clk: sunxi: Allwinner A20 output clock support
This patch adds support for the external clock outputs on the
Allwinner A20 SoC. The clock outputs are similar to "module 0"
type clocks, with different offsets and widths for clock factors.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Emilio López <emilio@elopez.com.ar>
diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c
index 124113e..659e4ea 100644
--- a/drivers/clk/sunxi/clk-sunxi.c
+++ b/drivers/clk/sunxi/clk-sunxi.c
@@ -336,6 +336,47 @@
/**
+ * sun7i_a20_get_out_factors() - calculates m, p factors for CLK_OUT_A/B
+ * CLK_OUT rate is calculated as follows
+ * rate = (parent_rate >> p) / (m + 1);
+ */
+
+static void sun7i_a20_get_out_factors(u32 *freq, u32 parent_rate,
+ u8 *n, u8 *k, u8 *m, u8 *p)
+{
+ u8 div, calcm, calcp;
+
+ /* These clocks can only divide, so we will never be able to achieve
+ * frequencies higher than the parent frequency */
+ if (*freq > parent_rate)
+ *freq = parent_rate;
+
+ div = parent_rate / *freq;
+
+ if (div < 32)
+ calcp = 0;
+ else if (div / 2 < 32)
+ calcp = 1;
+ else if (div / 4 < 32)
+ calcp = 2;
+ else
+ calcp = 3;
+
+ calcm = DIV_ROUND_UP(div, 1 << calcp);
+
+ *freq = (parent_rate >> calcp) / calcm;
+
+ /* we were called to round the frequency, we can now return */
+ if (n == NULL)
+ return;
+
+ *m = calcm - 1;
+ *p = calcp;
+}
+
+
+
+/**
* sunxi_factors_clk_setup() - Setup function for factor clocks
*/
@@ -390,6 +431,14 @@
.pwidth = 2,
};
+/* user manual says "n" but it's really "p" */
+static struct clk_factors_config sun7i_a20_out_config = {
+ .mshift = 8,
+ .mwidth = 5,
+ .pshift = 20,
+ .pwidth = 2,
+};
+
static const struct factors_data sun4i_pll1_data __initconst = {
.enable = 31,
.table = &sun4i_pll1_config,
@@ -420,6 +469,13 @@
.getter = sun4i_get_mod0_factors,
};
+static const struct factors_data sun7i_a20_out_data __initconst = {
+ .enable = 31,
+ .mux = 24,
+ .table = &sun7i_a20_out_config,
+ .getter = sun7i_a20_get_out_factors,
+};
+
static struct clk * __init sunxi_factors_clk_setup(struct device_node *node,
const struct factors_data *data)
{
@@ -918,6 +974,7 @@
{.compatible = "allwinner,sun6i-a31-pll1-clk", .data = &sun6i_a31_pll1_data,},
{.compatible = "allwinner,sun4i-apb1-clk", .data = &sun4i_apb1_data,},
{.compatible = "allwinner,sun4i-mod0-clk", .data = &sun4i_mod0_data,},
+ {.compatible = "allwinner,sun7i-a20-out-clk", .data = &sun7i_a20_out_data,},
{}
};