Re: [PATCH 2/2] phy: intel: Add driver support for combo phy

[Dilip Kota]

On 12/20/2019 6:45 PM, Andy Shevchenko wrote:
> On Fri, Dec 20, 2019 at 03:28:28PM +0800, Dilip Kota wrote:
> > Combo phy subsystem provides PHYs for various
> > controllers like PCIe, SATA and EMAC.
> ...
>
> > +#define REG_COMBO_MODE(x)	((x) * 0x200)
> Perhaps  + 0x000
Yes, but i think not required to add explicitly.
> > +#define REG_CLK_DISABLE(x)	((x) * 0x200 + 0x124)
> ...
>
> > +static const char *const intel_iphy_names[] = {"pcie", "xpcs", "sata"};
> > +static const unsigned long intel_iphy_clk_rate[] = {
> names (note S)
> rate -> rates
Ok, will correct it to rates.
> > +	CLK_100MHZ, CLK_156_25MHZ, CLK_100MHZ
> > +};
> ...
>
> > +static ssize_t intel_cbphy_info_show(struct device *dev,
> > +				     struct device_attribute *attr, char *buf)
> > +{
> > +	struct intel_combo_phy *cbphy;
> > +	int i, off;
> > +
> > +	cbphy = dev_get_drvdata(dev);
> > +
> > +	off = sprintf(buf, "mode: %u\n", cbphy->mode);
> > +
> > +	off += sprintf(buf + off, "aggr mode: %s\n",
> > +		      cbphy->aggr_mode == PHY_DL_MODE ? "Yes" : "No");
> Can't you do
>
> static inline const char *yesno(bool choice)
> {
> 	return choice ? "Yes" : "No";
> }
>
> and use it here and below?
>
> Somebody already shared the idea that the above helper should be available
> globally.
>
> > +
> > +	off += sprintf(buf + off, "capability: ");
> > +	for (i = PHY_PCIE_MODE; i < PHY_MAX_MODE; i++) {
> > +		if (BIT(i) & cbphy->phy_cap)
> > +			off += sprintf(buf + off, "%s ", intel_iphy_names[i]);
> > +	}
> > +
> > +	off += sprintf(buf + off, "\n");
> > +
> > +	for (i = 0; i < PHY_MAX_NUM; i++) {
> > +		off += sprintf(buf + off, "PHY%d mode: %s, enable: %s\n",
> > +			       i, intel_iphy_names[cbphy->iphy[i].phy_mode],
> > +			       cbphy->iphy[i].enable ? "Yes" : "No");
> > +	}
> > +
> > +	return off;
> > +}
> ...
>
> > +static struct attribute *intel_cbphy_attrs[] = {
> > +	&dev_attr_intel_cbphy_info.attr,
> > +	NULL,
> Comma is redundant for terminator lines.
>
> > +};
>
> > +static int intel_cbphy_sysfs_init(struct intel_combo_phy *cbphy)
> > +{
> > +	return devm_device_add_groups(cbphy->dev, intel_cbphy_groups);
> > +}
> What the point?
For debug purpose only... can be removed in upstream. I will clean it up 
in next patch version.
> Moreover, can't you use .dev_groups member of struct device_driver?
>
> ...
>
> > +		ret =  phy_cfg(sphy);
> In several places you have extra unneeded white spaces.
>
> ...
>
> > +	combo_phy_w32_off_mask(iphy->app_base, PCIE_PHY_CLK_PAD,
> > +			       0, PCIE_PHY_GEN_CTRL);
> Configure your editor properly! There is plenty of room on the previous line.
Sure, will fix at all the places.
> ...
>
> > +	combo_phy_w32_off_mask(iphy->app_base, PCIE_PHY_CLK_PAD,
> > +			       1, PCIE_PHY_GEN_CTRL);
> Ditto.
>
> ...
>
> > +static int intel_cbphy_init(struct phy *phy)
> > +{
> > +	struct intel_cbphy_iphy *iphy;
>
> > +	int ret = 0;
> Redundant assignment. See below.
Sure, will fix it.
> > +
> > +	iphy = phy_get_drvdata(phy);
> > +
> > +	if (iphy->phy_mode == PHY_PCIE_MODE) {
> > +		ret = intel_cbphy_iphy_cfg(iphy,
> > +					   intel_cbphy_pcie_en_pad_refclk);
> > +	}
> > +
> > +	if (!ret)
> > +		ret = intel_cbphy_iphy_cfg(iphy, intel_cbphy_iphy_power_on);
> > +
> > +	return ret;
> Why not to simple do
>
> 	if (A) {
> 		ret = ...;
> 		if (ret)
> 			return ret;
> 	}
>
> 	return intel_...;
Looks good, i will update.
> ?
>
> > +}
> > +
> > +static int intel_cbphy_exit(struct phy *phy)
> > +{
> > +	struct intel_cbphy_iphy *iphy;
> > +	int ret = 0;
> > +
> > +	iphy = phy_get_drvdata(phy);
> > +
> > +	if (iphy->power_en)
> > +		ret = intel_cbphy_iphy_cfg(iphy, intel_cbphy_iphy_power_off);
> > +
> > +	if (!ret && iphy->phy_mode == PHY_PCIE_MODE)
> > +		ret = intel_cbphy_iphy_cfg(iphy,
> > +					   intel_cbphy_pcie_dis_pad_refclk);
> > +
> > +	return ret;
> Ditto.
Ok
> > +}
> ...
>
> > +static int intel_cbphy_iphy_mem_resource(struct intel_cbphy_iphy *iphy)
> > +{
> > +	void __iomem *base;
> > +
> > +	base = devm_platform_ioremap_resource(iphy->pdev, 0);
> > +	if (IS_ERR(base))
> > +		return PTR_ERR(base);
> > +
> > +	iphy->app_base = base;
> > +
> > +	return 0;
> > +}
> What's the point of this helper?
Defined as separate function for traversing memory entry from DT.
Similarly get_clks() and get_reset() functions.
> ...
>
> > +static int intel_cbphy_iphy_get_clks(struct intel_cbphy_iphy *iphy)
> > +{
> > +	enum intel_phy_mode mode = iphy->phy_mode;
> > +	struct device *dev = iphy->dev;
> > +	int ret = 0;
> Redundant. Simple return 0 explicitly at the end.
> Ditto for other places in this patch.
Ok, i will fix at all the places.
> > +	if (IS_ERR(iphy->freq_clk)) {
> > +		ret = PTR_ERR(iphy->freq_clk);
> > +		if (ret != -EPROBE_DEFER) {
> > +			dev_err(dev, "PHY[%u:%u] No %s freq clock\n",
> > +				COMBO_PHY_ID(iphy), PHY_ID(iphy),
> > +				intel_iphy_names[mode]);
> > +		}
> > +
> > +		return ret;
> > +	}
> > +
> > +	iphy->clk_rate = intel_iphy_clk_rate[mode];
> > +
> > +	return ret;
> > +}
> ...
>
> > +static int intel_cbphy_iphy_dt_parse(struct intel_combo_phy *cbphy,
> > +				     struct fwnode_handle *fwn, int idx)
> fwn -> fwnode.
Sure, i will replace it.
> > +{
> > +	struct intel_cbphy_iphy *iphy = &cbphy->iphy[idx];
> > +	struct platform_device *pdev;
> > +	struct device *dev;
> > +	int ret = 0;
> > +	u32 prop;
> > +
> > +	iphy->id = idx;
> > +	iphy->enable = false;
> > +	iphy->power_en = false;
> > +	iphy->parent = cbphy;
> > +	iphy->np = to_of_node(fwn);
> > +	pdev = of_find_device_by_node(iphy->np);
> Why? Can't it be done simpler?
There is no direct helper function to get platform device from fwnode,
I will simplify it to get fwnode->device-> platform device. However 
iphy->np is no longer required.

> > +	if (!pdev) {
> > +		dev_warn(cbphy->dev, "Combo-PHY%u: PHY device: %d disabled!\n",
> > +			 cbphy->id, idx);
> > +		return 0;
> > +	}
> > +	if (!(BIT(iphy->phy_mode) & cbphy->phy_cap)) {
> Yoda style?

I will correct it to ...

if (!(cbphy->phy_cap & BIT(iphy->phy_node)))

> ...
>
> > +				" Mode mismatch lane0 : %u, lane1 : %u\n",
> Extra leading space.
Sure, i will fix it.
> ...
>
> > +static int intel_cbphy_dt_parse(struct intel_combo_phy *cbphy)
> > +{
> > +	struct device *dev = cbphy->dev;
> > +	struct device_node *np = dev->of_node;
> Why do you need this one? You have to device if it's OF centric driver or not.
Used during syscon_regmap call.
> > +	struct fwnode_handle *fwn;
> Better name is fwnode as done in plenty other drivers.
Sure will fix it.
> > +	int i = 0, ret = 0;
> i = 0 better to have near to its user.
> ret = 0 is redundant assignment.
Sure, will fix it.
> > +	ret = device_property_read_u32(dev, "intel,bid", &cbphy->bid);
> > +	if (ret) {
> > +		dev_err(dev, "NO intel,bid provided!\n");
> > +		return ret;
> > +	}
> > +
> > +	device_for_each_child_node(dev, fwn) {
> > +		if (i >= PHY_MAX_NUM) {
> > +			fwnode_handle_put(fwn);
> > +			dev_err(dev, "Error: DT child number larger than %d\n",
> > +				PHY_MAX_NUM);
> > +			return -EINVAL;
> > +		}
> > +
> > +		ret = intel_cbphy_iphy_dt_parse(cbphy, fwn, i);
> > +		if (ret) {
> > +			fwnode_handle_put(fwn);
> > +			return ret;
> > +		}
> > +
> > +		i++;
> > +	}
> > +
> > +	return intel_cbphy_dt_sanity_check(cbphy);
> > +}
> ...
>
> > +	regmap_write(cbphy->hsiocfg, REG_COMBO_MODE(cbphy->bid), cb_mode);
> No error check?
Sure, will add it.
> > +
> > +	return 0;
> ...
>
> > +	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
> > +	if (IS_ERR(phy_provider)) {
> > +		dev_err(dev, "PHY[%u:%u]: register phy provider failed!\n",
> > +			COMBO_PHY_ID(iphy), PHY_ID(iphy));
> > +		return PTR_ERR(phy_provider);
> > +	}
> > +
> > +	return 0;
> return PTR_ERR_OR_ZERO(...);
>
> ...
I will update it.
> > +	ret = of_property_read_u32(dev->of_node, "cell-index", &id);
> You should decide either you go with OF centric API(s) or with device property
> one as below.

I missed to change to device property.

I will correct it.

> > +	if (!device_property_read_bool(dev, "intel,cap-pcie-only"))
> > +		cbphy->phy_cap |= PHY_XPCS_CAP | PHY_SATA_CAP;
> ...
>
> > +	ret = intel_cbphy_sysfs_init(cbphy);
> > +
> > +	return ret;
> return intel_...();
Sure, will update it.
> ...
>
> > +static struct platform_driver intel_cbphy_driver = {
> > +	.probe = intel_cbphy_probe,
> > +	.driver = {
> > +		.name = "intel-combo-phy",
> > +		.of_match_table = of_intel_cbphy_match,
> > +	}
> > +};
> > +
> > +builtin_platform_driver(intel_cbphy_driver);
> Can we unbound it? Is it okay to do unbind/bind cycle? Had it been tested for
> that?

Unbound can be done here, i will add the respective code.

Thanks a lot for reviewing and providing the inputs.
Regards,
Dilip

>