Re: [PATCH v9 1/2] i2c: buses: add i2c bus driver for NVIDIA GPU
On 2018-09-08 16:13, Ajay Gupta wrote: > > Hi Peter, > > . > >> SMBUS has nothing to do with the >problem, that was just an example. An I2C >> >client driver can issue such I2C xfers all by >itself without going through >> emulation, so >just dropping the _EMUL flag is not the >answer. And I'd be >> surprised if the >hardware doesn't support single message >reads. > >> There is no quirk flag for this abnormality, >so you will have to open code >> the check in >your master_xfer if you can't make such >xfers work, but the >> best fix is certainly to >just make them work... > > I have fixed that in v10. Please check Ah, I didn't even bother to look earlier. I have now taken a peek, and there are still issues. I'll comment inline for the v10 1/2 patch as usual, but I'm short on time at the moment so it will probably be a few hours. It's an option to hold on to v11 until that happens... Cheers, Peter
Re: [PATCH v9 1/2] i2c: buses: add i2c bus driver for NVIDIA GPU
Hi Peter, . >SMBUS has nothing to do with the >problem, that was just an example. An I2C >>client driver can issue such I2C xfers all by >itself without going through >emulation, so >just dropping the _EMUL flag is not the >answer. And I'd be >surprised if the >hardware doesn't support single message >reads. >There is no quirk flag for this abnormality, >so you will have to open code >the check in >your master_xfer if you can't make such >xfers work, but the >best fix is certainly to >just make them work... I have fixed that in v10. Please check >Cheers, >Peter — nvpublic —
RE: [PATCH v9 1/2] i2c: buses: add i2c bus driver for NVIDIA GPU
On September 7, 2018 11:48:37 PM GMT+02:00, Ajay Gupta wrote: >> >> Per your comments on v8, the address has to be programmed before >the >> >> transfer, but you fail to do that if the first message is a read. >> > This will never happen. Hint: I2C_AQ_COMB_WRITE_FIRST >> >> Yes, it will. If the transfer consists of a single read, i.e. w/o any >leading write. >> E.g. i2c_smbus_read_byte (which is emulated in your case and will >generate >> this pattern). >I don't think we intend to support SMBUS commands and so I will drop >I2C_FUNC_SMBUS_EMUL. SMBUS has nothing to do with the problem, that was just an example. An I2C client driver can issue such I2C xfers all by itself without going through emulation, so just dropping the _EMUL flag is not the answer. And I'd be surprised if the hardware doesn't support single message reads. There is no quirk flag for this abnormality, so you will have to open code the check in your master_xfer if you can't make such xfers work, but the best fix is certainly to just make them work... Cheers, Peter
RE: [PATCH v9 1/2] i2c: buses: add i2c bus driver for NVIDIA GPU
Hi Peter,
> >> Hmm, what do you need to sync read/write with?
> > What if there are multiple clients and each of them wants to use I2C bus for
> read/write?
> > Even in UCSI client, user may want to change alt mode which will
> > result in read/write request in a thread. So we have to synchronize between
> UCSI ISR and the user thread.
>
> Synchronization of reads/writes from multiple clients is handled by the I2C
> core and the adapter lock. Lock in i2c_transfer() for the details.
Ok. I hope it will be good to drop mutex then.
> >> The only thing I can find is
> >> that busy-check in gpu_i2c_idle, but can runtime-pm really try to
> >> idle an adapter that has an xfer in flight? If that's the case, what
> >> stops a new xfer from being initiated after runtime-pm has checked if
> >> ->runtime_idle returns ok but before the device is really suspended?
> >>
> >> PM is not an area I'm familiar with, so it's an honest question.
> >>
> >>> +};
> >>> +
> >>> +static void gpu_enable_i2c_bus(struct gpu_i2c_dev *i2cd) {
> >>> + u32 val;
> >>> +
> >>> + /* enable I2C */
> >>> + val = readl(i2cd->regs + I2C_MST_HYBRID_PADCTL);
> >>> + val |= I2C_MST_HYBRID_PADCTL_MODE_I2C |
> >>> + I2C_MST_HYBRID_PADCTL_I2C_SCL_INPUT_RCV |
> >>> + I2C_MST_HYBRID_PADCTL_I2C_SDA_INPUT_RCV;
> >>> + writel(val, i2cd->regs + I2C_MST_HYBRID_PADCTL);
> >>> +
> >>> + /* enable 100KHZ mode */
> >>> + val = I2C_MST_I2C0_TIMING_SCL_PERIOD_100KHZ;
> >>> + val |= (I2C_MST_I2C0_TIMING_TIMEOUT_CLK_CNT_MAX
> >>> + << I2C_MST_I2C0_TIMING_TIMEOUT_CLK_CNT);
> >>> + val |= I2C_MST_I2C0_TIMING_TIMEOUT_CHECK;
> >>> + writel(val, i2cd->regs + I2C_MST_I2C0_TIMING); }
> >>> +
> >>> +static int gpu_i2c_check_status(struct gpu_i2c_dev *i2cd) {
> >>> + unsigned long target = jiffies + msecs_to_jiffies(1000);
> >>> + u32 val;
> >>> +
> >>> + do {
> >>> + val = readl(i2cd->regs + I2C_MST_CNTL);
> >>> + if (!(val & I2C_MST_CNTL_CYCLE_TRIGGER))
> >>> + break;
> >>> + if ((val & I2C_MST_CNTL_STATUS) !=
> >>> + I2C_MST_CNTL_STATUS_BUS_BUSY)
> >>> + break;
> >>> + usleep_range(1000, 2000);
> >>> + } while (time_is_after_jiffies(target));
> >>> + if (time_is_before_jiffies(target)) {
> >>> + dev_err(i2cd->dev, "i2c timeout error %x\n", val);
> >>> + return -EIO;
> >>> + }
> >>> +
> >>> + val = readl(i2cd->regs + I2C_MST_CNTL);
> >>> + switch (val & I2C_MST_CNTL_STATUS) {
> >>> + case I2C_MST_CNTL_STATUS_OKAY:
> >>> + return 0;
> >>> + case I2C_MST_CNTL_STATUS_NO_ACK:
> >>> + return -EIO;
> >>> + case I2C_MST_CNTL_STATUS_TIMEOUT:
> >>> + return -ETIME;
> >>> + case I2C_MST_CNTL_STATUS_BUS_BUSY:
> >>> + return -EBUSY;
> >>> + default:
> >>> + return 0;
> >>> + }
> >>> +}
> >>> +
> >>> +static int gpu_i2c_read(struct gpu_i2c_dev *i2cd, u8 *data, u16
> >>> +len) {
> >>> + int status;
> >>> + u32 val;
> >>> +
> >>> + val = I2C_MST_CNTL_GEN_START | I2C_MST_CNTL_GEN_STOP |
> >>> + I2C_MST_CNTL_CMD_READ | (len <<
> >> I2C_MST_CNTL_BURST_SIZE_SHIFT) |
> >>> + I2C_MST_CNTL_CYCLE_TRIGGER |
> >> I2C_MST_CNTL_GEN_NACK;
> >>> + val &= ~I2C_MST_CNTL_GEN_RAB;
> >>> + writel(val, i2cd->regs + I2C_MST_CNTL);
> >>> +
> >>> + status = gpu_i2c_check_status(i2cd);
> >>> + if (status < 0)
> >>> + return status;
> >>> +
> >>> + val = readl(i2cd->regs + I2C_MST_DATA);
> >>> + switch (len) {
> >>> + case 1:
> >>> + data[0] = val;
> >>> + break;
> >>> + case 2:
> >>> + put_unaligned_be16(val, data);
> >>> + break;
> >>> + case 3:
> >>> + put_unaligned_be16(val >> 8, data);
> >>> + data[2] = val;
> >>> + break;
> >>> + case 4:
> >>> + put_unaligned_be32(val, data);
> >>> + break;
> >>> + default:
> >>> + break;
> >>> + }
> >>> + return status;
> >>> +}
> >>> +
> >>> +static int gpu_i2c_start(struct gpu_i2c_dev *i2cd, u16 addr) {
> >>> + u32 val;
> >>> +
> >>> + val = addr << I2C_MST_ADDR_DAB;
> >>> + writel(val, i2cd->regs + I2C_MST_ADDR);
> >>> +
> >>> + val = I2C_MST_CNTL_GEN_START | I2C_MST_CNTL_CMD_NONE |
> >>> + I2C_MST_CNTL_GEN_NACK;
> >>> + val &= ~(I2C_MST_CNTL_GEN_STOP | I2C_MST_CNTL_GEN_RAB);
> >>> + writel(val, i2cd->regs + I2C_MST_CNTL);
> >>> +
> >>> + return gpu_i2c_check_status(i2cd); }
> >>> +
> >>> +static int gpu_i2c_stop(struct gpu_i2c_dev *i2cd) {
> >>> + u32 val;
> >>> +
> >>> + val = I2C_MST_CNTL_GEN_STOP | I2C_MST_CNTL_CMD_NONE |
> >>> + I2C_MST_CNTL_GEN_NACK;
> >>> + val &= ~(I2C_MST_CNTL_GEN_START | I2C_MST_CNTL_GEN_RAB);
> >>> + writel(val, i2cd->regs + I2C_MST_CNTL);
> >>> +
> >>> + return gpu_i2c_check_status(i2cd); }
> >>> +
> >>> +static int gpu_i2c_write(struct gpu_i2c_dev *i2cd, u8 data) {
> >>> + u32 val;
> >>> +
> >>> + writel(data, i2cd->regs + I2C_MST_DATA);
> >>> +
> >>> + val = I2C_MST_CNTL_CMD_WRITE | (1 <<
> >> I2C_MST_CNTL_BURST_SIZE_SHIFT) |
> >>> + I2C_MST_CNTL_GEN_
Re: [PATCH v9 1/2] i2c: buses: add i2c bus driver for NVIDIA GPU
On 2018-09-07 19:15, Ajay Gupta wrote: > Hi Peter, >>> Signed-off-by: Ajay Gupta >>> Reviewed-by: Andy Shevchenko >>> Reviewed-by: Heikki Krogerus >>> --- >>> Changes from v1 -> v2 >>> None >>> Changes from v2 -> v3 >>> Fixed review comments from Andy and Thierry >>> Rename i2c-gpu.c -> i2c-nvidia-gpu.c >>> Changes from v3 -> v4 >>> Fixed review comments from Andy >>> Changes from v4 -> v5 >>> Fixed review comments from Andy >>> Changes from v5 -> v6 >>> None >>> Changes from v6 -> v7 -> v8 >>> Fixed review comments from Peter >>> - Add implicit STOP for last write message >>> - Add i2c_adapter_quirks with max_read_len and >>> I2C_AQ_COMB flags >>> Changes from v8 -> v9 >>> Fixed review comments from Peter >>> - Drop do_start flag >>> - Use i2c_8bit_addr_from_msg() >>> >>> Documentation/i2c/busses/i2c-nvidia-gpu | 18 ++ >>> MAINTAINERS | 7 + >>> drivers/i2c/busses/Kconfig | 9 + >>> drivers/i2c/busses/Makefile | 1 + >>> drivers/i2c/busses/i2c-nvidia-gpu.c | 396 >> >>> 5 files changed, 431 insertions(+) >>> create mode 100644 Documentation/i2c/busses/i2c-nvidia-gpu >>> create mode 100644 drivers/i2c/busses/i2c-nvidia-gpu.c >>> >>> diff --git a/Documentation/i2c/busses/i2c-nvidia-gpu >>> b/Documentation/i2c/busses/i2c-nvidia-gpu >>> new file mode 100644 >>> index 000..31884d2 >>> --- /dev/null >>> +++ b/Documentation/i2c/busses/i2c-nvidia-gpu >>> @@ -0,0 +1,18 @@ >>> +Kernel driver i2c-nvidia-gpu >>> + >>> +Datasheet: not publicly available. >>> + >>> +Authors: >>> + Ajay Gupta >>> + >>> +Description >>> +--- >>> + >>> +i2c-nvidia-gpu is a driver for I2C controller included in NVIDIA >>> +Turing and later GPUs and it is used to communicate with Type-C controller >> on GPUs. >>> + >>> +If your 'lspci -v' listing shows something like the following, >>> + >>> +01:00.3 Serial bus controller [0c80]: NVIDIA Corporation Device 1ad9 >>> +(rev a1) >>> + >>> +then this driver should support the I2C controller of your GPU. >>> diff --git a/MAINTAINERS b/MAINTAINERS index 9ad052a..2d1c5a1 100644 >>> --- a/MAINTAINERS >>> +++ b/MAINTAINERS >>> @@ -6797,6 +6797,13 @@ L: linux-a...@vger.kernel.org >>> S: Maintained >>> F: drivers/i2c/i2c-core-acpi.c >>> >>> +I2C CONTROLLER DRIVER FOR NVIDIA GPU >>> +M: Ajay Gupta >>> +L: linux-...@vger.kernel.org >>> +S: Maintained >>> +F: Documentation/i2c/busses/i2c-nvidia-gpu >>> +F: drivers/i2c/busses/i2c-nvidia-gpu.c >>> + >>> I2C MUXES >>> M: Peter Rosin >>> L: linux-...@vger.kernel.org >>> diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig >>> index 451d4ae..eed827b 100644 >>> --- a/drivers/i2c/busses/Kconfig >>> +++ b/drivers/i2c/busses/Kconfig >>> @@ -224,6 +224,15 @@ config I2C_NFORCE2_S4985 >>> This driver can also be built as a module. If so, the module >>> will be called i2c-nforce2-s4985. >>> >>> +config I2C_NVIDIA_GPU >>> + tristate "NVIDIA GPU I2C controller" >>> + depends on PCI >>> + help >>> + If you say yes to this option, support will be included for the >>> + NVIDIA GPU I2C controller which is used to communicate with the >> GPU's >>> + Type-C controller. This driver can also be built as a module called >>> + i2c-nvidia-gpu. >>> + >>> config I2C_SIS5595 >>> tristate "SiS 5595" >>> depends on PCI >>> diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile >>> index 18b26af..d499813 100644 >>> --- a/drivers/i2c/busses/Makefile >>> +++ b/drivers/i2c/busses/Makefile >>> @@ -140,5 +140,6 @@ obj-$(CONFIG_I2C_SIBYTE)+= i2c-sibyte.o >>> obj-$(CONFIG_I2C_XGENE_SLIMPRO) += i2c-xgene-slimpro.o >>> obj-$(CONFIG_SCx200_ACB) += scx200_acb.o >>> obj-$(CONFIG_I2C_FSI) += i2c-fsi.o >>> +obj-$(CONFIG_I2C_NVIDIA_GPU) += i2c-nvidia-gpu.o >>> >>> ccflags-$(CONFIG_I2C_DEBUG_BUS) := -DDEBUG diff --git >>> a/drivers/i2c/busses/i2c-nvidia-gpu.c >>> b/drivers/i2c/busses/i2c-nvidia-gpu.c >>> new file mode 100644 >>> index 000..4a63a4e4 >>> --- /dev/null >>> +++ b/drivers/i2c/busses/i2c-nvidia-gpu.c >>> @@ -0,0 +1,396 @@ >>> +// SPDX-License-Identifier: GPL-2.0 >>> +/* >>> + * Nvidia GPU I2C controller Driver >>> + * >>> + * Copyright (C) 2018 NVIDIA Corporation. All rights reserved. >>> + * Author: Ajay Gupta */ #include >>> +#include #include #include >>> + #include #include >>> + #include #include >>> + >>> + >>> +#include >>> + >>> +/* I2C definitions */ >>> +#define I2C_MST_CNTL 0x00 >>> +#define I2C_MST_CNTL_GEN_START BIT(0) >>> +#define I2C_MST_CNTL_GEN_STOP BIT(1) >>> +#define I2C_MST_CNTL_CMD_NONE (0 << 2) >>> +#define I2C_MST_CNTL_CMD_READ (1 << 2) >>> +#define I2C_MST_CNTL_CMD_WRITE (2 << 2) >>> +#define I2C_MST_CNTL_GEN_RAB BIT(4)
RE: [PATCH v9 1/2] i2c: buses: add i2c bus driver for NVIDIA GPU
Hi Peter, > > Signed-off-by: Ajay Gupta > > Reviewed-by: Andy Shevchenko > > Reviewed-by: Heikki Krogerus > > --- > > Changes from v1 -> v2 > > None > > Changes from v2 -> v3 > > Fixed review comments from Andy and Thierry > > Rename i2c-gpu.c -> i2c-nvidia-gpu.c > > Changes from v3 -> v4 > > Fixed review comments from Andy > > Changes from v4 -> v5 > > Fixed review comments from Andy > > Changes from v5 -> v6 > > None > > Changes from v6 -> v7 -> v8 > > Fixed review comments from Peter > > - Add implicit STOP for last write message > > - Add i2c_adapter_quirks with max_read_len and > > I2C_AQ_COMB flags > > Changes from v8 -> v9 > > Fixed review comments from Peter > > - Drop do_start flag > > - Use i2c_8bit_addr_from_msg() > > > > Documentation/i2c/busses/i2c-nvidia-gpu | 18 ++ > > MAINTAINERS | 7 + > > drivers/i2c/busses/Kconfig | 9 + > > drivers/i2c/busses/Makefile | 1 + > > drivers/i2c/busses/i2c-nvidia-gpu.c | 396 > > > 5 files changed, 431 insertions(+) > > create mode 100644 Documentation/i2c/busses/i2c-nvidia-gpu > > create mode 100644 drivers/i2c/busses/i2c-nvidia-gpu.c > > > > diff --git a/Documentation/i2c/busses/i2c-nvidia-gpu > > b/Documentation/i2c/busses/i2c-nvidia-gpu > > new file mode 100644 > > index 000..31884d2 > > --- /dev/null > > +++ b/Documentation/i2c/busses/i2c-nvidia-gpu > > @@ -0,0 +1,18 @@ > > +Kernel driver i2c-nvidia-gpu > > + > > +Datasheet: not publicly available. > > + > > +Authors: > > + Ajay Gupta > > + > > +Description > > +--- > > + > > +i2c-nvidia-gpu is a driver for I2C controller included in NVIDIA > > +Turing and later GPUs and it is used to communicate with Type-C controller > on GPUs. > > + > > +If your 'lspci -v' listing shows something like the following, > > + > > +01:00.3 Serial bus controller [0c80]: NVIDIA Corporation Device 1ad9 > > +(rev a1) > > + > > +then this driver should support the I2C controller of your GPU. > > diff --git a/MAINTAINERS b/MAINTAINERS index 9ad052a..2d1c5a1 100644 > > --- a/MAINTAINERS > > +++ b/MAINTAINERS > > @@ -6797,6 +6797,13 @@ L: linux-a...@vger.kernel.org > > S: Maintained > > F: drivers/i2c/i2c-core-acpi.c > > > > +I2C CONTROLLER DRIVER FOR NVIDIA GPU > > +M: Ajay Gupta > > +L: linux-...@vger.kernel.org > > +S: Maintained > > +F: Documentation/i2c/busses/i2c-nvidia-gpu > > +F: drivers/i2c/busses/i2c-nvidia-gpu.c > > + > > I2C MUXES > > M: Peter Rosin > > L: linux-...@vger.kernel.org > > diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig > > index 451d4ae..eed827b 100644 > > --- a/drivers/i2c/busses/Kconfig > > +++ b/drivers/i2c/busses/Kconfig > > @@ -224,6 +224,15 @@ config I2C_NFORCE2_S4985 > > This driver can also be built as a module. If so, the module > > will be called i2c-nforce2-s4985. > > > > +config I2C_NVIDIA_GPU > > + tristate "NVIDIA GPU I2C controller" > > + depends on PCI > > + help > > + If you say yes to this option, support will be included for the > > + NVIDIA GPU I2C controller which is used to communicate with the > GPU's > > + Type-C controller. This driver can also be built as a module called > > + i2c-nvidia-gpu. > > + > > config I2C_SIS5595 > > tristate "SiS 5595" > > depends on PCI > > diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile > > index 18b26af..d499813 100644 > > --- a/drivers/i2c/busses/Makefile > > +++ b/drivers/i2c/busses/Makefile > > @@ -140,5 +140,6 @@ obj-$(CONFIG_I2C_SIBYTE)+= i2c-sibyte.o > > obj-$(CONFIG_I2C_XGENE_SLIMPRO) += i2c-xgene-slimpro.o > > obj-$(CONFIG_SCx200_ACB) += scx200_acb.o > > obj-$(CONFIG_I2C_FSI) += i2c-fsi.o > > +obj-$(CONFIG_I2C_NVIDIA_GPU) += i2c-nvidia-gpu.o > > > > ccflags-$(CONFIG_I2C_DEBUG_BUS) := -DDEBUG diff --git > > a/drivers/i2c/busses/i2c-nvidia-gpu.c > > b/drivers/i2c/busses/i2c-nvidia-gpu.c > > new file mode 100644 > > index 000..4a63a4e4 > > --- /dev/null > > +++ b/drivers/i2c/busses/i2c-nvidia-gpu.c > > @@ -0,0 +1,396 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > +/* > > + * Nvidia GPU I2C controller Driver > > + * > > + * Copyright (C) 2018 NVIDIA Corporation. All rights reserved. > > + * Author: Ajay Gupta */ #include > > +#include #include #include > > + #include #include > > + #include #include > > + > > + > > +#include > > + > > +/* I2C definitions */ > > +#define I2C_MST_CNTL 0x00 > > +#define I2C_MST_CNTL_GEN_START BIT(0) > > +#define I2C_MST_CNTL_GEN_STOP BIT(1) > > +#define I2C_MST_CNTL_CMD_NONE (0 << 2) > > +#define I2C_MST_CNTL_CMD_READ (1 << 2) > > +#define I2C_MST_CNTL_CMD_WRITE (2 << 2) > > +#define I2C_MST_CNTL_GEN_RAB BIT(4) > > +#define I2C_MST_CNTL_BURST_SIZE_SHIFT
Re: [PATCH v9 1/2] i2c: buses: add i2c bus driver for NVIDIA GPU
On 2018-09-07 01:56, Ajay Gupta wrote: > Latest NVIDIA GPU card has USB Type-C interface. There is a > Type-C controller which can be accessed over I2C. > > This driver adds I2C bus driver to communicate with Type-C controller. > I2C client driver will be part of USB Type-C UCSI driver. > > Signed-off-by: Ajay Gupta > Reviewed-by: Andy Shevchenko > Reviewed-by: Heikki Krogerus > --- > Changes from v1 -> v2 > None > Changes from v2 -> v3 > Fixed review comments from Andy and Thierry > Rename i2c-gpu.c -> i2c-nvidia-gpu.c > Changes from v3 -> v4 > Fixed review comments from Andy > Changes from v4 -> v5 > Fixed review comments from Andy > Changes from v5 -> v6 > None > Changes from v6 -> v7 -> v8 > Fixed review comments from Peter > - Add implicit STOP for last write message > - Add i2c_adapter_quirks with max_read_len and > I2C_AQ_COMB flags > Changes from v8 -> v9 > Fixed review comments from Peter > - Drop do_start flag > - Use i2c_8bit_addr_from_msg() > > Documentation/i2c/busses/i2c-nvidia-gpu | 18 ++ > MAINTAINERS | 7 + > drivers/i2c/busses/Kconfig | 9 + > drivers/i2c/busses/Makefile | 1 + > drivers/i2c/busses/i2c-nvidia-gpu.c | 396 > > 5 files changed, 431 insertions(+) > create mode 100644 Documentation/i2c/busses/i2c-nvidia-gpu > create mode 100644 drivers/i2c/busses/i2c-nvidia-gpu.c > > diff --git a/Documentation/i2c/busses/i2c-nvidia-gpu > b/Documentation/i2c/busses/i2c-nvidia-gpu > new file mode 100644 > index 000..31884d2 > --- /dev/null > +++ b/Documentation/i2c/busses/i2c-nvidia-gpu > @@ -0,0 +1,18 @@ > +Kernel driver i2c-nvidia-gpu > + > +Datasheet: not publicly available. > + > +Authors: > + Ajay Gupta > + > +Description > +--- > + > +i2c-nvidia-gpu is a driver for I2C controller included in NVIDIA Turing > +and later GPUs and it is used to communicate with Type-C controller on GPUs. > + > +If your 'lspci -v' listing shows something like the following, > + > +01:00.3 Serial bus controller [0c80]: NVIDIA Corporation Device 1ad9 (rev a1) > + > +then this driver should support the I2C controller of your GPU. > diff --git a/MAINTAINERS b/MAINTAINERS > index 9ad052a..2d1c5a1 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -6797,6 +6797,13 @@ L: linux-a...@vger.kernel.org > S: Maintained > F: drivers/i2c/i2c-core-acpi.c > > +I2C CONTROLLER DRIVER FOR NVIDIA GPU > +M: Ajay Gupta > +L: linux-...@vger.kernel.org > +S: Maintained > +F: Documentation/i2c/busses/i2c-nvidia-gpu > +F: drivers/i2c/busses/i2c-nvidia-gpu.c > + > I2C MUXES > M: Peter Rosin > L: linux-...@vger.kernel.org > diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig > index 451d4ae..eed827b 100644 > --- a/drivers/i2c/busses/Kconfig > +++ b/drivers/i2c/busses/Kconfig > @@ -224,6 +224,15 @@ config I2C_NFORCE2_S4985 > This driver can also be built as a module. If so, the module > will be called i2c-nforce2-s4985. > > +config I2C_NVIDIA_GPU > + tristate "NVIDIA GPU I2C controller" > + depends on PCI > + help > + If you say yes to this option, support will be included for the > + NVIDIA GPU I2C controller which is used to communicate with the GPU's > + Type-C controller. This driver can also be built as a module called > + i2c-nvidia-gpu. > + > config I2C_SIS5595 > tristate "SiS 5595" > depends on PCI > diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile > index 18b26af..d499813 100644 > --- a/drivers/i2c/busses/Makefile > +++ b/drivers/i2c/busses/Makefile > @@ -140,5 +140,6 @@ obj-$(CONFIG_I2C_SIBYTE) += i2c-sibyte.o > obj-$(CONFIG_I2C_XGENE_SLIMPRO) += i2c-xgene-slimpro.o > obj-$(CONFIG_SCx200_ACB) += scx200_acb.o > obj-$(CONFIG_I2C_FSI)+= i2c-fsi.o > +obj-$(CONFIG_I2C_NVIDIA_GPU) += i2c-nvidia-gpu.o > > ccflags-$(CONFIG_I2C_DEBUG_BUS) := -DDEBUG > diff --git a/drivers/i2c/busses/i2c-nvidia-gpu.c > b/drivers/i2c/busses/i2c-nvidia-gpu.c > new file mode 100644 > index 000..4a63a4e4 > --- /dev/null > +++ b/drivers/i2c/busses/i2c-nvidia-gpu.c > @@ -0,0 +1,396 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Nvidia GPU I2C controller Driver > + * > + * Copyright (C) 2018 NVIDIA Corporation. All rights reserved. > + * Author: Ajay Gupta > + */ > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#include > + > +/* I2C definitions */ > +#define I2C_MST_CNTL 0x00 > +#define I2C_MST_CNTL_GEN_START BIT(0) > +#define I2C_MST_CNTL_GEN_STOPBIT(1) > +#define I2C_MST_CNTL_CMD_NONE(0 << 2) > +#define I2C_MST_CNTL_CMD_READ(1 << 2) > +#define I2C_MST_CNTL_CMD_WRITE (2 << 2)
