge_timings default_tc358768_timings = {
> + .input_bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE
> + | DRM_BUS_FLAG_SYNC_SAMPLE_NEGEDGE
> + | DRM_BUS_FLAG_DE_HIGH,
> +};
> +
> +static bool tc358768_is_reserved_reg(unsigned int reg)
> +{
> + switch (reg) {
> + case 0x114 ... 0x13f:
> + case 0x200:
> + case 0x20c:
> + case 0x400 ... 0x408:
> + case 0x41c ... 0x42f:
> + return true;
> + default:
> + return false;
> + }
> +}
> +
> +static bool tc358768_writeable_reg(struct device *dev, unsigned int reg)
> +{
> + if (tc358768_is_reserved_reg(reg))
> + return false;
> +
> + switch (reg) {
> + case TC358768_CHIPID:
> + case TC358768_FIFOSTATUS:
> + case TC358768_DSITXSTATUS ... (TC358768_DSITXSTATUS + 2):
> + case TC358768_DSI_CONTROL ... (TC358768_DSI_INT_ENA + 2):
> + case TC358768_DSICMD_RDFIFO ... (TC358768_DSI_ERR_HALT + 2):
> + return false;
> + default:
> + return true;
> + }
> +}
> +
> +static bool tc358768_readable_reg(struct device *dev, unsigned int reg)
> +{
> + if (tc358768_is_reserved_reg(reg))
> + return false;
> +
> + switch (reg) {
> + case TC358768_STARTCNTRL:
> + case TC358768_DSI_CONFW ... (TC358768_DSI_CONFW + 2):
> + case TC358768_DSI_INT_CLR ... (TC358768_DSI_INT_CLR + 2):
> + case TC358768_DSI_START ... (TC358768_DSI_START + 2):
> + case TC358768_DBG_DATA:
> + return false;
> + default:
> + return true;
> + }
> +}
> +
> +static const struct regmap_config tc358768_regmap_config = {
> + .name = "tc358768",
> + .reg_bits = 16,
> + .val_bits = 16,
> + .max_register = TC358768_DSI_HACT,
> + .cache_type = REGCACHE_NONE,
> + .writeable_reg = tc358768_writeable_reg,
> + .readable_reg = tc358768_readable_reg,
> + .reg_format_endian = REGMAP_ENDIAN_BIG,
> + .val_format_endian = REGMAP_ENDIAN_BIG,
> +};
> +
> +static const struct i2c_device_id tc358768_i2c_ids[] = {
> + { "tc358768", 0 },
> + { "tc358778", 0 },
> + { }
> +};
> +MODULE_DEVICE_TABLE(i2c, tc358768_i2c_ids);
> +
> +static const struct of_device_id tc358768_of_ids[] = {
> + { .compatible = "toshiba,tc358768", },
> + { .compatible = "toshiba,tc358778", },
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, tc358768_of_ids);
> +
> +static int tc358768_get_regulators(struct tc358768_priv *priv)
> +{
> + int i, ret;
> +
> + for (i = 0; i < ARRAY_SIZE(priv->supplies); ++i)
> + priv->supplies[i].supply = tc358768_supplies[i];
> +
> + ret = devm_regulator_bulk_get(priv->dev, ARRAY_SIZE(priv->supplies),
> + priv->supplies);
> + if (ret < 0)
> + dev_err(priv->dev, "failed to get regulators: %d\n", ret);
> +
> + return ret;
> +}
> +
> +static int tc358768_i2c_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + struct tc358768_priv *priv;
> + struct device *dev = &client->dev;
> + struct device_node *np = dev->of_node;
> + int ret;
> +
> + if (!np)
> + return -ENODEV;
> +
> + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> + if (!priv)
> + return -ENOMEM;
> +
> + dev_set_drvdata(dev, priv);
> + priv->dev = dev;
> +
> + ret = tc358768_get_regulators(priv);
> + if (ret)
> + return ret;
> +
> + priv->refclk = devm_clk_get(dev, "refclk");
> + if (IS_ERR(priv->refclk))
> + return PTR_ERR(priv->refclk);
> +
> + /*
> + * RESX is low active, to disable tc358768 initially (keep in reset)
> + * the gpio line must be LOW. This is the ASSERTED state of
> + * GPIO_ACTIVE_LOW (GPIOD_OUT_HIGH == ASSERTED).
> + */
> + priv->reset_gpio = devm_gpiod_get_optional(dev, "reset",
> + GPIOD_OUT_HIGH);
> + if (IS_ERR(priv->reset_gpio))
> + return PTR_ERR(priv->reset_gpio);
> +
> + priv->regmap = devm_regmap_init_i2c(client, &tc358768_regmap_config);
> + if (IS_ERR(priv->regmap)) {
> + dev_err(dev, "Failed to init regmap\n");
> + return PTR_ERR(priv->regmap);
> + }
> +
> + priv->dsi_host.dev = dev;
> + priv->dsi_host.ops = &tc358768_dsi_host_ops;
> +
> + priv->bridge.funcs = &tc358768_bridge_funcs;
> + priv->bridge.timings = &default_tc358768_timings;
> + priv->bridge.of_node = np;
> +
> + i2c_set_clientdata(client, priv);
> +
> + ret = mipi_dsi_host_register(&priv->dsi_host);
> + if (ret)
> + return ret;
> +
> + return 0;
It could be replaced by:
ÂÂÂ return mipi_dsi_host_register(&priv->dsi_host);
Matter of taste, up to you.
Overall the driver is in good shape, except hw_enable refcounting, which
I hope we will clarify quickly.
Regards
Andrzej
> +}
> +
> +static int tc358768_i2c_remove(struct i2c_client *client)
> +{
> + struct tc358768_priv *priv = i2c_get_clientdata(client);
> +
> + mipi_dsi_host_unregister(&priv->dsi_host);
> +
> + return 0;
> +}
> +
> +static struct i2c_driver tc358768_driver = {
> + .driver = {
> + .name = "tc358768",
> + .of_match_table = tc358768_of_ids,
> + },
> + .id_table = tc358768_i2c_ids,
> + .probe = tc358768_i2c_probe,
> + .remove = tc358768_i2c_remove,
> +};
> +module_i2c_driver(tc358768_driver);
> +
> +MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@xxxxxx>");
> +MODULE_DESCRIPTION("TC358768AXBG/TC358778XBG DSI bridge");
> +MODULE_LICENSE("GPL v2");