Hi, On 2/16/23 13:23, Orlando Chamberlain wrote: > In some newer dual gpu MacBooks, gmux is controlled by the T2 security > chip, and acessed with MMIO. Add support for these gmux controllers > > Interestingly, the ACPI table only allocates 8 bytes for GMUX, but we > actually need 16, and as such we request 16 with request_mem_region. > > Reading and writing from ports: > 16 bytes from 0xfe0b0200 are used. 0x0 to 0x4 are where data > to read appears, and where data to write goes. Writing to 0xe > sets the gmux port being accessed, and writing to 0xf sends commands. > > These commands are 0x40 & data_length for write, and data_length for > read, where data_length is 1, 2 or 4. Once byte base+0xf is 0, the > command is done. > > Issues: > As with other retina models, we can't switch DDC lines so > switching at runtime doesn't work if the inactive gpu driver > already disabled eDP due to it not being connected when that > driver loaded. > > Additionally, turning on the dgpu back on the MacBookPro16,1 does > not work. > > Signed-off-by: Orlando Chamberlain <orlandoch.dev@xxxxxxxxx> > --- > v1->v2: Document some chips present, and clarify which chips aren't > present on MMIO gmux laptops. > drivers/platform/x86/apple-gmux.c | 142 +++++++++++++++++++++++++++--- > include/linux/apple-gmux.h | 40 ++++++--- > 2 files changed, 158 insertions(+), 26 deletions(-) > > diff --git a/drivers/platform/x86/apple-gmux.c b/drivers/platform/x86/apple-gmux.c > index 12a93fc49c36..5bac6dcfada0 100644 > --- a/drivers/platform/x86/apple-gmux.c > +++ b/drivers/platform/x86/apple-gmux.c > @@ -28,15 +28,17 @@ > * DOC: Overview > * > * gmux is a microcontroller built into the MacBook Pro to support dual GPUs: > - * A `Lattice XP2`_ on pre-retinas, a `Renesas R4F2113`_ on retinas. > + * A `Lattice XP2`_ on pre-retinas, a `Renesas R4F2113`_ on pre-T2 retinas. > + * The chip used on T2 Macs is not known. > * > * (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 pre-T2 > + * retina gmux are infixed ``_index_``, and those on T2 Macs are infixed > + * with ``_mmio_``. > * > * .. _Lattice XP2: > * http://www.latticesemi.com/en/Products/FPGAandCPLD/LatticeXP2.aspx > @@ -47,6 +49,7 @@ > struct apple_gmux_config; > > struct apple_gmux_data { > + u8 *__iomem iomem_base; > unsigned long iostart; > unsigned long iolen; > const struct apple_gmux_config *config; > @@ -209,6 +212,79 @@ static void gmux_index_write32(struct apple_gmux_data *gmux_data, int port, > mutex_unlock(&gmux_data->index_lock); > } > > +static int gmux_mmio_wait(struct apple_gmux_data *gmux_data) > +{ > + int i = 200; > + u8 gwr = ioread8(gmux_data->iomem_base + GMUX_MMIO_COMMAND_SEND); > + > + while (i && gwr) { > + gwr = ioread8(gmux_data->iomem_base + GMUX_MMIO_COMMAND_SEND); > + udelay(100); > + i--; > + } > + > + return !!i; > +} > + > +static u8 gmux_mmio_read8(struct apple_gmux_data *gmux_data, int port) > +{ > + u8 val; > + > + mutex_lock(&gmux_data->index_lock); > + gmux_mmio_wait(gmux_data); > + iowrite8((port & 0xff), gmux_data->iomem_base + GMUX_MMIO_PORT_SELECT); > + iowrite8(GMUX_MMIO_READ | sizeof(val), > + gmux_data->iomem_base + GMUX_MMIO_COMMAND_SEND); > + gmux_mmio_wait(gmux_data); > + val = ioread8(gmux_data->iomem_base); > + mutex_unlock(&gmux_data->index_lock); > + > + return val; > +} > + > +static void gmux_mmio_write8(struct apple_gmux_data *gmux_data, int port, > + u8 val) > +{ > + mutex_lock(&gmux_data->index_lock); > + gmux_mmio_wait(gmux_data); > + iowrite8(val, gmux_data->iomem_base); > + > + iowrite8(port & 0xff, gmux_data->iomem_base + GMUX_MMIO_PORT_SELECT); > + iowrite8(GMUX_MMIO_WRITE | sizeof(val), > + gmux_data->iomem_base + GMUX_MMIO_COMMAND_SEND); > + > + gmux_mmio_wait(gmux_data); > + mutex_unlock(&gmux_data->index_lock); > +} > + > +static u32 gmux_mmio_read32(struct apple_gmux_data *gmux_data, int port) > +{ > + u32 val; > + > + mutex_lock(&gmux_data->index_lock); > + gmux_mmio_wait(gmux_data); > + iowrite8((port & 0xff), gmux_data->iomem_base + GMUX_MMIO_PORT_SELECT); > + iowrite8(GMUX_MMIO_READ | sizeof(val), > + gmux_data->iomem_base + GMUX_MMIO_COMMAND_SEND); > + gmux_mmio_wait(gmux_data); > + val = be32_to_cpu(ioread32(gmux_data->iomem_base)); > + mutex_unlock(&gmux_data->index_lock); > + > + return val; > +} > + > +static void gmux_mmio_write32(struct apple_gmux_data *gmux_data, int port, > + u32 val) > +{ > + mutex_lock(&gmux_data->index_lock); > + iowrite32(cpu_to_be32(val), gmux_data->iomem_base); > + iowrite8(port & 0xff, gmux_data->iomem_base + GMUX_MMIO_PORT_SELECT); > + iowrite8(GMUX_MMIO_WRITE | sizeof(val), > + gmux_data->iomem_base + GMUX_MMIO_COMMAND_SEND); > + gmux_mmio_wait(gmux_data); > + mutex_unlock(&gmux_data->index_lock); > +} > + > static u8 gmux_read8(struct apple_gmux_data *gmux_data, int port) > { > return gmux_data->config->read8(gmux_data, port); > @@ -237,8 +313,8 @@ static void gmux_write32(struct apple_gmux_data *gmux_data, int port, > * 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 `TI LP8543`_ backlight driver. All newer models > - * use a `TI LP8545`_. > + * MBP5 2008/09 uses a `TI LP8543`_ backlight driver. Newer models > + * use a `TI LP8545`_ or a TI LP8548. > * > * .. _TI LP8543: https://www.ti.com/lit/ds/symlink/lp8543.pdf > * .. _TI LP8545: https://www.ti.com/lit/ds/symlink/lp8545.pdf > @@ -302,8 +378,8 @@ static const struct backlight_ops gmux_bl_ops = { > * 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 `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, > + * MBP8 2011 and MBP9 2012) or two `TI TS3DS10224`_ (on pre-t2 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. > * > * gmux receives the HPD signal of all display connectors and sends an > @@ -506,6 +582,20 @@ static const struct apple_gmux_config apple_gmux_index = { > .name = "indexed" > }; > > +static const struct apple_gmux_config apple_gmux_mmio = { > + .read8 = &gmux_mmio_read8, > + .write8 = &gmux_mmio_write8, > + .read32 = &gmux_mmio_read32, > + .write32 = &gmux_mmio_write32, > + .gmux_handler = &gmux_handler_no_ddc, > + .handler_flags = VGA_SWITCHEROO_NEEDS_EDP_CONFIG, > + .resource_type = IORESOURCE_MEM, > + .read_version_as_u32 = true, > + .use_acpi_gmsp = true, > + .name = "T2" > +}; > + > + > /** > * DOC: Interrupt > * > @@ -637,6 +727,25 @@ static int gmux_probe(struct pnp_dev *pnp, const struct pnp_device_id *id) > pnp_set_drvdata(pnp, gmux_data); > > switch (type) { > + case APPLE_GMUX_TYPE_MMIO: > + gmux_data->config = &apple_gmux_mmio; > + mutex_init(&gmux_data->index_lock); > + > + res = pnp_get_resource(pnp, IORESOURCE_MEM, 0); > + gmux_data->iostart = res->start; > + /* Although the ACPI table only allocates 8 bytes, we need 16. */ > + gmux_data->iolen = 16; > + if (!request_mem_region(gmux_data->iostart, gmux_data->iolen, > + "Apple gmux")) { > + pr_err("gmux I/O already in use\n"); > + goto err_free; > + } > + gmux_data->iomem_base = ioremap(gmux_data->iostart, gmux_data->iolen); > + if (!gmux_data->iomem_base) { > + pr_err("couldn't remap gmux mmio region"); > + goto err_release; > + } > + goto get_version; > case APPLE_GMUX_TYPE_INDEXED: > gmux_data->config = &apple_gmux_index; > mutex_init(&gmux_data->index_lock); > @@ -656,6 +765,7 @@ static int gmux_probe(struct pnp_dev *pnp, const struct pnp_device_id *id) > goto err_free; > } > > +get_version: > if (gmux_data->config->read_version_as_u32) { > version = gmux_read32(gmux_data, GMUX_PORT_VERSION_MAJOR); > ver_major = (version >> 24) & 0xff; > @@ -686,7 +796,7 @@ static int gmux_probe(struct pnp_dev *pnp, const struct pnp_device_id *id) > gmux_data, &gmux_bl_ops, &props); > if (IS_ERR(bdev)) { > ret = PTR_ERR(bdev); > - goto err_release; > + goto err_unmap; > } > > gmux_data->bdev = bdev; > @@ -753,7 +863,7 @@ static int gmux_probe(struct pnp_dev *pnp, const struct pnp_device_id *id) > /* > * Retina MacBook Pros cannot switch the panel's AUX separately > * and need eDP pre-calibration. They are distinguishable from > - * pre-retinas by having an "indexed" gmux. > + * pre-retinas by having an "indexed" or "T2" gmux. > * > * Pre-retina MacBook Pros can switch the panel's DDC separately. > */ > @@ -778,8 +888,14 @@ static int gmux_probe(struct pnp_dev *pnp, const struct pnp_device_id *id) > &gmux_notify_handler); > err_notify: > backlight_device_unregister(bdev); > +err_unmap: > + if (gmux_data->iomem_base) > + iounmap(gmux_data->iomem_base); > err_release: > - release_region(gmux_data->iostart, gmux_data->iolen); > + if (gmux_data->config->resource_type == IORESOURCE_MEM) > + release_mem_region(gmux_data->iostart, gmux_data->iolen); > + else > + release_region(gmux_data->iostart, gmux_data->iolen); > err_free: > kfree(gmux_data); > return ret; > @@ -800,7 +916,11 @@ static void gmux_remove(struct pnp_dev *pnp) > > backlight_device_unregister(gmux_data->bdev); > > - release_region(gmux_data->iostart, gmux_data->iolen); > + if (gmux_data->iomem_base) { > + iounmap(gmux_data->iomem_base); > + release_mem_region(gmux_data->iostart, gmux_data->iolen); > + } else > + release_region(gmux_data->iostart, gmux_data->iolen); > apple_gmux_data = NULL; > kfree(gmux_data); > > diff --git a/include/linux/apple-gmux.h b/include/linux/apple-gmux.h > index 5f658439f7f8..b7532f26b756 100644 > --- a/include/linux/apple-gmux.h > +++ b/include/linux/apple-gmux.h > @@ -34,11 +34,18 @@ > #define GMUX_PORT_READ 0xd0 > #define GMUX_PORT_WRITE 0xd4 > > +#define GMUX_MMIO_PORT_SELECT 0x0e > +#define GMUX_MMIO_COMMAND_SEND 0x0f > + > +#define GMUX_MMIO_READ 0x00 > +#define GMUX_MMIO_WRITE 0x40 > + > #define GMUX_MIN_IO_LEN (GMUX_PORT_BRIGHTNESS + 4) > > enum apple_gmux_type { > APPLE_GMUX_TYPE_PIO, > - APPLE_GMUX_TYPE_INDEXED > + APPLE_GMUX_TYPE_INDEXED, > + APPLE_GMUX_TYPE_MMIO > }; With my suggested change to patch 2/5 the - + for APPLE_GMUX_TYPE_INDEXED will go away because the , is already there. Likewise please add a , after APPLE_GMUX_TYPE_MMIO in case we want to add more entries in the future. Otherwise this patch looks good to me. Regards, Hans > > #if IS_ENABLED(CONFIG_APPLE_GMUX) > @@ -93,19 +100,24 @@ static inline bool apple_gmux_detect(struct pnp_dev *pnp_dev, enum apple_gmux_ty > } > > res = pnp_get_resource(pnp_dev, IORESOURCE_IO, 0); > - if (!res || resource_size(res) < GMUX_MIN_IO_LEN) > - goto out; > - > - /* > - * Invalid version information may indicate either that the gmux > - * device isn't present or that it's a new one that uses indexed io. > - */ > - ver_major = inb(res->start + GMUX_PORT_VERSION_MAJOR); > - ver_minor = inb(res->start + GMUX_PORT_VERSION_MINOR); > - ver_release = inb(res->start + GMUX_PORT_VERSION_RELEASE); > - if (ver_major == 0xff && ver_minor == 0xff && ver_release == 0xff) { > - if (apple_gmux_is_indexed(res->start)) > - type = APPLE_GMUX_TYPE_INDEXED; > + if (res && resource_size(res) >= GMUX_MIN_IO_LEN) { > + /* > + * Invalid version information may indicate either that the gmux > + * device isn't present or that it's a new one that uses indexed io. > + */ > + ver_major = inb(res->start + GMUX_PORT_VERSION_MAJOR); > + ver_minor = inb(res->start + GMUX_PORT_VERSION_MINOR); > + ver_release = inb(res->start + GMUX_PORT_VERSION_RELEASE); > + if (ver_major == 0xff && ver_minor == 0xff && ver_release == 0xff) { > + if (apple_gmux_is_indexed(res->start)) > + type = APPLE_GMUX_TYPE_INDEXED; > + else > + goto out; > + } > + } else { > + res = pnp_get_resource(pnp_dev, IORESOURCE_MEM, 0); > + if (res) > + type = APPLE_GMUX_TYPE_MMIO; > else > goto out; > }
