Re: [PATCH v4 2/2] scsi: ufs: Add UFS platform driver for Cadence UFS

[Janek Kotas]

A very gentle ping. 

Could you please take a look at the proposed patch?

Thanks,
Jan

> On 20 Sep 2018, at 15:08, Janek Kotas <jank@xxxxxxxxxxx> wrote:
> 
> This patch adds a device tree platform driver for
> Cadence UFS Host Controller.
> It can be enabled with SCSI_UFS_CDNS_PLATFORM Kconfig option.
> 
> Signed-off-by: Jan Kotas <jank@xxxxxxxxxxx>
> ---
> drivers/scsi/ufs/Kconfig       |   8 +++
> drivers/scsi/ufs/Makefile      |   1 +
> drivers/scsi/ufs/cdns-pltfrm.c | 149 +++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 158 insertions(+)
> create mode 100644 drivers/scsi/ufs/cdns-pltfrm.c
> 
> diff --git a/drivers/scsi/ufs/Kconfig b/drivers/scsi/ufs/Kconfig
> index e09fe6a..8f884c3 100644
> --- a/drivers/scsi/ufs/Kconfig
> +++ b/drivers/scsi/ufs/Kconfig
> @@ -80,6 +80,14 @@ config SCSI_UFSHCD_PLATFORM
> 
> 	  If unsure, say N.
> 
> +config SCSI_UFS_CDNS_PLATFORM
> +	tristate "Cadence UFS Controller platform driver"
> +	depends on SCSI_UFSHCD_PLATFORM
> +	help
> +	This selects the Cadence specific additions to UFSHCD platform driver.
> +
> +	  If unsure, say N.
> +
> config SCSI_UFS_DWC_TC_PLATFORM
> 	tristate "DesignWare platform support using a G210 Test Chip"
> 	depends on SCSI_UFSHCD_PLATFORM
> diff --git a/drivers/scsi/ufs/Makefile b/drivers/scsi/ufs/Makefile
> index 2c50f03..e17d14a 100644
> --- a/drivers/scsi/ufs/Makefile
> +++ b/drivers/scsi/ufs/Makefile
> @@ -2,6 +2,7 @@
> # UFSHCD makefile
> obj-$(CONFIG_SCSI_UFS_DWC_TC_PCI) += tc-dwc-g210-pci.o ufshcd-dwc.o tc-dwc-g210.o
> obj-$(CONFIG_SCSI_UFS_DWC_TC_PLATFORM) += tc-dwc-g210-pltfrm.o ufshcd-dwc.o tc-dwc-g210.o
> +obj-$(CONFIG_SCSI_UFS_CDNS_PLATFORM) += cdns-pltfrm.o
> obj-$(CONFIG_SCSI_UFS_QCOM) += ufs-qcom.o
> obj-$(CONFIG_SCSI_UFSHCD) += ufshcd-core.o
> ufshcd-core-objs := ufshcd.o ufs-sysfs.o
> diff --git a/drivers/scsi/ufs/cdns-pltfrm.c b/drivers/scsi/ufs/cdns-pltfrm.c
> new file mode 100644
> index 0000000..8bcf863
> --- /dev/null
> +++ b/drivers/scsi/ufs/cdns-pltfrm.c
> @@ -0,0 +1,149 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Platform UFS Host driver for Cadence controller
> + *
> + * Copyright (C) 2018 Cadence Design Systems, Inc.
> + *
> + * Authors:
> + *	Jan Kotas <jank@xxxxxxxxxxx>
> + *
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/of.h>
> +#include <linux/time.h>
> +
> +#include "ufshcd-pltfrm.h"
> +
> +#define CDNS_UFS_REG_HCLKDIV 0xFC
> +
> +/**
> + * Sets HCLKDIV register value based on the core_clk
> + * @hba: host controller instance
> + *
> + * Return zero for success and non-zero for failure
> + */
> +static int cdns_ufs_set_hclkdiv(struct ufs_hba *hba)
> +{
> +	struct ufs_clk_info *clki;
> +	struct list_head *head = &hba->clk_list_head;
> +	unsigned long core_clk_rate = 0;
> +	u32 core_clk_div = 0;
> +
> +	if (list_empty(head))
> +		return 0;
> +
> +	list_for_each_entry(clki, head, list) {
> +		if (IS_ERR_OR_NULL(clki->clk))
> +			continue;
> +		if (!strcmp(clki->name, "core_clk"))
> +			core_clk_rate = clk_get_rate(clki->clk);
> +	}
> +
> +	if (!core_clk_rate) {
> +		dev_err(hba->dev, "%s: unable to find core_clk rate\n",
> +			__func__);
> +		return -EINVAL;
> +	}
> +
> +	core_clk_div = core_clk_rate / USEC_PER_SEC;
> +
> +	ufshcd_writel(hba, core_clk_div, CDNS_UFS_REG_HCLKDIV);
> +	/**
> +	 * Make sure the register was updated,
> +	 * UniPro layer will not work with an incorrect value.
> +	 */
> +	mb();
> +
> +	return 0;
> +}
> +
> +/**
> + * Sets clocks used by the controller
> + * @hba: host controller instance
> + * @on: if true, enable clocks, otherwise disable
> + * @status: notify stage (pre, post change)
> + *
> + * Return zero for success and non-zero for failure
> + */
> +static int cdns_ufs_setup_clocks(struct ufs_hba *hba, bool on,
> +				 enum ufs_notify_change_status status)
> +{
> +	if ((!on) || (status == PRE_CHANGE))
> +		return 0;
> +
> +	return cdns_ufs_set_hclkdiv(hba);
> +}
> +
> +static struct ufs_hba_variant_ops cdns_pltfm_hba_vops = {
> +	.name = "cdns-ufs-pltfm",
> +	.setup_clocks = cdns_ufs_setup_clocks,
> +};
> +
> +/**
> + * cdns_ufs_pltfrm_probe - probe routine of the driver
> + * @pdev: pointer to platform device handle
> + *
> + * Return zero for success and non-zero for failure
> + */
> +static int cdns_ufs_pltfrm_probe(struct platform_device *pdev)
> +{
> +	int err;
> +	struct device *dev = &pdev->dev;
> +
> +	/* Perform generic probe */
> +	err = ufshcd_pltfrm_init(pdev, &cdns_pltfm_hba_vops);
> +	if (err)
> +		dev_err(dev, "ufshcd_pltfrm_init() failed %d\n", err);
> +
> +	return err;
> +}
> +
> +/**
> + * cdns_ufs_pltfrm_remove - removes the ufs driver
> + * @pdev: pointer to platform device handle
> + *
> + * Always returns 0
> + */
> +static int cdns_ufs_pltfrm_remove(struct platform_device *pdev)
> +{
> +	struct ufs_hba *hba =  platform_get_drvdata(pdev);
> +
> +	ufshcd_remove(hba);
> +	return 0;
> +}
> +
> +static const struct of_device_id cdns_ufs_of_match[] = {
> +	{ .compatible = "cdns,ufshc" },
> +	{},
> +};
> +
> +MODULE_DEVICE_TABLE(of, cdns_ufs_of_match);
> +
> +static const struct dev_pm_ops cdns_ufs_dev_pm_ops = {
> +	.suspend         = ufshcd_pltfrm_suspend,
> +	.resume          = ufshcd_pltfrm_resume,
> +	.runtime_suspend = ufshcd_pltfrm_runtime_suspend,
> +	.runtime_resume  = ufshcd_pltfrm_runtime_resume,
> +	.runtime_idle    = ufshcd_pltfrm_runtime_idle,
> +};
> +
> +static struct platform_driver cdns_ufs_pltfrm_driver = {
> +	.probe	= cdns_ufs_pltfrm_probe,
> +	.remove	= cdns_ufs_pltfrm_remove,
> +	.driver	= {
> +		.name   = "cdns-ufshcd",
> +		.owner  = THIS_MODULE,
> +		.pm     = &cdns_ufs_dev_pm_ops,
> +		.of_match_table = cdns_ufs_of_match,
> +	},
> +};
> +
> +module_platform_driver(cdns_ufs_pltfrm_driver);
> +
> +MODULE_AUTHOR("Jan Kotas <jank@xxxxxxxxxxx>");
> +MODULE_DESCRIPTION("Cadence UFS host controller platform driver");
> +MODULE_LICENSE("GPL v2");
> +MODULE_VERSION(UFSHCD_DRIVER_VERSION);
> -- 
> 1.9.0
> 
>