Waiting for review comments.
> -----Original Message-----
> From: Deepak, M
> Sent: Friday, March 11, 2016 3:55 PM
> To: intel-gfx@xxxxxxxxxxxxxxxxxxxxx
> Cc: Deepak, M <m.deepak@xxxxxxxxx>; Nikula, Jani <jani.nikula@xxxxxxxxx>;
> Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> Subject: [PATCH 1/2] drm/i915: Get the i2c bus number from the ACPI
>
> Currently for executing the i2c MIPI sequence, we are relaying on the i2c bus
> number which is specified in the VBT. But there are cases where different
> Fab versions of the board will drive the same chip with different i2c port, in
> which case the i2c bus number from the VBT cant be relied on. To overcome
> this the i2c bus number is read from the BIOS acpi table; BIOS can detect the
> Fab version in runtime and will store the correct i2c bus number in the ACPI
> table.
>
> v2 by Deepak:
> - Reading the i2c from the ACPI and storing them in list
>
> Cc: Jani Nikula <jani.nikula@xxxxxxxxx>
> Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> Signed-off-by: Deepak M <m.deepak@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/i915_dma.c | 2 ++
> drivers/gpu/drm/i915/i915_drv.h | 11 ++++++++
> drivers/gpu/drm/i915/intel_acpi.c | 59
> +++++++++++++++++++++++++++++++++++++++
> 3 files changed, 72 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/i915_dma.c
> b/drivers/gpu/drm/i915/i915_dma.c index 4aa3db6..57be99b 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 f37ac12..5c6279d 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -41,6 +41,7 @@
> #include "intel_lrc.h"
> #include "i915_gem_gtt.h"
> #include "i915_gem_render_state.h"
> +#include <linux/acpi.h>
> #include <linux/io-mapping.h>
> #include <linux/i2c.h>
> #include <linux/i2c-algo-bit.h>
> @@ -1739,6 +1740,12 @@ struct intel_wm_config {
> bool sprites_scaled;
> };
>
> +struct acpi_i2c_data_node {
> + struct list_head head;
> + int i2c_bus_number;
> + int i2c_slave_address;
> +};
> +
> struct drm_i915_private {
> struct drm_device *dev;
> struct kmem_cache *objects;
> @@ -1823,6 +1830,8 @@ struct drm_i915_private {
> /* backlight registers and fields in struct intel_panel */
> struct mutex backlight_lock;
>
> + struct list_head acpi_i2c_list;
> +
> /* LVDS info */
> bool no_aux_handshake;
>
> @@ -1892,6 +1901,7 @@ struct drm_i915_private {
>
> struct i915_workarounds workarounds;
>
> +
> /* Reclocking support */
> bool render_reclock_avail;
>
> @@ -3439,6 +3449,7 @@ 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..afe42ab 100644
> --- a/drivers/gpu/drm/i915/intel_acpi.c
> +++ b/drivers/gpu/drm/i915/intel_acpi.c
> @@ -110,6 +110,65 @@ 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) {
> + struct acpi_i2c_data_node *i2c_entry = NULL;
> +
> + resource = sb->resource_source.string_ptr;
> + resource = strstr(resource, "I2C");
> + error = kstrtouint(resource+3, 0, &val);
> + if (error)
> + return error;
> +
> + i2c_entry = kzalloc(sizeof(struct
> acpi_i2c_data_node),
> + GFP_NOWAIT);
> + i2c_entry->i2c_bus_number = val;
> + i2c_entry->i2c_slave_address = sb->slave_address;
> +
> + list_add_tail(&i2c_entry->head,
> + &dev_priv->acpi_i2c_list);
> + }
> + }
> +
> + 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);
> + INIT_LIST_HEAD(&dev_priv->acpi_i2c_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
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