Re: [PATCH] i2c: amd-isp: Add ISP i2c-designware driver

Christophe JAILLET
2025-03-01T08:41:49Z

Le 28/02/2025 à 17:45, Pratap Nirujogi a écrit :
> The camera sensor is connected via ISP I2C bus in AMD SOC
> architectures. Add new I2C designware driver to support
> new camera sensors on AMD HW.
>
> Signed-off-by: Pratap Nirujogi <pratap.nirujogi@amd.com>

...

> diff --git a/drivers/i2c/busses/i2c-designware-amdisp.c b/drivers/i2c/busses/i2c-designware-amdisp.c
> new file mode 100644
> index 000000000000..dc90510a440b
> --- /dev/null
> +++ b/drivers/i2c/busses/i2c-designware-amdisp.c
> @@ -0,0 +1,266 @@
> +/* SPDX-License-Identifier: MIT */

I think that this should be // comment style for SPDX-License-Identifier
en c files.

> +/*
> + * Copyright 2024-2025 Advanced Micro Devices, Inc.
> + *

...

> +static int amd_isp_dw_i2c_plat_probe(struct platform_device *pdev)
> +{
> + struct i2c_adapter *adap;
> + struct amd_isp_i2c_dev *isp_i2c_dev;
> + struct dw_i2c_dev *dev;
> + int ret;
> +
> + isp_i2c_dev = devm_kzalloc(&pdev->dev, sizeof(struct amd_isp_i2c_dev),

sizeof(*isp_i2c_dev) maybe?

> + GFP_KERNEL);
> + if (!isp_i2c_dev)
> + return -ENOMEM;
> +
> + dev = &isp_i2c_dev->dw_dev;
> + dev->dev = &pdev->dev;
> +
> + /**

Just /*

> + * Use the polling mode to send/receive the data, because
> + * no IRQ connection from ISP I2C
> + */
> + dev->flags |= ACCESS_POLLING;
> + platform_set_drvdata(pdev, dev);
> +
> + dev->base = devm_platform_ioremap_resource(pdev, 0);
> + if (IS_ERR(dev->base))
> + return PTR_ERR(dev->base);
> +
> + ret = isp_power_set(true);
> + if (ret) {
> + dev_err(dev->dev, "unable to turn on the amdisp i2c power:%d\n", ret);

return dev_err_probe() would make code slightly simpler.

> + return ret;
> + }
> +
> + dev->get_clk_rate_khz = amd_isp_dw_i2c_get_clk_rate;
> + ret = i2c_dw_fw_parse_and_configure(dev);
> + if (ret)
> + goto exit;
> +
> + i2c_dw_configure(dev);
> +
> + adap = &dev->adapter;
> + adap->owner = THIS_MODULE;
> + ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev));
> + adap->dev.of_node = pdev->dev.of_node;
> + /* arbitrary large number to avoid any conflicts */
> + adap->nr = 99;
> +
> + if (dev->flags & ACCESS_NO_IRQ_SUSPEND) {
> + dev_pm_set_driver_flags(&pdev->dev,
> + DPM_FLAG_SMART_PREPARE);
> + } else {
> + dev_pm_set_driver_flags(&pdev->dev,
> + DPM_FLAG_SMART_PREPARE |
> + DPM_FLAG_SMART_SUSPEND);
> + }

Unneeded { } in both branches.

> +
> + device_enable_async_suspend(&pdev->dev);
> +
> + /* The code below assumes runtime PM to be disabled. */
> + WARN_ON(pm_runtime_enabled(&pdev->dev));
> +
> + pm_runtime_dont_use_autosuspend(&pdev->dev);
> + pm_runtime_set_active(&pdev->dev);
> +
> + if (dev->shared_with_punit)
> + pm_runtime_get_noresume(&pdev->dev);
> +
> + pm_runtime_enable(&pdev->dev);
> +
> + ret = i2c_dw_probe(dev);
> + if (ret) {
> + dev_err(dev->dev, "i2c_dw_probe failed %d\n", ret);

dev_err_probe() would make code slightly simpler.

> + goto exit_probe;
> + }
> +
> + isp_power_set(false);
> + return ret;
> +
> +exit_probe:
> + amd_isp_dw_i2c_plat_pm_cleanup(dev);
> + isp_power_set(false);
> +exit:
> + isp_power_set(false);
> + return ret;
> +}
> +
> +static void amd_isp_dw_i2c_plat_remove(struct platform_device *pdev)
> +{
> + struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
> +
> + pm_runtime_get_sync(&pdev->dev);
> +
> + i2c_del_adapter(&dev->adapter);
> +
> + i2c_dw_disable(dev);
> +
> + pm_runtime_dont_use_autosuspend(&pdev->dev);
> + pm_runtime_put_sync(&pdev->dev);
> + amd_isp_dw_i2c_plat_pm_cleanup(dev);
> +
> + reset_control_assert(dev->rst);

Is it needed? (there is apparently no reset_control_deassert() in this
driver)

> +}

...

> +MODULE_AUTHOR("Venkata Narendra Kumar Gutta <vengutta@amd.com>");
> +MODULE_AUTHOR("Pratap Nirujogi <pratap.nirujogi@amd.com>");
> +MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter in AMD ISP");
> +MODULE_LICENSE("GPL");

MIT is stated in SPDX-License-Identifier

> +MODULE_IMPORT_NS("I2C_DW");
> +MODULE_IMPORT_NS("I2C_DW_COMMON");
> +MODULE_LICENSE("GPL and additional rights");

Is it allowed to have several MODULE_LICENSE?

...

CJ