On Wed, Apr 18, 2018 at 05:49:59PM +0530, Sandeep Panda wrote:
> Add support for TI's sn65dsi86 dsi2edp bridge chip.
> The chip converts DSI transmitted signal to eDP signal,
> which is fed to the connected eDP panel.
>
> This chip can be controlled via either i2c interface or
> dsi interface. Currently in driver all the control registers
> are being accessed through i2c interface only.
> Also as of now HPD support has not been added to bridge
> chip driver.
>
> Signed-off-by: Sandeep Panda <spanda@xxxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/bridge/ti-sn65dsi86.c | 742 ++++++++++++++++++++++++++++++++++
> 1 file changed, 742 insertions(+)
> create mode 100644 drivers/gpu/drm/bridge/ti-sn65dsi86.c
>
> diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
> new file mode 100644
> index 0000000..c798f2f
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
> @@ -0,0 +1,742 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
There should be a copyright here.
> +
> +#include <linux/types.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/device.h>
> +#include <linux/platform_device.h>
> +#include <linux/delay.h>
> +#include <linux/i2c.h>
> +#include <linux/gpio.h>
> +#include <linux/of_gpio.h>
> +#include <linux/of_graph.h>
> +#include <linux/regulator/consumer.h>
> +#include <drm/drmP.h>
> +#include <drm/drm_atomic.h>
> +#include <drm/drm_atomic_helper.h>
> +#include <drm/drm_crtc_helper.h>
> +#include <drm/drm_mipi_dsi.h>
> +#include <drm/drm_panel.h>
> +
> +#define SN_BRIDGE_REVISION_ID 0x2
> +
> +/* Link Training specific registers */
> +#define SN_DEVICE_REV_REG 0x08
> +#define SN_REFCLK_FREQ_REG 0x0A
> +#define SN_DSI_LANES_REG 0x10
> +#define SN_DSIA_CLK_FREQ_REG 0x12
> +#define SN_ENH_FRAME_REG 0x5A
> +#define SN_SSC_CONFIG_REG 0x93
> +#define SN_DATARATE_CONFIG_REG 0x94
> +#define SN_PLL_ENABLE_REG 0x0D
> +#define SN_SCRAMBLE_CONFIG_REG 0x95
> +#define SN_AUX_WDATA0_REG 0x64
> +#define SN_AUX_ADDR_19_16_REG 0x74
> +#define SN_AUX_ADDR_15_8_REG 0x75
> +#define SN_AUX_ADDR_7_0_REG 0x76
> +#define SN_AUX_LENGTH_REG 0x77
> +#define SN_AUX_CMD_REG 0x78
> +#define SN_ML_TX_MODE_REG 0x96
> +#define SN_PAGE_SELECT_REG 0xFF
> +#define SN_AUX_RDATA0_REG 0x79
> +/* video config specific registers */
> +#define SN_CHA_ACTIVE_LINE_LENGTH_LOW_REG 0x20
> +#define SN_CHA_ACTIVE_LINE_LENGTH_HIGH_REG 0x21
> +#define SN_CHA_VERTICAL_DISPLAY_SIZE_LOW_REG 0x24
> +#define SN_CHA_VERTICAL_DISPLAY_SIZE_HIGH_REG 0x25
> +#define SN_CHA_HSYNC_PULSE_WIDTH_LOW_REG 0x2C
> +#define SN_CHA_HSYNC_PULSE_WIDTH_HIGH_REG 0x2D
> +#define SN_CHA_VSYNC_PULSE_WIDTH_LOW_REG 0x30
> +#define SN_CHA_VSYNC_PULSE_WIDTH_HIGH_REG 0x31
> +#define SN_CHA_HORIZONTAL_BACK_PORCH_REG 0x34
> +#define SN_CHA_VERTICAL_BACK_PORCH_REG 0x36
> +#define SN_CHA_HORIZONTAL_FRONT_PORCH_REG 0x38
> +#define SN_CHA_VERTICAL_FRONT_PORCH_REG 0x3A
> +#define SN_DATA_FORMAT_REG 0x5B
> +#define SN_COLOR_BAR_CONFIG_REG 0x3C
> +
> +#define DPPLL_CLK_SRC_REFCLK 0
> +#define DPPLL_CLK_SRC_DSICLK 1
> +#define MIN_DSI_CLK_FREQ_MHZ 40
> +
> +enum ti_sn_bridge_ref_clks {
> + SN_REF_CLK_12_MHZ = 0,
> + SN_REF_CLK_19_2_MHZ,
> + SN_REF_CLK_26_MHZ,
> + SN_REF_CLK_27_MHZ,
> + SN_REF_CLK_38_4_MHZ,
> + SN_REF_CLK_MAX,
> +};
> +
> +struct ti_sn_bridge {
> + struct device *dev;
> + struct drm_bridge bridge;
> + struct drm_connector connector;
> + struct device_node *host_node;
> + struct mipi_dsi_device *dsi;
> + /* handle to the connected eDP panel */
> + struct drm_panel *panel;
> + int irq;
> + struct gpio_desc *irq_gpio;
> + /* list of gpios needed to enable the bridge functionality */
> + struct gpio_descs *enable_gpios;
> + unsigned int num_supplies;
> + struct regulator_bulk_data *supplies;
> + struct i2c_client *i2c_client;
> + struct i2c_adapter *ddc;
> + bool power_on;
> + u32 num_modes;
> + struct drm_display_mode curr_mode;
> +};
> +
> +static int ti_sn_bridge_write(struct ti_sn_bridge *pdata, u8 reg, u8 val)
> +{
> + struct i2c_client *client = pdata->i2c_client;
> + u8 buf[2] = {reg, val};
> + struct i2c_msg msg = {
> + .addr = client->addr,
> + .flags = 0,
> + .len = 2,
> + .buf = buf,
> + };
> +
> + if (i2c_transfer(client->adapter, &msg, 1) < 1) {
> + DRM_ERROR("i2c write failed\n");
> + return -EIO;
> + }
> +
> + return 0;
> +}
> +
> +static int ti_sn_bridge_read(struct ti_sn_bridge *pdata,
> + u8 reg, char *buf, u32 size)
> +{
> + struct i2c_client *client = pdata->i2c_client;
> + struct i2c_msg msg[2] = {
> + {
> + .addr = client->addr,
> + .flags = 0,
> + .len = 1,
> + .buf = ®,
> + },
> + {
> + .addr = client->addr,
> + .flags = I2C_M_RD,
> + .len = size,
> + .buf = buf,
> + }
> + };
> +
> + if (i2c_transfer(client->adapter, msg, 2) != 2) {
> + DRM_ERROR("i2c read failed\n");
> + return -EIO;
> + }
> +
> + return 0;
> +}
> +
> +static void ti_sn_bridge_gpio_configure(struct ti_sn_bridge *pdata, bool on)
> +{
> + int value, i = 0, num = 0;
> + int *value_array = NULL;
> +
> + if (!pdata)
> + return;
pdata should always be valid here.
> + value = on ? 1 : 0;
> + num = pdata->enable_gpios->ndescs;
> + value_array = kmalloc(num * sizeof(int), GFP_KERNEL);
> + if (value_array) {
> + for (i = 0; i < num; i++)
> + value_array[i] = value;
> + gpiod_set_array_value(num, pdata->enable_gpios->desc,
> + value_array);
> + kfree(value_array);
> + }
> +
> + if (pdata->irq_gpio)
> + gpiod_set_value(pdata->irq_gpio, value);
> +
> + DRM_DEBUG("config to: %d\n", value);
> +}
> +
> +static void ti_sn_bridge_power_ctrl(struct ti_sn_bridge *pdata, bool enable)
> +{
> + static int ref_count;
> +
> + if (!pdata)
> + return;
pdata should always be valid here.
> + if (enable)
> + ref_count++;
> + else
> + ref_count--;
> +
> + if (enable && (ref_count == 1)) {
> + ti_sn_bridge_gpio_configure(pdata, true);
> +
> + if (regulator_bulk_enable(pdata->num_supplies,
> + pdata->supplies)) {
> + DRM_ERROR("bridge regulator enable failed\n");
> + return;
> + }
> + pdata->power_on = true;
> + } else if (!enable && !ref_count) {
> + regulator_bulk_disable(pdata->num_supplies, pdata->supplies);
> +
> + ti_sn_bridge_gpio_configure(pdata, false);
> + pdata->power_on = false;
> + } else {
> + DRM_DEBUG("ti_sn_bridge power ctrl: %d refcount: %d\n",
> + enable, ref_count);
> + }
> +}
> +
> +/* Connector funcs */
> +static struct ti_sn_bridge *
> +connector_to_ti_sn_bridge(struct drm_connector *connector)
> +{
> + return container_of(connector, struct ti_sn_bridge, connector);
> +}
> +
> +static int ti_sn_bridge_connector_get_modes(struct drm_connector *connector)
> +{
> + struct ti_sn_bridge *pdata = connector_to_ti_sn_bridge(connector);
> + struct drm_panel *panel = pdata->panel;
> + struct edid *edid;
> +
> + if (panel) {
> + DRM_DEBUG("get mode from connected drm_panel\n");
> + pdata->num_modes = drm_panel_get_modes(panel);
> + } else {
> + /* get from EDID */
> + if (!pdata->ddc)
> + return 0;
> + ti_sn_bridge_power_ctrl(pdata, true);
> + edid = drm_get_edid(connector, pdata->ddc);
> + if (edid) {
> + drm_mode_connector_update_edid_property(connector,
> + edid);
> + pdata->num_modes = drm_add_edid_modes(connector, edid);
> + drm_edid_to_eld(connector, edid);
> + kfree(edid);
> + } else {
> + DRM_DEBUG("failed to get edid\n");
> + }
> + ti_sn_bridge_power_ctrl(pdata, false);
> + }
> +
> + return pdata->num_modes;
> +}
> +
> +static enum drm_mode_status
> +ti_sn_bridge_connector_mode_valid(struct drm_connector *connector,
> + struct drm_display_mode *mode)
> +{
> + /* maximum supported resolution is 4K at 60 fps */
> + if (mode->clock > 594000)
> + return MODE_CLOCK_HIGH;
> +
> + return MODE_OK;
> +}
> +
> +static struct drm_connector_helper_funcs ti_sn_bridge_connector_helper_funcs = {
> + .get_modes = ti_sn_bridge_connector_get_modes,
> + .mode_valid = ti_sn_bridge_connector_mode_valid,
> +};
> +
> +static enum drm_connector_status
> +ti_sn_bridge_connector_detect(struct drm_connector *connector, bool force)
> +{
> + struct ti_sn_bridge *pdata = connector_to_ti_sn_bridge(connector);
> +
> + /**
> + * TODO: Currently if drm_panel is present, then always
> + * return the status as connected. Need to add support to detect
> + * device state for no panel(hot pluggable) scenarios.
> + */
> + if (pdata->panel)
> + return connector_status_connected;
> + else
> + return connector_status_disconnected;
> +}
> +
> +static const struct drm_connector_funcs ti_sn_bridge_connector_funcs = {
> + .fill_modes = drm_helper_probe_single_connector_modes,
> + .detect = ti_sn_bridge_connector_detect,
> + .destroy = drm_connector_cleanup,
> + .reset = drm_atomic_helper_connector_reset,
> + .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
> + .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
> +};
> +
> +static struct ti_sn_bridge *bridge_to_ti_sn_bridge(struct drm_bridge *bridge)
> +{
> + return container_of(bridge, struct ti_sn_bridge, bridge);
> +}
> +
> +static int ti_sn_bridge_read_device_rev(struct ti_sn_bridge *pdata)
> +{
> + u8 rev = 0;
> + int ret = 0;
> +
> + ret = ti_sn_bridge_read(pdata, SN_DEVICE_REV_REG, &rev, 1);
> + if (ret)
> + goto exit;
> +
> + if (rev == SN_BRIDGE_REVISION_ID) {
> + DRM_DEBUG("ti_sn_bridge revision id: 0x%x\n", rev);
> + } else {
> + DRM_ERROR("ti_sn_bridge revision id mismatch\n");
I find it useful to print what the mismatch is so you can debug more
effectively.
> + ret = -EINVAL;
> + }
> +
> +exit:
> + return ret;
> +}
> +
> +static const char * const ti_sn_bridge_supply_names[] = {
> + "vccio",
> + "vcca",
> +};
> +
> +static int ti_sn_bridge_parse_regulators(struct ti_sn_bridge *pdata)
> +{
> + unsigned int i;
> + int ret;
> +
> + pdata->num_supplies = ARRAY_SIZE(ti_sn_bridge_supply_names);
> +
> + pdata->supplies = devm_kcalloc(pdata->dev, pdata->num_supplies,
> + sizeof(*pdata->supplies), GFP_KERNEL);
> + if (!pdata->supplies)
> + return -ENOMEM;
> +
> + for (i = 0; i < pdata->num_supplies; i++)
> + pdata->supplies[i].supply = ti_sn_bridge_supply_names[i];
> +
> + ret = devm_regulator_bulk_get(pdata->dev,
> + pdata->num_supplies, pdata->supplies);
> +
> + return ret;
Nit: you can combine the above two lines and get rid of 'ret'.
> +}
> +
> +static void ti_sn_bridge_attach_panel(struct ti_sn_bridge *pdata)
> +{
> + struct device_node *panel_node, *port, *endpoint;
> + struct drm_panel *panel = NULL;
> +
> + port = of_graph_get_port_by_id(pdata->dev->of_node, 1);
> + if (port) {
> + endpoint = of_get_child_by_name(port, "endpoint");
> + of_node_put(port);
> + if (!endpoint) {
> + dev_err(pdata->dev, "no output endpoint found\n");
> + goto error;
> + }
> +
> + panel_node = of_graph_get_remote_port_parent(endpoint);
> + of_node_put(endpoint);
> + if (!panel_node) {
> + dev_err(pdata->dev, "no output node found\n");
> + goto error;
> + }
> +
> + panel = of_drm_find_panel(panel_node);
> + of_node_put(panel_node);
> + if (!panel) {
> + dev_err(pdata->dev, "no panel node found\n");
> + goto error;
> + }
> + }
> +
> + pdata->panel = panel;
> + drm_panel_attach(panel, &pdata->connector);
> +
> + return;
> +
> +error:
> + pdata->panel = NULL;
Is this needed? isn't pdata->panel already null when we come in? If so
you can just return the error cases and remove the label.
> +}
> +
> +static int ti_sn_bridge_attach(struct drm_bridge *bridge)
> +{
> + struct mipi_dsi_host *host;
> + struct mipi_dsi_device *dsi;
> + struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge);
> + int ret;
> + const struct mipi_dsi_device_info info = { .type = "ti_sn_bridge",
> + .channel = 0,
> + .node = NULL,
> + };
> +
> + if (!bridge->encoder) {
> + DRM_ERROR("Parent encoder object not found");
Missing \n on the end of the string.
> + return -ENODEV;
> + }
> +
> + /* HPD not supported */
> + pdata->connector.polled = 0;
> +
> + ret = drm_connector_init(bridge->dev, &pdata->connector,
> + &ti_sn_bridge_connector_funcs,
> + DRM_MODE_CONNECTOR_eDP);
The actual #define is CONNNECTOR_eDP?
> + if (ret) {
> + DRM_ERROR("Failed to initialize connector with drm\n");
> + return ret;
> + }
> +
> + drm_connector_helper_add(&pdata->connector,
> + &ti_sn_bridge_connector_helper_funcs);
> + drm_mode_connector_attach_encoder(&pdata->connector, bridge->encoder);
> +
> + host = of_find_mipi_dsi_host_by_node(pdata->host_node);
> + if (!host) {
> + DRM_ERROR("failed to find dsi host\n");
There isn't any tear down that needs to happen here?
> + return -ENODEV;
> + }
> +
> + dsi = mipi_dsi_device_register_full(host, &info);
> + if (IS_ERR(dsi)) {
> + DRM_ERROR("failed to create dsi device\n");
> + ret = PTR_ERR(dsi);
> + goto err_dsi_device;
Above you return directly but here you goto a return. You should use the same
consistent approach in both cases.
> + }
> +
> + /* TODO: setting to 4 lanes always for now */
> + dsi->lanes = 4;
> + dsi->format = MIPI_DSI_FMT_RGB888;
> + dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_SYNC_PULSE |
> + MIPI_DSI_MODE_EOT_PACKET | MIPI_DSI_MODE_VIDEO_HSE;
> +
> + ret = mipi_dsi_attach(dsi);
> + if (ret < 0) {
> + DRM_ERROR("failed to attach dsi to host\n");
> + goto err_dsi_attach;
> + }
> +
> + pdata->dsi = dsi;
> +
> + DRM_DEBUG("bridge attached\n");
> + /* attach panel to bridge */
> + ti_sn_bridge_attach_panel(pdata);
> +
> + return 0;
> +
> +err_dsi_attach:
> + mipi_dsi_device_unregister(dsi);
> +err_dsi_device:
> + return ret;
> +}
> +
> +static void ti_sn_bridge_mode_set(struct drm_bridge *bridge,
> + struct drm_display_mode *mode,
> + struct drm_display_mode *adj_mode)
> +{
> + struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge);
> +
> + DRM_DEBUG("mode_set: hdisplay=%d, vdisplay=%d, vrefresh=%d, clock=%d\n",
> + adj_mode->hdisplay, adj_mode->vdisplay,
> + adj_mode->vrefresh, adj_mode->clock);
> +
> + drm_mode_copy(&pdata->curr_mode, adj_mode);
> +}
> +
> +static void ti_sn_bridge_disable(struct drm_bridge *bridge)
> +{
> + struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge);
> + struct drm_panel *panel = pdata->panel;
> +
> + if (panel) {
> + drm_panel_disable(panel);
> + drm_panel_unprepare(panel);
> + }
> +
> + ti_sn_bridge_power_ctrl(pdata, false);
> +}
> +
> +static void ti_sn_bridge_enable(struct drm_bridge *bridge)
> +{
> + struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge);
> + struct drm_panel *panel = pdata->panel;
> + struct drm_display_mode *mode = &pdata->curr_mode;
> + u32 bit_rate_mhz, clk_freq_mhz;
> + u8 val = 0;
> +
> + if (!pdata->num_modes)
> + return;
> +
> + ti_sn_bridge_power_ctrl(pdata, true);
> +
> + if (panel)
> + drm_panel_prepare(panel);
> +
> + /* CLK_SRC config */
> + ti_sn_bridge_write(pdata, SN_REFCLK_FREQ_REG,
> + (DPPLL_CLK_SRC_REFCLK | (SN_REF_CLK_19_2_MHZ << 0x1)));
> +
> + /* DSI_A lane config */
> + ti_sn_bridge_read(pdata, SN_DSI_LANES_REG, &val, 0x1);
> + val |= ((0x4 - pdata->dsi->lanes) & 0x03) << 0x3;
> + ti_sn_bridge_write(pdata, SN_DSI_LANES_REG, val);
> +
> + /* DP lane config */
> + ti_sn_bridge_read(pdata, SN_SSC_CONFIG_REG, &val, 0x1);
> + val |= ((pdata->dsi->lanes - 0x1) & 0x03) << 0x4;
> + ti_sn_bridge_write(pdata, SN_SSC_CONFIG_REG, val);
> +
> + /* set dsi clk frequency value */
> + bit_rate_mhz = (mode->clock / 1000) *
> + mipi_dsi_pixel_format_to_bpp(pdata->dsi->format);
> + clk_freq_mhz = bit_rate_mhz / (pdata->dsi->lanes * 2);
> + /* for each increment in val, frequency increases by 5MHz */
> + val = (MIN_DSI_CLK_FREQ_MHZ / 0x5) +
> + (((clk_freq_mhz - MIN_DSI_CLK_FREQ_MHZ) / 0x5) & 0xFF);
> + ti_sn_bridge_write(pdata, SN_DSIA_CLK_FREQ_REG, val);
> +
> + ti_sn_bridge_write(pdata, SN_DATARATE_CONFIG_REG, 0x80); /* set HBR */
> +
> + ti_sn_bridge_write(pdata, SN_PLL_ENABLE_REG, 0x1); /* Enable PLL */
> + usleep_range(10000, 10001);
> +
> + /* DPCD Register 0x0010A in Sink */
> + ti_sn_bridge_write(pdata, SN_AUX_WDATA0_REG, 0x01);
> + ti_sn_bridge_write(pdata, SN_AUX_ADDR_19_16_REG, 0x00);
> + ti_sn_bridge_write(pdata, SN_AUX_ADDR_15_8_REG, 0x01);
> + ti_sn_bridge_write(pdata, SN_AUX_ADDR_7_0_REG, 0x0A);
> + ti_sn_bridge_write(pdata, SN_AUX_LENGTH_REG, 0x01);
> + ti_sn_bridge_write(pdata, SN_AUX_CMD_REG, 0x81);
> + usleep_range(10000, 10001);
> +
> + /* Semi auto link training mode */
> + ti_sn_bridge_write(pdata, SN_ML_TX_MODE_REG, 0x0A);
> + usleep_range(20000, 20001);
> +
> + /* config video parameters */
> + ti_sn_bridge_write(pdata, SN_CHA_ACTIVE_LINE_LENGTH_LOW_REG,
> + mode->hdisplay & 0xFF);
> + ti_sn_bridge_write(pdata, SN_CHA_ACTIVE_LINE_LENGTH_HIGH_REG,
> + (mode->hdisplay >> 0x8) & 0xFF);
> + ti_sn_bridge_write(pdata, SN_CHA_VERTICAL_DISPLAY_SIZE_LOW_REG,
> + mode->vdisplay & 0xFF);
> + ti_sn_bridge_write(pdata, SN_CHA_VERTICAL_DISPLAY_SIZE_HIGH_REG,
> + (mode->hdisplay >> 0x8) & 0xFF);
> + ti_sn_bridge_write(pdata, SN_CHA_HSYNC_PULSE_WIDTH_LOW_REG,
> + (mode->htotal - mode->hsync_end) & 0xFF);
> + ti_sn_bridge_write(pdata, SN_CHA_HSYNC_PULSE_WIDTH_HIGH_REG,
> + ((mode->htotal - mode->hsync_end) >> 0x8) & 0xFF);
> + ti_sn_bridge_write(pdata, SN_CHA_VSYNC_PULSE_WIDTH_LOW_REG,
> + (mode->vtotal - mode->vsync_end) & 0xFF);
> + ti_sn_bridge_write(pdata, SN_CHA_VSYNC_PULSE_WIDTH_HIGH_REG,
> + ((mode->vtotal - mode->vsync_end) >> 0x8) & 0xFF);
> + ti_sn_bridge_write(pdata, SN_CHA_HORIZONTAL_BACK_PORCH_REG,
> + (mode->hsync_start - mode->hdisplay) & 0xFF);
> + ti_sn_bridge_write(pdata, SN_CHA_VERTICAL_BACK_PORCH_REG,
> + (mode->vsync_start - mode->vdisplay) & 0xFF);
> + ti_sn_bridge_write(pdata, SN_CHA_HORIZONTAL_FRONT_PORCH_REG,
> + (mode->hsync_end - mode->hsync_start) & 0xFF);
> + ti_sn_bridge_write(pdata, SN_CHA_VERTICAL_FRONT_PORCH_REG,
> + (mode->vsync_end - mode->vsync_start) & 0xFF);
> + if (pdata->dsi->format == MIPI_DSI_FMT_RGB888)
> + ti_sn_bridge_write(pdata, SN_DATA_FORMAT_REG, 0x00);
> + else
> + ti_sn_bridge_write(pdata, SN_DATA_FORMAT_REG, 0x01);
> + usleep_range(10000, 10001);
> +
> + /* enable video stream */
> + ti_sn_bridge_read(pdata, SN_ENH_FRAME_REG, &val, 0x1);
> + val |= BIT(3);
> + ti_sn_bridge_write(pdata, SN_ENH_FRAME_REG, val);
> +
> + if (panel)
> + drm_panel_enable(panel);
> +}
> +
> +static const struct drm_bridge_funcs ti_sn_bridge_funcs = {
> + .attach = ti_sn_bridge_attach,
> + .enable = ti_sn_bridge_enable,
> + .disable = ti_sn_bridge_disable,
> + .mode_set = ti_sn_bridge_mode_set,
> +};
> +
> +static int ti_sn_bridge_parse_gpios(struct ti_sn_bridge *pdata)
> +{
> + int ret = 0;
> +
> + if (!pdata || !pdata->dev)
> + return -EINVAL;
Both of these are known to be valid at this point.
> + pdata->enable_gpios = devm_gpiod_get_array(pdata->dev,
> + "enable", GPIOD_OUT_LOW);
> + if (IS_ERR(pdata->enable_gpios)) {
> + DRM_ERROR("failed to get enable gpio from DT\n");
> + ret = PTR_ERR(pdata->enable_gpios);
> + goto exit;
> + }
> +
> + pdata->irq_gpio = devm_gpiod_get_optional(pdata->dev, "irq",
> + GPIOD_OUT_LOW);
> + if (IS_ERR(pdata->irq_gpio))
> + DRM_ERROR("failed to get irq gpio from DT\n");
You need to set ret to PTR_ERR(pdata->irq_gpio) here.
> +
> +exit:
> + return ret;
> +}
> +
> +static int ti_sn_bridge_parse_dsi_host(struct ti_sn_bridge *pdata)
> +{
> + struct device_node *np = pdata->dev->of_node;
> + struct device_node *end_node;
> +
> + end_node = of_graph_get_endpoint_by_regs(np, 0, 0);
> + if (!end_node) {
> + DRM_ERROR("remote endpoint not found\n");
> + return -ENODEV;
> + }
> +
> + pdata->host_node = of_graph_get_remote_port_parent(end_node);
> + of_node_put(end_node);
> + if (!pdata->host_node) {
> + DRM_ERROR("remote node not found\n");
> + return -ENODEV;
> + }
> + of_node_put(pdata->host_node);
> +
> + return 0;
> +}
> +
> +static int ti_sn_bridge_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + struct ti_sn_bridge *pdata;
> + struct device_node *ddc_node;
> + int ret = 0;
> +
> + if (!client || !client->dev.of_node) {
I doubt the i2c probe would send you a NULL value for client and you are
matching on a DT device, so there is a pretty solid argument that
client->dev.of_node will be valid as well.
> + DRM_ERROR("invalid input\n");
> + return -EINVAL;
> + }
> +
> + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
> + DRM_ERROR("device doesn't support I2C\n");
> + return -ENODEV;
> + }
> +
> + pdata = devm_kzalloc(&client->dev,
> + sizeof(struct ti_sn_bridge), GFP_KERNEL);
> + if (!pdata)
> + return -ENOMEM;
> +
> + pdata->power_on = false;
> + pdata->dev = &client->dev;
> + pdata->i2c_client = client;
> + DRM_DEBUG("I2C address is %x\n", client->addr);
> +
> + ret = ti_sn_bridge_parse_dsi_host(pdata);
> + if (ret) {
> + DRM_ERROR("failed to parse device tree\n");
ti_sn_bridge_parse_dsi_host prints a error message on every failure point - you
don't need another one here.
> + goto err_dt_parse;
> + }
> +
> + ret = ti_sn_bridge_parse_gpios(pdata);
> + if (ret) {
> + DRM_ERROR("failed to parse gpios from DT\n");
Same - all the paths are covered in the child function.
> + goto err_dt_parse;
> + }
> +
> + ret = ti_sn_bridge_parse_regulators(pdata);
> + if (ret) {
> + DRM_ERROR("failed to parse regulators\n");
> + goto err_dt_parse;
> + }
> +
> + ddc_node = of_parse_phandle(pdata->dev->of_node, "ddc-i2c-bus", 0);
> + if (ddc_node) {
> + pdata->ddc = of_find_i2c_adapter_by_node(ddc_node);
> + of_node_put(ddc_node);
> + if (!pdata->ddc) {
> + dev_dbg(pdata->dev, "failed to read ddc node\n");
> + return -EPROBE_DEFER;
> + }
> + } else {
> + dev_dbg(pdata->dev, "no ddc property found\n");
> + }
> +
> + ti_sn_bridge_power_ctrl(pdata, true);
> + ret = ti_sn_bridge_read_device_rev(pdata);
> + if (ret) {
> + DRM_ERROR("failed to read chip rev\n");
ti_sn_bridge_read_device_rev has you covered with the error messages.
> + goto err_config;
> + } else {
> + DRM_DEBUG("bridge chip enabled successfully\n");
> + }
And also the debug messages for whatever its worth.
> + ti_sn_bridge_power_ctrl(pdata, false);
> +
> + i2c_set_clientdata(client, pdata);
> + dev_set_drvdata(&client->dev, pdata);
> +
> + pdata->bridge.funcs = &ti_sn_bridge_funcs;
> + pdata->bridge.of_node = client->dev.of_node;
> +
> + drm_bridge_add(&pdata->bridge);
> +
> + return ret;
> +
> +err_config:
> + ti_sn_bridge_power_ctrl(pdata, false);
> +err_dt_parse:
> + devm_kfree(&client->dev, pdata);
> + return ret;
> +}
> +
> +static int ti_sn_bridge_remove(struct i2c_client *client)
> +{
> + int ret = -EINVAL;
> + struct ti_sn_bridge *pdata = i2c_get_clientdata(client);
> +
> + if (!pdata)
> + goto end;
pdata is very unlikely to be null here, but as long as this is a light weight
check, I don't think it hurts too much.
> +
> + mipi_dsi_detach(pdata->dsi);
> + mipi_dsi_device_unregister(pdata->dsi);
> +
> + drm_bridge_remove(&pdata->bridge);
> +
> + disable_irq(pdata->irq);
> + free_irq(pdata->irq, pdata);
> +
> + ti_sn_bridge_gpio_configure(pdata, false);
> + i2c_put_adapter(pdata->ddc);
> +
> + devm_kfree(&client->dev, pdata);
> +
> +end:
> + return ret;
> +}
> +
> +static struct i2c_device_id ti_sn_bridge_id[] = {
> + { "ti,sn65dsi86", 0},
> + {}
Missing a comma on the end of the empty entry.
> +};
> +MODULE_DEVICE_TABLE(i2c, ti_sn_bridge_id);
> +
> +static const struct of_device_id ti_sn_bridge_match_table[] = {
> + {.compatible = "ti,sn65dsi86"},
> + {}
Same.
> +};
> +MODULE_DEVICE_TABLE(of, ti_sn_bridge_match_table);
> +
> +static struct i2c_driver ti_sn_bridge_driver = {
> + .driver = {
> + .name = "ti_sn65dsi86",
> + .owner = THIS_MODULE,
> + .of_match_table = ti_sn_bridge_match_table,
> + },
> + .probe = ti_sn_bridge_probe,
> + .remove = ti_sn_bridge_remove,
> + .id_table = ti_sn_bridge_id,
> +};
> +
> +module_i2c_driver(ti_sn_bridge_driver);
> +MODULE_DESCRIPTION("sn65dsi86 DSI to eDP bridge driver");
Looks like you are missing the module license here.
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