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authorLukas Wunner <lukas@wunner.de>2016-07-04 06:40:35 -0400
committerDaniel Vetter <daniel.vetter@ffwll.ch>2016-07-28 04:04:03 -0400
commit305964b7a0437e3feea7a29971da18dd92408129 (patch)
tree185fa35e61a4d194b48db95ed032e8766a87cb10
parent3c31760e760c87eaa5fbcbb90d54ccab576429c8 (diff)
apple-gmux: Sphinxify docs
Convert asciidoc-formatted docs to rst in accordance with Jonathan's and Jani's effort to use sphinx for kernel-doc rendering in 4.8. Cc: Jonathan Corbet <corbet@lwn.net> Cc: Jani Nikula <jani.nikula@intel.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Acked-by: Darren Hart <dvhart@linux.intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/4c1b29986fa77772156b1af0c965d3799e43a47b.1467628307.git.lukas@wunner.de
-rw-r--r--drivers/platform/x86/apple-gmux.c55
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 @@
31/** 31/**
32 * DOC: Overview 32 * DOC: Overview
33 * 33 *
34 * :1: http://www.latticesemi.com/en/Products/FPGAandCPLD/LatticeXP2.aspx
35 * :2: http://www.renesas.com/products/mpumcu/h8s/h8s2100/h8s2113/index.jsp
36 *
37 * gmux is a microcontroller built into the MacBook Pro to support dual GPUs: 34 * gmux is a microcontroller built into the MacBook Pro to support dual GPUs:
38 * A {1}[Lattice XP2] on pre-retinas, a {2}[Renesas R4F2113] on retinas. 35 * A `Lattice XP2`_ on pre-retinas, a `Renesas R4F2113`_ on retinas.
39 * 36 *
40 * (The MacPro6,1 2013 also has a gmux, however it is unclear why since it has 37 * (The MacPro6,1 2013 also has a gmux, however it is unclear why since it has
41 * dual GPUs but no built-in display.) 38 * dual GPUs but no built-in display.)
42 * 39 *
43 * gmux is connected to the LPC bus of the southbridge. Its I/O ports are 40 * gmux is connected to the LPC bus of the southbridge. Its I/O ports are
44 * accessed differently depending on the microcontroller: Driver functions 41 * accessed differently depending on the microcontroller: Driver functions
45 * to access a pre-retina gmux are infixed `_pio_`, those for a retina gmux 42 * to access a pre-retina gmux are infixed ``_pio_``, those for a retina gmux
46 * are infixed `_index_`. 43 * are infixed ``_index_``.
44 *
45 * .. _Lattice XP2:
46 * http://www.latticesemi.com/en/Products/FPGAandCPLD/LatticeXP2.aspx
47 * .. _Renesas R4F2113:
48 * http://www.renesas.com/products/mpumcu/h8s/h8s2100/h8s2113/index.jsp
47 */ 49 */
48 50
49struct apple_gmux_data { 51struct apple_gmux_data {
@@ -272,15 +274,15 @@ static bool gmux_is_indexed(struct apple_gmux_data *gmux_data)
272/** 274/**
273 * DOC: Backlight control 275 * DOC: Backlight control
274 * 276 *
275 * :3: http://www.ti.com/lit/ds/symlink/lp8543.pdf
276 * :4: http://www.ti.com/lit/ds/symlink/lp8545.pdf
277 *
278 * On single GPU MacBooks, the PWM signal for the backlight is generated by 277 * On single GPU MacBooks, the PWM signal for the backlight is generated by
279 * the GPU. On dual GPU MacBook Pros by contrast, either GPU may be suspended 278 * the GPU. On dual GPU MacBook Pros by contrast, either GPU may be suspended
280 * to conserve energy. Hence the PWM signal needs to be generated by a separate 279 * to conserve energy. Hence the PWM signal needs to be generated by a separate
281 * backlight driver which is controlled by gmux. The earliest generation 280 * backlight driver which is controlled by gmux. The earliest generation
282 * MBP5 2008/09 uses a {3}[TI LP8543] backlight driver. All newer models 281 * MBP5 2008/09 uses a `TI LP8543`_ backlight driver. All newer models
283 * use a {4}[TI LP8545]. 282 * use a `TI LP8545`_.
283 *
284 * .. _TI LP8543: http://www.ti.com/lit/ds/symlink/lp8543.pdf
285 * .. _TI LP8545: http://www.ti.com/lit/ds/symlink/lp8545.pdf
284 */ 286 */
285 287
286static int gmux_get_brightness(struct backlight_device *bd) 288static int gmux_get_brightness(struct backlight_device *bd)
@@ -312,28 +314,20 @@ static const struct backlight_ops gmux_bl_ops = {
312/** 314/**
313 * DOC: Graphics mux 315 * DOC: Graphics mux
314 * 316 *
315 * :5: http://pimg-fpiw.uspto.gov/fdd/07/870/086/0.pdf
316 * :6: http://www.nxp.com/documents/data_sheet/CBTL06141.pdf
317 * :7: http://www.ti.com/lit/ds/symlink/hd3ss212.pdf
318 * :8: https://www.pericom.com/assets/Datasheets/PI3VDP12412.pdf
319 * :9: http://www.ti.com/lit/ds/symlink/sn74lv4066a.pdf
320 * :10: http://pdf.datasheetarchive.com/indexerfiles/Datasheets-SW16/DSASW00308511.pdf
321 * :11: http://www.ti.com/lit/ds/symlink/ts3ds10224.pdf
322 *
323 * On pre-retinas, the LVDS outputs of both GPUs feed into gmux which muxes 317 * On pre-retinas, the LVDS outputs of both GPUs feed into gmux which muxes
324 * either of them to the panel. One of the tricks gmux has up its sleeve is 318 * either of them to the panel. One of the tricks gmux has up its sleeve is
325 * to lengthen the blanking interval of its output during a switch to 319 * to lengthen the blanking interval of its output during a switch to
326 * synchronize it with the GPU switched to. This allows for a flicker-free 320 * synchronize it with the GPU switched to. This allows for a flicker-free
327 * switch that is imperceptible by the user ({5}[US 8,687,007 B2]). 321 * switch that is imperceptible by the user (`US 8,687,007 B2`_).
328 * 322 *
329 * On retinas, muxing is no longer done by gmux itself, but by a separate 323 * On retinas, muxing is no longer done by gmux itself, but by a separate
330 * chip which is controlled by gmux. The chip is triple sourced, it is 324 * chip which is controlled by gmux. The chip is triple sourced, it is
331 * either an {6}[NXP CBTL06142], {7}[TI HD3SS212] or {8}[Pericom PI3VDP12412]. 325 * either an `NXP CBTL06142`_, `TI HD3SS212`_ or `Pericom PI3VDP12412`_.
332 * The panel is driven with eDP instead of LVDS since the pixel clock 326 * The panel is driven with eDP instead of LVDS since the pixel clock
333 * required for retina resolution exceeds LVDS' limits. 327 * required for retina resolution exceeds LVDS' limits.
334 * 328 *
335 * Pre-retinas are able to switch the panel's DDC pins separately. 329 * Pre-retinas are able to switch the panel's DDC pins separately.
336 * This is handled by a {9}[TI SN74LV4066A] which is controlled by gmux. 330 * This is handled by a `TI SN74LV4066A`_ which is controlled by gmux.
337 * The inactive GPU can thus probe the panel's EDID without switching over 331 * The inactive GPU can thus probe the panel's EDID without switching over
338 * the entire panel. Retinas lack this functionality as the chips used for 332 * the entire panel. Retinas lack this functionality as the chips used for
339 * eDP muxing are incapable of switching the AUX channel separately (see 333 * eDP muxing are incapable of switching the AUX channel separately (see
@@ -344,15 +338,15 @@ static const struct backlight_ops gmux_bl_ops = {
344 * 338 *
345 * The external DP port is only fully switchable on the first two unibody 339 * The external DP port is only fully switchable on the first two unibody
346 * MacBook Pro generations, MBP5 2008/09 and MBP6 2010. This is done by an 340 * MacBook Pro generations, MBP5 2008/09 and MBP6 2010. This is done by an
347 * {6}[NXP CBTL06141] which is controlled by gmux. It's the predecessor of the 341 * `NXP CBTL06141`_ which is controlled by gmux. It's the predecessor of the
348 * eDP mux on retinas, the difference being support for 2.7 versus 5.4 Gbit/s. 342 * eDP mux on retinas, the difference being support for 2.7 versus 5.4 Gbit/s.
349 * 343 *
350 * The following MacBook Pro generations replaced the external DP port with a 344 * The following MacBook Pro generations replaced the external DP port with a
351 * combined DP/Thunderbolt port and lost the ability to switch it between GPUs, 345 * combined DP/Thunderbolt port and lost the ability to switch it between GPUs,
352 * connecting it either to the discrete GPU or the Thunderbolt controller. 346 * connecting it either to the discrete GPU or the Thunderbolt controller.
353 * Oddly enough, while the full port is no longer switchable, AUX and HPD 347 * Oddly enough, while the full port is no longer switchable, AUX and HPD
354 * are still switchable by way of an {10}[NXP CBTL03062] (on pre-retinas 348 * are still switchable by way of an `NXP CBTL03062`_ (on pre-retinas
355 * MBP8 2011 and MBP9 2012) or two {11}[TI TS3DS10224] (on retinas) under the 349 * MBP8 2011 and MBP9 2012) or two `TI TS3DS10224`_ (on retinas) under the
356 * control of gmux. Since the integrated GPU is missing the main link, 350 * control of gmux. Since the integrated GPU is missing the main link,
357 * external displays appear to it as phantoms which fail to link-train. 351 * external displays appear to it as phantoms which fail to link-train.
358 * 352 *
@@ -365,10 +359,19 @@ static const struct backlight_ops gmux_bl_ops = {
365 * of this feature. 359 * of this feature.
366 * 360 *
367 * gmux' initial switch state on bootup is user configurable via the EFI 361 * gmux' initial switch state on bootup is user configurable via the EFI
368 * variable `gpu-power-prefs-fa4ce28d-b62f-4c99-9cc3-6815686e30f9` (5th byte, 362 * variable ``gpu-power-prefs-fa4ce28d-b62f-4c99-9cc3-6815686e30f9`` (5th byte,
369 * 1 = IGD, 0 = DIS). Based on this setting, the EFI firmware tells gmux to 363 * 1 = IGD, 0 = DIS). Based on this setting, the EFI firmware tells gmux to
370 * switch the panel and the external DP connector and allocates a framebuffer 364 * switch the panel and the external DP connector and allocates a framebuffer
371 * for the selected GPU. 365 * for the selected GPU.
366 *
367 * .. _US 8,687,007 B2: http://pimg-fpiw.uspto.gov/fdd/07/870/086/0.pdf
368 * .. _NXP CBTL06141: http://www.nxp.com/documents/data_sheet/CBTL06141.pdf
369 * .. _NXP CBTL06142: http://www.nxp.com/documents/data_sheet/CBTL06141.pdf
370 * .. _TI HD3SS212: http://www.ti.com/lit/ds/symlink/hd3ss212.pdf
371 * .. _Pericom PI3VDP12412: https://www.pericom.com/assets/Datasheets/PI3VDP12412.pdf
372 * .. _TI SN74LV4066A: http://www.ti.com/lit/ds/symlink/sn74lv4066a.pdf
373 * .. _NXP CBTL03062: http://pdf.datasheetarchive.com/indexerfiles/Datasheets-SW16/DSASW00308511.pdf
374 * .. _TI TS3DS10224: http://www.ti.com/lit/ds/symlink/ts3ds10224.pdf
372 */ 375 */
373 376
374static void gmux_read_switch_state(struct apple_gmux_data *gmux_data) 377static void gmux_read_switch_state(struct apple_gmux_data *gmux_data)