This commit adds the clk_get_parent_rate() function, which is responsible for getting the rate of parent clock. Unfortunately, u-boot's DM support for getting parent is different (the parent relationship is in udevice) than the one in common clock framework (CCF) in Linux.
To alleviate this problem - the clk_get_parent_rate() function has been introduced to clk-uclass.c.
As written in the in-code comment - some clocks do not set clk->id (and require it to be set to 0) and hence the standard ckl_{request|get_rate| free} API is used.
Signed-off-by: Lukasz Majewski lukma@denx.de ---
Changes in v2: None
drivers/clk/clk-uclass.c | 41 +++++++++++++++++++++++++++++++++++++++++ include/clk.h | 9 +++++++++ 2 files changed, 50 insertions(+)
diff --git a/drivers/clk/clk-uclass.c b/drivers/clk/clk-uclass.c index 6d7a514006..f1640dda67 100644 --- a/drivers/clk/clk-uclass.c +++ b/drivers/clk/clk-uclass.c @@ -340,6 +340,47 @@ ulong clk_get_rate(struct clk *clk) return ops->get_rate(clk); }
+ulong clk_get_parent_rate(struct clk *clk) +{ + const struct clk_ops *ops; + struct udevice *pdev; + struct clk pclk; + ulong rate; + int ret; + + debug("%s(clk=%p)\n", __func__, clk); + + pdev = clk->dev->parent; + if (!pdev) + return -ENODEV; + + ops = clk_dev_ops(pdev); + if (!ops->get_rate) + return -ENOSYS; + + /* + * We do use memset, clk_{request|get_rate|free} + * as there are clocks - like the "fixed" ones, which + * doesn't posses the clk wrapper struct (just added to + * UCLASS_CLK) and explicitly check if clk->id = 0. + * + * In fact the "clock" resources (like ops, description) + * are accessed via udevice structure (pdev - parent's one) + */ + + memset(&pclk, 0, sizeof(pclk)); + ret = clk_request(pdev, &pclk); + if (ret) { + printf("%s: pclk: %s request failed!\n", __func__, pdev->name); + return ret; + } + + rate = clk_get_rate(&pclk); + clk_free(&pclk); + + return rate; +} + ulong clk_set_rate(struct clk *clk, ulong rate) { const struct clk_ops *ops = clk_dev_ops(clk->dev); diff --git a/include/clk.h b/include/clk.h index f6fbcc6634..8224295ec3 100644 --- a/include/clk.h +++ b/include/clk.h @@ -238,6 +238,15 @@ int clk_free(struct clk *clk); ulong clk_get_rate(struct clk *clk);
/** + * clk_get_parent_rate() - Get parent of current clock rate. + * + * @clk: A clock struct that was previously successfully requested by + * clk_request/get_by_*(). + * @return clock rate in Hz, or -ve error code. + */ +ulong clk_get_parent_rate(struct clk *clk); + +/** * clk_set_rate() - Set current clock rate. * * @clk: A clock struct that was previously successfully requested by