86 lines
2.8 KiB
Diff
86 lines
2.8 KiB
Diff
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From 5d7b644aad721ecca20bd8976b38fb243fdc84f9 Mon Sep 17 00:00:00 2001
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From: Chuanhong Guo <gch981213@gmail.com>
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Date: Sun, 15 Mar 2020 20:13:37 +0800
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Subject: [PATCH] gpio: mmio: introduce BGPIOF_NO_SET_ON_INPUT
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MIME-Version: 1.0
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Content-Type: text/plain; charset=UTF-8
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Content-Transfer-Encoding: 8bit
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Some gpio controllers ignores pin value writing when that pin is
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configured as input mode. As a result, bgpio_dir_out should set
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pin to output before configuring pin values or gpio pin values
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can't be set up properly.
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Introduce two variants of bgpio_dir_out: bgpio_dir_out_val_first
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and bgpio_dir_out_dir_first, and assign direction_output according
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to a new flag: BGPIOF_NO_SET_ON_INPUT.
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Signed-off-by: Chuanhong Guo <gch981213@gmail.com>
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Tested-by: René van Dorst <opensource@vdorst.com>
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Reviewed-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
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Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
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---
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drivers/gpio/gpio-mmio.c | 23 +++++++++++++++++++----
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include/linux/gpio/driver.h | 1 +
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2 files changed, 20 insertions(+), 4 deletions(-)
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--- a/drivers/gpio/gpio-mmio.c
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+++ b/drivers/gpio/gpio-mmio.c
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@@ -381,12 +381,10 @@ static int bgpio_get_dir(struct gpio_chi
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return 1;
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}
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-static int bgpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
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+static void bgpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
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{
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unsigned long flags;
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- gc->set(gc, gpio, val);
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-
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spin_lock_irqsave(&gc->bgpio_lock, flags);
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gc->bgpio_dir |= bgpio_line2mask(gc, gpio);
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@@ -397,7 +395,21 @@ static int bgpio_dir_out(struct gpio_chi
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gc->write_reg(gc->reg_dir_out, gc->bgpio_dir);
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spin_unlock_irqrestore(&gc->bgpio_lock, flags);
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+}
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+static int bgpio_dir_out_dir_first(struct gpio_chip *gc, unsigned int gpio,
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+ int val)
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+{
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+ bgpio_dir_out(gc, gpio, val);
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+ gc->set(gc, gpio, val);
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+ return 0;
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+}
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+
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+static int bgpio_dir_out_val_first(struct gpio_chip *gc, unsigned int gpio,
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+ int val)
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+{
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+ gc->set(gc, gpio, val);
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+ bgpio_dir_out(gc, gpio, val);
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return 0;
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}
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@@ -530,7 +542,10 @@ static int bgpio_setup_direction(struct
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if (dirout || dirin) {
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gc->reg_dir_out = dirout;
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gc->reg_dir_in = dirin;
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- gc->direction_output = bgpio_dir_out;
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+ if (flags & BGPIOF_NO_SET_ON_INPUT)
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+ gc->direction_output = bgpio_dir_out_dir_first;
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+ else
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+ gc->direction_output = bgpio_dir_out_val_first;
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gc->direction_input = bgpio_dir_in;
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gc->get_direction = bgpio_get_dir;
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} else {
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--- a/include/linux/gpio/driver.h
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+++ b/include/linux/gpio/driver.h
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@@ -567,6 +567,7 @@ int bgpio_init(struct gpio_chip *gc, str
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#define BGPIOF_BIG_ENDIAN_BYTE_ORDER BIT(3)
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#define BGPIOF_READ_OUTPUT_REG_SET BIT(4) /* reg_set stores output value */
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#define BGPIOF_NO_OUTPUT BIT(5) /* only input */
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+#define BGPIOF_NO_SET_ON_INPUT BIT(6)
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int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
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irq_hw_number_t hwirq);
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