On 11/01/2013 10:11 PM, Nishanth Menon wrote:
On 10/25/2013 10:57 AM, Tero Kristo wrote:
This patch adds support for TI specific gate clocks. These behave as basic
gate-clock, but have different ops / hw-ops for controlling the actual
gate, for example waiting until the clock is ready. Several sub-types
are supported:
- ti,gate-clock: basic gate clock with default ops/hwops
- ti,clkdm-gate-clock: clockdomain level gate control
- ti,dss-gate-clock: gate clock with DSS specific hardware handling
- ti,am35xx-gate-clock: gate clock with AM35xx specific hardware handling
- ti,hsdiv-gate-clock: gate clock with OMAP36xx hardware errata handling
Signed-off-by: Tero Kristo <t-kristo@xxxxxx>
---
.../devicetree/bindings/clock/ti/gate.txt | 77 ++++++
arch/arm/mach-omap2/clock.h | 29 ---
drivers/clk/ti/Makefile | 2 +-
drivers/clk/ti/gate.c | 258 ++++++++++++++++++++
include/linux/clk/ti.h | 36 +++
5 files changed, 372 insertions(+), 30 deletions(-)
create mode 100644 Documentation/devicetree/bindings/clock/ti/gate.txt
create mode 100644 drivers/clk/ti/gate.c
diff --git a/Documentation/devicetree/bindings/clock/ti/gate.txt b/Documentation/devicetree/bindings/clock/ti/gate.txt
new file mode 100644
index 0000000..18c4d86
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/ti/gate.txt
@@ -0,0 +1,77 @@
+Binding for Texas Instruments gate clock.
+
+Binding status: Unstable - ABI compatibility may be broken in the future
+
+This binding uses the common clock binding[1]. This clock is
+quite much similar to the basic gate-clock [2], however,
+it supports a number of additional features. If no register
+is provided for this clock, the code assumes that a clockdomain
+will be controlled instead and the corresponding hw-ops for
+that is used.
+
+[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
+[2] Documentation/devicetree/bindings/clock/gate-clock.txt
+[3] Documentation/devicetree/bindings/clock/ti/clockdomain.txt
i think you may want to sequence patch #12 before this if you would
like to refer to this.
Yea, can re-order based on this. Compiler doesn't really catch issues
like this. :)
+
+Required properties:
+- compatible : shall be one of:
+ "ti,gate-clock" - basic gate clock
+ "ti,wait-gate-clock" - gate clock which waits until clock is active before
+ returning from clk_enable()
an example will be nice for this.
Will add.
[...]
diff --git a/drivers/clk/ti/gate.c b/drivers/clk/ti/gate.c
new file mode 100644
index 0000000..1a201f8
--- /dev/null
+++ b/drivers/clk/ti/gate.c
[...]
+/**
+ * omap36xx_gate_clk_enable_with_hsdiv_restore - enable clocks suffering
+ * from HSDivider PWRDN problem Implements Errata ID: i556.
+ * @clk: DPLL output struct clk
+ *
+ * 3630 only: dpll3_m3_ck, dpll4_m2_ck, dpll4_m3_ck, dpll4_m4_ck,
+ * dpll4_m5_ck & dpll4_m6_ck dividers gets loaded with reset
+ * valueafter their respective PWRDN bits are set. Any dummy write
+ * (Any other value different from the Read value) to the
+ * corresponding CM_CLKSEL register will refresh the dividers.
+ */
+static int omap36xx_gate_clk_enable_with_hsdiv_restore(struct clk_hw *clk)
+{
+ struct clk_divider *parent;
+ struct clk_hw *parent_hw;
+ u32 dummy_v, orig_v;
+ int ret;
+
+ /* Clear PWRDN bit of HSDIVIDER */
+ ret = omap2_dflt_clk_enable(clk);
+
+ /* Parent is the x2 node, get parent of parent for the m2 div */
+ parent_hw = __clk_get_hw(__clk_get_parent(__clk_get_parent(clk->clk)));
+ parent = to_clk_divider(parent_hw);
+
+ /* Restore the dividers */
+ if (!ret) {
+ orig_v = __raw_readl(parent->reg);
+ dummy_v = orig_v;
+
+ /* Write any other value different from the Read value */
+ dummy_v ^= (1 << parent->shift);
+ __raw_writel(dummy_v, parent->reg);
+
+ /* Write the original divider */
+ __raw_writel(orig_v, parent->reg);
i think we already did state that these need to be regmap_updatebits..
Yea.
+ }
+
+ return ret;
+}
+
+static int __init _of_ti_gate_clk_setup(struct device_node *node,
+ const struct clk_ops *ops,
+ const struct clk_hw_omap_ops *hw_ops,
+ struct regmap *regmap)
+{
+ struct clk *clk;
+ struct clk_init_data init = { NULL };
+ struct clk_hw_omap *clk_hw;
+ const char *clk_name = node->name;
+ const char *parent_name;
+ u32 val;
+
+ clk_hw = kzalloc(sizeof(*clk_hw), GFP_KERNEL);
+ if (!clk_hw) {
+ pr_err("%s: could not allocate clk_hw_omap\n", __func__);
+ return -ENOMEM;
+ }
+
+ clk_hw->hw.init = &init;
+
+ of_property_read_string(node, "clock-output-names", &clk_name);
+
+ init.name = clk_name;
+ init.ops = ops;
+
+ if (!of_property_read_u32(node, "reg", &val))
+ clk_hw->enable_reg = (void *)val;
seems reg is a mandatory as per bindings for everything other than
ti,clkdm-gate-clock.. no error handling?
Will add.
+
+ clk_hw->regmap = regmap;
+
+ if (!of_property_read_u32(node, "ti,bit-shift", &val))
+ clk_hw->enable_bit = val;
Again -> bindings state this is mandatory for non ti,clkdm-gate-clock
clocks. no error handling?
Will add.
+ clk_hw->ops = hw_ops;
+
+ parent_name = of_clk_get_parent_name(node, 0);
+ init.parent_names = &parent_name;
+ init.num_parents = 1;
error checks for parent clk which seems to be mandatory?
Will add.
+
+ if (of_property_read_bool(node, "ti,set-rate-parent"))
+ init.flags |= CLK_SET_RATE_PARENT;
+
+ if (of_property_read_bool(node, "ti,set-bit-to-disable"))
+ clk_hw->flags |= INVERT_ENABLE;
+
+ clk = clk_register(NULL, &clk_hw->hw);
+
+ if (!IS_ERR(clk)) {
+ of_clk_add_provider(node, of_clk_src_simple_get, clk);
+ return 0;
+ }
+
free(clk_hw)?
Hmm yea, missing.
+ return PTR_ERR(clk);
+}
+
--
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