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authorRajan Vaja <rajan.vaja@xilinx.com>2019-12-04 22:35:57 -0800
committerStephen Boyd <sboyd@kernel.org>2020-01-23 13:25:32 -0800
commite942171bbb762977afaa1eb24a312c3bd56386a5 (patch)
tree265e220ba90f00bf0051dfa207d135bb86d684e6 /drivers/clk/zynqmp
parentdf2a4d94f1720e24643a9870a01a1c2895d13b20 (diff)
downloadlinux-e942171bbb762977afaa1eb24a312c3bd56386a5.tar.bz2
clk: zynqmp: Add support for get max divider
To achieve best possible rate, maximum limit of divider is required while computation. Get maximum supported divisor from firmware. To maintain backward compatibility assign maximum possible value(0xFFFF) if query for max divisor is not successful. Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com> Link: https://lkml.kernel.org/r/1575527759-26452-5-git-send-email-rajan.vaja@xilinx.com Acked-by: Michal Simek <michal.simek@xilinx.com> [sboyd@kernel.org: Remove else return and just return] Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Diffstat (limited to 'drivers/clk/zynqmp')
-rw-r--r--drivers/clk/zynqmp/divider.c36
1 files changed, 36 insertions, 0 deletions
diff --git a/drivers/clk/zynqmp/divider.c b/drivers/clk/zynqmp/divider.c
index d8f5b70d2709..da6903197fc7 100644
--- a/drivers/clk/zynqmp/divider.c
+++ b/drivers/clk/zynqmp/divider.c
@@ -41,6 +41,7 @@ struct zynqmp_clk_divider {
bool is_frac;
u32 clk_id;
u32 div_type;
+ u16 max_div;
};
static inline int zynqmp_divider_get_val(unsigned long parent_rate,
@@ -176,6 +177,35 @@ static const struct clk_ops zynqmp_clk_divider_ops = {
};
/**
+ * zynqmp_clk_get_max_divisor() - Get maximum supported divisor from firmware.
+ * @clk_id: Id of clock
+ * @type: Divider type
+ *
+ * Return: Maximum divisor of a clock if query data is successful
+ * U16_MAX in case of query data is not success
+ */
+u32 zynqmp_clk_get_max_divisor(u32 clk_id, u32 type)
+{
+ const struct zynqmp_eemi_ops *eemi_ops = zynqmp_pm_get_eemi_ops();
+ struct zynqmp_pm_query_data qdata = {0};
+ u32 ret_payload[PAYLOAD_ARG_CNT];
+ int ret;
+
+ qdata.qid = PM_QID_CLOCK_GET_MAX_DIVISOR;
+ qdata.arg1 = clk_id;
+ qdata.arg2 = type;
+ ret = eemi_ops->query_data(qdata, ret_payload);
+ /*
+ * To maintain backward compatibility return maximum possible value
+ * (0xFFFF) if query for max divisor is not successful.
+ */
+ if (ret)
+ return U16_MAX;
+
+ return ret_payload[1];
+}
+
+/**
* zynqmp_clk_register_divider() - Register a divider clock
* @name: Name of this clock
* @clk_id: Id of clock
@@ -215,6 +245,12 @@ struct clk_hw *zynqmp_clk_register_divider(const char *name,
div->clk_id = clk_id;
div->div_type = nodes->type;
+ /*
+ * To achieve best possible rate, maximum limit of divider is required
+ * while computation.
+ */
+ div->max_div = zynqmp_clk_get_max_divisor(clk_id, nodes->type);
+
hw = &div->hw;
ret = clk_hw_register(NULL, hw);
if (ret) {