On Fri, 10 Jan 2020, Vivek Kasireddy <vivek.kasireddy@xxxxxxxxx> wrote: > Parsing the i2c element is mainly done to transfer the payload from the > MIPI sequence block to the relevant slave device. In some cases, the > commands that are part of the payload can be used to turn on the backlight. > > This patch is actually a refactored version of this old patch: > https://lists.freedesktop.org/archives/intel-gfx/2014-December/056897.html > > In addition to the refactoring, the original patch is augmented by looking up > the i2c bus from ACPI NS instead of relying on the bus number provided > in the VBT. All this acpi business in the patch will fail the build on CONFIG_ACPI=n. BR, Jani. > > This patch was tested on Aava Mobile's Inari 10 tablet. It enabled > turning on the backlight by transfering the payload to the device. > > v2: > - Add DRM_DEV_ERROR for invalid adapter and failed transfer and also > drop the DRM_DEBUG that existed originally. (Hans) > - Add two gotos instead of one to clean things up properly. > > v3: > - Identify the device on which this patch was tested in the commit > message (Ville) > > Cc: Hans de Goede <hdegoede@xxxxxxxxxx> > Cc: Nabendu Maiti <nabendu.bikash.maiti@xxxxxxxxx> > Cc: Matt Roper <matthew.d.roper@xxxxxxxxx> > Cc: Bob Paauwe <bob.j.paauwe@xxxxxxxxx> > Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > Reviewed-by: Hans de Goede <hdegoede@xxxxxxxxxx> > Signed-off-by: Vivek Kasireddy <vivek.kasireddy@xxxxxxxxx> > --- > drivers/gpu/drm/i915/display/intel_dsi.h | 3 + > drivers/gpu/drm/i915/display/intel_dsi_vbt.c | 99 +++++++++++++++++++- > 2 files changed, 100 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/i915/display/intel_dsi.h b/drivers/gpu/drm/i915/display/intel_dsi.h > index 7481a5aa3084..6cef1356b4e6 100644 > --- a/drivers/gpu/drm/i915/display/intel_dsi.h > +++ b/drivers/gpu/drm/i915/display/intel_dsi.h > @@ -69,6 +69,9 @@ struct intel_dsi { > /* number of DSI lanes */ > unsigned int lane_count; > > + /* i2c bus associated with the slave device */ > + int i2c_bus_num; > + > /* > * video mode pixel format > * > diff --git a/drivers/gpu/drm/i915/display/intel_dsi_vbt.c b/drivers/gpu/drm/i915/display/intel_dsi_vbt.c > index 0032161e0f76..89fb0d90b694 100644 > --- a/drivers/gpu/drm/i915/display/intel_dsi_vbt.c > +++ b/drivers/gpu/drm/i915/display/intel_dsi_vbt.c > @@ -86,6 +86,12 @@ static struct gpio_map vlv_gpio_table[] = { > { VLV_GPIO_NC_11_PANEL1_BKLTCTL }, > }; > > +struct i2c_adapter_lookup { > + u16 slave_addr; > + struct intel_dsi *intel_dsi; > + acpi_handle dev_handle; > +}; > + > #define CHV_GPIO_IDX_START_N 0 > #define CHV_GPIO_IDX_START_E 73 > #define CHV_GPIO_IDX_START_SW 100 > @@ -378,11 +384,98 @@ static const u8 *mipi_exec_gpio(struct intel_dsi *intel_dsi, const u8 *data) > return data; > } > > +static int i2c_adapter_lookup(struct acpi_resource *ares, void *data) > +{ > + struct i2c_adapter_lookup *lookup = data; > + struct intel_dsi *intel_dsi = lookup->intel_dsi; > + struct acpi_resource_i2c_serialbus *sb; > + struct i2c_adapter *adapter; > + acpi_handle adapter_handle; > + acpi_status status; > + > + if (intel_dsi->i2c_bus_num >= 0 || > + !i2c_acpi_get_i2c_resource(ares, &sb)) > + return 1; > + > + if (lookup->slave_addr != sb->slave_address) > + return 1; > + > + status = acpi_get_handle(lookup->dev_handle, > + sb->resource_source.string_ptr, > + &adapter_handle); > + if (ACPI_FAILURE(status)) > + return 1; > + > + adapter = i2c_acpi_find_adapter_by_handle(adapter_handle); > + if (adapter) > + intel_dsi->i2c_bus_num = adapter->nr; > + > + return 1; > +} > + > static const u8 *mipi_exec_i2c(struct intel_dsi *intel_dsi, const u8 *data) > { > - DRM_DEBUG_KMS("Skipping I2C element execution\n"); > + struct drm_device *drm_dev = intel_dsi->base.base.dev; > + struct device *dev = &drm_dev->pdev->dev; > + struct i2c_adapter *adapter; > + struct acpi_device *acpi_dev; > + struct list_head resource_list; > + struct i2c_adapter_lookup lookup; > + struct i2c_msg msg; > + int ret; > + u8 vbt_i2c_bus_num = *(data + 2); > + u16 slave_addr = *(u16 *)(data + 3); > + u8 reg_offset = *(data + 5); > + u8 payload_size = *(data + 6); > + u8 *payload_data; > + > + if (intel_dsi->i2c_bus_num < 0) { > + intel_dsi->i2c_bus_num = vbt_i2c_bus_num; > + > + acpi_dev = ACPI_COMPANION(dev); > + if (acpi_dev) { > + memset(&lookup, 0, sizeof(lookup)); > + lookup.slave_addr = slave_addr; > + lookup.intel_dsi = intel_dsi; > + lookup.dev_handle = acpi_device_handle(acpi_dev); > + > + INIT_LIST_HEAD(&resource_list); > + acpi_dev_get_resources(acpi_dev, &resource_list, > + i2c_adapter_lookup, > + &lookup); > + acpi_dev_free_resource_list(&resource_list); > + } > + } > > - return data + *(data + 6) + 7; > + adapter = i2c_get_adapter(intel_dsi->i2c_bus_num); > + if (!adapter) { > + DRM_DEV_ERROR(dev, "Cannot find a valid i2c bus for xfer\n"); > + goto err_bus; > + } > + > + payload_data = kzalloc(payload_size + 1, GFP_KERNEL); > + if (!payload_data) > + goto err_alloc; > + > + payload_data[0] = reg_offset; > + memcpy(&payload_data[1], (data + 7), payload_size); > + > + msg.addr = slave_addr; > + msg.flags = 0; > + msg.len = payload_size + 1; > + msg.buf = payload_data; > + > + ret = i2c_transfer(adapter, &msg, 1); > + if (ret < 0) > + DRM_DEV_ERROR(dev, > + "Failed to xfer payload of size (%u) to reg (%u)\n", > + payload_size, reg_offset); > + > + kfree(payload_data); > +err_alloc: > + i2c_put_adapter(adapter); > +err_bus: > + return data + payload_size + 7; > } > > static const u8 *mipi_exec_spi(struct intel_dsi *intel_dsi, const u8 *data) > @@ -683,6 +776,8 @@ bool intel_dsi_vbt_init(struct intel_dsi *intel_dsi, u16 panel_id) > intel_dsi->panel_off_delay = pps->panel_off_delay / 10; > intel_dsi->panel_pwr_cycle_delay = pps->panel_power_cycle_delay / 10; > > + intel_dsi->i2c_bus_num = -1; > + > /* a regular driver would get the device in probe */ > for_each_dsi_port(port, intel_dsi->ports) { > mipi_dsi_attach(intel_dsi->dsi_hosts[port]->device); -- Jani Nikula, Intel Open Source Graphics Center _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
