[PATCH 3/3] phy: bcm-ns-usb2: support updated single CRU reg DT binding

Rafał Miłecki
2021-02-26T11:47:43Z

From: Rafał Miłecki <rafal@milecki.pl>

Updated DT binding maps a single CRU register that is directly used for
the PHY control. Accessing common CRU reg is handled using syscon &
regmap.

The old binding has been deprecated and stays as a fallback method.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
---
It's a reworked version of my abonded 2019 patch:
[PATCH V2 2/2] phy: bcm-ns-usb2: support updated DT binding with the CRU syscon
https://lore.kernel.org/patchwork/patch/1029863/
---
drivers/phy/broadcom/phy-bcm-ns-usb2.c | 52 +++++++++++++++++++++-----
1 file changed, 43 insertions(+), 9 deletions(-)

diff --git a/drivers/phy/broadcom/phy-bcm-ns-usb2.c b/drivers/phy/broadcom/phy-bcm-ns-usb2.c
index 4b015b8a71c3..98d32729a45d 100644
--- a/drivers/phy/broadcom/phy-bcm-ns-usb2.c
+++ b/drivers/phy/broadcom/phy-bcm-ns-usb2.c
@@ -9,17 +9,23 @@
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/err.h>
+#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
+#include <linux/regmap.h>
#include <linux/slab.h>

struct bcm_ns_usb2 {
struct device *dev;
struct clk *ref_clk;
struct phy *phy;
+ struct regmap *clkset;
+ void __iomem *base;
+
+ /* Deprecated binding */
void __iomem *dmu;
};

@@ -27,7 +33,6 @@ static int bcm_ns_usb2_phy_init(struct phy *phy)
{
struct bcm_ns_usb2 *usb2 = phy_get_drvdata(phy);
struct device *dev = usb2->dev;
- void __iomem *dmu = usb2->dmu;
u32 ref_clk_rate, usb2ctl, usb_pll_ndiv, usb_pll_pdiv;
int err = 0;

@@ -44,7 +49,10 @@ static int bcm_ns_usb2_phy_init(struct phy *phy)
goto err_clk_off;
}

- usb2ctl = readl(dmu + BCMA_DMU_CRU_USB2_CONTROL);
+ if (usb2->base)
+ usb2ctl = readl(usb2->base);
+ else
+ usb2ctl = readl(usb2->dmu + BCMA_DMU_CRU_USB2_CONTROL);

if (usb2ctl & BCMA_DMU_CRU_USB2_CONTROL_USB_PLL_PDIV_MASK) {
usb_pll_pdiv = usb2ctl;
@@ -58,15 +66,24 @@ static int bcm_ns_usb2_phy_init(struct phy *phy)
usb_pll_ndiv = (1920000000 * usb_pll_pdiv) / ref_clk_rate;

/* Unlock DMU PLL settings with some magic value */
- writel(0x0000ea68, dmu + BCMA_DMU_CRU_CLKSET_KEY);
+ if (usb2->clkset)
+ regmap_write(usb2->clkset, 0, 0x0000ea68);
+ else
+ writel(0x0000ea68, usb2->dmu + BCMA_DMU_CRU_CLKSET_KEY);

/* Write USB 2.0 PLL control setting */
usb2ctl &= ~BCMA_DMU_CRU_USB2_CONTROL_USB_PLL_NDIV_MASK;
usb2ctl |= usb_pll_ndiv << BCMA_DMU_CRU_USB2_CONTROL_USB_PLL_NDIV_SHIFT;
- writel(usb2ctl, dmu + BCMA_DMU_CRU_USB2_CONTROL);
+ if (usb2->base)
+ writel(usb2ctl, usb2->base);
+ else
+ writel(usb2ctl, usb2->dmu + BCMA_DMU_CRU_USB2_CONTROL);

/* Lock DMU PLL settings */
- writel(0x00000000, dmu + BCMA_DMU_CRU_CLKSET_KEY);
+ if (usb2->clkset)
+ regmap_write(usb2->clkset, 0, 0x00000000);
+ else
+ writel(0x00000000, usb2->dmu + BCMA_DMU_CRU_CLKSET_KEY);

err_clk_off:
clk_disable_unprepare(usb2->ref_clk);
@@ -90,10 +107,27 @@ static int bcm_ns_usb2_probe(struct platform_device *pdev)
return -ENOMEM;
usb2->dev = dev;

- usb2->dmu = devm_platform_ioremap_resource_byname(pdev, "dmu");
- if (IS_ERR(usb2->dmu)) {
- dev_err(dev, "Failed to map DMU regs\n");
- return PTR_ERR(usb2->dmu);
+ if (of_find_property(dev->of_node, "brcm,syscon-clkset", NULL)) {
+ usb2->base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(usb2->base)) {
+ dev_err(dev, "Failed to map control reg\n");
+ return PTR_ERR(usb2->base);
+ }
+
+ usb2->clkset = syscon_regmap_lookup_by_phandle(dev->of_node,
+ "brcm,syscon-clkset");
+ if (IS_ERR(usb2->clkset)) {
+ dev_err(dev, "Failed to lookup clkset regmap\n");
+ return PTR_ERR(usb2->clkset);
+ }
+ } else {
+ usb2->dmu = devm_platform_ioremap_resource_byname(pdev, "dmu");
+ if (IS_ERR(usb2->dmu)) {
+ dev_err(dev, "Failed to map DMU regs\n");
+ return PTR_ERR(usb2->dmu);
+ }
+
+ dev_warn(dev, "using deprecated DT binding\n");
}

usb2->ref_clk = devm_clk_get(dev, "phy-ref-clk");
--
2.26.2