Re: [PATCH v2 1/5] mfd: tps65217: Add support for IRQs

[Lee Jones <lee.jones@linaro.org>]

On Thu, 16 Jun 2016, Marcin Niestroj wrote:

> Hi,
> 
> On 15.06.2016 17:13, Lee Jones wrote:
> >On Tue, 14 Jun 2016, Marcin Niestroj wrote:
> >
> >>Add support for handling IRQs: power button, AC and USB power state
> >>changes. Mask and interrupt bits are shared within one register, which
> >>prevents us to use regmap_irq implementation. New irq_domain is created in
> >>order to add interrupt handling for each tps65217's subsystem. IRQ
> >>resources have been added for charger subsystem to be able to notify about
> >>AC and USB state changes.
> >>
> >>Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
> >>---
> >> drivers/mfd/Kconfig          |   1 +
> >> drivers/mfd/tps65217.c       | 182 ++++++++++++++++++++++++++++++++++++++++++-
> >> include/linux/mfd/tps65217.h |  11 +++
> >> 3 files changed, 192 insertions(+), 2 deletions(-)
> >>
> >>diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> >>index 1bcf601..f8c9580 100644
> >>--- a/drivers/mfd/Kconfig
> >>+++ b/drivers/mfd/Kconfig
> >>@@ -1200,6 +1200,7 @@ config MFD_TPS65217
> >> 	depends on I2C
> >> 	select MFD_CORE
> >> 	select REGMAP_I2C
> >>+	select IRQ_DOMAIN
> >> 	help
> >> 	  If you say yes here you get support for the TPS65217 series of
> >> 	  Power Management / White LED chips.
> >>diff --git a/drivers/mfd/tps65217.c b/drivers/mfd/tps65217.c
> >>index 049a6fc..d49f94e 100644
> >>--- a/drivers/mfd/tps65217.c
> >>+++ b/drivers/mfd/tps65217.c
> >>@@ -23,6 +23,9 @@
> >> #include <linux/i2c.h>
> >> #include <linux/slab.h>
> >> #include <linux/regmap.h>
> >>+#include <linux/interrupt.h>
> >>+#include <linux/irq.h>
> >>+#include <linux/irqdomain.h>
> >
> >Header includes should be alphabetical.
> >
> >Please take the opportunity to recorder them.
> 
> Ok, will do that.
> 
> >
> >> #include <linux/err.h>
> >> #include <linux/of.h>
> >> #include <linux/of_device.h>
> >>@@ -30,7 +33,81 @@
> >> #include <linux/mfd/core.h>
> >> #include <linux/mfd/tps65217.h>
> >>
> >>-static const struct mfd_cell tps65217s[] = {
> >>+static struct resource charger_resources[] = {
> >>+	DEFINE_RES_IRQ_NAMED(TPS65217_IRQ_AC, "AC"),
> >>+	DEFINE_RES_IRQ_NAMED(TPS65217_IRQ_USB, "USB"),
> >>+};
> >>+
> >>+struct tps65217_irq {
> >>+	int mask;
> >>+	int interrupt;
> >>+};
> >>+
> >>+static const struct tps65217_irq tps65217_irqs[] = {
> >
> >Not sure how this compiles, since you have this struct and the enums
> >in the header named the same.  Better to differentiate between them.
> 
> I think that in C these two names are in different namespaces. The name
> in the header is just a enum tag name, but tps65217_irqs object here is
> an ordinary identifier. Similarly we use "struct regmap *regmap;"
> declaration in other places in the kernel.
> I also tried to be consistent with other drivers: tps65218, tps65086,
> tps65912.

Yes, I think the 'static' helps you there.

> Please confirm if I should change these names.

It would save a little confusion.

> >>+	[TPS65217_IRQ_PB] = {
> >>+		.mask = TPS65217_INT_PBM,
> >>+		.interrupt = TPS65217_INT_PBI,
> >>+	},
> >>+	[TPS65217_IRQ_AC] = {
> >>+		.mask = TPS65217_INT_ACM,
> >>+		.interrupt = TPS65217_INT_ACI,
> >>+	},
> >>+	[TPS65217_IRQ_USB] = {
> >>+		.mask = TPS65217_INT_USBM,
> >>+		.interrupt = TPS65217_INT_USBI,
> >>+	},
> >>+};
> >>+
> >>+static void tps65217_irq_lock(struct irq_data *data)
> >>+{
> >>+	struct tps65217 *tps = irq_data_get_irq_chip_data(data);
> >>+
> >>+	mutex_lock(&tps->irq_lock);
> >>+}
> >>+
> >>+static void tps65217_irq_sync_unlock(struct irq_data *data)
> >>+{
> >>+	struct tps65217 *tps = irq_data_get_irq_chip_data(data);
> >>+	int ret;
> >>+
> >>+	ret = tps65217_reg_write(tps, TPS65217_REG_INT, tps->irq_mask,
> >>+				TPS65217_PROTECT_NONE);
> >>+	if (ret != 0)
> >>+		dev_err(tps->dev, "Failed to sync IRQ masks\n");
> >>+
> >>+	mutex_unlock(&tps->irq_lock);
> >>+}
> >>+
> >>+static const inline struct tps65217_irq *
> >>+irq_to_tps65217_irq(struct tps65217 *tps, struct irq_data *data)
> >>+{
> >>+	return &tps65217_irqs[data->hwirq];
> >>+}
> >>+
> >>+static void tps65217_irq_enable(struct irq_data *data)
> >>+{
> >>+	struct tps65217 *tps = irq_data_get_irq_chip_data(data);
> >>+	const struct tps65217_irq *irq_data = irq_to_tps65217_irq(tps, data);
> >>+
> >>+	tps->irq_mask &= ~irq_data->mask;
> >>+}
> >>+
> >>+static void tps65217_irq_disable(struct irq_data *data)
> >>+{
> >>+	struct tps65217 *tps = irq_data_get_irq_chip_data(data);
> >>+	const struct tps65217_irq *irq_data = irq_to_tps65217_irq(tps, data);
> >>+
> >>+	tps->irq_mask |= irq_data->mask;
> >>+}
> >
> >Nit: Swap this with enable, either here or in the struct below.
> 
> Sure
> 
> >
> >>+static struct irq_chip tps65217_irq_chip = {
> >>+	.irq_bus_lock		= tps65217_irq_lock,
> >>+	.irq_bus_sync_unlock	= tps65217_irq_sync_unlock,
> >>+	.irq_disable		= tps65217_irq_disable,
> >>+	.irq_enable		= tps65217_irq_enable,
> >>+};
> >>+
> >>+static struct mfd_cell tps65217s[] = {
> >> 	{
> >> 		.name = "tps65217-pmic",
> >> 		.of_compatible = "ti,tps65217-pmic",
> >>@@ -41,10 +118,89 @@ static const struct mfd_cell tps65217s[] = {
> >> 	},
> >> 	{
> >> 		.name = "tps65217-charger",
> >>+		.num_resources = ARRAY_SIZE(charger_resources),
> >>+		.resources = charger_resources,
> >> 		.of_compatible = "ti,tps65217-charger",
> >> 	},
> >> };
> >>
> >>+static irqreturn_t tps65217_irq_thread(int irq, void *data)
> >>+{
> >>+	struct tps65217 *tps = data;
> >>+	unsigned int status;
> >>+	bool handled = false;
> >>+	int i;
> >>+	int ret;
> >>+
> >>+	ret = tps65217_reg_read(tps, TPS65217_REG_INT, &status);
> >>+	if (ret < 0) {
> >>+		dev_err(tps->dev, "Failed to read IRQ status: %d\n",
> >>+			ret);
> >>+		return IRQ_NONE;
> >>+	}
> >>+
> >>+	for (i = 0; i < ARRAY_SIZE(tps65217_irqs); i++) {
> >>+		if (status & tps65217_irqs[i].interrupt) {
> >>+			handle_nested_irq(irq_find_mapping(tps->irq_domain, i));
> >>+			handled = true;
> >>+		}
> >>+	}
> >>+
> >>+	if (handled)
> >>+		return IRQ_HANDLED;
> >>+	else
> >>+		return IRQ_NONE;
> >
> >The else is kinda redundant here.
> >
> >... and I think it's possible to get a warning saying something about
> >coming to the end of a non-void function.
> 
> Will change that in new patch version.
> 
> >
> >>+}
> >>+
> >>+static int tps65217_irq_map(struct irq_domain *h, unsigned int virq,
> >>+			irq_hw_number_t hw)
> >>+{
> >>+	struct tps65217 *tps = h->host_data;
> >>+
> >>+	irq_set_chip_data(virq, tps);
> >>+	irq_set_chip_and_handler(virq, &tps65217_irq_chip, handle_edge_irq);
> >>+	irq_set_nested_thread(virq, 1);
> >>+	irq_set_noprobe(virq);
> >>+
> >>+	return 0;
> >>+}
> >>+
> >>+static const struct irq_domain_ops tps65217_irq_domain_ops = {
> >>+	.map = tps65217_irq_map,
> >>+};
> >>+
> >>+static int tps65217_irq_init(struct tps65217 *tps, int irq)
> >>+{
> >>+	int ret;
> >>+
> >>+	mutex_init(&tps->irq_lock);
> >>+
> >>+	/* Mask all interrupt sources */
> >>+	tps->irq_mask = (TPS65217_INT_RESERVEDM | TPS65217_INT_PBM
> >>+			| TPS65217_INT_ACM | TPS65217_INT_USBM);
> >>+	tps65217_reg_write(tps, TPS65217_REG_INT, tps->irq_mask,
> >>+			TPS65217_PROTECT_NONE);
> >>+
> >>+	tps->irq_domain = irq_domain_add_linear(tps->dev->of_node,
> >
> >I think it's suggested that you use *add_simple() these days.
> 
> In Documentation/IRQ-domain.txt they are both described.
> *add_simple() is under 'Legacy' section and "It is used when the
> driver cannot be immediately converted to use the linear mapping."

So that's how they're doing it now.  Very well.

> >>+		TPS65217_NUM_IRQ, &tps65217_irq_domain_ops, tps);
> >>+	if (!tps->irq_domain) {
> >>+		dev_err(tps->dev, "Could not create IRQ domain\n");
> >>+		return -ENOMEM;
> >>+	}
> >>+
> >>+	ret = devm_request_threaded_irq(tps->dev, irq, NULL,
> >>+					tps65217_irq_thread,
> >>+					IRQF_TRIGGER_RISING | IRQF_ONESHOT,
> >>+					"tps65217-irq", tps);
> >>+	if (ret) {
> >>+		dev_err(tps->dev, "Failed to request IRQ %d: %d\n",
> >>+			irq, ret);
> >>+		return ret;
> >>+	}
> >>+
> >>+	return 0;
> >>+}
> >>+
> >> /**
> >>  * tps65217_reg_read: Read a single tps65217 register.
> >>  *
> >>@@ -149,11 +305,22 @@ int tps65217_clear_bits(struct tps65217 *tps, unsigned int reg,
> >> }
> >> EXPORT_SYMBOL_GPL(tps65217_clear_bits);
> >>
> >>+static bool tps65217_volatile_reg(struct device *dev, unsigned int reg)
> >>+{
> >>+	switch (reg) {
> >>+	case TPS65217_REG_INT:
> >>+		return true;
> >>+	default:
> >>+		return false;
> >>+	}
> >>+}
> >>+
> >> static const struct regmap_config tps65217_regmap_config = {
> >> 	.reg_bits = 8,
> >> 	.val_bits = 8,
> >>
> >> 	.max_register = TPS65217_REG_MAX,
> >>+	.volatile_reg = tps65217_volatile_reg,
> >> };
> >>
> >> static const struct of_device_id tps65217_of_match[] = {
> >>@@ -205,8 +372,19 @@ static int tps65217_probe(struct i2c_client *client,
> >> 		return ret;
> >> 	}
> >>
> >>+	if (client->irq) {
> >>+		tps65217_irq_init(tps, client->irq);
> >>+	} else {
> >>+		int i;
> >>+
> >>+		/* Don't tell children about IRQ resources which won't fire */
> >>+		for (i = 0; i < ARRAY_SIZE(tps65217s); i++)
> >>+			tps65217s[i].num_resources = 0;
> >>+	}
> >>+
> >> 	ret = devm_mfd_add_devices(tps->dev, -1, tps65217s,
> >>-				   ARRAY_SIZE(tps65217s), NULL, 0, NULL);
> >>+				   ARRAY_SIZE(tps65217s), NULL, 0,
> >>+				   tps->irq_domain);
> >> 	if (ret < 0) {
> >> 		dev_err(tps->dev, "mfd_add_devices failed: %d\n", ret);
> >> 		return ret;
> >>diff --git a/include/linux/mfd/tps65217.h b/include/linux/mfd/tps65217.h
> >>index ac7fba4..f80a5d3 100644
> >>--- a/include/linux/mfd/tps65217.h
> >>+++ b/include/linux/mfd/tps65217.h
> >>@@ -73,6 +73,7 @@
> >> #define TPS65217_PPATH_AC_CURRENT_MASK	0x0C
> >> #define TPS65217_PPATH_USB_CURRENT_MASK	0x03
> >>
> >>+#define TPS65217_INT_RESERVEDM		BIT(7)
> >> #define TPS65217_INT_PBM		BIT(6)
> >> #define TPS65217_INT_ACM		BIT(5)
> >> #define TPS65217_INT_USBM		BIT(4)
> >>@@ -233,6 +234,13 @@ struct tps65217_bl_pdata {
> >> 	int dft_brightness;
> >> };
> >>
> >>+enum tps65217_irqs {
> >>+	TPS65217_IRQ_PB,
> >>+	TPS65217_IRQ_AC,
> >>+	TPS65217_IRQ_USB,
> >>+	TPS65217_NUM_IRQ
> >>+};
> >>+
> >> /**
> >>  * struct tps65217_board - packages regulator init data
> >>  * @tps65217_regulator_data: regulator initialization values
> >>@@ -257,6 +265,9 @@ struct tps65217 {
> >> 	unsigned long id;
> >> 	struct regulator_desc desc[TPS65217_NUM_REGULATOR];
> >> 	struct regmap *regmap;
> >>+	struct irq_domain *irq_domain;
> >>+	struct mutex irq_lock;
> >>+	u8 irq_mask;
> >> };
> >>
> >> static inline struct tps65217 *dev_to_tps65217(struct device *dev)
> >
> 

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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