On 23.7.2018 20:42, Stefan Herbrechtsmeier wrote:
Hi Michal,
Am 23.07.2018 um 13:43 schrieb Michal Simek:
Reading registers for finding out output value is not working because input value is read instead in case of tristate.
Reported-by: Stefan Herbrechtsmeier stefan@herbrechtsmeier.net Signed-off-by: Michal Simek michal.simek@xilinx.com
drivers/gpio/xilinx_gpio.c | 38 +++++++++++++++++++++++++++++++++----- 1 file changed, 33 insertions(+), 5 deletions(-)
diff --git a/drivers/gpio/xilinx_gpio.c b/drivers/gpio/xilinx_gpio.c index 4da9ae114d87..9d3e9379d0e5 100644 --- a/drivers/gpio/xilinx_gpio.c +++ b/drivers/gpio/xilinx_gpio.c @@ -358,6 +358,11 @@ struct xilinx_gpio_platdata { int bank_max[XILINX_GPIO_MAX_BANK]; int bank_input[XILINX_GPIO_MAX_BANK]; int bank_output[XILINX_GPIO_MAX_BANK]; + u32 dout_default[XILINX_GPIO_MAX_BANK]; +};
+struct xilinx_gpio_privdata { + u32 output_val[XILINX_GPIO_MAX_BANK]; }; static int xilinx_gpio_get_bank_pin(unsigned offset, u32 *bank_num, @@ -387,6 +392,7 @@ static int xilinx_gpio_set_value(struct udevice *dev, unsigned offset, int value) { struct xilinx_gpio_platdata *platdata = dev_get_platdata(dev); + struct xilinx_gpio_privdata *priv = dev_get_priv(dev); int val, ret; u32 bank, pin; @@ -394,19 +400,21 @@ static int xilinx_gpio_set_value(struct udevice *dev, unsigned offset, if (ret) return ret; - debug("%s: regs: %lx, value: %x, gpio: %x, bank %x, pin %x\n", - __func__, (ulong)platdata->regs, value, offset, bank, pin); + val = priv->output_val[bank];
+ debug("%s: regs: %lx, value: %x, gpio: %x, bank %x, pin %x, out %x\n", + __func__, (ulong)platdata->regs, value, offset, bank, pin, val); if (value) { - val = readl(&platdata->regs->gpiodata + bank * 2); val = val | (1 << pin); writel(val, &platdata->regs->gpiodata + bank * 2); } else { - val = readl(&platdata->regs->gpiodata + bank * 2); val = val & ~(1 << pin); writel(val, &platdata->regs->gpiodata + bank * 2); }
You could replace the two writel function calls by one.
Will update this in v2.
+ priv->output_val[bank] = val;
return val; }; @@ -441,6 +449,7 @@ static int xilinx_gpio_get_function(struct udevice *dev, unsigned offset) static int xilinx_gpio_get_value(struct udevice *dev, unsigned offset) { struct xilinx_gpio_platdata *platdata = dev_get_platdata(dev); + struct xilinx_gpio_privdata *priv = dev_get_priv(dev); int val, ret; u32 bank, pin; @@ -451,7 +460,14 @@ static int xilinx_gpio_get_value(struct udevice *dev, unsigned offset) debug("%s: regs: %lx, gpio: %x, bank %x, pin %x\n", __func__, (ulong)platdata->regs, offset, bank, pin); - val = readl(&platdata->regs->gpiodata + bank * 2); + if (xilinx_gpio_get_function(dev, offset) == GPIOF_INPUT) { + debug("%s: Read input value from reg\n", __func__); + val = readl(&platdata->regs->gpiodata + bank * 2); + } else { + debug("%s: Read saved output value\n", __func__); + val = priv->output_val[bank]; + }
Why you don't always read the data register? This doesn't work for three state outputs.
In three state register every bit/pin is 0 - output, 1 input. It means else part is output and I read saved value in priv->output_val. If pin is setup as INPUT then I need read data reg to find out input value. Maybe you are commenting something else but please let me know if there is any other bug.
Thanks, Michal