On Fri, 3 Jan 2020 12:05:11 +0100 Hans de Goede <hdegoede@xxxxxxxxxx> wrote: Hi Hans, > Hi Vivek, > > On 03-01-2020 01:00, Vivek Kasireddy 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 old patch is augmented by > > looking up the i2c bus from ACPI NS instead of relying on the bus > > number provided in the VBT. > > > > Cc: Deepak M <m.deepak@xxxxxxxxx> > > Cc: Nabendu Maiti <nabendu.bikash.maiti@xxxxxxxxx> > > Cc: Matt Roper <matthew.d.roper@xxxxxxxxx> > > Cc: Bob Paauwe <bob.j.paauwe@xxxxxxxxx> > > Signed-off-by: Vivek Kasireddy <vivek.kasireddy@xxxxxxxxx> > > Thank you for this patch, I have been doing a lot of work to make > DSI panels on Bay Trail and Cherry Trail devices work better, as such > I've done a lot of testing of DSI panels. But I have never seen any > MIPI sequences actually use the i2c commands. May I ask how you have > tested this? Do you have a device which actually uses the i2c > commands? Oh, they sure exist; we do have a device that uses i2c commands to turn on the backlight that we have tested this patch on. > > I also have some small review comments inline: > > > --- > > drivers/gpu/drm/i915/display/intel_dsi.h | 3 + > > drivers/gpu/drm/i915/display/intel_dsi_vbt.c | 93 > > ++++++++++++++++++++ 2 files changed, 96 insertions(+) > > > > diff --git a/drivers/gpu/drm/i915/display/intel_dsi.h > > b/drivers/gpu/drm/i915/display/intel_dsi.h index > > b15be5814599..5651bc8aa5c2 100644 --- > > a/drivers/gpu/drm/i915/display/intel_dsi.h +++ > > b/drivers/gpu/drm/i915/display/intel_dsi.h @@ -68,6 +68,9 @@ 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 > > f90946c912ee..60441a5a3dba 100644 --- > > a/drivers/gpu/drm/i915/display/intel_dsi_vbt.c +++ > > b/drivers/gpu/drm/i915/display/intel_dsi_vbt.c @@ -83,6 +83,12 @@ > > 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 > > @@ -375,8 +381,93 @@ 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) { > > + struct drm_device *dev = intel_dsi->base.base.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->pdev->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); > > + } > > + } > > + > > + adapter = i2c_get_adapter(intel_dsi->i2c_bus_num); > > + if (!adapter) > > + goto out; > > This should never happen, so you should put a DRM_DEV_WARN here. Ok, will do. > > > + > > + payload_data = kzalloc(payload_size + 1, GFP_KERNEL); > > + if (!payload_data) > > + goto out; > > + > > + 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_ERROR("i2c transfer failed"); > > DRM_DEV_ERROR? And maybe some more info, like the register which > the transfer is going to + payload size? Ok, adding extra info makes sense. > > > + > > + kfree(payload_data); > > + i2c_put_adapter(adapter); > > + > > Just put out here, no need for the DRM_DEBUG (which should no > longer be a debug now that we implement this) below, since we > WARN or ERROR on all goto out; statements above. Ok, will do. Thanks, Vivek > > out: > > > + return data + payload_size + 7; > > And drop these 3 lines: > > > +out: > > DRM_DEBUG_KMS("Skipping I2C element execution\n"); > > > > return data + *(data + 6) + 7; > > > > > @@ -664,6 +755,8 @@ 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); > > > > Regards, > > Hans > _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
