[PATCH RESEND 2/3] pwm: kona: Add support for Broadcom iproc pwm controller

From: Yendapally Reddy Dhananjaya Reddy
Date: Tue Mar 29 2016 - 10:32:28 EST

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Update the kona driver to support Broadcom iproc pwm controller

Signed-off-by: Yendapally Reddy Dhananjaya Reddy <yendapally.reddy@xxxxxxxxxxxx>
---
drivers/pwm/Kconfig | 6 +-
drivers/pwm/pwm-bcm-kona.c | 183 +++++++++++++++++++++++++++++++++++++++------
2 files changed, 163 insertions(+), 26 deletions(-)

diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index c182efc..e45ea33 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -76,9 +76,11 @@ config PWM_ATMEL_TCB

config PWM_BCM_KONA
tristate "Kona PWM support"
- depends on ARCH_BCM_MOBILE
+ depends on ARCH_BCM_MOBILE || ARCH_BCM_IPROC
+ default ARCH_BCM_IPROC
help
- Generic PWM framework driver for Broadcom Kona PWM block.
+ Generic PWM framework driver for Broadcom Kona PWM block. The
+ same block is also used in Broadcom iProc SoC's.

To compile this driver as a module, choose M here: the module
will be called pwm-bcm-kona.
diff --git a/drivers/pwm/pwm-bcm-kona.c b/drivers/pwm/pwm-bcm-kona.c
index c634183..ef152e3a 100644
--- a/drivers/pwm/pwm-bcm-kona.c
+++ b/drivers/pwm/pwm-bcm-kona.c
@@ -19,6 +19,7 @@
#include <linux/math64.h>
#include <linux/module.h>
#include <linux/of.h>
+#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/pwm.h>
#include <linux/slab.h>
@@ -47,30 +48,90 @@

#define PWM_CONTROL_OFFSET (0x00000000)
#define PWM_CONTROL_SMOOTH_SHIFT(chan) (24 + (chan))
-#define PWM_CONTROL_TYPE_SHIFT(chan) (16 + (chan))
+#define PWM_CONTROL_TYPE_SHIFT(shift, chan) (shift + chan)
#define PWM_CONTROL_POLARITY_SHIFT(chan) (8 + (chan))
#define PWM_CONTROL_TRIGGER_SHIFT(chan) (chan)

#define PRESCALE_OFFSET (0x00000004)
-#define PRESCALE_SHIFT(chan) ((chan) << 2)
-#define PRESCALE_MASK(chan) (0x7 << PRESCALE_SHIFT(chan))
+#define PRESCALE_SHIFT (0x00000004)
+#define PRESCALE_MASK (0x00000007)
#define PRESCALE_MIN (0x00000000)
#define PRESCALE_MAX (0x00000007)

-#define PERIOD_COUNT_OFFSET(chan) (0x00000008 + ((chan) << 3))
+#define PERIOD_COUNT_OFFSET(offset, chan) (offset + (chan << 3))
#define PERIOD_COUNT_MIN (0x00000002)
#define PERIOD_COUNT_MAX (0x00ffffff)
+#define KONA_PERIOD_COUNT_OFFSET (0x00000008)

-#define DUTY_CYCLE_HIGH_OFFSET(chan) (0x0000000c + ((chan) << 3))
+#define DUTY_CYCLE_HIGH_OFFSET(offset, chan) (offset + (chan << 3))
#define DUTY_CYCLE_HIGH_MIN (0x00000000)
#define DUTY_CYCLE_HIGH_MAX (0x00ffffff)
+#define KONA_DUTY_CYCLE_HIGH_OFFSET (0x0000000c)
+
+#define PWM_CHANNEL_CNT (0x00000006)
+#define SIGNAL_PUSH_PULL (0x00000001)
+#define PWMOUT_TYPE_SHIFT (0x00000010)
+
+#define IPROC_PRESCALE_OFFSET (0x00000024)
+#define IPROC_PRESCALE_SHIFT (0x00000006)
+#define IPROC_PRESCALE_MAX (0x0000003f)
+
+#define IPROC_PERIOD_COUNT_OFFSET (0x00000004)
+#define IPROC_PERIOD_COUNT_MIN (0x00000002)
+#define IPROC_PERIOD_COUNT_MAX (0x0000ffff)
+
+#define IPROC_DUTY_CYCLE_HIGH_OFFSET (0x00000008)
+#define IPROC_DUTY_CYCLE_HIGH_MIN (0x00000000)
+#define IPROC_DUTY_CYCLE_HIGH_MAX (0x0000ffff)
+
+#define IPROC_PWM_CHANNEL_CNT (0x00000004)
+#define IPROC_SIGNAL_PUSH_PULL (0x00000000)
+#define IPROC_PWMOUT_TYPE_SHIFT (0x0000000f)
+
+/*
+ * pwm controller reg structure
+ *
+ * @prescale_offset: prescale register offset
+ * @period_offset: period register offset
+ * @duty_offset: duty register offset
+ * @no_of_channels: number of channels
+ * @out_type_shift: out type shift in the register
+ * @signal_type: push-pull or open drain
+ * @prescale_max: prescale max
+ * @prescale_shift: prescale shift in register
+ * @prescale_ch_ascending: prescale ch order in prescale register
+ * @duty_cycle_max: value of max duty cycle
+ * @duty_cycle_min: value of min duty cycle
+ * @period_count_max: max period count val
+ * @period_count_min: min period count val
+ * @smooth_output_support: pwm smooth output support
+ */
+struct kona_pwmc_reg {
+ u32 prescale_offset;
+ u32 period_offset;
+ u32 duty_offset;
+ u32 no_of_channels;
+ u32 out_type_shift;
+ u32 signal_type;
+ u32 prescale_max;
+ u32 prescale_shift;
+ bool prescale_ch_ascending;
+ u32 duty_cycle_max;
+ u32 duty_cycle_min;
+ u32 period_count_max;
+ u32 period_count_min;
+ bool smooth_output_support;
+};

struct kona_pwmc {
struct pwm_chip chip;
void __iomem *base;
struct clk *clk;
+ const struct kona_pwmc_reg *reg;
};

+static const struct of_device_id bcm_kona_pwmc_dt[];
+
static inline struct kona_pwmc *to_kona_pwmc(struct pwm_chip *_chip)
{
return container_of(_chip, struct kona_pwmc, chip);
@@ -84,7 +145,9 @@ static void kona_pwmc_prepare_for_settings(struct kona_pwmc *kp,
{
unsigned int value = readl(kp->base + PWM_CONTROL_OFFSET);

- value |= 1 << PWM_CONTROL_SMOOTH_SHIFT(chan);
+ if (kp->reg->smooth_output_support)
+ value |= 1 << PWM_CONTROL_SMOOTH_SHIFT(chan);
+
value &= ~(1 << PWM_CONTROL_TRIGGER_SHIFT(chan));
writel(value, kp->base + PWM_CONTROL_OFFSET);

@@ -100,7 +163,9 @@ static void kona_pwmc_apply_settings(struct kona_pwmc *kp, unsigned int chan)
unsigned int value = readl(kp->base + PWM_CONTROL_OFFSET);

/* Set trigger bit and clear smooth bit to apply new settings */
- value &= ~(1 << PWM_CONTROL_SMOOTH_SHIFT(chan));
+ if (kp->reg->smooth_output_support)
+ value &= ~(1 << PWM_CONTROL_SMOOTH_SHIFT(chan));
+
value |= 1 << PWM_CONTROL_TRIGGER_SHIFT(chan);
writel(value, kp->base + PWM_CONTROL_OFFSET);

@@ -138,15 +203,17 @@ static int kona_pwmc_config(struct pwm_chip *chip, struct pwm_device *pwm,
dc = div64_u64(val, div);

/* If duty_ns or period_ns are not achievable then return */
- if (pc < PERIOD_COUNT_MIN || dc < DUTY_CYCLE_HIGH_MIN)
+ if (pc < kp->reg->period_count_min ||
+ dc < kp->reg->duty_cycle_min)
return -EINVAL;

/* If pc and dc are in bounds, the calculation is done */
- if (pc <= PERIOD_COUNT_MAX && dc <= DUTY_CYCLE_HIGH_MAX)
+ if (pc <= kp->reg->period_count_max &&
+ dc <= kp->reg->duty_cycle_max)
break;

/* Otherwise, increase prescale and recalculate pc and dc */
- if (++prescale > PRESCALE_MAX)
+ if (++prescale > kp->reg->prescale_max)
return -EINVAL;
}

@@ -156,16 +223,30 @@ static int kona_pwmc_config(struct pwm_chip *chip, struct pwm_device *pwm,
* validated immediately instead of on enable.
*/
if (pwm_is_enabled(pwm)) {
+ u32 ch_pre_shift = kp->reg->prescale_shift;
+
kona_pwmc_prepare_for_settings(kp, chan);

- value = readl(kp->base + PRESCALE_OFFSET);
- value &= ~PRESCALE_MASK(chan);
- value |= prescale << PRESCALE_SHIFT(chan);
- writel(value, kp->base + PRESCALE_OFFSET);
+ if (kp->reg->prescale_ch_ascending)
+ /*
+ * The prescale bits mask is in ascending
+ * order in the register
+ * "ch(n-2)bits..ch(n-1)bits..ch(n)bits".
+ */
+ ch_pre_shift *= ((kp->reg->no_of_channels - 1) - chan);
+ else
+ ch_pre_shift *= chan;

- writel(pc, kp->base + PERIOD_COUNT_OFFSET(chan));
+ value = readl(kp->base + kp->reg->prescale_offset);
+ value &= ~(kp->reg->prescale_max << ch_pre_shift);
+ value |= prescale << ch_pre_shift;
+ writel(value, kp->base + kp->reg->prescale_offset);

- writel(dc, kp->base + DUTY_CYCLE_HIGH_OFFSET(chan));
+ writel(pc, kp->base +
+ PERIOD_COUNT_OFFSET(kp->reg->period_offset, chan));
+
+ writel(dc, kp->base +
+ DUTY_CYCLE_HIGH_OFFSET(kp->reg->duty_offset, chan));

kona_pwmc_apply_settings(kp, chan);
}
@@ -231,17 +312,29 @@ static void kona_pwmc_disable(struct pwm_chip *chip, struct pwm_device *pwm)
struct kona_pwmc *kp = to_kona_pwmc(chip);
unsigned int chan = pwm->hwpwm;
unsigned int value;
+ u32 ch_pre_shift = kp->reg->prescale_shift;
+
+ if (kp->reg->prescale_ch_ascending)
+ /*
+ * The prescale bits mask is in ascending order
+ * in the register "ch(n-2)bits..ch(n-1)bits..ch(n)bits".
+ */
+ ch_pre_shift *= ((kp->reg->no_of_channels - 1) - chan);
+ else
+ ch_pre_shift *= chan;

kona_pwmc_prepare_for_settings(kp, chan);

/* Simulate a disable by configuring for zero duty */
- writel(0, kp->base + DUTY_CYCLE_HIGH_OFFSET(chan));
- writel(0, kp->base + PERIOD_COUNT_OFFSET(chan));
+ writel(0, kp->base +
+ DUTY_CYCLE_HIGH_OFFSET(kp->reg->duty_offset, chan));
+ writel(0, kp->base +
+ PERIOD_COUNT_OFFSET(kp->reg->period_offset, chan));

/* Set prescale to 0 for this channel */
- value = readl(kp->base + PRESCALE_OFFSET);
- value &= ~PRESCALE_MASK(chan);
- writel(value, kp->base + PRESCALE_OFFSET);
+ value = readl(kp->base + kp->reg->prescale_offset);
+ value &= ~(kp->reg->prescale_max << ch_pre_shift);
+ writel(value, kp->base + kp->reg->prescale_offset);

kona_pwmc_apply_settings(kp, chan);

@@ -263,17 +356,23 @@ static int kona_pwmc_probe(struct platform_device *pdev)
unsigned int chan;
unsigned int value = 0;
int ret = 0;
+ const struct of_device_id *match;

kp = devm_kzalloc(&pdev->dev, sizeof(*kp), GFP_KERNEL);
if (kp == NULL)
return -ENOMEM;

+ match = of_match_device(bcm_kona_pwmc_dt, &pdev->dev);
+ if (!match)
+ return -EINVAL;
+
+ kp->reg = (struct kona_pwmc_reg *)match->data;
platform_set_drvdata(pdev, kp);

kp->chip.dev = &pdev->dev;
kp->chip.ops = &kona_pwm_ops;
kp->chip.base = -1;
- kp->chip.npwm = 6;
+ kp->chip.npwm = kp->reg->no_of_channels;
kp->chip.of_xlate = of_pwm_xlate_with_flags;
kp->chip.of_pwm_n_cells = 3;
kp->chip.can_sleep = true;
@@ -298,7 +397,8 @@ static int kona_pwmc_probe(struct platform_device *pdev)

/* Set push/pull for all channels */
for (chan = 0; chan < kp->chip.npwm; chan++)
- value |= (1 << PWM_CONTROL_TYPE_SHIFT(chan));
+ value |= (kp->reg->signal_type <<
+ PWM_CONTROL_TYPE_SHIFT(kp->reg->out_type_shift, chan));

writel(value, kp->base + PWM_CONTROL_OFFSET);

@@ -323,8 +423,43 @@ static int kona_pwmc_remove(struct platform_device *pdev)
return pwmchip_remove(&kp->chip);
}

+static const struct kona_pwmc_reg kona_pwmc_reg_data = {
+ .prescale_offset = PRESCALE_OFFSET,
+ .period_offset = KONA_PERIOD_COUNT_OFFSET,
+ .duty_offset = KONA_DUTY_CYCLE_HIGH_OFFSET,
+ .no_of_channels = PWM_CHANNEL_CNT,
+ .out_type_shift = PWMOUT_TYPE_SHIFT,
+ .signal_type = SIGNAL_PUSH_PULL,
+ .prescale_max = PRESCALE_MAX,
+ .prescale_shift = PRESCALE_SHIFT,
+ .prescale_ch_ascending = false,
+ .duty_cycle_max = DUTY_CYCLE_HIGH_MAX,
+ .duty_cycle_min = DUTY_CYCLE_HIGH_MIN,
+ .period_count_max = PERIOD_COUNT_MAX,
+ .period_count_min = PERIOD_COUNT_MIN,
+ .smooth_output_support = true,
+};
+
+static const struct kona_pwmc_reg iproc_pwmc_reg_data = {
+ .prescale_offset = IPROC_PRESCALE_OFFSET,
+ .period_offset = IPROC_PERIOD_COUNT_OFFSET,
+ .duty_offset = IPROC_DUTY_CYCLE_HIGH_OFFSET,
+ .no_of_channels = IPROC_PWM_CHANNEL_CNT,
+ .out_type_shift = IPROC_PWMOUT_TYPE_SHIFT,
+ .signal_type = IPROC_SIGNAL_PUSH_PULL,
+ .prescale_max = IPROC_PRESCALE_MAX,
+ .prescale_shift = IPROC_PRESCALE_SHIFT,
+ .prescale_ch_ascending = true,
+ .duty_cycle_max = IPROC_DUTY_CYCLE_HIGH_MAX,
+ .duty_cycle_min = IPROC_DUTY_CYCLE_HIGH_MIN,
+ .period_count_max = IPROC_PERIOD_COUNT_MAX,
+ .period_count_min = IPROC_PERIOD_COUNT_MIN,
+ .smooth_output_support = false,
+};
+
static const struct of_device_id bcm_kona_pwmc_dt[] = {
- { .compatible = "brcm,kona-pwm" },
+ { .compatible = "brcm,kona-pwm", .data = &kona_pwmc_reg_data},
+ { .compatible = "brcm,iproc-pwm", .data = &iproc_pwmc_reg_data},
{ },
};
MODULE_DEVICE_TABLE(of, bcm_kona_pwmc_dt);
--
2.1.0

Next message: Yendapally Reddy Dhananjaya Reddy: "[PATCH RESEND 1/3] Documentation: dt: Add Broadcom iproc pwm controller binding"
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In reply to: Yendapally Reddy Dhananjaya Reddy: "[PATCH RESEND 3/3] ARM: dts: NSP: Add PWM Support to DT"
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