diff options
Diffstat (limited to 'drivers/platform')
| -rw-r--r-- | drivers/platform/x86/apple-gmux.c | 55 |
1 files changed, 29 insertions, 26 deletions
diff --git a/drivers/platform/x86/apple-gmux.c b/drivers/platform/x86/apple-gmux.c index 4034d2d4c507..a66be137324c 100644 --- a/drivers/platform/x86/apple-gmux.c +++ b/drivers/platform/x86/apple-gmux.c @@ -31,19 +31,21 @@ /** * DOC: Overview * - * :1: http://www.latticesemi.com/en/Products/FPGAandCPLD/LatticeXP2.aspx - * :2: http://www.renesas.com/products/mpumcu/h8s/h8s2100/h8s2113/index.jsp - * * gmux is a microcontroller built into the MacBook Pro to support dual GPUs: - * A {1}[Lattice XP2] on pre-retinas, a {2}[Renesas R4F2113] on retinas. + * A `Lattice XP2`_ on pre-retinas, a `Renesas R4F2113`_ on retinas. * * (The MacPro6,1 2013 also has a gmux, however it is unclear why since it has * dual GPUs but no built-in display.) * * gmux is connected to the LPC bus of the southbridge. Its I/O ports are * accessed differently depending on the microcontroller: Driver functions - * to access a pre-retina gmux are infixed `_pio_`, those for a retina gmux - * are infixed `_index_`. + * to access a pre-retina gmux are infixed ``_pio_``, those for a retina gmux + * are infixed ``_index_``. + * + * .. _Lattice XP2: + * http://www.latticesemi.com/en/Products/FPGAandCPLD/LatticeXP2.aspx + * .. _Renesas R4F2113: + * http://www.renesas.com/products/mpumcu/h8s/h8s2100/h8s2113/index.jsp */ struct apple_gmux_data { @@ -272,15 +274,15 @@ static bool gmux_is_indexed(struct apple_gmux_data *gmux_data) /** * DOC: Backlight control * - * :3: http://www.ti.com/lit/ds/symlink/lp8543.pdf - * :4: http://www.ti.com/lit/ds/symlink/lp8545.pdf - * * On single GPU MacBooks, the PWM signal for the backlight is generated by * the GPU. On dual GPU MacBook Pros by contrast, either GPU may be suspended * to conserve energy. Hence the PWM signal needs to be generated by a separate * backlight driver which is controlled by gmux. The earliest generation - * MBP5 2008/09 uses a {3}[TI LP8543] backlight driver. All newer models - * use a {4}[TI LP8545]. + * MBP5 2008/09 uses a `TI LP8543`_ backlight driver. All newer models + * use a `TI LP8545`_. + * + * .. _TI LP8543: http://www.ti.com/lit/ds/symlink/lp8543.pdf + * .. _TI LP8545: http://www.ti.com/lit/ds/symlink/lp8545.pdf */ static int gmux_get_brightness(struct backlight_device *bd) @@ -312,28 +314,20 @@ static const struct backlight_ops gmux_bl_ops = { /** * DOC: Graphics mux * - * :5: http://pimg-fpiw.uspto.gov/fdd/07/870/086/0.pdf - * :6: http://www.nxp.com/documents/data_sheet/CBTL06141.pdf - * :7: http://www.ti.com/lit/ds/symlink/hd3ss212.pdf - * :8: https://www.pericom.com/assets/Datasheets/PI3VDP12412.pdf - * :9: http://www.ti.com/lit/ds/symlink/sn74lv4066a.pdf - * :10: http://pdf.datasheetarchive.com/indexerfiles/Datasheets-SW16/DSASW00308511.pdf - * :11: http://www.ti.com/lit/ds/symlink/ts3ds10224.pdf - * * On pre-retinas, the LVDS outputs of both GPUs feed into gmux which muxes * either of them to the panel. One of the tricks gmux has up its sleeve is * to lengthen the blanking interval of its output during a switch to * synchronize it with the GPU switched to. This allows for a flicker-free - * switch that is imperceptible by the user ({5}[US 8,687,007 B2]). + * switch that is imperceptible by the user (`US 8,687,007 B2`_). * * On retinas, muxing is no longer done by gmux itself, but by a separate * chip which is controlled by gmux. The chip is triple sourced, it is - * either an {6}[NXP CBTL06142], {7}[TI HD3SS212] or {8}[Pericom PI3VDP12412]. + * either an `NXP CBTL06142`_, `TI HD3SS212`_ or `Pericom PI3VDP12412`_. * The panel is driven with eDP instead of LVDS since the pixel clock * required for retina resolution exceeds LVDS' limits. * * Pre-retinas are able to switch the panel's DDC pins separately. - * This is handled by a {9}[TI SN74LV4066A] which is controlled by gmux. + * This is handled by a `TI SN74LV4066A`_ which is controlled by gmux. * The inactive GPU can thus probe the panel's EDID without switching over * the entire panel. Retinas lack this functionality as the chips used for * eDP muxing are incapable of switching the AUX channel separately (see @@ -344,15 +338,15 @@ static const struct backlight_ops gmux_bl_ops = { * * The external DP port is only fully switchable on the first two unibody * MacBook Pro generations, MBP5 2008/09 and MBP6 2010. This is done by an - * {6}[NXP CBTL06141] which is controlled by gmux. It's the predecessor of the + * `NXP CBTL06141`_ which is controlled by gmux. It's the predecessor of the * eDP mux on retinas, the difference being support for 2.7 versus 5.4 Gbit/s. * * The following MacBook Pro generations replaced the external DP port with a * combined DP/Thunderbolt port and lost the ability to switch it between GPUs, * connecting it either to the discrete GPU or the Thunderbolt controller. * Oddly enough, while the full port is no longer switchable, AUX and HPD - * are still switchable by way of an {10}[NXP CBTL03062] (on pre-retinas - * MBP8 2011 and MBP9 2012) or two {11}[TI TS3DS10224] (on retinas) under the + * are still switchable by way of an `NXP CBTL03062`_ (on pre-retinas + * MBP8 2011 and MBP9 2012) or two `TI TS3DS10224`_ (on retinas) under the * control of gmux. Since the integrated GPU is missing the main link, * external displays appear to it as phantoms which fail to link-train. * @@ -365,10 +359,19 @@ static const struct backlight_ops gmux_bl_ops = { * of this feature. * * gmux' initial switch state on bootup is user configurable via the EFI - * variable `gpu-power-prefs-fa4ce28d-b62f-4c99-9cc3-6815686e30f9` (5th byte, + * variable ``gpu-power-prefs-fa4ce28d-b62f-4c99-9cc3-6815686e30f9`` (5th byte, * 1 = IGD, 0 = DIS). Based on this setting, the EFI firmware tells gmux to * switch the panel and the external DP connector and allocates a framebuffer * for the selected GPU. + * + * .. _US 8,687,007 B2: http://pimg-fpiw.uspto.gov/fdd/07/870/086/0.pdf + * .. _NXP CBTL06141: http://www.nxp.com/documents/data_sheet/CBTL06141.pdf + * .. _NXP CBTL06142: http://www.nxp.com/documents/data_sheet/CBTL06141.pdf + * .. _TI HD3SS212: http://www.ti.com/lit/ds/symlink/hd3ss212.pdf + * .. _Pericom PI3VDP12412: https://www.pericom.com/assets/Datasheets/PI3VDP12412.pdf + * .. _TI SN74LV4066A: http://www.ti.com/lit/ds/symlink/sn74lv4066a.pdf + * .. _NXP CBTL03062: http://pdf.datasheetarchive.com/indexerfiles/Datasheets-SW16/DSASW00308511.pdf + * .. _TI TS3DS10224: http://www.ti.com/lit/ds/symlink/ts3ds10224.pdf */ static void gmux_read_switch_state(struct apple_gmux_data *gmux_data) |