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author | Maxime Ripard <maxime.ripard@free-electrons.com> | 2016-11-14 21:53:03 +0100 |
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committer | Linus Walleij <linus.walleij@linaro.org> | 2016-11-15 10:23:02 +0100 |
commit | 7c926492d38a3feef4b4b29c91b7c03eb1b8b546 (patch) | |
tree | dc8f3376d7b16c7c424517e25d639fddd8230400 /drivers/pinctrl | |
parent | 51814827190214986c452a166718bf12d32211c7 (diff) | |
download | linux-7c926492d38a3feef4b4b29c91b7c03eb1b8b546.tar.gz linux-7c926492d38a3feef4b4b29c91b7c03eb1b8b546.tar.bz2 linux-7c926492d38a3feef4b4b29c91b7c03eb1b8b546.zip |
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>
Diffstat (limited to 'drivers/pinctrl')
-rw-r--r-- | drivers/pinctrl/sunxi/pinctrl-sunxi.c | 84 | ||||
-rw-r--r-- | drivers/pinctrl/sunxi/pinctrl-sunxi.h | 7 |
2 files changed, 91 insertions, 0 deletions
diff --git a/drivers/pinctrl/sunxi/pinctrl-sunxi.c b/drivers/pinctrl/sunxi/pinctrl-sunxi.c index fa11a3100346..2339d4718b4d 100644 --- a/drivers/pinctrl/sunxi/pinctrl-sunxi.c +++ b/drivers/pinctrl/sunxi/pinctrl-sunxi.c @@ -1122,6 +1122,88 @@ static int sunxi_pinctrl_build_state(struct platform_device *pdev) 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_device *pdev, pctl); } + sunxi_pinctrl_setup_debounce(pctl, node); + dev_info(&pdev->dev, "initialized sunXi PIO driver\n"); return 0; diff --git a/drivers/pinctrl/sunxi/pinctrl-sunxi.h b/drivers/pinctrl/sunxi/pinctrl-sunxi.h index a7efb31d6523..f78a44a03189 100644 --- 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(u16 irq) 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; |