[PATCH v3 05/10] spmi: pmic_arb: add support for interrupt handling

Josh Cartwright
2013-10-28T19:16:14Z

The Qualcomm PMIC Arbiter, in addition to being a basic SPMI controller,
also implements interrupt handling for slave devices. Note, this is
outside the scope of SPMI, as SPMI leaves interrupt handling completely
unspecified.

Extend the driver to provide a irq_chip implementation and chained irq
handling which allows for these interrupts to be used.

Signed-off-by: Josh Cartwright <joshc@codeaurora.org>
---
drivers/spmi/spmi-pmic-arb.c | 359 ++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 357 insertions(+), 2 deletions(-)

diff --git a/drivers/spmi/spmi-pmic-arb.c b/drivers/spmi/spmi-pmic-arb.c
index 92e1416..6926a6b 100644
--- a/drivers/spmi/spmi-pmic-arb.c
+++ b/drivers/spmi/spmi-pmic-arb.c
@@ -13,6 +13,9 @@
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/io.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqdomain.h>
+#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
@@ -108,12 +111,17 @@ struct spmi_pmic_arb_dev {
void __iomem *base;
void __iomem *intr;
void __iomem *cnfg;
+ unsigned int irq;
bool allow_wakeup;
spinlock_t lock;
u8 channel;
u8 min_apid;
u8 max_apid;
u32 mapping_table[SPMI_MAPPING_TABLE_LEN];
+ int bus_nr;
+ struct irq_domain *domain;
+ struct spmi_controller *spmic;
+ u16 apid_to_ppid[256];
};

static inline u32 pmic_arb_base_read(struct spmi_pmic_arb_dev *dev, u32 offset)
@@ -315,18 +323,340 @@ static int pmic_arb_write_cmd(struct spmi_controller *ctrl,
return rc;
}

+enum qpnpint_regs {
+ QPNPINT_REG_RT_STS = 0x10,
+ QPNPINT_REG_SET_TYPE = 0x11,
+ QPNPINT_REG_POLARITY_HIGH = 0x12,
+ QPNPINT_REG_POLARITY_LOW = 0x13,
+ QPNPINT_REG_LATCHED_CLR = 0x14,
+ QPNPINT_REG_EN_SET = 0x15,
+ QPNPINT_REG_EN_CLR = 0x16,
+ QPNPINT_REG_LATCHED_STS = 0x18,
+};
+
+struct spmi_pmic_arb_qpnpint_type {
+ u8 type; /* 1 -> edge */
+ u8 polarity_high;
+ u8 polarity_low;
+} __packed;
+
+/* Simplified accessor functions for irqchip callbacks */
+static void qpnpint_spmi_write(struct irq_data *d, u8 reg, void *buf,
+ size_t len)
+{
+ struct spmi_pmic_arb_dev *pa = irq_data_get_irq_chip_data(d);
+ u8 sid = d->hwirq >> 24;
+ u8 per = d->hwirq >> 16;
+
+ if (pmic_arb_write_cmd(pa->spmic, SPMI_CMD_EXT_WRITEL, sid,
+ (per << 8) + reg, len, buf))
+ dev_err_ratelimited(&pa->spmic->dev,
+ "failed irqchip transaction on %x\n",
+ d->irq);
+}
+
+static void qpnpint_spmi_read(struct irq_data *d, u8 reg, void *buf, size_t len)
+{
+ struct spmi_pmic_arb_dev *pa = irq_data_get_irq_chip_data(d);
+ u8 sid = d->hwirq >> 24;
+ u8 per = d->hwirq >> 16;
+
+ if (pmic_arb_read_cmd(pa->spmic, SPMI_CMD_EXT_READL, sid,
+ (per << 8) + reg, len, buf))
+ dev_err_ratelimited(&pa->spmic->dev,
+ "failed irqchip transaction on %x\n",
+ d->irq);
+}
+
+static void periph_interrupt(struct spmi_pmic_arb_dev *pa, u8 apid)
+{
+ unsigned int irq;
+ u32 status;
+ int id;
+
+ status = readl_relaxed(pa->intr + SPMI_PIC_IRQ_STATUS(apid));
+ while (status) {
+ id = ffs(status) - 1;
+ status &= ~(1 << id);
+ irq = irq_find_mapping(pa->domain,
+ pa->apid_to_ppid[apid] << 16
+ | id << 8
+ | apid);
+ generic_handle_irq(irq);
+ }
+}
+
+static void pmic_arb_chained_irq(unsigned int irq, struct irq_desc *desc)
+{
+ struct spmi_pmic_arb_dev *pa = irq_get_handler_data(irq);
+ struct irq_chip *chip = irq_get_chip(irq);
+ void __iomem *intr = pa->intr;
+ int first = pa->min_apid >> 5;
+ int last = pa->max_apid >> 5;
+ int i, id;
+ u8 ee = 0; /*pa->owner;*/
+ u32 status;
+
+ chained_irq_enter(chip, desc);
+
+ for (i = first; i <= last; ++i) {
+ status = readl_relaxed(intr + SPMI_PIC_OWNER_ACC_STATUS(ee, i));
+ while (status) {
+ id = ffs(status) - 1;
+ status &= ~(1 << id);
+ periph_interrupt(pa, id + i * 32);
+ }
+ }
+
+ chained_irq_exit(chip, desc);
+}
+
+static void qpnpint_irq_ack(struct irq_data *d)
+{
+ struct spmi_pmic_arb_dev *pa = irq_data_get_irq_chip_data(d);
+ u8 irq = d->hwirq >> 8;
+ u8 apid = d->hwirq;
+ unsigned long flags;
+ u8 data;
+
+ dev_dbg(&pa->spmic->dev, "hwirq %lu irq: %d\n", d->hwirq, d->irq);
+
+ spin_lock_irqsave(&pa->lock, flags);
+ writel_relaxed(1 << irq, pa->intr + SPMI_PIC_IRQ_CLEAR(apid));
+ spin_unlock_irqrestore(&pa->lock, flags);
+
+ data = 1 << irq;
+ qpnpint_spmi_write(d, QPNPINT_REG_LATCHED_CLR, &data, 1);
+}
+
+static void qpnpint_irq_mask(struct irq_data *d)
+{
+ struct spmi_pmic_arb_dev *pa = irq_data_get_irq_chip_data(d);
+ u8 irq = d->hwirq >> 8;
+ u8 apid = d->hwirq;
+ unsigned long flags;
+ u32 status;
+ u8 data;
+
+ dev_dbg(&pa->spmic->dev, "hwirq %lu irq: %d\n", d->hwirq, d->irq);
+
+ spin_lock_irqsave(&pa->lock, flags);
+ status = readl_relaxed(pa->intr + SPMI_PIC_ACC_ENABLE(apid));
+ if (status & SPMI_PIC_ACC_ENABLE_BIT) {
+ status = status & ~SPMI_PIC_ACC_ENABLE_BIT;
+ writel_relaxed(status, pa->intr + SPMI_PIC_ACC_ENABLE(apid));
+ }
+ spin_unlock_irqrestore(&pa->lock, flags);
+
+ data = 1 << irq;
+ qpnpint_spmi_write(d, QPNPINT_REG_EN_CLR, &data, 1);
+}
+
+static void qpnpint_irq_unmask(struct irq_data *d)
+{
+ struct spmi_pmic_arb_dev *pa = irq_data_get_irq_chip_data(d);
+ u8 irq = d->hwirq >> 8;
+ u8 apid = d->hwirq;
+ unsigned long flags;
+ u32 status;
+ u8 data;
+
+ dev_dbg(&pa->spmic->dev, "hwirq %lu irq: %d, apid = %02x\n", d->hwirq,
+ d->irq, apid);
+
+ spin_lock_irqsave(&pa->lock, flags);
+ status = readl_relaxed(pa->intr + SPMI_PIC_ACC_ENABLE(apid));
+ if (!(status & SPMI_PIC_ACC_ENABLE_BIT)) {
+ writel_relaxed(status | SPMI_PIC_ACC_ENABLE_BIT,
+ pa->intr + SPMI_PIC_ACC_ENABLE(apid));
+ }
+ spin_unlock_irqrestore(&pa->lock, flags);
+
+ data = 1 << irq;
+ qpnpint_spmi_write(d, QPNPINT_REG_EN_SET, &data, 1);
+}
+
+static void qpnpint_irq_enable(struct irq_data *d)
+{
+ struct spmi_pmic_arb_dev *pa = irq_data_get_irq_chip_data(d);
+ u8 irq = d->hwirq >> 8;
+ u8 data;
+
+ dev_dbg(&pa->spmic->dev, "hwirq %lu irq: %d\n", d->hwirq, d->irq);
+
+ qpnpint_irq_unmask(d);
+
+ data = 1 << irq;
+ qpnpint_spmi_write(d, QPNPINT_REG_LATCHED_CLR, &data, 1);
+}
+
+static int qpnpint_irq_set_type(struct irq_data *d, unsigned int flow_type)
+{
+ struct spmi_pmic_arb_dev *pa = irq_data_get_irq_chip_data(d);
+ struct spmi_pmic_arb_qpnpint_type type;
+ u8 irq = d->hwirq >> 8;
+
+ dev_dbg(&pa->spmic->dev, "qpnpint_irq_set_type %p, %x\n", d, flow_type);
+
+ qpnpint_spmi_read(d, QPNPINT_REG_SET_TYPE, &type, 3);
+
+ if (flow_type & (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING)) {
+ type.type |= 1 << irq;
+ if (flow_type & IRQF_TRIGGER_RISING)
+ type.polarity_high |= 1 << irq;
+ if (flow_type & IRQF_TRIGGER_FALLING)
+ type.polarity_low |= 1 << irq;
+ } else {
+ if ((flow_type & (IRQF_TRIGGER_HIGH)) &&
+ (flow_type & (IRQF_TRIGGER_LOW)))
+ return -EINVAL;
+
+ type.type &= ~(1 << irq); /* level trig */
+ if (flow_type & IRQF_TRIGGER_HIGH)
+ type.polarity_high |= 1 << irq;
+ else
+ type.polarity_low |= 1 << irq;
+ }
+
+ qpnpint_spmi_write(d, QPNPINT_REG_SET_TYPE, &type, 3);
+ return 0;
+}
+
+static struct irq_chip pmic_arb_irqchip = {
+ .name = "pmic_arb",
+ .irq_enable = qpnpint_irq_enable,
+ .irq_ack = qpnpint_irq_ack,
+ .irq_mask = qpnpint_irq_mask,
+ .irq_unmask = qpnpint_irq_unmask,
+ .irq_set_type = qpnpint_irq_set_type,
+ .flags = IRQCHIP_MASK_ON_SUSPEND
+ | IRQCHIP_SKIP_SET_WAKE,
+};
+
+struct spmi_pmic_arb_irq_spec {
+ unsigned slave:4;
+ unsigned per:8;
+ unsigned irq:3;
+};
+
+static int search_mapping_table(struct spmi_pmic_arb_dev *pa,
+ struct spmi_pmic_arb_irq_spec *spec,
+ u8 *apid)
+{
+ u16 ppid = spec->slave << 8 | spec->per;
+ u32 *mapping_table = pa->mapping_table;
+ int index = 0, i;
+ u32 data;
+
+ for (i = 0; i < SPMI_MAPPING_TABLE_TREE_DEPTH; ++i) {
+ data = mapping_table[index];
+
+ if (ppid & (1 << SPMI_MAPPING_BIT_INDEX(data))) {
+ if (SPMI_MAPPING_BIT_IS_1_FLAG(data)) {
+ index = SPMI_MAPPING_BIT_IS_1_RESULT(data);
+ } else {
+ *apid = SPMI_MAPPING_BIT_IS_1_RESULT(data);
+ return 0;
+ }
+ } else {
+ if (SPMI_MAPPING_BIT_IS_0_FLAG(data)) {
+ index = SPMI_MAPPING_BIT_IS_0_RESULT(data);
+ } else {
+ *apid = SPMI_MAPPING_BIT_IS_0_RESULT(data);
+ return 0;
+ }
+ }
+ }
+
+ return -ENODEV;
+}
+
+static int qpnpint_irq_domain_dt_translate(struct irq_domain *d,
+ struct device_node *controller,
+ const u32 *intspec,
+ unsigned int intsize,
+ unsigned long *out_hwirq,
+ unsigned int *out_type)
+{
+ struct spmi_pmic_arb_dev *pa = d->host_data;
+ struct spmi_pmic_arb_irq_spec spec;
+ int err;
+ u8 apid;
+
+ dev_dbg(&pa->spmic->dev,
+ "intspec[0] 0x%1x intspec[1] 0x%02x intspec[2] 0x%02x\n",
+ intspec[0], intspec[1], intspec[2]);
+
+ if (d->of_node != controller)
+ return -EINVAL;
+ if (intsize != 4)
+ return -EINVAL;
+ if (intspec[0] > 0xF || intspec[1] > 0xFF || intspec[2] > 0x7)
+ return -EINVAL;
+
+ spec.slave = intspec[0];
+ spec.per = intspec[1];
+ spec.irq = intspec[2];
+
+ err = search_mapping_table(pa, &spec, &apid);
+ if (err)
+ return err;
+
+ pa->apid_to_ppid[apid] = spec.slave << 8 | spec.per;
+
+ /* Keep track of {max,min}_apid for bounding search during interrupt */
+ if (apid > pa->max_apid)
+ pa->max_apid = apid;
+ if (apid < pa->min_apid)
+ pa->min_apid = apid;
+
+ *out_hwirq = spec.slave << 24
+ | spec.per << 16
+ | spec.irq << 8
+ | apid;
+ *out_type = intspec[3] & IRQ_TYPE_SENSE_MASK;
+
+ dev_dbg(&pa->spmic->dev, "out_hwirq = %lu\n", *out_hwirq);
+
+ return 0;
+}
+
+static int qpnpint_irq_domain_map(struct irq_domain *d,
+ unsigned int virq,
+ irq_hw_number_t hwirq)
+{
+ struct spmi_pmic_arb_dev *pa = d->host_data;
+
+ dev_dbg(&pa->spmic->dev, "virq = %u, hwirq = %lu\n", virq, hwirq);
+
+ irq_set_chip_and_handler(virq, &pmic_arb_irqchip, handle_level_irq);
+ irq_set_chip_data(virq, d->host_data);
+#ifdef CONFIG_ARM
+ set_irq_flags(virq, IRQF_VALID);
+#else
+ irq_set_noprobe(virq);
+#endif
+ return 0;
+}
+
+static const struct irq_domain_ops pmic_arb_irq_domain_ops = {
+ .map = qpnpint_irq_domain_map,
+ .xlate = qpnpint_irq_domain_dt_translate,
+};
+
static int spmi_pmic_arb_probe(struct platform_device *pdev)
{
struct spmi_pmic_arb_dev *pa;
struct spmi_controller *ctrl;
struct resource *res;
- int err, i;
+ int err = 0, i;

ctrl = spmi_controller_alloc(&pdev->dev, sizeof(*pa));
if (!ctrl)
return -ENOMEM;

pa = spmi_controller_get_drvdata(ctrl);
+ pa->spmic = ctrl;

res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "core");
pa->base = devm_ioremap_resource(&ctrl->dev, res);
@@ -349,6 +679,12 @@ static int spmi_pmic_arb_probe(struct platform_device *pdev)
goto err_put_ctrl;
}

+ pa->irq = platform_get_irq(pdev, 0);
+ if (pa->irq < 0) {
+ err = pa->irq;
+ goto err_put_ctrl;
+ }
+
for (i = 0; i < ARRAY_SIZE(pa->mapping_table); ++i)
pa->mapping_table[i] = readl_relaxed(
pa->cnfg + SPMI_MAPPING_TABLE_REG(i));
@@ -364,15 +700,30 @@ static int spmi_pmic_arb_probe(struct platform_device *pdev)
ctrl->read_cmd = pmic_arb_read_cmd;
ctrl->write_cmd = pmic_arb_write_cmd;

+ dev_dbg(&pdev->dev, "adding irq domain\n");
+ pa->domain = irq_domain_add_tree(pdev->dev.of_node,
+ &pmic_arb_irq_domain_ops, pa);
+ if (!pa->domain) {
+ dev_err(&pdev->dev, "unable to create irq_domain\n");
+ goto err_put_ctrl;
+ }
+
+ irq_set_handler_data(pa->irq, pa);
+ irq_set_chained_handler(pa->irq, pmic_arb_chained_irq);
+
err = spmi_controller_add(ctrl);
if (err)
- goto err_put_ctrl;
+ goto err_domain_remove;

dev_dbg(&ctrl->dev, "PMIC Arb Version 0x%x\n",
pmic_arb_base_read(pa, PMIC_ARB_VERSION));

return 0;

+err_domain_remove:
+ irq_set_chained_handler(pa->irq, NULL);
+ irq_set_handler_data(pa->irq, NULL);
+ irq_domain_remove(pa->domain);
err_put_ctrl:
spmi_controller_put(ctrl);
return err;
@@ -381,6 +732,10 @@ err_put_ctrl:
static int __exit spmi_pmic_arb_remove(struct platform_device *pdev)
{
struct spmi_controller *ctrl = platform_get_drvdata(pdev);
+ struct spmi_pmic_arb_dev *pa = spmi_controller_get_drvdata(ctrl);
+ irq_set_chained_handler(pa->irq, NULL);
+ irq_set_handler_data(pa->irq, NULL);
+ irq_domain_remove(pa->domain);
spmi_controller_remove(ctrl);
return 0;
}