Hi Thierry,
I think there are a couple typos (one in a message and one that
actually looks important), and one question below.
On Fri, Apr 08, 2016 at 06:13:14PM +0200, Thierry Reding wrote:
> From: Thierry Reding <treding@xxxxxxxxxx>
>
> The current XUSB pad controller bindings are insufficient to describe
> PHY devices attached to USB controllers. New bindings have been created
> to overcome these restrictions. As a side-effect each root port now is
> assigned a set of PHY devices, one for each lane associated with the
> root port. This has the benefit of allowing fine-grained control of the
> power management for each lane.
>
> Signed-off-by: Thierry Reding <treding@xxxxxxxxxx>
> ---
> Changes in v4:
> - propagate failure from PHY power on
> - refactor PHY power off sequence
>
> Changes in v3:
> - cache result of check for new PHY bindings usage (Stephen Warren)
>
> Changes in v2:
> - rework commit message to more accurately describe this change
>
> drivers/pci/host/pci-tegra.c | 243 ++++++++++++++++++++++++++++++++++++++++---
> 1 file changed, 226 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c
> index 68d1f41b3cbf..d50568bf93c5 100644
> --- a/drivers/pci/host/pci-tegra.c
> +++ b/drivers/pci/host/pci-tegra.c
> @@ -295,6 +295,7 @@ struct tegra_pcie {
> struct reset_control *afi_rst;
> struct reset_control *pcie_xrst;
>
> + bool legacy_phy;
> struct phy *phy;
>
> struct tegra_msi msi;
> @@ -311,11 +312,14 @@ struct tegra_pcie {
>
> struct tegra_pcie_port {
> struct tegra_pcie *pcie;
> + struct device_node *np;
> struct list_head list;
> struct resource regs;
> void __iomem *base;
> unsigned int index;
> unsigned int lanes;
> +
> + struct phy **phys;
> };
>
> struct tegra_pcie_bus {
> @@ -860,6 +864,128 @@ static int tegra_pcie_phy_enable(struct tegra_pcie *pcie)
> return 0;
> }
>
> +static int tegra_pcie_phy_disable(struct tegra_pcie *pcie)
> +{
> + const struct tegra_pcie_soc_data *soc = pcie->soc_data;
> + u32 value;
> +
> + /* disable TX/RX data */
> + value = pads_readl(pcie, PADS_CTL);
> + value &= ~(PADS_CTL_TX_DATA_EN_1L | PADS_CTL_RX_DATA_EN_1L);
> + pads_writel(pcie, value, PADS_CTL);
> +
> + /* override IDDQ */
> + value = pads_readl(pcie, PADS_CTL);
> + value |= PADS_CTL_IDDQ_1L;
> + pads_writel(pcie, PADS_CTL, value);
> +
> + /* reset PLL */
> + value = pads_readl(pcie, soc->pads_pll_ctl);
> + value &= ~PADS_PLL_CTL_RST_B4SM;
> + pads_writel(pcie, value, soc->pads_pll_ctl);
> +
> + usleep_range(20, 100);
> +
> + return 0;
> +}
> +
> +static int tegra_pcie_port_phy_power_on(struct tegra_pcie_port *port)
> +{
> + struct device *dev = port->pcie->dev;
> + unsigned int i;
> + int err;
> +
> + for (i = 0; i < port->lanes; i++) {
> + err = phy_power_on(port->phys[i]);
> + if (err < 0) {
> + dev_err(dev, "failed to power on PHY#%u: %d\n", i,
> + err);
> + return err;
> + }
> + }
> +
> + return 0;
> +}
> +
> +static int tegra_pcie_port_phy_power_off(struct tegra_pcie_port *port)
> +{
> + struct device *dev = port->pcie->dev;
> + unsigned int i;
> + int err;
> +
> + for (i = 0; i < port->lanes; i++) {
> + err = phy_power_off(port->phys[i]);
> + if (err < 0) {
> + dev_err(dev, "failed to power off PHY#%u: %d\n", i,
> + err);
> + return err;
> + }
> + }
> +
> + return 0;
> +}
> +
> +static int tegra_pcie_phy_power_on(struct tegra_pcie *pcie)
> +{
> + struct tegra_pcie_port *port;
> + int err;
> +
> + if (pcie->legacy_phy) {
> + if (pcie->phy)
> + err = phy_power_on(pcie->phy);
> + else
> + err = tegra_pcie_phy_enable(pcie);
> +
> + if (err < 0)
> + dev_err(pcie->dev, "failed to power on PHY: %d\n", err);
> +
> + return err;
> + }
> +
> + list_for_each_entry(port, &pcie->ports, list) {
> + err = tegra_pcie_port_phy_power_on(port);
> + if (err < 0) {
> + dev_err(pcie->dev,
> + "failed to power on PCIe port %u PHY: %d\n",
> + port->index, err);
> + return err;
> + }
> + }
> +
> + return 0;
> +}
> +
> +static int tegra_pcie_phy_power_off(struct tegra_pcie *pcie)
> +{
> + struct tegra_pcie_port *port;
> + int err;
> +
> + if (pcie->legacy_phy) {
> + if (pcie->phy)
> + err = phy_power_on(pcie->phy);
s/phy_power_on/phy_power_off/
> + else
> + err = tegra_pcie_phy_disable(pcie);
> +
> + if (err < 0)
> + dev_err(pcie->dev, "failed to power off PHY: %d\n",
> + err);
> +
> + return err;
> + }
> +
> + list_for_each_entry(port, &pcie->ports, list) {
> + err = tegra_pcie_port_phy_power_off(port);
> + if (err < 0) {
> + dev_err(pcie->dev,
> + "failed to power off PCIe port %u PHY: %d\n",
> + port->index, err);
> + return err;
> + }
> + }
> +
> + return 0;
> +}
> +
> static int tegra_pcie_enable_controller(struct tegra_pcie *pcie)
> {
> const struct tegra_pcie_soc_data *soc = pcie->soc_data;
> @@ -899,13 +1025,9 @@ static int tegra_pcie_enable_controller(struct tegra_pcie *pcie)
> afi_writel(pcie, value, AFI_FUSE);
> }
>
> - if (!pcie->phy)
> - err = tegra_pcie_phy_enable(pcie);
> - else
> - err = phy_power_on(pcie->phy);
> -
> + err = tegra_pcie_phy_power_on(pcie);
> if (err < 0) {
> - dev_err(pcie->dev, "failed to power on PHY: %d\n", err);
> + dev_err(pcie->dev, "failed to power off PHY(s): %d\n", err);
s/off/on/
> return err;
> }
>
> @@ -942,9 +1064,9 @@ static void tegra_pcie_power_off(struct tegra_pcie *pcie)
>
> /* TODO: disable and unprepare clocks? */
>
> - err = phy_power_off(pcie->phy);
> + err = tegra_pcie_phy_power_off(pcie);
> if (err < 0)
> - dev_warn(pcie->dev, "failed to power off PHY: %d\n", err);
> + dev_err(pcie->dev, "failed to power off PHY(s): %d\n", err);
>
> reset_control_assert(pcie->pcie_xrst);
> reset_control_assert(pcie->afi_rst);
> @@ -1049,6 +1171,99 @@ static int tegra_pcie_resets_get(struct tegra_pcie *pcie)
> return 0;
> }
>
> +static int tegra_pcie_phys_get_legacy(struct tegra_pcie *pcie)
> +{
> + int err;
> +
> + pcie->phy = devm_phy_optional_get(pcie->dev, "pcie");
> + if (IS_ERR(pcie->phy)) {
> + err = PTR_ERR(pcie->phy);
> + dev_err(pcie->dev, "failed to get PHY: %d\n", err);
> + return err;
> + }
> +
> + err = phy_init(pcie->phy);
> + if (err < 0) {
> + dev_err(pcie->dev, "failed to initialize PHY: %d\n", err);
> + return err;
> + }
> +
> + pcie->legacy_phy = true;
> +
> + return 0;
> +}
> +
> +static struct phy *devm_of_phy_optional_get_index(struct device *dev,
> + struct device_node *np,
> + const char *consumer,
> + unsigned int index)
> +{
> + struct phy *phy;
> + char *name;
> +
> + name = kasprintf(GFP_KERNEL, "%s-%u", consumer, index);
> + if (!name)
> + return ERR_PTR(-ENOMEM);
> +
> + phy = devm_of_phy_get(dev, np, name);
> + kfree(name);
> +
> + if (IS_ERR(phy) && PTR_ERR(phy) == -ENODEV)
> + phy = NULL;
> +
> + return phy;
> +}
> +
> +static int tegra_pcie_port_get_phys(struct tegra_pcie_port *port)
> +{
> + struct device *dev = port->pcie->dev;
> + struct phy *phy;
> + unsigned int i;
> + int err;
> +
> + port->phys = devm_kcalloc(dev, sizeof(phy), port->lanes, GFP_KERNEL);
> + if (!port->phys)
> + return -ENOMEM;
> +
> + for (i = 0; i < port->lanes; i++) {
> + phy = devm_of_phy_optional_get_index(dev, port->np, "pcie", i);
> + if (IS_ERR(phy)) {
> + dev_err(dev, "failed to get PHY#%u: %ld\n", i,
> + PTR_ERR(phy));
> + return PTR_ERR(phy);
> + }
> +
> + err = phy_init(phy);
> + if (err < 0) {
> + dev_err(dev, "failed to initialize PHY#%u: %d\n", i,
> + err);
> + return err;
> + }
> +
> + port->phys[i] = phy;
> + }
> +
> + return 0;
> +}
> +
> +static int tegra_pcie_phys_get(struct tegra_pcie *pcie)
> +{
> + struct tegra_pcie_port *port;
> + int err;
> +
> + if (of_get_property(pcie->dev->of_node, "phys", NULL) != NULL)
> + return tegra_pcie_phys_get_legacy(pcie);
> +
> + list_for_each_entry(port, &pcie->ports, list) {
> + err = tegra_pcie_port_get_phys(port);
> + if (err < 0) {
> + return err;
> + }
> + }
This seems backwards: if I'm reading this right, you first check for
the legacy property ("phys") and use it if you find it. If there is
no legacy property, you look for the new per-lane PHYs.
The usual pattern would be "look for the new stuff, and if you don't
find it, fall back to the old stuff." Is there a configuration that
could be described either way, e.g., something with only one lane and
only one PHY?
I'm not sure whether it matters, but if it *could* use the "new, fall
back to old" pattern, that would be nice and would keep people from
wondering whether it's safe to do it backwards.
> +
> + return 0;
> +}
> +
> static int tegra_pcie_get_resources(struct tegra_pcie *pcie)
> {
> struct platform_device *pdev = to_platform_device(pcie->dev);
> @@ -1067,16 +1282,9 @@ static int tegra_pcie_get_resources(struct tegra_pcie *pcie)
> return err;
> }
>
> - pcie->phy = devm_phy_optional_get(pcie->dev, "pcie");
> - if (IS_ERR(pcie->phy)) {
> - err = PTR_ERR(pcie->phy);
> - dev_err(&pdev->dev, "failed to get PHY: %d\n", err);
> - return err;
> - }
> -
> - err = phy_init(pcie->phy);
> + err = tegra_pcie_phys_get(pcie);
> if (err < 0) {
> - dev_err(&pdev->dev, "failed to initialize PHY: %d\n", err);
> + dev_err(&pdev->dev, "failed to get PHYs: %d\n", err);
> return err;
> }
>
> @@ -1752,6 +1960,7 @@ static int tegra_pcie_parse_dt(struct tegra_pcie *pcie)
> rp->index = index;
> rp->lanes = value;
> rp->pcie = pcie;
> + rp->np = port;
>
> rp->base = devm_ioremap_resource(pcie->dev, &rp->regs);
> if (IS_ERR(rp->base))
> --
> 2.8.0
>
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