The primary consumer of the lpss pwm is the i915 kms driver, but
currently that driver cannot get the pwm because i915 platforms are
not using devicetree and pwm-lpss does not call pwm_add_table.
Another problem is that i915 does not support get_pwm returning
-EPROBE_DEFER and i915's init is very complex and this is almost
impossible to fix.
This commit changes the PWM_LPSS Kconfig from a tristate to a bool, so
that when the i915 driver loads the lpss pwm will be available avoiding
the -EPROBE_DEFER issue. Note that this is identical to how the same
problem was solved for the pwm-crc driver.
Being builtin also allows calling pwm_add_table directly from the
pwm-lpss code, otherwise the pwm_add_table call would need to be put
somewhere else to ensure it happens before i915 calls pwm_get,
even if i915 would support -EPROBE_DEFER.
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
---
drivers/pwm/Kconfig | 12 +++---------
drivers/pwm/pwm-lpss.c | 11 +++++++++++
2 files changed, 14 insertions(+), 9 deletions(-)
diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index bf01288..cda31ea 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -240,28 +240,22 @@ config PWM_LPC32XX
will be called pwm-lpc32xx.
config PWM_LPSS
- tristate
+ bool
config PWM_LPSS_PCI
- tristate "Intel LPSS PWM PCI driver"
+ bool "Intel LPSS PWM PCI driver"
depends on X86 && PCI
select PWM_LPSS
help
The PCI driver for Intel Low Power Subsystem PWM controller.
- To compile this driver as a module, choose M here: the module
- will be called pwm-lpss-pci.
-
config PWM_LPSS_PLATFORM
- tristate "Intel LPSS PWM platform driver"
+ bool "Intel LPSS PWM platform driver"
depends on X86 && ACPI
select PWM_LPSS
help
The platform driver for Intel Low Power Subsystem PWM controller.
- To compile this driver as a module, choose M here: the module
- will be called pwm-lpss-platform.
-
config PWM_MESON
tristate "Amlogic Meson PWM driver"
depends on ARCH_MESON
diff --git a/drivers/pwm/pwm-lpss.c b/drivers/pwm/pwm-lpss.c
index 72c0bce..b4d8835 100644
--- a/drivers/pwm/pwm-lpss.c
+++ b/drivers/pwm/pwm-lpss.c
@@ -161,6 +161,12 @@ static const struct pwm_ops pwm_lpss_ops = {
.owner = THIS_MODULE,
};
+/* PWM consumed by the Intel GFX */
+static struct pwm_lookup pwm_lpss_lookup[] = {
+ PWM_LOOKUP("pwm-lpss", 0, "0000:00:02.0", "pwm_backlight", 0,
+ PWM_POLARITY_NORMAL),
+};
+
struct pwm_lpss_chip *pwm_lpss_probe(struct device *dev, struct resource *r,
const struct pwm_lpss_boardinfo *info)
{
@@ -193,12 +199,17 @@ struct pwm_lpss_chip *pwm_lpss_probe(struct device *dev, struct resource *r,
return ERR_PTR(ret);
}
+ /* Add lookup table for pwm_backlight */
+ pwm_lpss_lookup[0].provider = dev_name(dev);
+ pwm_add_table(pwm_lpss_lookup, ARRAY_SIZE(pwm_lpss_lookup));
+
return lpwm;
}
EXPORT_SYMBOL_GPL(pwm_lpss_probe);
int pwm_lpss_remove(struct pwm_lpss_chip *lpwm)
{
+ pwm_remove_table(pwm_lpss_lookup, ARRAY_SIZE(pwm_lpss_lookup));
return pwmchip_remove(&lpwm->chip);
}
EXPORT_SYMBOL_GPL(pwm_lpss_remove);
--
2.9.3
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