> -----Original Message-----
> From: Ville Syrjälä [mailto:[email protected]]
> Sent: Friday, February 19, 2016 7:38 PM
> To: Deepak, M <[email protected]>
> Cc: [email protected]
> Subject: Re: [Intel-gfx] [PATCH] drm/i915: Get the i2c bus number from the
> ACPI
>
> On Fri, Feb 19, 2016 at 07:25:57PM +0530, Deepak M wrote:
> > Currently for executing the i2c MIPI sequence, we are relaying on the
> > i2c bus bunmber which is specified in the VBT.
> >
> > Signed-off-by: Deepak M <[email protected]>
> > ---
> > drivers/gpu/drm/i915/i915_dma.c | 2 ++
> > drivers/gpu/drm/i915/i915_drv.h | 7 ++++++
> > drivers/gpu/drm/i915/intel_acpi.c | 49
> > +++++++++++++++++++++++++++++++++++++++
> > 3 files changed, 58 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/i915/i915_dma.c
> > b/drivers/gpu/drm/i915/i915_dma.c index 1c6d227..8cd1d9d 100644
> > --- a/drivers/gpu/drm/i915/i915_dma.c
> > +++ b/drivers/gpu/drm/i915/i915_dma.c
> > @@ -387,6 +387,8 @@ static int i915_load_modeset_init(struct
> > drm_device *dev)
> >
> > intel_register_dsm_handler();
> >
> > + intel_acpi_find_i2c(dev_priv);
> > +
> > ret = vga_switcheroo_register_client(dev->pdev,
> &i915_switcheroo_ops, false);
> > if (ret)
> > goto cleanup_vga_client;
> > diff --git a/drivers/gpu/drm/i915/i915_drv.h
> > b/drivers/gpu/drm/i915/i915_drv.h index 6644c2e..6fe8b64 100644
> > --- a/drivers/gpu/drm/i915/i915_drv.h
> > +++ b/drivers/gpu/drm/i915/i915_drv.h
> > @@ -47,6 +47,7 @@
> > #include <drm/intel-gtt.h>
> > #include <drm/drm_legacy.h> /* for struct drm_dma_handle */ #include
> > <drm/drm_gem.h>
> > +#include <linux/acpi.h>
> > #include <linux/backlight.h>
> > #include <linux/hashtable.h>
> > #include <linux/intel-iommu.h>
> > @@ -1880,6 +1881,11 @@ struct drm_i915_private {
> >
> > struct i915_workarounds workarounds;
> >
> > + struct {
> > + int i2c_bus_number;
> > + int i2c_slave_address;
> > + } acpi_data;
>
> The naming is rather vague. i2c bus for what?
>
> Also is one bus always enough? The VBT i2c stuff could use multiple i2c
> busses. Also how do we map this to the bus number that the VBT has?
>
[Deepak, M] Most of the cases I have seen only one i2c being used, If there are
multiple i2c busses used then need to check which i2c is used for what purpose
and is there a protocol which is followed by BIOS team when more than one i2c
bus is used.
> > +
> > /* Reclocking support */
> > bool render_reclock_avail;
> >
> > @@ -3426,6 +3432,7 @@ intel_opregion_notify_adapter(struct
> drm_device
> > *dev, pci_power_t state) #ifdef CONFIG_ACPI extern void
> > intel_register_dsm_handler(void); extern void
> > intel_unregister_dsm_handler(void);
> > +extern acpi_status intel_acpi_find_i2c(struct drm_i915_private
> > +*dev_priv);
> > #else
> > static inline void intel_register_dsm_handler(void) { return; }
> > static inline void intel_unregister_dsm_handler(void) { return; } diff
> > --git a/drivers/gpu/drm/i915/intel_acpi.c
> > b/drivers/gpu/drm/i915/intel_acpi.c
> > index eb638a1..f62be5c 100644
> > --- a/drivers/gpu/drm/i915/intel_acpi.c
> > +++ b/drivers/gpu/drm/i915/intel_acpi.c
> > @@ -110,6 +110,55 @@ static void intel_dsm_platform_mux_info(void)
> > ACPI_FREE(pkg);
> > }
> >
> > +static int i2c_acpi_get_name(struct acpi_resource *ares, void *data)
> > +{
> > + struct drm_i915_private *dev_priv = data;
> > + struct acpi_resource_i2c_serialbus *sb;
> > + unsigned int val;
> > + char *resource;
> > + int error;
> > +
> > + if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
> > + sb = &ares->data.i2c_serial_bus;
> > +
> > + if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_I2C) {
> > + resource = sb->resource_source.string_ptr;
> > + resource = strstr(resource, "I2C");
> > + error = kstrtouint(resource+3, 0, &val);
> > + if (error)
> > + return error;
> > + dev_priv->acpi_data.i2c_bus_number = val;
> > + dev_priv->acpi_data.i2c_slave_address =
> > + sb->slave_address;
> > + }
> > + }
> > + return 1;
> > +}
> > +
> > +acpi_status intel_acpi_find_i2c(struct drm_i915_private *dev_priv) {
> > + struct pci_dev *pdev = dev_priv->dev->pdev;
> > + struct list_head resource_list;
> > + struct acpi_device *adev;
> > + acpi_handle dhandle;
> > +
> > + dhandle = ACPI_HANDLE(&pdev->dev);
> > + if (!dhandle)
> > + return false;
> > +
> > + if (acpi_bus_get_device(dhandle, &adev))
> > + return AE_OK;
> > + if (acpi_bus_get_status(adev) || !adev->status.present)
> > + return AE_OK;
> > +
> > + INIT_LIST_HEAD(&resource_list);
> > + acpi_dev_get_resources(adev, &resource_list,
> > + i2c_acpi_get_name, dev_priv);
> > + acpi_dev_free_resource_list(&resource_list);
> > +
> > + return AE_OK;
> > +}
> > +
> > static bool intel_dsm_pci_probe(struct pci_dev *pdev) {
> > acpi_handle dhandle;
> > --
> > 1.9.1
> >
> > _______________________________________________
> > Intel-gfx mailing list
> > [email protected]
> > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
>
> --
> Ville Syrjälä
> Intel OTC
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