From: Hao Wu <wuhaotsh@google.com>

This patch adds GPIOs in NPCM7xx PWM module for its duty values.
The purpose of this is to connect it to the MFT module to provide
an input for measuring a PWM fan's RPM. Each PWM module has
NPCM7XX_PWM_PER_MODULE of GPIOs, each one corresponds to
one PWM instance and can connect to multiple fan instances in MFT.

Reviewed-by: Doug Evans <dje@google.com>
Reviewed-by: Tyrone Ting <kfting@nuvoton.com>
Signed-off-by: Hao Wu <wuhaotsh@google.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20210311180855.149764-2-wuhaotsh@google.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 include/hw/misc/npcm7xx_pwm.h | 4 +++-
 hw/misc/npcm7xx_pwm.c         | 4 ++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/include/hw/misc/npcm7xx_pwm.h b/include/hw/misc/npcm7xx_pwm.h
index 5a689d3f669..7ad632a93a1 100644
--- a/include/hw/misc/npcm7xx_pwm.h
+++ b/include/hw/misc/npcm7xx_pwm.h
@@ -77,6 +77,7 @@ typedef struct NPCM7xxPWM {
  * @iomem: Memory region through which registers are accessed.
  * @clock: The PWM clock.
  * @pwm: The PWM channels owned by this module.
+ * @duty_gpio_out: The duty cycle of each PWM channels as a output GPIO.
  * @ppr: The prescaler register.
  * @csr: The clock selector register.
  * @pcr: The control register.
@@ -89,7 +90,8 @@ struct NPCM7xxPWMState {
     MemoryRegion iomem;
 
     Clock       *clock;
-    NPCM7xxPWM pwm[NPCM7XX_PWM_PER_MODULE];
+    NPCM7xxPWM  pwm[NPCM7XX_PWM_PER_MODULE];
+    qemu_irq    duty_gpio_out[NPCM7XX_PWM_PER_MODULE];
 
     uint32_t    ppr;
     uint32_t    csr;
diff --git a/hw/misc/npcm7xx_pwm.c b/hw/misc/npcm7xx_pwm.c
index ce192bb2741..2be5bd25c6c 100644
--- a/hw/misc/npcm7xx_pwm.c
+++ b/hw/misc/npcm7xx_pwm.c
@@ -139,6 +139,7 @@ static void npcm7xx_pwm_update_duty(NPCM7xxPWM *p)
         trace_npcm7xx_pwm_update_duty(DEVICE(p->module)->canonical_path,
                                       p->index, p->duty, duty);
         p->duty = duty;
+        qemu_set_irq(p->module->duty_gpio_out[p->index], p->duty);
     }
 }
 
@@ -483,6 +484,7 @@ static void npcm7xx_pwm_init(Object *obj)
     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
     int i;
 
+    QEMU_BUILD_BUG_ON(ARRAY_SIZE(s->pwm) != NPCM7XX_PWM_PER_MODULE);
     for (i = 0; i < NPCM7XX_PWM_PER_MODULE; i++) {
         NPCM7xxPWM *p = &s->pwm[i];
         p->module = s;
@@ -501,6 +503,8 @@ static void npcm7xx_pwm_init(Object *obj)
         object_property_add_uint32_ptr(obj, "duty[*]",
                 &s->pwm[i].duty, OBJ_PROP_FLAG_READ);
     }
+    qdev_init_gpio_out_named(DEVICE(s), s->duty_gpio_out,
+                             "duty-gpio-out", NPCM7XX_PWM_PER_MODULE);
 }
 
 static const VMStateDescription vmstate_npcm7xx_pwm = {
-- 
2.20.1