Re: [PATCH v2 6/9] usb: xhci-mtk: add optional mcu and dma bus clocks

From: Matthias Brugger
Date: Fri Oct 13 2017 - 09:55:39 EST




On 10/13/2017 10:26 AM, Chunfeng Yun wrote:
There are mcu_bus and dma_bus clocks needed to be controlled by
driver on some SoCs, so add them as optional ones

Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
---

Reviewed-by: Matthias Brugger <matthias.bgg@xxxxxxxxx>

drivers/usb/host/xhci-mtk.c | 79 ++++++++++++++++++++++++++++++++-----------
drivers/usb/host/xhci-mtk.h | 2 ++
2 files changed, 62 insertions(+), 19 deletions(-)

diff --git a/drivers/usb/host/xhci-mtk.c b/drivers/usb/host/xhci-mtk.c
index d60463c..e5caabe 100644
--- a/drivers/usb/host/xhci-mtk.c
+++ b/drivers/usb/host/xhci-mtk.c
@@ -221,6 +221,44 @@ static int xhci_mtk_ssusb_config(struct xhci_hcd_mtk *mtk)
return xhci_mtk_host_enable(mtk);
}
+/* ignore the error if the clock does not exist */
+static struct clk *optional_clk_get(struct device *dev, const char *id)
+{
+ struct clk *opt_clk;
+
+ opt_clk = devm_clk_get(dev, id);
+ /* ignore error number except EPROBE_DEFER */
+ if (IS_ERR(opt_clk) && (PTR_ERR(opt_clk) != -EPROBE_DEFER))
+ opt_clk = NULL;
+
+ return opt_clk;
+}
+
+static int xhci_mtk_clks_get(struct xhci_hcd_mtk *mtk)
+{
+ struct device *dev = mtk->dev;
+
+ mtk->sys_clk = devm_clk_get(dev, "sys_ck");
+ if (IS_ERR(mtk->sys_clk)) {
+ dev_err(dev, "fail to get sys_ck\n");
+ return PTR_ERR(mtk->sys_clk);
+ }
+
+ mtk->ref_clk = optional_clk_get(dev, "ref_ck");
+ if (IS_ERR(mtk->ref_clk))
+ return PTR_ERR(mtk->ref_clk);
+
+ mtk->mcu_clk = optional_clk_get(dev, "mcu_ck");
+ if (IS_ERR(mtk->mcu_clk))
+ return PTR_ERR(mtk->mcu_clk);
+
+ mtk->dma_clk = optional_clk_get(dev, "dma_ck");
+ if (IS_ERR(mtk->dma_clk))
+ return PTR_ERR(mtk->dma_clk);
+
+ return 0;
+}
+
static int xhci_mtk_clks_enable(struct xhci_hcd_mtk *mtk)
{
int ret;
@@ -237,16 +275,34 @@ static int xhci_mtk_clks_enable(struct xhci_hcd_mtk *mtk)
goto sys_clk_err;
}
+ ret = clk_prepare_enable(mtk->mcu_clk);
+ if (ret) {
+ dev_err(mtk->dev, "failed to enable mcu_clk\n");
+ goto mcu_clk_err;
+ }
+
+ ret = clk_prepare_enable(mtk->dma_clk);
+ if (ret) {
+ dev_err(mtk->dev, "failed to enable dma_clk\n");
+ goto dma_clk_err;
+ }
+
return 0;
+dma_clk_err:
+ clk_disable_unprepare(mtk->mcu_clk);
+mcu_clk_err:
+ clk_disable_unprepare(mtk->sys_clk);
sys_clk_err:
clk_disable_unprepare(mtk->ref_clk);
ref_clk_err:
- return -EINVAL;
+ return ret;
}
static void xhci_mtk_clks_disable(struct xhci_hcd_mtk *mtk)
{
+ clk_disable_unprepare(mtk->dma_clk);
+ clk_disable_unprepare(mtk->mcu_clk);
clk_disable_unprepare(mtk->sys_clk);
clk_disable_unprepare(mtk->ref_clk);
}
@@ -529,24 +585,9 @@ static int xhci_mtk_probe(struct platform_device *pdev)
return PTR_ERR(mtk->vusb33);
}
- mtk->sys_clk = devm_clk_get(dev, "sys_ck");
- if (IS_ERR(mtk->sys_clk)) {
- dev_err(dev, "fail to get sys_ck\n");
- return PTR_ERR(mtk->sys_clk);
- }
-
- /*
- * reference clock is usually a "fixed-clock", make it optional
- * for backward compatibility and ignore the error if it does
- * not exist.
- */
- mtk->ref_clk = devm_clk_get(dev, "ref_ck");
- if (IS_ERR(mtk->ref_clk)) {
- if (PTR_ERR(mtk->ref_clk) == -EPROBE_DEFER)
- return -EPROBE_DEFER;
-
- mtk->ref_clk = NULL;
- }
+ ret = xhci_mtk_clks_get(mtk);
+ if (ret)
+ return ret;
mtk->lpm_support = of_property_read_bool(node, "usb3-lpm-capable");
/* optional property, ignore the error if it does not exist */
diff --git a/drivers/usb/host/xhci-mtk.h b/drivers/usb/host/xhci-mtk.h
index 67783a7..45ff5c6 100644
--- a/drivers/usb/host/xhci-mtk.h
+++ b/drivers/usb/host/xhci-mtk.h
@@ -126,6 +126,8 @@ struct xhci_hcd_mtk {
struct regulator *vbus;
struct clk *sys_clk; /* sys and mac clock */
struct clk *ref_clk;
+ struct clk *mcu_clk;
+ struct clk *dma_clk;
struct regmap *pericfg;
struct phy **phys;
int num_phys;