[PATCH v4 4/4] drm/amdgpu: Vega20 SMU I2C HW engine controller.

Grodzovsky, Andrey Andrey.Grodzovsky at amd.com
Thu Aug 22 16:45:02 UTC 2019


On 8/22/19 11:59 AM, Alex Deucher wrote:
> On Thu, Aug 22, 2019 at 11:35 AM Grodzovsky, Andrey
> <Andrey.Grodzovsky at amd.com> wrote:
>>
>> On 8/21/19 10:32 PM, Alex Deucher wrote:
>>> On Wed, Aug 21, 2019 at 4:02 PM Andrey Grodzovsky
>>> <andrey.grodzovsky at amd.com> wrote:
>>>> Implement HW I2C enigne controller to be used by the RAS EEPROM
>>>> table manager. This is based on code from ATITOOLs.
>>>>
>>>> v2:
>>>> Rename the file and all function prefixes to smu_v11_0_i2c
>>>>
>>>> By Luben's observation always fill the TX fifo to full so
>>>> we don't have garbadge interpreted by the slave as valid data.
>>>>
>>>> v3:
>>>> Remove preemption disable as the HW I2C controller will not
>>>> stop the clock on empty TX fifo and so it's not critical to
>>>> keep not empty queue.
>>>> Switch to fast mode 400 khz SCL clock for faster read and write.
>>>>
>>>> Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky at amd.com>
>>>> ---
>>>>    drivers/gpu/drm/amd/amdgpu/Makefile            |   5 +-
>>>>    drivers/gpu/drm/amd/amdgpu/amdgpu_ras_eeprom.c |   5 +-
>>>>    drivers/gpu/drm/amd/amdgpu/smu_v11_0_i2c.c     | 710 +++++++++++++++++++++++++
>>>>    drivers/gpu/drm/amd/amdgpu/smu_v11_0_i2c.h     |  34 ++
>>>>    4 files changed, 751 insertions(+), 3 deletions(-)
>>>>    create mode 100644 drivers/gpu/drm/amd/amdgpu/smu_v11_0_i2c.c
>>>>    create mode 100644 drivers/gpu/drm/amd/amdgpu/smu_v11_0_i2c.h
>>>>
>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/Makefile b/drivers/gpu/drm/amd/amdgpu/Makefile
>>>> index f016cf1..14733ff 100644
>>>> --- a/drivers/gpu/drm/amd/amdgpu/Makefile
>>>> +++ b/drivers/gpu/drm/amd/amdgpu/Makefile
>>>> @@ -38,6 +38,9 @@ ccflags-y := -I$(FULL_AMD_PATH)/include/asic_reg \
>>>>           -I$(FULL_AMD_DISPLAY_PATH)/amdgpu_dm \
>>>>           -I$(FULL_AMD_PATH)/amdkfd
>>>>
>>>> +
>>>> +
>>>> +
>>> Drop this random whitespace change.
>>>
>>>>    amdgpu-y := amdgpu_drv.o
>>>>
>>>>    # add KMS driver
>>>> @@ -54,7 +57,7 @@ amdgpu-y += amdgpu_device.o amdgpu_kms.o \
>>>>           amdgpu_gtt_mgr.o amdgpu_vram_mgr.o amdgpu_virt.o amdgpu_atomfirmware.o \
>>>>           amdgpu_vf_error.o amdgpu_sched.o amdgpu_debugfs.o amdgpu_ids.o \
>>>>           amdgpu_gmc.o amdgpu_xgmi.o amdgpu_csa.o amdgpu_ras.o amdgpu_vm_cpu.o \
>>>> -       amdgpu_vm_sdma.o amdgpu_pmu.o amdgpu_discovery.o amdgpu_ras_eeprom.o
>>>> +       amdgpu_vm_sdma.o amdgpu_pmu.o amdgpu_discovery.o amdgpu_ras_eeprom.o smu_v11_0_i2c.o
>>>>
>>>>    amdgpu-$(CONFIG_PERF_EVENTS) += amdgpu_pmu.o
>>>>
>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras_eeprom.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras_eeprom.c
>>>> index bf07515..e6b2e17 100644
>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras_eeprom.c
>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras_eeprom.c
>>>> @@ -25,6 +25,7 @@
>>>>    #include "amdgpu.h"
>>>>    #include "amdgpu_ras.h"
>>>>    #include <linux/bits.h>
>>>> +#include "smu_v11_0_i2c.h"
>>>>
>>>>    #define EEPROM_I2C_TARGET_ADDR 0xA0
>>>>
>>>> @@ -111,7 +112,7 @@ int amdgpu_ras_eeprom_init(struct amdgpu_ras_eeprom_control *control)
>>>>
>>>>           switch (adev->asic_type) {
>>>>           case CHIP_VEGA20:
>>>> -       /*TODO Add MI-60 */
>>>> +               ret = smu_v11_0_i2c_eeprom_control_init(&control->eeprom_accessor);
>>>>                   break;
>>>>
>>>>           default:
>>>> @@ -163,7 +164,7 @@ void amdgpu_ras_eeprom_fini(struct amdgpu_ras_eeprom_control *control)
>>>>
>>>>           switch (adev->asic_type) {
>>>>           case CHIP_VEGA20:
>>>> -               /*TODO Add MI-60 */
>>>> +               smu_v11_0_i2c_eeprom_control_fini(&control->eeprom_accessor);
>>>>                   break;
>>>>
>>>>           default:
>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/smu_v11_0_i2c.c b/drivers/gpu/drm/amd/amdgpu/smu_v11_0_i2c.c
>>>> new file mode 100644
>>>> index 0000000..24405fa
>>>> --- /dev/null
>>>> +++ b/drivers/gpu/drm/amd/amdgpu/smu_v11_0_i2c.c
>>>> @@ -0,0 +1,710 @@
>>>> +/*
>>>> + * Copyright 2019 Advanced Micro Devices, Inc.
>>>> + *
>>>> + * Permission is hereby granted, free of charge, to any person obtaining a
>>>> + * copy of this software and associated documentation files (the "Software"),
>>>> + * to deal in the Software without restriction, including without limitation
>>>> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
>>>> + * and/or sell copies of the Software, and to permit persons to whom the
>>>> + * Software is furnished to do so, subject to the following conditions:
>>>> + *
>>>> + * The above copyright notice and this permission notice shall be included in
>>>> + * all copies or substantial portions of the Software.
>>>> + *
>>>> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
>>>> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
>>>> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
>>>> + * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
>>>> + * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
>>>> + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
>>>> + * OTHER DEALINGS IN THE SOFTWARE.
>>>> + *
>>>> + */
>>>> +
>>>> +#include "smuio/smuio_11_0_0_offset.h"
>>>> +#include "smuio/smuio_11_0_0_sh_mask.h"
>>>> +
>>>> +#include "smu_v11_0_i2c.h"
>>>> +#include "amdgpu.h"
>>>> +#include "soc15_common.h"
>>>> +#include <drm/drm_fixed.h>
>>>> +#include "amdgpu_amdkfd.h"
>>>> +#include <linux/i2c.h>
>>>> +#include "amdgpu_ras.h"
>>>> +
>>>> +/* error codes */
>>>> +#define I2C_OK                         0
>>>> +#define I2C_NAK_7B_ADDR_NOACK          1
>>>> +#define I2C_NAK_TXDATA_NOACK           2
>>>> +#define I2C_TIMEOUT                    4
>>>> +#define I2C_SW_TIMEOUT                 8
>>>> +#define I2C_ABORT                      0x10
>>>> +
>>>> +/* I2C transaction flags */
>>>> +#define I2C_NO_STOP    1
>>>> +#define I2C_RESTART    2
>>>> +
>>>> +#define to_amdgpu_device(x) (container_of(x, struct amdgpu_ras, eeprom_control.eeprom_accessor))->adev
>>>> +#define to_eeprom_control(x) container_of(x, struct amdgpu_ras_eeprom_control, eeprom_accessor)
>>>> +
>>>> +static void smu_v11_0_i2c_dis_clock_gating(struct i2c_adapter *control)
>>>> +{
>>>> +       struct amdgpu_device *adev = to_amdgpu_device(control);
>>>> +       uint32_t reg;
>>>> +
>>>> +       reg = RREG32_SOC15(SMUIO, 0, mmSMUIO_PWRMGT);
>>>> +       reg = REG_SET_FIELD(reg, SMUIO_PWRMGT, i2c_clk_gate_en, 0);
>>>> +       WREG32_SOC15(SMUIO, 0, mmSMUIO_PWRMGT, reg);
>>>> +}
>>> Do we need to worry about re-enabling clock gating when we are done?
>>
>> In smu_11_smuio_mas doc this step is missing for I2C0 (sec. 18.4.1.1)
>> and hence probably also was missing from the original code this was
>> ported so I am not sure. The side effect of this staying disabled is
>> less  power saving I think.
> Can we check the state of SMUIO_PWRMGT.i2c_clk_gate_en at init time,
> and then, if it's enabled, we can disable it in lock_bus and enable it
> in unlock_bus.
>
> Alex


smu_v11_0_i2c_init is called after the lock_bus. I think we should just 
do what you suggest inĀ  smu_v11_0_i2c_init and smu_v11_0_i2c_fini 
respectively.


>
>> Andrey
>>
>>
>>>
>>>> +
>>>> +
>>>> +static void smu_v11_0_i2c_enable(struct i2c_adapter *control, bool enable)
>>>> +{
>>>> +       struct amdgpu_device *adev = to_amdgpu_device(control);
>>>> +
>>>> +       WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE, enable ? 1 : 0);
>>>> +}
>>>> +
>>>> +static void smu_v11_0_i2c_clear_status(struct i2c_adapter *control)
>>>> +{
>>>> +       struct amdgpu_device *adev = to_amdgpu_device(control);
>>>> +       /* do */
>>>> +       {
>>>> +               RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_CLR_INTR);
>>>> +
>>>> +       } /* while (reg_CKSVII2C_ic_clr_intr == 0) */
>>>> +}
>>>> +
>>>> +static void smu_v11_0_i2c_configure(struct i2c_adapter *control)
>>>> +{
>>>> +       struct amdgpu_device *adev = to_amdgpu_device(control);
>>>> +       uint32_t reg = 0;
>>>> +
>>>> +       reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_SLAVE_DISABLE, 1);
>>>> +       reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_RESTART_EN, 1);
>>>> +       reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_10BITADDR_MASTER, 0);
>>>> +       reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_10BITADDR_SLAVE, 0);
>>>> +       /* Standard mode */
>>>> +       reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_MAX_SPEED_MODE, 2);
>>>> +       reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_MASTER_MODE, 1);
>>>> +
>>>> +       WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_CON, reg);
>>>> +}
>>>> +
>>>> +static void smu_v11_0_i2c_set_clock(struct i2c_adapter *control)
>>>> +{
>>>> +       struct amdgpu_device *adev = to_amdgpu_device(control);
>>>> +
>>>> +       /*
>>>> +        * Standard mode speed, These values are taken from SMUIO MAS,
>>>> +        * but are different from what is given is
>>>> +        * Synopsys spec. The values here are based on assumption
>>>> +        * that refclock is 100MHz
>>>> +        *
>>>> +        * Configuration for standard mode; Speed = 100kbps
>>>> +        * Scale linearly, for now only support standard speed clock
>>>> +        * This will work only with 100M ref clock
>>>> +        *
>>>> +        * TBD:Change the calculation to take into account ref clock values also.
>>>> +        */
>>>> +
>>>> +       WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_FS_SPKLEN, 2);
>>>> +       WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_SS_SCL_HCNT, 120);
>>>> +       WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_SS_SCL_LCNT, 130);
>>>> +       WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_SDA_HOLD, 20);
>>>> +}
>>>> +
>>>> +static void smu_v11_0_i2c_set_address(struct i2c_adapter *control, uint8_t address)
>>>> +{
>>>> +       struct amdgpu_device *adev = to_amdgpu_device(control);
>>>> +
>>>> +       /* Convert fromr 8-bit to 7-bit address */
>>>> +       address >>= 1;
>>>> +       WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_TAR, (address & 0xFF));
>>>> +}
>>>> +
>>>> +static uint32_t smu_v11_0_i2c_poll_tx_status(struct i2c_adapter *control)
>>>> +{
>>>> +       struct amdgpu_device *adev = to_amdgpu_device(control);
>>>> +       uint32_t ret = I2C_OK;
>>>> +       uint32_t reg, reg_c_tx_abrt_source;
>>>> +
>>>> +       /*Check if transmission is completed */
>>>> +       unsigned long  timeout_counter = jiffies + msecs_to_jiffies(20);
>>>> +
>>>> +       do {
>>>> +               reg = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_STATUS);
>>>> +
>>>> +               if (time_after(jiffies, timeout_counter)) {
>>>> +                       ret |= I2C_SW_TIMEOUT;
>>>> +                       break;
>>>> +               }
>>>> +       } while (REG_GET_FIELD(reg, CKSVII2C_IC_STATUS, TFE) == 0);
>>>> +
>>>> +       if (ret != I2C_OK)
>>>> +               return ret;
>>>> +
>>>> +       /* This only checks if NAK is received and transaction got aborted */
>>>> +       reg = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_INTR_STAT);
>>>> +
>>>> +       if (REG_GET_FIELD(reg, CKSVII2C_IC_INTR_STAT, R_TX_ABRT) == 1) {
>>>> +               reg_c_tx_abrt_source = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_TX_ABRT_SOURCE);
>>>> +               DRM_INFO("TX was terminated, IC_TX_ABRT_SOURCE val is:%x", reg_c_tx_abrt_source);
>>>> +
>>>> +               /* Check for stop due to NACK */
>>>> +               if (REG_GET_FIELD(reg_c_tx_abrt_source,
>>>> +                                 CKSVII2C_IC_TX_ABRT_SOURCE,
>>>> +                                 ABRT_TXDATA_NOACK) == 1) {
>>>> +
>>>> +                       ret |= I2C_NAK_TXDATA_NOACK;
>>>> +
>>>> +               } else if (REG_GET_FIELD(reg_c_tx_abrt_source,
>>>> +                                        CKSVII2C_IC_TX_ABRT_SOURCE,
>>>> +                                        ABRT_7B_ADDR_NOACK) == 1) {
>>>> +
>>>> +                       ret |= I2C_NAK_7B_ADDR_NOACK;
>>>> +               } else {
>>>> +                       ret |= I2C_ABORT;
>>>> +               }
>>>> +
>>>> +               smu_v11_0_i2c_clear_status(control);
>>>> +       }
>>>> +
>>>> +       return ret;
>>>> +}
>>>> +
>>>> +static uint32_t smu_v11_0_i2c_poll_rx_status(struct i2c_adapter *control)
>>>> +{
>>>> +       struct amdgpu_device *adev = to_amdgpu_device(control);
>>>> +       uint32_t ret = I2C_OK;
>>>> +       uint32_t reg_ic_status, reg_c_tx_abrt_source;
>>>> +
>>>> +       reg_c_tx_abrt_source = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_TX_ABRT_SOURCE);
>>>> +
>>>> +       /* If slave is not present */
>>>> +       if (REG_GET_FIELD(reg_c_tx_abrt_source,
>>>> +                         CKSVII2C_IC_TX_ABRT_SOURCE,
>>>> +                         ABRT_7B_ADDR_NOACK) == 1) {
>>>> +               ret |= I2C_NAK_7B_ADDR_NOACK;
>>>> +
>>>> +               smu_v11_0_i2c_clear_status(control);
>>>> +       } else {  /* wait till some data is there in RXFIFO */
>>>> +               /* Poll for some byte in RXFIFO */
>>>> +               unsigned long  timeout_counter = jiffies + msecs_to_jiffies(20);
>>>> +
>>>> +               do {
>>>> +                       reg_ic_status = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_STATUS);
>>>> +
>>>> +                       if (time_after(jiffies, timeout_counter)) {
>>>> +                               ret |= I2C_SW_TIMEOUT;
>>>> +                               break;
>>>> +                       }
>>>> +               } while (REG_GET_FIELD(reg_ic_status, CKSVII2C_IC_STATUS, RFNE) == 0);
>>>> +       }
>>>> +
>>>> +       return ret;
>>>> +}
>>>> +
>>>> +
>>>> +
>>>> +
>>>> +/**
>>>> + * smu_v11_0_i2c_transmit - Send a block of data over the I2C bus to a slave device.
>>>> + *
>>>> + * @address: The I2C address of the slave device.
>>>> + * @data: The data to transmit over the bus.
>>>> + * @numbytes: The amount of data to transmit.
>>>> + * @i2c_flag: Flags for transmission
>>>> + *
>>>> + * Returns 0 on success or error.
>>>> + */
>>>> +static uint32_t smu_v11_0_i2c_transmit(struct i2c_adapter *control,
>>>> +                                 uint8_t address, uint8_t *data,
>>>> +                                 uint32_t numbytes, uint32_t i2c_flag)
>>>> +{
>>>> +       struct amdgpu_device *adev = to_amdgpu_device(control);
>>>> +       uint32_t bytes_sent, reg, ret = 0;
>>>> +       unsigned long  timeout_counter;
>>>> +
>>>> +       bytes_sent = 0;
>>>> +
>>>> +       DRM_DEBUG_DRIVER("I2C_Transmit(), address = %x, bytes = %d , data: ",
>>>> +                (uint16_t)address, numbytes);
>>>> +
>>>> +       if (drm_debug & DRM_UT_DRIVER) {
>>>> +               print_hex_dump(KERN_INFO, "data: ", DUMP_PREFIX_NONE,
>>>> +                              16, 1, data, numbytes, false);
>>>> +       }
>>>> +
>>>> +       /* Set the I2C slave address */
>>>> +       smu_v11_0_i2c_set_address(control, address);
>>>> +       /* Enable I2C */
>>>> +       smu_v11_0_i2c_enable(control, true);
>>>> +
>>>> +       /* Clear status bits */
>>>> +       smu_v11_0_i2c_clear_status(control);
>>>> +
>>>> +
>>>> +       timeout_counter = jiffies + msecs_to_jiffies(20);
>>>> +
>>>> +       while (numbytes > 0) {
>>>> +               reg = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_STATUS);
>>>> +               if (REG_GET_FIELD(reg, CKSVII2C_IC_STATUS, TFNF)) {
>>>> +                       do {
>>>> +                               reg = 0;
>>>> +                               /*
>>>> +                                * Prepare transaction, no need to set RESTART. I2C engine will send
>>>> +                                * START as soon as it sees data in TXFIFO
>>>> +                                */
>>>> +                               if (bytes_sent == 0)
>>>> +                                       reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, RESTART,
>>>> +                                                           (i2c_flag & I2C_RESTART) ? 1 : 0);
>>>> +                               reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, DAT, data[bytes_sent]);
>>>> +
>>>> +                               /* determine if we need to send STOP bit or not */
>>>> +                               if (numbytes == 1)
>>>> +                                       /* Final transaction, so send stop unless I2C_NO_STOP */
>>>> +                                       reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, STOP,
>>>> +                                                           (i2c_flag & I2C_NO_STOP) ? 0 : 1);
>>>> +                               /* Write */
>>>> +                               reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, CMD, 0);
>>>> +                               WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_DATA_CMD, reg);
>>>> +
>>>> +                               /* Record that the bytes were transmitted */
>>>> +                               bytes_sent++;
>>>> +                               numbytes--;
>>>> +
>>>> +                               reg = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_STATUS);
>>>> +
>>>> +                       } while (numbytes &&  REG_GET_FIELD(reg, CKSVII2C_IC_STATUS, TFNF));
>>>> +               }
>>>> +
>>>> +
>>>> +               if (time_after(jiffies, timeout_counter)) {
>>>> +                       ret |= I2C_SW_TIMEOUT;
>>>> +                       goto err;
>>>> +               }
>>>> +       }
>>>> +
>>>> +       ret = smu_v11_0_i2c_poll_tx_status(control);
>>>> +
>>>> +err:
>>>> +       /* Any error, no point in proceeding */
>>>> +       if (ret != I2C_OK) {
>>>> +               if (ret & I2C_SW_TIMEOUT)
>>>> +                       DRM_ERROR("TIMEOUT ERROR !!!");
>>>> +
>>>> +               if (ret & I2C_NAK_7B_ADDR_NOACK)
>>>> +                       DRM_ERROR("Received I2C_NAK_7B_ADDR_NOACK !!!");
>>>> +
>>>> +
>>>> +               if (ret & I2C_NAK_TXDATA_NOACK)
>>>> +                       DRM_ERROR("Received I2C_NAK_TXDATA_NOACK !!!");
>>>> +       }
>>>> +
>>>> +       return ret;
>>>> +}
>>>> +
>>>> +
>>>> +/**
>>>> + * smu_v11_0_i2c_receive - Receive a block of data over the I2C bus from a slave device.
>>>> + *
>>>> + * @address: The I2C address of the slave device.
>>>> + * @numbytes: The amount of data to transmit.
>>>> + * @i2c_flag: Flags for transmission
>>>> + *
>>>> + * Returns 0 on success or error.
>>>> + */
>>>> +static uint32_t smu_v11_0_i2c_receive(struct i2c_adapter *control,
>>>> +                                uint8_t address, uint8_t *data,
>>>> +                                uint32_t numbytes, uint8_t i2c_flag)
>>>> +{
>>>> +       struct amdgpu_device *adev = to_amdgpu_device(control);
>>>> +       uint32_t bytes_received, ret = I2C_OK;
>>>> +
>>>> +       bytes_received = 0;
>>>> +
>>>> +       /* Set the I2C slave address */
>>>> +       smu_v11_0_i2c_set_address(control, address);
>>>> +
>>>> +       /* Enable I2C */
>>>> +       smu_v11_0_i2c_enable(control, true);
>>>> +
>>>> +       while (numbytes > 0) {
>>>> +               uint32_t reg = 0;
>>>> +
>>>> +               smu_v11_0_i2c_clear_status(control);
>>>> +
>>>> +
>>>> +               /* Prepare transaction */
>>>> +
>>>> +               /* Each time we disable I2C, so this is not a restart */
>>>> +               if (bytes_received == 0)
>>>> +                       reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, RESTART,
>>>> +                                           (i2c_flag & I2C_RESTART) ? 1 : 0);
>>>> +
>>>> +               reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, DAT, 0);
>>>> +               /* Read */
>>>> +               reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, CMD, 1);
>>>> +
>>>> +               /* Transmitting last byte */
>>>> +               if (numbytes == 1)
>>>> +                       /* Final transaction, so send stop if requested */
>>>> +                       reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, STOP,
>>>> +                                           (i2c_flag & I2C_NO_STOP) ? 0 : 1);
>>>> +
>>>> +               WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_DATA_CMD, reg);
>>>> +
>>>> +               ret = smu_v11_0_i2c_poll_rx_status(control);
>>>> +
>>>> +               /* Any error, no point in proceeding */
>>>> +               if (ret != I2C_OK) {
>>>> +                       if (ret & I2C_SW_TIMEOUT)
>>>> +                               DRM_ERROR("TIMEOUT ERROR !!!");
>>>> +
>>>> +                       if (ret & I2C_NAK_7B_ADDR_NOACK)
>>>> +                               DRM_ERROR("Received I2C_NAK_7B_ADDR_NOACK !!!");
>>>> +
>>>> +                       if (ret & I2C_NAK_TXDATA_NOACK)
>>>> +                               DRM_ERROR("Received I2C_NAK_TXDATA_NOACK !!!");
>>>> +
>>>> +                       break;
>>>> +               }
>>>> +
>>>> +               reg = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_DATA_CMD);
>>>> +               data[bytes_received] = REG_GET_FIELD(reg, CKSVII2C_IC_DATA_CMD, DAT);
>>>> +
>>>> +               /* Record that the bytes were received */
>>>> +               bytes_received++;
>>>> +               numbytes--;
>>>> +       }
>>>> +
>>>> +       DRM_DEBUG_DRIVER("I2C_Receive(), address = %x, bytes = %d, data :",
>>>> +                 (uint16_t)address, bytes_received);
>>>> +
>>>> +       if (drm_debug & DRM_UT_DRIVER) {
>>>> +               print_hex_dump(KERN_INFO, "data: ", DUMP_PREFIX_NONE,
>>>> +                              16, 1, data, bytes_received, false);
>>>> +       }
>>>> +
>>>> +       return ret;
>>>> +}
>>>> +
>>>> +static void smu_v11_0_i2c_abort(struct i2c_adapter *control)
>>>> +{
>>>> +       struct amdgpu_device *adev = to_amdgpu_device(control);
>>>> +       uint32_t reg = 0;
>>>> +
>>>> +       /* Enable I2C engine; */
>>>> +       reg = REG_SET_FIELD(reg, CKSVII2C_IC_ENABLE, ENABLE, 1);
>>>> +       WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE, reg);
>>>> +
>>>> +       /* Abort previous transaction */
>>>> +       reg = REG_SET_FIELD(reg, CKSVII2C_IC_ENABLE, ABORT, 1);
>>>> +       WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE, reg);
>>>> +
>>>> +       DRM_DEBUG_DRIVER("I2C_Abort() Done.");
>>>> +}
>>>> +
>>>> +
>>>> +static bool smu_v11_0_i2c_activity_done(struct i2c_adapter *control)
>>>> +{
>>>> +       struct amdgpu_device *adev = to_amdgpu_device(control);
>>>> +
>>>> +       const uint32_t IDLE_TIMEOUT = 1024;
>>>> +       uint32_t timeoutCount = 0;
>>> kernel coding style prefers non CamelCase.  E.g., timeout_count.
>>>
>>>> +       uint32_t reg_ic_enable, reg_ic_enable_status, reg_ic_clr_activity;
>>>> +
>>>> +       reg_ic_enable_status = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE_STATUS);
>>>> +       reg_ic_enable = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE);
>>>> +
>>>> +
>>>> +       if ((REG_GET_FIELD(reg_ic_enable, CKSVII2C_IC_ENABLE, ENABLE) == 0) &&
>>>> +           (REG_GET_FIELD(reg_ic_enable_status, CKSVII2C_IC_ENABLE_STATUS, IC_EN) == 1)) {
>>>> +               /*
>>>> +                * Nobody is using I2C engine, but engine remains active because
>>>> +                * someone missed to send STOP
>>>> +                */
>>>> +               smu_v11_0_i2c_abort(control);
>>>> +       } else if (REG_GET_FIELD(reg_ic_enable, CKSVII2C_IC_ENABLE, ENABLE) == 0) {
>>>> +               /* Nobody is using I2C engine */
>>>> +               return true;
>>>> +       }
>>>> +
>>>> +       /* Keep reading activity bit until it's cleared */
>>>> +       do {
>>>> +               reg_ic_clr_activity = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_CLR_ACTIVITY);
>>>> +
>>>> +               if (REG_GET_FIELD(reg_ic_clr_activity,
>>>> +                   CKSVII2C_IC_CLR_ACTIVITY, CLR_ACTIVITY) == 0)
>>>> +                       return true;
>>>> +
>>>> +               ++timeoutCount;
>>>> +
>>>> +       } while (timeoutCount < IDLE_TIMEOUT);
>>>> +
>>>> +       return false;
>>>> +}
>>>> +
>>>> +static void smu_v11_0_i2c_init(struct i2c_adapter *control)
>>>> +{
>>>> +       /* Disable clock gating */
>>>> +       smu_v11_0_i2c_dis_clock_gating(control);
>>>> +
>>>> +       if (!smu_v11_0_i2c_activity_done(control))
>>>> +               DRM_WARN("I2C busy !");
>>>> +
>>>> +       /* Disable I2C */
>>>> +       smu_v11_0_i2c_enable(control, false);
>>>> +
>>>> +       /* Configure I2C to operate as master and in standard mode */
>>>> +       smu_v11_0_i2c_configure(control);
>>>> +
>>>> +       /* Initialize the clock to 50 kHz default */
>>>> +       smu_v11_0_i2c_set_clock(control);
>>>> +
>>>> +}
>>>> +
>>>> +static void smu_v11_0_i2c_fini(struct i2c_adapter *control)
>>>> +{
>>>> +       struct amdgpu_device *adev = to_amdgpu_device(control);
>>>> +       uint32_t reg_ic_enable_status, reg_ic_enable;
>>>> +
>>>> +       smu_v11_0_i2c_enable(control, false);
>>>> +
>>>> +       /* Double check if disabled, else force abort */
>>>> +       reg_ic_enable_status = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE_STATUS);
>>>> +       reg_ic_enable = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE);
>>>> +
>>>> +       if ((REG_GET_FIELD(reg_ic_enable, CKSVII2C_IC_ENABLE, ENABLE) == 0) &&
>>>> +           (REG_GET_FIELD(reg_ic_enable_status,
>>>> +                          CKSVII2C_IC_ENABLE_STATUS, IC_EN) == 1)) {
>>>> +               /*
>>>> +                * Nobody is using I2C engine, but engine remains active because
>>>> +                * someone missed to send STOP
>>>> +                */
>>>> +               smu_v11_0_i2c_abort(control);
>>>> +       }
>>>> +
>>>> +}
>>>> +
>>>> +static bool smu_v11_0_i2c_bus_lock(struct i2c_adapter *control)
>>>> +{
>>>> +       struct amdgpu_device *adev = to_amdgpu_device(control);
>>>> +
>>>> +       /* Send  PPSMC_MSG_RequestI2CBus */
>>>> +       if (!adev->powerplay.pp_funcs->smu_i2c_bus_access)
>>>> +               goto fail;
>>>> +
>>>> +
>>>> +       if (!adev->powerplay.pp_funcs->smu_i2c_bus_access(adev->powerplay.pp_handle, true))
>>>> +               return true;
>>>> +
>>>> +fail:
>>>> +       return false;
>>>> +}
>>>> +
>>>> +static bool smu_v11_0_i2c_bus_unlock(struct i2c_adapter *control)
>>>> +{
>>>> +       struct amdgpu_device *adev = to_amdgpu_device(control);
>>>> +
>>>> +       /* Send  PPSMC_MSG_RequestI2CBus */
>>>> +       if (!adev->powerplay.pp_funcs->smu_i2c_bus_access)
>>>> +               goto fail;
>>>> +
>>>> +       /* Send  PPSMC_MSG_ReleaseI2CBus */
>>>> +       if (!adev->powerplay.pp_funcs->smu_i2c_bus_access(adev->powerplay.pp_handle,
>>>> +                                                            false))
>>>> +               return true;
>>>> +
>>>> +fail:
>>>> +       return false;
>>>> +}
>>>> +
>>>> +/***************************** EEPROM I2C GLUE ****************************/
>>>> +
>>>> +static uint32_t smu_v11_0_i2c_eeprom_read_data(struct i2c_adapter *control,
>>>> +                                              uint8_t address,
>>>> +                                              uint8_t *data,
>>>> +                                              uint32_t numbytes)
>>>> +{
>>>> +       uint32_t  ret = 0;
>>>> +
>>>> +       /* First 2 bytes are dummy write to set EEPROM address */
>>>> +       ret = smu_v11_0_i2c_transmit(control, address, data, 2, I2C_NO_STOP);
>>>> +       if (ret != I2C_OK)
>>>> +               goto fail;
>>>> +
>>>> +       /* Now read data starting with that address */
>>>> +       ret = smu_v11_0_i2c_receive(control, address, data + 2, numbytes - 2,
>>>> +                                   I2C_RESTART);
>>>> +
>>>> +fail:
>>>> +       if (ret != I2C_OK)
>>>> +               DRM_ERROR("ReadData() - I2C error occurred :%x", ret);
>>>> +
>>>> +       return ret;
>>>> +}
>>>> +
>>>> +static uint32_t smu_v11_0_i2c_eeprom_write_data(struct i2c_adapter *control,
>>>> +                                               uint8_t address,
>>>> +                                               uint8_t *data,
>>>> +                                               uint32_t numbytes)
>>>> +{
>>>> +       uint32_t  ret;
>>>> +
>>>> +       ret = smu_v11_0_i2c_transmit(control, address, data, numbytes, 0);
>>>> +
>>>> +       if (ret != I2C_OK)
>>>> +               DRM_ERROR("WriteI2CData() - I2C error occurred :%x", ret);
>>>> +       else
>>>> +               /*
>>>> +                * According to EEPROM spec there is a MAX of 10 ms required for
>>>> +                * EEPROM to flush internal RX buffer after STOP was issued at the
>>>> +                * end of write transaction. During this time the EEPROM will not be
>>>> +                * responsive to any more commands - so wait a bit more.
>>>> +                *
>>>> +                * TODO Improve to wait for first ACK for slave address after
>>>> +                * internal write cycle done.
>>>> +                */
>>>> +               msleep(10);
>>>> +
>>>> +       return ret;
>>>> +
>>>> +}
>>>> +
>>>> +static void lock_bus(struct i2c_adapter *i2c, unsigned int flags)
>>>> +{
>>>> +       struct amdgpu_ras_eeprom_control *control = to_eeprom_control(i2c);
>>>> +
>>>> +       if (!smu_v11_0_i2c_bus_lock(i2c)) {
>>>> +               DRM_ERROR("Failed to lock the bus from SMU");
>>>> +               return;
>>>> +       }
>>>> +
>>>> +       control->bus_locked = true;
>>>> +}
>>>> +
>>>> +static int trylock_bus(struct i2c_adapter *i2c, unsigned int flags)
>>>> +{
>>>> +       WARN_ONCE(1, "This operation not supposed to run in atomic context!");
>>>> +       return false;
>>>> +}
>>>> +
>>>> +static void unlock_bus(struct i2c_adapter *i2c, unsigned int flags)
>>>> +{
>>>> +       struct amdgpu_ras_eeprom_control *control = to_eeprom_control(i2c);
>>>> +
>>>> +       if (!smu_v11_0_i2c_bus_unlock(i2c)) {
>>>> +               DRM_ERROR("Failed to unlock the bus from SMU");
>>>> +               return;
>>>> +       }
>>>> +
>>>> +       control->bus_locked = false;
>>>> +}
>>>> +
>>>> +static const struct i2c_lock_operations smu_v11_0_i2c_i2c_lock_ops = {
>>>> +       .lock_bus = lock_bus,
>>>> +       .trylock_bus = trylock_bus,
>>>> +       .unlock_bus = unlock_bus,
>>>> +};
>>>> +
>>>> +static int smu_v11_0_i2c_eeprom_i2c_xfer(struct i2c_adapter *i2c_adap,
>>>> +                             struct i2c_msg *msgs, int num)
>>>> +{
>>>> +       int i, ret;
>>>> +       struct amdgpu_ras_eeprom_control *control = to_eeprom_control(i2c_adap);
>>>> +
>>>> +       if (!control->bus_locked) {
>>>> +               DRM_ERROR("I2C bus unlocked, stopping transaction!");
>>>> +               return -EIO;
>>>> +       }
>>>> +
>>>> +       smu_v11_0_i2c_init(i2c_adap);
>>>> +
>>>> +       for (i = 0; i < num; i++) {
>>>> +               if (msgs[i].flags & I2C_M_RD)
>>>> +                       ret = smu_v11_0_i2c_eeprom_read_data(i2c_adap,
>>>> +                                                       (uint8_t)msgs[i].addr,
>>>> +                                                       msgs[i].buf, msgs[i].len);
>>>> +               else
>>>> +                       ret = smu_v11_0_i2c_eeprom_write_data(i2c_adap,
>>>> +                                                        (uint8_t)msgs[i].addr,
>>>> +                                                        msgs[i].buf, msgs[i].len);
>>>> +
>>>> +               if (ret != I2C_OK) {
>>>> +                       num = -EIO;
>>>> +                       break;
>>>> +               }
>>>> +       }
>>>> +
>>>> +       smu_v11_0_i2c_fini(i2c_adap);
>>>> +       return num;
>>>> +}
>>>> +
>>>> +static u32 smu_v11_0_i2c_eeprom_i2c_func(struct i2c_adapter *adap)
>>>> +{
>>>> +       return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
>>>> +}
>>>> +
>>>> +
>>>> +static const struct i2c_algorithm smu_v11_0_i2c_eeprom_i2c_algo = {
>>>> +       .master_xfer = smu_v11_0_i2c_eeprom_i2c_xfer,
>>>> +       .functionality = smu_v11_0_i2c_eeprom_i2c_func,
>>>> +};
>>>> +
>>>> +int smu_v11_0_i2c_eeprom_control_init(struct i2c_adapter *control)
>>>> +{
>>>> +       struct amdgpu_device *adev = to_amdgpu_device(control);
>>>> +       int res;
>>>> +
>>>> +       control->owner = THIS_MODULE;
>>>> +       control->class = I2C_CLASS_SPD;
>>>> +       control->dev.parent = &adev->pdev->dev;
>>>> +       control->algo = &smu_v11_0_i2c_eeprom_i2c_algo;
>>>> +       snprintf(control->name, sizeof(control->name), "RAS EEPROM");
>>>> +       control->lock_ops = &smu_v11_0_i2c_i2c_lock_ops;
>>>> +
>>>> +       res = i2c_add_adapter(control);
>>>> +       if (res)
>>>> +               DRM_ERROR("Failed to register hw i2c, err: %d\n", res);
>>>> +
>>>> +       return res;
>>>> +}
>>>> +
>>>> +void smu_v11_0_i2c_eeprom_control_fini(struct i2c_adapter *control)
>>>> +{
>>>> +       i2c_del_adapter(control);
>>>> +}
>>>> +
>>>> +#define I2C_TARGET_ADDR 0xA0
>>>> +
>>>> +bool smu_v11_0_i2c_test_bus(struct i2c_adapter *control)
>>>> +{
>>>> +
>>>> +       uint32_t ret = I2C_OK;
>>>> +       uint8_t data[6] = {0xf, 0, 0xde, 0xad, 0xbe, 0xef};
>>>> +
>>>> +
>>>> +       DRM_INFO("Begin");
>>>> +
>>>> +       if (!smu_v11_0_i2c_bus_lock(control)) {
>>>> +               DRM_ERROR("Failed to lock the bus!.");
>>>> +               return false;
>>>> +       }
>>>> +
>>>> +       smu_v11_0_i2c_init(control);
>>>> +
>>>> +       /* Write 0xde to address 0x0000 on the EEPROM */
>>>> +       ret = smu_v11_0_i2c_eeprom_write_data(control, I2C_TARGET_ADDR, data, 6);
>>>> +
>>>> +       ret = smu_v11_0_i2c_eeprom_read_data(control, I2C_TARGET_ADDR, data, 6);
>>>> +
>>>> +       smu_v11_0_i2c_fini(control);
>>>> +
>>>> +       smu_v11_0_i2c_bus_unlock(control);
>>>> +
>>>> +
>>>> +       DRM_INFO("End");
>>>> +       return true;
>>>> +}
>>> Leftover debugging function?


Missed that one, yes. Should I remove it ? Could be useful at some point 
for future bugs debugging...

Andrey


>>>
>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/smu_v11_0_i2c.h b/drivers/gpu/drm/amd/amdgpu/smu_v11_0_i2c.h
>>>> new file mode 100644
>>>> index 0000000..973f28d
>>>> --- /dev/null
>>>> +++ b/drivers/gpu/drm/amd/amdgpu/smu_v11_0_i2c.h
>>>> @@ -0,0 +1,34 @@
>>>> +/*
>>>> + * Copyright 2019 Advanced Micro Devices, Inc.
>>>> + *
>>>> + * Permission is hereby granted, free of charge, to any person obtaining a
>>>> + * copy of this software and associated documentation files (the "Software"),
>>>> + * to deal in the Software without restriction, including without limitation
>>>> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
>>>> + * and/or sell copies of the Software, and to permit persons to whom the
>>>> + * Software is furnished to do so, subject to the following conditions:
>>>> + *
>>>> + * The above copyright notice and this permission notice shall be included in
>>>> + * all copies or substantial portions of the Software.
>>>> + *
>>>> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
>>>> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
>>>> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
>>>> + * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
>>>> + * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
>>>> + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
>>>> + * OTHER DEALINGS IN THE SOFTWARE.
>>>> + *
>>>> + */
>>>> +
>>>> +#ifndef SMU_V11_I2C_CONTROL_H
>>>> +#define SMU_V11_I2C_CONTROL_H
>>>> +
>>>> +#include <linux/types.h>
>>>> +
>>>> +struct i2c_adapter;
>>>> +
>>>> +int smu_v11_0_i2c_eeprom_control_init(struct i2c_adapter *control);
>>>> +void smu_v11_0_i2c_eeprom_control_fini(struct i2c_adapter *control);
>>>> +
>>>> +#endif
>>>> --
>>>> 2.7.4
>>>>
>>>> _______________________________________________
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>>>> amd-gfx at lists.freedesktop.org
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