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From 3473e6acea4bd01ba2b334628970390207f9f4fd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20L=C3=B3pez?= <emilio@elopez.com.ar>
Date: Tue, 21 May 2013 21:25:05 -0300
Subject: [PATCH] clk: sunxi: mod0 support
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
This commit implements support for the "module 0" type of clocks, as
used by MMC, IR, NAND, SATA and other components.
Signed-off-by: Emilio López <emilio@elopez.com.ar>
---
Documentation/devicetree/bindings/clock/sunxi.txt | 1 +
drivers/clk/sunxi/clk-sunxi.c | 57 +++++++++++++++++++++++
2 files changed, 58 insertions(+)
diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt
index 773f3ae..ff3f61c 100644
--- a/Documentation/devicetree/bindings/clock/sunxi.txt
+++ b/Documentation/devicetree/bindings/clock/sunxi.txt
@@ -35,6 +35,7 @@ Required properties:
"allwinner,sun7i-a20-apb1-gates-clk" - for the APB1 gates on A20
"allwinner,sun6i-a31-apb2-div-clk" - for the APB2 gates on A31
"allwinner,sun6i-a31-apb2-gates-clk" - for the APB2 gates on A31
+ "allwinner,sun4i-mod0-clk" - for the module 0 family of clocks
Required properties for all clocks:
- reg : shall be the control register address for the clock.
diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c
index 6947ba9..96c01b2 100644
--- a/drivers/clk/sunxi/clk-sunxi.c
+++ b/drivers/clk/sunxi/clk-sunxi.c
@@ -287,6 +287,47 @@ static void sun4i_get_apb1_factors(u32 *freq, u32 parent_rate,
/**
+ * sun4i_get_mod0_factors() - calculates m, n factors for MOD0-style clocks
+ * MMC rate is calculated as follows
+ * rate = (parent_rate >> p) / (m + 1);
+ */
+
+static void sun4i_get_mod0_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 < 16)
+ calcp = 0;
+ else if (div / 2 < 16)
+ calcp = 1;
+ else if (div / 4 < 16)
+ 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
*/
@@ -333,6 +374,14 @@ struct factors_data {
.pwidth = 2,
};
+/* user manual says "n" but it's really "p" */
+static struct clk_factors_config sun4i_mod0_config = {
+ .mshift = 0,
+ .mwidth = 4,
+ .pshift = 16,
+ .pwidth = 2,
+};
+
static const struct factors_data sun4i_pll1_data __initconst = {
.enable = 31,
.table = &sun4i_pll1_config,
@@ -356,6 +405,13 @@ struct factors_data {
.getter = sun4i_get_apb1_factors,
};
+static const struct factors_data sun4i_mod0_data __initconst = {
+ .enable = 31,
+ .mux = 24,
+ .table = &sun4i_mod0_config,
+ .getter = sun4i_get_mod0_factors,
+};
+
static struct clk * __init sunxi_factors_clk_setup(struct device_node *node,
const struct factors_data *data)
{
@@ -779,6 +835,7 @@ static void __init sunxi_divs_clk_setup(struct device_node *node,
{.compatible = "allwinner,sun4i-pll1-clk", .data = &sun4i_pll1_data,},
{.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,},
{}
};
--
1.8.4
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