[v1,1/3] PCI: dwc: refactor common code

Refactor common code from RC(Root Complex) and EP(End Point)
drivers and move them to a common repository. This acts as placeholder
for common source code for both drivers avoiding duplication.

Signed-off-by: Shashank Babu Chinta Venkata <quic_schintav@quicinc.com>
---
 drivers/pci/controller/dwc/Kconfig         |  5 ++
 drivers/pci/controller/dwc/Makefile        |  1 +
 drivers/pci/controller/dwc/pcie-qcom-cmn.c | 85 ++++++++++++++++++++++
 drivers/pci/controller/dwc/pcie-qcom-cmn.h | 30 ++++++++
 drivers/pci/controller/dwc/pcie-qcom-ep.c  | 39 +---------
 drivers/pci/controller/dwc/pcie-qcom.c     | 67 ++---------------
 6 files changed, 133 insertions(+), 94 deletions(-)
 create mode 100644 drivers/pci/controller/dwc/pcie-qcom-cmn.c
 create mode 100644 drivers/pci/controller/dwc/pcie-qcom-cmn.h

tag should be  PCI: qcom:

Frank

On Thu, Feb 29, 2024 at 09:11:34PM -0800, Shashank Babu Chinta Venkata wrote:
> Refactor common code from RC(Root Complex) and EP(End Point)
> drivers and move them to a common repository. This acts as placeholder
> for common source code for both drivers avoiding duplication.
> 
> Signed-off-by: Shashank Babu Chinta Venkata <quic_schintav@quicinc.com>
> ---
>  drivers/pci/controller/dwc/Kconfig         |  5 ++
>  drivers/pci/controller/dwc/Makefile        |  1 +
>  drivers/pci/controller/dwc/pcie-qcom-cmn.c | 85 ++++++++++++++++++++++
>  drivers/pci/controller/dwc/pcie-qcom-cmn.h | 30 ++++++++
>  drivers/pci/controller/dwc/pcie-qcom-ep.c  | 39 +---------
>  drivers/pci/controller/dwc/pcie-qcom.c     | 67 ++---------------
>  6 files changed, 133 insertions(+), 94 deletions(-)
>  create mode 100644 drivers/pci/controller/dwc/pcie-qcom-cmn.c
>  create mode 100644 drivers/pci/controller/dwc/pcie-qcom-cmn.h
> 
> diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
> index 8afacc90c63b..41d2746edc5f 100644
> --- a/drivers/pci/controller/dwc/Kconfig
> +++ b/drivers/pci/controller/dwc/Kconfig
> @@ -265,12 +265,16 @@ config PCIE_DW_PLAT_EP
>  	  order to enable device-specific features PCI_DW_PLAT_EP must be
>  	  selected.
>  
> +config PCIE_QCOM_CMN
> +	bool
> +
>  config PCIE_QCOM
>  	bool "Qualcomm PCIe controller (host mode)"
>  	depends on OF && (ARCH_QCOM || COMPILE_TEST)
>  	depends on PCI_MSI
>  	select PCIE_DW_HOST
>  	select CRC8
> +	select PCIE_QCOM_CMN
>  	help
>  	  Say Y here to enable PCIe controller support on Qualcomm SoCs. The
>  	  PCIe controller uses the DesignWare core plus Qualcomm-specific
> @@ -281,6 +285,7 @@ config PCIE_QCOM_EP
>  	depends on OF && (ARCH_QCOM || COMPILE_TEST)
>  	depends on PCI_ENDPOINT
>  	select PCIE_DW_EP
> +	select PCIE_QCOM_CMN
>  	help
>  	  Say Y here to enable support for the PCIe controllers on Qualcomm SoCs
>  	  to work in endpoint mode. The PCIe controller uses the DesignWare core
> diff --git a/drivers/pci/controller/dwc/Makefile b/drivers/pci/controller/dwc/Makefile
> index bac103faa523..022dc73c38a5 100644
> --- a/drivers/pci/controller/dwc/Makefile
> +++ b/drivers/pci/controller/dwc/Makefile
> @@ -27,6 +27,7 @@ obj-$(CONFIG_PCIE_UNIPHIER) += pcie-uniphier.o
>  obj-$(CONFIG_PCIE_UNIPHIER_EP) += pcie-uniphier-ep.o
>  obj-$(CONFIG_PCIE_VISCONTI_HOST) += pcie-visconti.o
>  obj-$(CONFIG_PCIE_RCAR_GEN4) += pcie-rcar-gen4.o
> +obj-$(CONFIG_PCIE_QCOM_CMN) += pcie-qcom-cmn.o
>  
>  # The following drivers are for devices that use the generic ACPI
>  # pci_root.c driver but don't support standard ECAM config access.
> diff --git a/drivers/pci/controller/dwc/pcie-qcom-cmn.c b/drivers/pci/controller/dwc/pcie-qcom-cmn.c
> new file mode 100644
> index 000000000000..0f8d004fbc79
> --- /dev/null
> +++ b/drivers/pci/controller/dwc/pcie-qcom-cmn.c
> @@ -0,0 +1,85 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2014-2015, 2020 The Linux Foundation. All rights reserved.
> + * Copyright 2015, 2021 Linaro Limited.
> + * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
> + *
> + */
> +
> +#include <linux/debugfs.h>
> +#include <linux/pci.h>
> +#include <linux/interconnect.h>
> +
> +#include "../../pci.h"
> +#include "pcie-designware.h"
> +#include "pcie-qcom-cmn.h"
> +
> +
> +#define QCOM_PCIE_LINK_SPEED_TO_BW(speed) \
> +		Mbps_to_icc(PCIE_SPEED2MBS_ENC(pcie_link_speed[speed]))
> +
> +
> +int qcom_pcie_cmn_icc_get_resource(struct dw_pcie *pci, struct icc_path *icc_mem)
> +{
> +	int ret = 0;
> +
> +	if (IS_ERR(pci))
> +		return PTR_ERR(pci);
> +
> +	icc_mem = devm_of_icc_get(pci->dev, "pcie-mem");
> +	if (IS_ERR(icc_mem))
> +		return PTR_ERR(icc_mem);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(qcom_pcie_cmn_icc_get_resource);
> +
> +int qcom_pcie_cmn_icc_init(struct dw_pcie *pci, struct icc_path *icc_mem)
> +{
> +	int ret = 0;
> +
> +	if (IS_ERR(pci))
> +		return PTR_ERR(pci);
> +
> +	if (IS_ERR(icc_mem))
> +		return PTR_ERR(icc_mem);
> +
> +	/*
> +	 * Some Qualcomm platforms require interconnect bandwidth constraints
> +	 * to be set before enabling interconnect clocks.
> +	 *
> +	 * Set an initial peak bandwidth corresponding to single-lane Gen 1
> +	 * for the pcie-mem path.
> +	 */
> +	ret = icc_set_bw(icc_mem, 0, QCOM_PCIE_LINK_SPEED_TO_BW(1));
> +	if (ret) {
> +		dev_err(pci->dev, "failed to set interconnect bandwidth: %d\n",
> +			ret);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(qcom_pcie_cmn_icc_init);
> +
> +void qcom_pcie_cmn_icc_update(struct dw_pcie *pci, struct icc_path *icc_mem)
> +{
> +	u32 offset, status;
> +	int speed, width;
> +	int ret;
> +
> +	if (!icc_mem)
> +		return;
> +
> +	offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
> +	status = readw(pci->dbi_base + offset + PCI_EXP_LNKSTA);
> +
> +	speed = FIELD_GET(PCI_EXP_LNKSTA_CLS, status);
> +	width = FIELD_GET(PCI_EXP_LNKSTA_NLW, status);
> +
> +	ret = icc_set_bw(icc_mem, 0, width * QCOM_PCIE_LINK_SPEED_TO_BW(speed));
> +	if (ret)
> +		dev_err(pci->dev, "failed to set interconnect bandwidth: %d\n",
> +			ret);
> +}
> +EXPORT_SYMBOL_GPL(qcom_pcie_cmn_icc_update);
> diff --git a/drivers/pci/controller/dwc/pcie-qcom-cmn.h b/drivers/pci/controller/dwc/pcie-qcom-cmn.h
> new file mode 100644
> index 000000000000..8794dbd4775c
> --- /dev/null
> +++ b/drivers/pci/controller/dwc/pcie-qcom-cmn.h
> @@ -0,0 +1,30 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (c) 2014-2015, 2020 The Linux Foundation. All rights reserved.
> + * Copyright 2015, 2021 Linaro Limited.
> + * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +
> +#include <linux/pci.h>
> +#include "../../pci.h"
> +#include "pcie-designware.h"
> +
> +#ifdef CONFIG_PCIE_QCOM_CMN
> +int qcom_pcie_cmn_icc_get_resource(struct dw_pcie *pci, struct icc_path *icc_mem);
> +int qcom_pcie_cmn_icc_init(struct dw_pcie *pci, struct icc_path *icc_mem);
> +void qcom_pcie_cmn_icc_update(struct dw_pcie *pci, struct icc_path *icc_mem);
> +#else
> +static inline int qcom_pcie_cmn_icc_get_resource(struct dw_pcie *pci, struct icc_path *icc_mem)
> +{
> +	return 0;
> +}
> +
> +static inline int qcom_pcie_cmn_icc_init(struct dw_pcie *pci, struct icc_path *icc_mem)
> +{
> +	return 0;
> +}
> +
> +static inline void qcom_pcie_cmn_icc_update(struct dw_pcie *pci, struct icc_path *icc_mem)
> +{
> +}
> +#endif
> diff --git a/drivers/pci/controller/dwc/pcie-qcom-ep.c b/drivers/pci/controller/dwc/pcie-qcom-ep.c
> index 36e5e80cd22f..ce6343426de8 100644
> --- a/drivers/pci/controller/dwc/pcie-qcom-ep.c
> +++ b/drivers/pci/controller/dwc/pcie-qcom-ep.c
> @@ -25,6 +25,7 @@
>  
>  #include "../../pci.h"
>  #include "pcie-designware.h"
> +#include "pcie-qcom-cmn.h"
>  
>  /* PARF registers */
>  #define PARF_SYS_CTRL				0x00
> @@ -137,9 +138,6 @@
>  #define CORE_RESET_TIME_US_MAX			1005
>  #define WAKE_DELAY_US				2000 /* 2 ms */
>  
> -#define QCOM_PCIE_LINK_SPEED_TO_BW(speed) \
> -		Mbps_to_icc(PCIE_SPEED2MBS_ENC(pcie_link_speed[speed]))
> -
>  #define to_pcie_ep(x)				dev_get_drvdata((x)->dev)
>  
>  enum qcom_pcie_ep_link_status {
> @@ -278,28 +276,6 @@ static void qcom_pcie_dw_write_dbi2(struct dw_pcie *pci, void __iomem *base,
>  	writel(0, pcie_ep->elbi + ELBI_CS2_ENABLE);
>  }
>  
> -static void qcom_pcie_ep_icc_update(struct qcom_pcie_ep *pcie_ep)
> -{
> -	struct dw_pcie *pci = &pcie_ep->pci;
> -	u32 offset, status;
> -	int speed, width;
> -	int ret;
> -
> -	if (!pcie_ep->icc_mem)
> -		return;
> -
> -	offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
> -	status = readw(pci->dbi_base + offset + PCI_EXP_LNKSTA);
> -
> -	speed = FIELD_GET(PCI_EXP_LNKSTA_CLS, status);
> -	width = FIELD_GET(PCI_EXP_LNKSTA_NLW, status);
> -
> -	ret = icc_set_bw(pcie_ep->icc_mem, 0, width * QCOM_PCIE_LINK_SPEED_TO_BW(speed));
> -	if (ret)
> -		dev_err(pci->dev, "failed to set interconnect bandwidth: %d\n",
> -			ret);
> -}
> -
>  static int qcom_pcie_enable_resources(struct qcom_pcie_ep *pcie_ep)
>  {
>  	struct dw_pcie *pci = &pcie_ep->pci;
> @@ -325,14 +301,7 @@ static int qcom_pcie_enable_resources(struct qcom_pcie_ep *pcie_ep)
>  	if (ret)
>  		goto err_phy_exit;
>  
> -	/*
> -	 * Some Qualcomm platforms require interconnect bandwidth constraints
> -	 * to be set before enabling interconnect clocks.
> -	 *
> -	 * Set an initial peak bandwidth corresponding to single-lane Gen 1
> -	 * for the pcie-mem path.
> -	 */
> -	ret = icc_set_bw(pcie_ep->icc_mem, 0, QCOM_PCIE_LINK_SPEED_TO_BW(1));
> +	ret = qcom_pcie_cmn_icc_init(pci, pcie_ep->icc_mem);
>  	if (ret) {
>  		dev_err(pci->dev, "failed to set interconnect bandwidth: %d\n",
>  			ret);
> @@ -616,7 +585,7 @@ static int qcom_pcie_ep_get_resources(struct platform_device *pdev,
>  	if (IS_ERR(pcie_ep->phy))
>  		ret = PTR_ERR(pcie_ep->phy);
>  
> -	pcie_ep->icc_mem = devm_of_icc_get(dev, "pcie-mem");
> +	ret = qcom_pcie_cmn_icc_get_resource(&pcie_ep->pci, pcie_ep->icc_mem);
>  	if (IS_ERR(pcie_ep->icc_mem))
>  		ret = PTR_ERR(pcie_ep->icc_mem);
>  
> @@ -643,7 +612,7 @@ static irqreturn_t qcom_pcie_ep_global_irq_thread(int irq, void *data)
>  	} else if (FIELD_GET(PARF_INT_ALL_BME, status)) {
>  		dev_dbg(dev, "Received BME event. Link is enabled!\n");
>  		pcie_ep->link_status = QCOM_PCIE_EP_LINK_ENABLED;
> -		qcom_pcie_ep_icc_update(pcie_ep);
> +		qcom_pcie_cmn_icc_update(pci, pcie_ep->icc_mem);
>  		pci_epc_bme_notify(pci->ep.epc);
>  	} else if (FIELD_GET(PARF_INT_ALL_PM_TURNOFF, status)) {
>  		dev_dbg(dev, "Received PM Turn-off event! Entering L23\n");
> diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
> index 2ce2a3bd932b..57a08294c561 100644
> --- a/drivers/pci/controller/dwc/pcie-qcom.c
> +++ b/drivers/pci/controller/dwc/pcie-qcom.c
> @@ -32,6 +32,7 @@
>  #include <linux/types.h>
>  
>  #include "../../pci.h"
> +#include "pcie-qcom-cmn.h"
>  #include "pcie-designware.h"
>  
>  /* PARF registers */
> @@ -147,9 +148,6 @@
>  
>  #define QCOM_PCIE_CRC8_POLYNOMIAL		(BIT(2) | BIT(1) | BIT(0))
>  
> -#define QCOM_PCIE_LINK_SPEED_TO_BW(speed) \
> -		Mbps_to_icc(PCIE_SPEED2MBS_ENC(pcie_link_speed[speed]))
> -
>  #define QCOM_PCIE_1_0_0_MAX_CLOCKS		4
>  struct qcom_pcie_resources_1_0_0 {
>  	struct clk_bulk_data clks[QCOM_PCIE_1_0_0_MAX_CLOCKS];
> @@ -1363,59 +1361,6 @@ static const struct dw_pcie_ops dw_pcie_ops = {
>  	.start_link = qcom_pcie_start_link,
>  };
>  
> -static int qcom_pcie_icc_init(struct qcom_pcie *pcie)
> -{
> -	struct dw_pcie *pci = pcie->pci;
> -	int ret;
> -
> -	pcie->icc_mem = devm_of_icc_get(pci->dev, "pcie-mem");
> -	if (IS_ERR(pcie->icc_mem))
> -		return PTR_ERR(pcie->icc_mem);
> -
> -	/*
> -	 * Some Qualcomm platforms require interconnect bandwidth constraints
> -	 * to be set before enabling interconnect clocks.
> -	 *
> -	 * Set an initial peak bandwidth corresponding to single-lane Gen 1
> -	 * for the pcie-mem path.
> -	 */
> -	ret = icc_set_bw(pcie->icc_mem, 0, QCOM_PCIE_LINK_SPEED_TO_BW(1));
> -	if (ret) {
> -		dev_err(pci->dev, "failed to set interconnect bandwidth: %d\n",
> -			ret);
> -		return ret;
> -	}
> -
> -	return 0;
> -}
> -
> -static void qcom_pcie_icc_update(struct qcom_pcie *pcie)
> -{
> -	struct dw_pcie *pci = pcie->pci;
> -	u32 offset, status;
> -	int speed, width;
> -	int ret;
> -
> -	if (!pcie->icc_mem)
> -		return;
> -
> -	offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
> -	status = readw(pci->dbi_base + offset + PCI_EXP_LNKSTA);
> -
> -	/* Only update constraints if link is up. */
> -	if (!(status & PCI_EXP_LNKSTA_DLLLA))
> -		return;
> -
> -	speed = FIELD_GET(PCI_EXP_LNKSTA_CLS, status);
> -	width = FIELD_GET(PCI_EXP_LNKSTA_NLW, status);
> -
> -	ret = icc_set_bw(pcie->icc_mem, 0, width * QCOM_PCIE_LINK_SPEED_TO_BW(speed));
> -	if (ret) {
> -		dev_err(pci->dev, "failed to set interconnect bandwidth: %d\n",
> -			ret);
> -	}
> -}
> -
>  static int qcom_pcie_link_transition_count(struct seq_file *s, void *data)
>  {
>  	struct qcom_pcie *pcie = (struct qcom_pcie *)dev_get_drvdata(s->private);
> @@ -1524,7 +1469,11 @@ static int qcom_pcie_probe(struct platform_device *pdev)
>  		goto err_pm_runtime_put;
>  	}
>  
> -	ret = qcom_pcie_icc_init(pcie);
> +	ret = qcom_pcie_cmn_icc_get_resource(pcie->pci, pcie->icc_mem);
> +	if (ret)
> +		goto err_pm_runtime_put;
> +
> +	ret = qcom_pcie_cmn_icc_init(pcie->pci, pcie->icc_mem);
>  	if (ret)
>  		goto err_pm_runtime_put;
>  
> @@ -1546,7 +1495,7 @@ static int qcom_pcie_probe(struct platform_device *pdev)
>  		goto err_phy_exit;
>  	}
>  
> -	qcom_pcie_icc_update(pcie);
> +	qcom_pcie_cmn_icc_update(pcie->pci, pcie->icc_mem);
>  
>  	if (pcie->mhi)
>  		qcom_pcie_init_debugfs(pcie);
> @@ -1613,7 +1562,7 @@ static int qcom_pcie_resume_noirq(struct device *dev)
>  		pcie->suspended = false;
>  	}
>  
> -	qcom_pcie_icc_update(pcie);
> +	qcom_pcie_cmn_icc_update(pcie->pci, pcie->icc_mem);
>  
>  	return 0;
>  }
> -- 
> 2.43.2
>

On Thu, Feb 29, 2024 at 09:11:34PM -0800, Shashank Babu Chinta Venkata wrote:
> Refactor common code from RC(Root Complex) and EP(End Point)
> drivers and move them to a common repository. This acts as placeholder
> for common source code for both drivers avoiding duplication.
> 
> Signed-off-by: Shashank Babu Chinta Venkata <quic_schintav@quicinc.com>
> ---
>  drivers/pci/controller/dwc/Kconfig         |  5 ++
>  drivers/pci/controller/dwc/Makefile        |  1 +
>  drivers/pci/controller/dwc/pcie-qcom-cmn.c | 85 ++++++++++++++++++++++
>  drivers/pci/controller/dwc/pcie-qcom-cmn.h | 30 ++++++++
>  drivers/pci/controller/dwc/pcie-qcom-ep.c  | 39 +---------
>  drivers/pci/controller/dwc/pcie-qcom.c     | 67 ++---------------
>  6 files changed, 133 insertions(+), 94 deletions(-)
>  create mode 100644 drivers/pci/controller/dwc/pcie-qcom-cmn.c
>  create mode 100644 drivers/pci/controller/dwc/pcie-qcom-cmn.h

Hmm.  I'm a little ambivalent about adding two new files.  Overall I
think I prefer the drivers that include both RC and EP mode in a
single source file because one file is easier to browse than four and
more things can be static.

A single file would also reduce quite a bit more duplication between
pcie-qcom.c and pcie-qcom-ep.c, e.g., register names and fields with
needlessly different names:

  #define AUX_PWR_DET                     BIT(4)  # pcie-qcom.c
  #define PARF_SYS_CTRL_AUX_PWR_DET       BIT(4)  # pcie-qcom-ep.c

I do see PCIE_QCOM is bool and PCIE_QCOM_EP is tristate, so that and
other considerations might make a single source file impractical.

> +++ b/drivers/pci/controller/dwc/Makefile
> @@ -27,6 +27,7 @@ obj-$(CONFIG_PCIE_UNIPHIER) += pcie-uniphier.o
>  obj-$(CONFIG_PCIE_UNIPHIER_EP) += pcie-uniphier-ep.o
>  obj-$(CONFIG_PCIE_VISCONTI_HOST) += pcie-visconti.o
>  obj-$(CONFIG_PCIE_RCAR_GEN4) += pcie-rcar-gen4.o
> +obj-$(CONFIG_PCIE_QCOM_CMN) += pcie-qcom-cmn.o

If we have to have pcie-qcom-cmn.o, at least move this next to the
existing lines:

  obj-$(CONFIG_PCIE_QCOM) += pcie-qcom.o
  obj-$(CONFIG_PCIE_QCOM_EP) += pcie-qcom-ep.o

> +++ b/drivers/pci/controller/dwc/pcie-qcom-cmn.c
> @@ -0,0 +1,85 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2014-2015, 2020 The Linux Foundation. All rights reserved.
> + * Copyright 2015, 2021 Linaro Limited.
> + * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
> + *

Spurious blank line.

> +int qcom_pcie_cmn_icc_get_resource(struct dw_pcie *pci, struct icc_path *icc_mem)

I don't see the value of adding "cmn" in the middle of the names.

> +{
> +	int ret = 0;
> +
> +	if (IS_ERR(pci))
> +		return PTR_ERR(pci);
> +
> +	icc_mem = devm_of_icc_get(pci->dev, "pcie-mem");
> +	if (IS_ERR(icc_mem))
> +		return PTR_ERR(icc_mem);
> +
> +	return ret;

No need for the "ret" variable since it's never assigned.  "return 0"
here would be easier to read.

> +int qcom_pcie_cmn_icc_init(struct dw_pcie *pci, struct icc_path *icc_mem)
> +{
> +	int ret = 0;

Unnecessary initialization.

> +++ b/drivers/pci/controller/dwc/pcie-qcom-cmn.h
> @@ -0,0 +1,30 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (c) 2014-2015, 2020 The Linux Foundation. All rights reserved.
> + * Copyright 2015, 2021 Linaro Limited.
> + * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +
> +#include <linux/pci.h>
> +#include "../../pci.h"
> +#include "pcie-designware.h"
> +
> +#ifdef CONFIG_PCIE_QCOM_CMN

Why the #ifdef wrapper?  And why do we need the stubs when
CONFIG_PCIE_QCOM_CMN isn't defined?

> +#else
> +static inline int qcom_pcie_cmn_icc_get_resource(struct dw_pcie *pci, struct icc_path *icc_mem)
> +{
> +	return 0;
> +}

On 1.03.2024 06:11, Shashank Babu Chinta Venkata wrote:
> Refactor common code from RC(Root Complex) and EP(End Point)
> drivers and move them to a common repository. This acts as placeholder
> for common source code for both drivers avoiding duplication.
> 
> Signed-off-by: Shashank Babu Chinta Venkata <quic_schintav@quicinc.com>
> ---

This "conveniently" conflicts with your colleague's patches..

https://lore.kernel.org/linux-arm-msm/20240223-opp_support-v7-3-10b4363d7e71@quicinc.com/

Konrad

On Fri, Mar 01, 2024 at 01:44:56PM -0600, Bjorn Helgaas wrote:
> On Thu, Feb 29, 2024 at 09:11:34PM -0800, Shashank Babu Chinta Venkata wrote:
> > Refactor common code from RC(Root Complex) and EP(End Point)
> > drivers and move them to a common repository. This acts as placeholder
> > for common source code for both drivers avoiding duplication.
> > 
> > Signed-off-by: Shashank Babu Chinta Venkata <quic_schintav@quicinc.com>
> > ---
> >  drivers/pci/controller/dwc/Kconfig         |  5 ++
> >  drivers/pci/controller/dwc/Makefile        |  1 +
> >  drivers/pci/controller/dwc/pcie-qcom-cmn.c | 85 ++++++++++++++++++++++
> >  drivers/pci/controller/dwc/pcie-qcom-cmn.h | 30 ++++++++
> >  drivers/pci/controller/dwc/pcie-qcom-ep.c  | 39 +---------
> >  drivers/pci/controller/dwc/pcie-qcom.c     | 67 ++---------------
> >  6 files changed, 133 insertions(+), 94 deletions(-)
> >  create mode 100644 drivers/pci/controller/dwc/pcie-qcom-cmn.c
> >  create mode 100644 drivers/pci/controller/dwc/pcie-qcom-cmn.h
> 
> Hmm.  I'm a little ambivalent about adding two new files.  Overall I
> think I prefer the drivers that include both RC and EP mode in a
> single source file because one file is easier to browse than four and
> more things can be static.
> 
> A single file would also reduce quite a bit more duplication between
> pcie-qcom.c and pcie-qcom-ep.c, e.g., register names and fields with
> needlessly different names:
> 
>   #define AUX_PWR_DET                     BIT(4)  # pcie-qcom.c
>   #define PARF_SYS_CTRL_AUX_PWR_DET       BIT(4)  # pcie-qcom-ep.c
> 
> I do see PCIE_QCOM is bool and PCIE_QCOM_EP is tristate, so that and
> other considerations might make a single source file impractical.
> 

Yeah, we explored that option while adding the EP driver and it didn't look
feasible.

- Mani

> > +++ b/drivers/pci/controller/dwc/Makefile
> > @@ -27,6 +27,7 @@ obj-$(CONFIG_PCIE_UNIPHIER) += pcie-uniphier.o
> >  obj-$(CONFIG_PCIE_UNIPHIER_EP) += pcie-uniphier-ep.o
> >  obj-$(CONFIG_PCIE_VISCONTI_HOST) += pcie-visconti.o
> >  obj-$(CONFIG_PCIE_RCAR_GEN4) += pcie-rcar-gen4.o
> > +obj-$(CONFIG_PCIE_QCOM_CMN) += pcie-qcom-cmn.o
> 
> If we have to have pcie-qcom-cmn.o, at least move this next to the
> existing lines:
> 
>   obj-$(CONFIG_PCIE_QCOM) += pcie-qcom.o
>   obj-$(CONFIG_PCIE_QCOM_EP) += pcie-qcom-ep.o
> 
> > +++ b/drivers/pci/controller/dwc/pcie-qcom-cmn.c
> > @@ -0,0 +1,85 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright (c) 2014-2015, 2020 The Linux Foundation. All rights reserved.
> > + * Copyright 2015, 2021 Linaro Limited.
> > + * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
> > + *
> 
> Spurious blank line.
> 
> > +int qcom_pcie_cmn_icc_get_resource(struct dw_pcie *pci, struct icc_path *icc_mem)
> 
> I don't see the value of adding "cmn" in the middle of the names.
> 
> > +{
> > +	int ret = 0;
> > +
> > +	if (IS_ERR(pci))
> > +		return PTR_ERR(pci);
> > +
> > +	icc_mem = devm_of_icc_get(pci->dev, "pcie-mem");
> > +	if (IS_ERR(icc_mem))
> > +		return PTR_ERR(icc_mem);
> > +
> > +	return ret;
> 
> No need for the "ret" variable since it's never assigned.  "return 0"
> here would be easier to read.
> 
> > +int qcom_pcie_cmn_icc_init(struct dw_pcie *pci, struct icc_path *icc_mem)
> > +{
> > +	int ret = 0;
> 
> Unnecessary initialization.
> 
> > +++ b/drivers/pci/controller/dwc/pcie-qcom-cmn.h
> > @@ -0,0 +1,30 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +/*
> > + * Copyright (c) 2014-2015, 2020 The Linux Foundation. All rights reserved.
> > + * Copyright 2015, 2021 Linaro Limited.
> > + * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
> > + */
> > +
> > +#include <linux/pci.h>
> > +#include "../../pci.h"
> > +#include "pcie-designware.h"
> > +
> > +#ifdef CONFIG_PCIE_QCOM_CMN
> 
> Why the #ifdef wrapper?  And why do we need the stubs when
> CONFIG_PCIE_QCOM_CMN isn't defined?
> 
> > +#else
> > +static inline int qcom_pcie_cmn_icc_get_resource(struct dw_pcie *pci, struct icc_path *icc_mem)
> > +{
> > +	return 0;
> > +}