On 05/19/2015 05:59 PM, Thierry Reding wrote:
On Tue, May 19, 2015 at 02:39:27PM +0300, Mikko Perttunen wrote:
This patch allows SoC-specific CAR initialization routines to register
their own reset_assert and reset_deassert callbacks with the common Tegra
CAR code. If defined, the common code will call these callbacks when a
reset control with number >= num_periph_banks * 32 is attempted to be asserted
or deasserted respectively. Numbers greater than or equal to num_periph_banks * 32
are used to avoid clashes with low numbers that are automatically mapped to
standard CAR reset lines.
Each SoC with these special resets should specify the defined reset control
numbers in a device tree header file.
This is looking pretty good, but I think we can simplify a wee bit
more...
Signed-off-by: Mikko Perttunen <mikko.perttunen@xxxxxxxx>
Acked-by: Michael Turquette <mturquette@xxxxxxxxxx>
---
drivers/clk/tegra/clk.c | 39 +++++++++++++++++++++++++++++++--------
drivers/clk/tegra/clk.h | 3 +++
2 files changed, 34 insertions(+), 8 deletions(-)
diff --git a/drivers/clk/tegra/clk.c b/drivers/clk/tegra/clk.c
index 41cd87c..c093ed9 100644
--- a/drivers/clk/tegra/clk.c
+++ b/drivers/clk/tegra/clk.c
@@ -49,7 +49,6 @@
#define RST_DEVICES_L 0x004
#define RST_DEVICES_H 0x008
#define RST_DEVICES_U 0x00C
-#define RST_DFLL_DVCO 0x2F4
#define RST_DEVICES_V 0x358
#define RST_DEVICES_W 0x35C
#define RST_DEVICES_X 0x28C
@@ -79,6 +78,11 @@ static struct clk **clks;
static int clk_num;
static struct clk_onecell_data clk_data;
+/* Handlers for SoC-specific reset lines */
+static int (*special_reset_assert)(unsigned long);
+static int (*special_reset_deassert)(unsigned long);
+static int special_reset_num;
I think we can get rid of this if we...
+
static struct tegra_clk_periph_regs periph_regs[] = {
[0] = {
.enb_reg = CLK_OUT_ENB_L,
@@ -152,19 +156,29 @@ static int tegra_clk_rst_assert(struct reset_controller_dev *rcdev,
*/
tegra_read_chipid();
- writel_relaxed(BIT(id % 32),
- clk_base + periph_regs[id / 32].rst_set_reg);
+ if (id < periph_banks * 32) {
+ writel_relaxed(BIT(id % 32),
+ clk_base + periph_regs[id / 32].rst_set_reg);
+ return 0;
+ } else if (id < periph_banks * 32 + special_reset_num) {
+ return special_reset_assert(id);
+ }
... pass id - periph_banks * 32 into special_reset_assert(). Oh, but
then...
The reason I don't subtract periph_banks * 32 is because this way the
code in the SoC-specific callback can just include the dt-bindings
header and use the same defines used in the device tree.
@@ -286,10 +300,19 @@ void __init tegra_add_of_provider(struct device_node *np)
of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data);
rst_ctlr.of_node = np;
- rst_ctlr.nr_resets = periph_banks * 32;
+ rst_ctlr.nr_resets = periph_banks * 32 + special_reset_num;
... this is no longer going to work. We could keep special_reset_num,
though obviously it should be an unsigned int and renamed to
num_special_reset, yet still pass the relative ID into the SoC-specific
callbacks, after all that's what they care about and each implementation
would have to subtract periph_banks * 32 anyway.
Mostly agreed, but see above :)
reset_controller_register(&rst_ctlr);
}
+void __init tegra_init_special_resets(int num,
+ int (*assert)(unsigned long),
+ int (*deassert)(unsigned long))
+{
+ special_reset_num = num;
+ special_reset_assert = assert;
+ special_reset_deassert = deassert;
+}
+
I think we could possibly improve this interface somewhat by turning it
upside-down, that is, make SoC-specific drivers call this in a helper
fashion. But this is good enough for now, I can always take a stab at
refactoring if I get bored.
Thierry
Thanks,
Mikko
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