openwrtv3/target/linux/sunxi/patches-4.9/0040-pinctrl-sunxi-Add-support-for-interrupt-debouncing.patch
Hauke Mehrtens 34a422794d sunxi: Backport patches needed for A64
This backports multiple patches from kernel 4.10 which are adding
missing support for the A64 and the pine64 board. These are the device
tree files, the pinctlk and the clock driver.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
2017-09-18 20:34:55 +02:00

171 lines
4.9 KiB
Diff

From 7c926492d38a3feef4b4b29c91b7c03eb1b8b546 Mon Sep 17 00:00:00 2001
From: Maxime Ripard <maxime.ripard@free-electrons.com>
Date: Mon, 14 Nov 2016 21:53:03 +0100
Subject: pinctrl: sunxi: Add support for interrupt debouncing
The pin controller found in the Allwinner SoCs has support for interrupts
debouncing.
However, this is not done per-pin, preventing us from using the generic
pinconf binding for that, but per irq bank, which, depending on the SoC,
ranges from one to five.
Introduce a device-wide property to deal with this using a microsecond
resolution. We can re-use the per-pin input-debounce property for that, so
let's do it!
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
.../bindings/pinctrl/allwinner,sunxi-pinctrl.txt | 14 ++++
drivers/pinctrl/sunxi/pinctrl-sunxi.c | 84 ++++++++++++++++++++++
drivers/pinctrl/sunxi/pinctrl-sunxi.h | 7 ++
3 files changed, 105 insertions(+)
--- a/Documentation/devicetree/bindings/pinctrl/allwinner,sunxi-pinctrl.txt
+++ b/Documentation/devicetree/bindings/pinctrl/allwinner,sunxi-pinctrl.txt
@@ -28,6 +28,20 @@ Required properties:
- reg: Should contain the register physical address and length for the
pin controller.
+- clocks: phandle to the clocks feeding the pin controller:
+ - "apb": the gated APB parent clock
+ - "hosc": the high frequency oscillator in the system
+ - "losc": the low frequency oscillator in the system
+
+Note: For backward compatibility reasons, the hosc and losc clocks are only
+required if you need to use the optional input-debounce property. Any new
+device tree should set them.
+
+Optional properties:
+ - input-debounce: Array of debouncing periods in microseconds. One period per
+ irq bank found in the controller. 0 if no setup required.
+
+
Please refer to pinctrl-bindings.txt in this directory for details of the
common pinctrl bindings used by client devices.
--- a/drivers/pinctrl/sunxi/pinctrl-sunxi.c
+++ b/drivers/pinctrl/sunxi/pinctrl-sunxi.c
@@ -1122,6 +1122,88 @@ static int sunxi_pinctrl_build_state(str
return 0;
}
+static int sunxi_pinctrl_get_debounce_div(struct clk *clk, int freq, int *diff)
+{
+ unsigned long clock = clk_get_rate(clk);
+ unsigned int best_diff = ~0, best_div;
+ int i;
+
+ for (i = 0; i < 8; i++) {
+ int cur_diff = abs(freq - (clock >> i));
+
+ if (cur_diff < best_diff) {
+ best_diff = cur_diff;
+ best_div = i;
+ }
+ }
+
+ *diff = best_diff;
+ return best_div;
+}
+
+static int sunxi_pinctrl_setup_debounce(struct sunxi_pinctrl *pctl,
+ struct device_node *node)
+{
+ unsigned int hosc_diff, losc_diff;
+ unsigned int hosc_div, losc_div;
+ struct clk *hosc, *losc;
+ u8 div, src;
+ int i, ret;
+
+ /* Deal with old DTs that didn't have the oscillators */
+ if (of_count_phandle_with_args(node, "clocks", "#clock-cells") != 3)
+ return 0;
+
+ /* If we don't have any setup, bail out */
+ if (!of_find_property(node, "input-debounce", NULL))
+ return 0;
+
+ losc = devm_clk_get(pctl->dev, "losc");
+ if (IS_ERR(losc))
+ return PTR_ERR(losc);
+
+ hosc = devm_clk_get(pctl->dev, "hosc");
+ if (IS_ERR(hosc))
+ return PTR_ERR(hosc);
+
+ for (i = 0; i < pctl->desc->irq_banks; i++) {
+ unsigned long debounce_freq;
+ u32 debounce;
+
+ ret = of_property_read_u32_index(node, "input-debounce",
+ i, &debounce);
+ if (ret)
+ return ret;
+
+ if (!debounce)
+ continue;
+
+ debounce_freq = DIV_ROUND_CLOSEST(USEC_PER_SEC, debounce);
+ losc_div = sunxi_pinctrl_get_debounce_div(losc,
+ debounce_freq,
+ &losc_diff);
+
+ hosc_div = sunxi_pinctrl_get_debounce_div(hosc,
+ debounce_freq,
+ &hosc_diff);
+
+ if (hosc_diff < losc_diff) {
+ div = hosc_div;
+ src = 1;
+ } else {
+ div = losc_div;
+ src = 0;
+ }
+
+ writel(src | div << 4,
+ pctl->membase +
+ sunxi_irq_debounce_reg_from_bank(i,
+ pctl->desc->irq_bank_base));
+ }
+
+ return 0;
+}
+
int sunxi_pinctrl_init(struct platform_device *pdev,
const struct sunxi_pinctrl_desc *desc)
{
@@ -1284,6 +1366,8 @@ int sunxi_pinctrl_init(struct platform_d
pctl);
}
+ sunxi_pinctrl_setup_debounce(pctl, node);
+
dev_info(&pdev->dev, "initialized sunXi PIO driver\n");
return 0;
--- a/drivers/pinctrl/sunxi/pinctrl-sunxi.h
+++ b/drivers/pinctrl/sunxi/pinctrl-sunxi.h
@@ -69,6 +69,8 @@
#define IRQ_STATUS_IRQ_BITS 1
#define IRQ_STATUS_IRQ_MASK ((1 << IRQ_STATUS_IRQ_BITS) - 1)
+#define IRQ_DEBOUNCE_REG 0x218
+
#define IRQ_MEM_SIZE 0x20
#define IRQ_EDGE_RISING 0x00
@@ -265,6 +267,11 @@ static inline u32 sunxi_irq_ctrl_offset(
return irq_num * IRQ_CTRL_IRQ_BITS;
}
+static inline u32 sunxi_irq_debounce_reg_from_bank(u8 bank, unsigned bank_base)
+{
+ return IRQ_DEBOUNCE_REG + (bank_base + bank) * IRQ_MEM_SIZE;
+}
+
static inline u32 sunxi_irq_status_reg_from_bank(u8 bank, unsigned bank_base)
{
return IRQ_STATUS_REG + (bank_base + bank) * IRQ_MEM_SIZE;