Re: [PATCH V2 4/5] PCI: exynos: support the using PHY generic framework

[Jaehoon Chung <jh80.chung@samsung.com>]

On 01/05/2017 02:50 AM, Krzysztof Kozlowski wrote:
> On Wed, Jan 04, 2017 at 09:34:34PM +0900, Jaehoon Chung wrote:
>> This patch is for using PHY generic framework.
>> To maintain backward compatibility, check whether phy is supported or
>> not with 'using_phy'.
>>
>> And if someone use the old dt-file, display the "deprecated" message.
>> But it's still working fine with it.
> 
> This needs improvements. How about:
> "Switch the pci-exynos driver to generic PHY framework. At the same time
> backward compatibility is preserved: warning will be printed for old
> DTB.

Thanks for comments. Will describe the commit-msg in more detail.

Best Regards,
Jaehoon Chung

> 
> Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
> 
> Best regards,
> Krzysztof
> 
>>
>> Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
>> ---
>> Changelog on V2:
>> - This patch is split from previous PATCH[1/4]
>> - Maintain the backward compatibility
>> - Adds 'using_phy' for cheching whether phy framework is used or not
>> - Adds 'DEPRECATED' message for old dt-binding way
>>
>>  drivers/pci/host/pci-exynos.c | 61 +++++++++++++++++++++++++++++++++++--------
>>  1 file changed, 50 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/pci/host/pci-exynos.c b/drivers/pci/host/pci-exynos.c
>> index feed0fd..34f2eed 100644
>> --- a/drivers/pci/host/pci-exynos.c
>> +++ b/drivers/pci/host/pci-exynos.c
>> @@ -21,6 +21,7 @@
>>  #include <linux/of_gpio.h>
>>  #include <linux/pci.h>
>>  #include <linux/platform_device.h>
>> +#include <linux/phy/phy.h>
>>  #include <linux/resource.h>
>>  #include <linux/signal.h>
>>  #include <linux/types.h>
>> @@ -110,6 +111,10 @@ struct exynos_pcie {
>>  	struct exynos_pcie_clk_res	*clk_res;
>>  	const struct exynos_pcie_ops	*ops;
>>  	int				reset_gpio;
>> +
>> +	/* For Generic PHY Framework */
>> +	bool				using_phy;
>> +	struct phy			*phy;
>>  };
>>  
>>  struct exynos_pcie_ops {
>> @@ -135,6 +140,10 @@ static int exynos5440_pcie_get_mem_resources(struct platform_device *pdev,
>>  	if (IS_ERR(ep->mem_res->elbi_base))
>>  		return PTR_ERR(ep->mem_res->elbi_base);
>>  
>> +	/* If using the PHY framework, doesn't need to get other resource */
>> +	if (ep->using_phy)
>> +		return 0;
>> +
>>  	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
>>  	ep->mem_res->phy_base = devm_ioremap_resource(dev, res);
>>  	if (IS_ERR(ep->mem_res->phy_base))
>> @@ -396,17 +405,28 @@ static int exynos_pcie_establish_link(struct exynos_pcie *exynos_pcie)
>>  	}
>>  
>>  	exynos_pcie_assert_core_reset(exynos_pcie);
>> -	exynos_pcie_assert_phy_reset(exynos_pcie);
>> -	exynos_pcie_deassert_phy_reset(exynos_pcie);
>> -	exynos_pcie_power_on_phy(exynos_pcie);
>> -	exynos_pcie_init_phy(exynos_pcie);
>> -
>> -	/* pulse for common reset */
>> -	exynos_pcie_writel(exynos_pcie->mem_res->block_base, 1,
>> -				PCIE_PHY_COMMON_RESET);
>> -	udelay(500);
>> -	exynos_pcie_writel(exynos_pcie->mem_res->block_base, 0,
>> -				PCIE_PHY_COMMON_RESET);
>> +
>> +	if (exynos_pcie->using_phy) {
>> +		phy_reset(exynos_pcie->phy);
>> +
>> +		exynos_pcie_writel(exynos_pcie->mem_res->elbi_base, 1,
>> +				PCIE_PWR_RESET);
>> +
>> +		phy_power_on(exynos_pcie->phy);
>> +		phy_init(exynos_pcie->phy);
>> +	} else {
>> +		exynos_pcie_assert_phy_reset(exynos_pcie);
>> +		exynos_pcie_deassert_phy_reset(exynos_pcie);
>> +		exynos_pcie_power_on_phy(exynos_pcie);
>> +		exynos_pcie_init_phy(exynos_pcie);
>> +
>> +		/* pulse for common reset */
>> +		exynos_pcie_writel(exynos_pcie->mem_res->block_base, 1,
>> +					PCIE_PHY_COMMON_RESET);
>> +		udelay(500);
>> +		exynos_pcie_writel(exynos_pcie->mem_res->block_base, 0,
>> +					PCIE_PHY_COMMON_RESET);
>> +	}
>>  
>>  	exynos_pcie_deassert_core_reset(exynos_pcie);
>>  	dw_pcie_setup_rc(pp);
>> @@ -420,6 +440,11 @@ static int exynos_pcie_establish_link(struct exynos_pcie *exynos_pcie)
>>  	if (!dw_pcie_wait_for_link(pp))
>>  		return 0;
>>  
>> +	if (exynos_pcie->using_phy) {
>> +		phy_power_off(exynos_pcie->phy);
>> +		return -ETIMEDOUT;
>> +	}
>> +
>>  	while (exynos_pcie_readl(exynos_pcie->mem_res->phy_base,
>>  				PCIE_PHY_PLL_LOCKED) == 0) {
>>  		val = exynos_pcie_readl(exynos_pcie->mem_res->block_base,
>> @@ -633,6 +658,17 @@ static int __init exynos_pcie_probe(struct platform_device *pdev)
>>  
>>  	exynos_pcie->reset_gpio = of_get_named_gpio(np, "reset-gpio", 0);
>>  
>> +	/* Assume that controller doesn't use the PHY framework */
>> +	exynos_pcie->using_phy = false;
>> +
>> +	exynos_pcie->phy = devm_of_phy_get(dev, np, NULL);
>> +	if (IS_ERR(exynos_pcie->phy)) {
>> +		if (PTR_ERR(exynos_pcie->phy) == -EPROBE_DEFER)
>> +			return PTR_ERR(exynos_pcie->phy);
>> +		dev_warn(dev, "Use the 'phy' property. Current DT of pci-exynos was deprecated!!\n");
>> +	} else
>> +		exynos_pcie->using_phy = true;
>> +
>>  	if (exynos_pcie->ops && exynos_pcie->ops->get_mem_resources) {
>>  		ret = exynos_pcie->ops->get_mem_resources(pdev, exynos_pcie);
>>  		if (ret)
>> @@ -657,6 +693,9 @@ static int __init exynos_pcie_probe(struct platform_device *pdev)
>>  	return 0;
>>  
>>  fail_probe:
>> +	if (exynos_pcie->using_phy)
>> +		phy_exit(exynos_pcie->phy);
>> +
>>  	if (exynos_pcie->ops && exynos_pcie->ops->deinit_clk_resources)
>>  		exynos_pcie->ops->deinit_clk_resources(exynos_pcie);
>>  	return ret;
>> -- 
>> 2.10.2
>>
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