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gpio: syscon: reuse for keystone 2 socs

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On Keystone SOCs, ARM host can send interrupts to DSP cores using the
DSP GPIO controller IP. Each DSP GPIO controller provides 28 IRQ signals for
each DSP core. This is one of the component used by the IPC mechanism used
on Keystone SOCs.

Keystone 2 DSP GPIO controller has specific features:
- each GPIO can be configured only as output pin;
- setting GPIO value to 1 causes IRQ generation on target DSP core;
- reading pin value returns 0 - if IRQ was handled or 1 - IRQ is still
  pending.

This patch updates gpio-syscon driver to be reused by Keystone 2 SoCs,
because the Keystone 2 DSP GPIO controller is controlled through Syscon
devices and, as requested by Linus Walleij, such kind of GPIO controllers
should be integrated with drivers/gpio/gpio-syscon.c driver.

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Grygorii Strashko 2014-09-03 20:05:34 +03:00 committed by Linus Walleij
parent 5a3e3f88b0
commit 2134cb997f
2 changed files with 74 additions and 0 deletions
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39
Documentation/devicetree/bindings/gpio/gpio-dsp-keystone.txt Normal file
View file

@ -0,0 +1,39 @@
Keystone 2 DSP GPIO controller bindings
HOST OS userland running on ARM can send interrupts to DSP cores using
the DSP GPIO controller IP. It provides 28 IRQ signals per each DSP core.
This is one of the component used by the IPC mechanism used on Keystone SOCs.
For example TCI6638K2K SoC has 8 DSP GPIO controllers:
- 8 for C66x CorePacx CPUs 0-7
Keystone 2 DSP GPIO controller has specific features:
- each GPIO can be configured only as output pin;
- setting GPIO value to 1 causes IRQ generation on target DSP core;
- reading pin value returns 0 - if IRQ was handled or 1 - IRQ is still
pending.
Required Properties:
- compatible: should be "ti,keystone-dsp-gpio"
- ti,syscon-dev: phandle/offset pair. The phandle to syscon used to
access device state control registers and the offset of device's specific
registers within device state control registers range.
- gpio-controller: Marks the device node as a gpio controller.
- #gpio-cells: Should be 2.
Please refer to gpio.txt in this directory for details of the common GPIO
bindings used by client devices.
Example:
dspgpio0: keystone_dsp_gpio@02620240 {
compatible = "ti,keystone-dsp-gpio";
ti,syscon-dev = <&devctrl 0x240>;
gpio-controller;
#gpio-cells = <2>;
};
dsp0: dsp0 {
compatible = "linux,rproc-user";
...
kick-gpio = <&dspgpio0 27>;
};

35
drivers/gpio/gpio-syscon.c
View file

@ -140,11 +140,46 @@ static const struct syscon_gpio_data clps711x_mctrl_gpio = {
.dat_bit_offset = 0x40 * 8 + 8,
};
#define KEYSTONE_LOCK_BIT BIT(0)
static void keystone_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
{
struct syscon_gpio_priv *priv = to_syscon_gpio(chip);
unsigned int offs;
int ret;
offs = priv->dreg_offset + priv->data->dat_bit_offset + offset;
if (!val)
return;
ret = regmap_update_bits(
priv->syscon,
(offs / SYSCON_REG_BITS) * SYSCON_REG_SIZE,
BIT(offs % SYSCON_REG_BITS) | KEYSTONE_LOCK_BIT,
BIT(offs % SYSCON_REG_BITS) | KEYSTONE_LOCK_BIT);
if (ret < 0)
dev_err(chip->dev, "gpio write failed ret(%d)\n", ret);
}
static const struct syscon_gpio_data keystone_dsp_gpio = {
/* ARM Keystone 2 */
.compatible = NULL,
.flags = GPIO_SYSCON_FEAT_OUT,
.bit_count = 28,
.dat_bit_offset = 4,
.set = keystone_gpio_set,
};
static const struct of_device_id syscon_gpio_ids[] = {
{
.compatible = "cirrus,clps711x-mctrl-gpio",
.data = &clps711x_mctrl_gpio,
},
{
.compatible = "ti,keystone-dsp-gpio",
.data = &keystone_dsp_gpio,
},
{ }
};
MODULE_DEVICE_TABLE(of, syscon_gpio_ids);