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Subject[PATCH v6 4/6] spmi: pmic_arb: add support for interrupt handling
Date
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.

Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Josh Cartwright <joshc@codeaurora.org>
---
Thomas-

You've looked at this before[1], but I conservatively didn't turn your "Looks
sane otherwise" comment into full Ack. The only thing that has changed is now
a raw spinlock is used for locking.

Thanks,
Josh

[1]: http://marc.info/?l=linux-kernel&m=139154465617561&w=2

drivers/spmi/Kconfig | 1 +
drivers/spmi/spmi-pmic-arb.c | 377 ++++++++++++++++++++++++++++++++++++++++++-
2 files changed, 376 insertions(+), 2 deletions(-)

diff --git a/drivers/spmi/Kconfig b/drivers/spmi/Kconfig
index 80b7901..075bd79 100644
--- a/drivers/spmi/Kconfig
+++ b/drivers/spmi/Kconfig
@@ -13,6 +13,7 @@ if SPMI
config SPMI_MSM_PMIC_ARB
tristate "Qualcomm MSM SPMI Controller (PMIC Arbiter)"
depends on ARM
+ depends on IRQ_DOMAIN
depends on ARCH_MSM || COMPILE_TEST
default ARCH_MSM
help
diff --git a/drivers/spmi/spmi-pmic-arb.c b/drivers/spmi/spmi-pmic-arb.c
index 2dd27e8..246e03a 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>
@@ -103,6 +106,14 @@ enum pmic_arb_cmd_op_code {
* @cnfg: address of the PMIC Arbiter configuration registers.
* @lock: lock to synchronize accesses.
* @channel: which channel to use for accesses.
+ * @irq: PMIC ARB interrupt.
+ * @ee: the current Execution Environment
+ * @min_apid: minimum APID (used for bounding IRQ search)
+ * @max_apid: maximum APID
+ * @mapping_table: in-memory copy of PPID -> APID mapping table.
+ * @domain: irq domain object for PMIC IRQ domain
+ * @spmic: SPMI controller object
+ * @apid_to_ppid: cached mapping from APID to PPID
*/
struct spmi_pmic_arb_dev {
void __iomem *base;
@@ -110,6 +121,14 @@ struct spmi_pmic_arb_dev {
void __iomem *cnfg;
raw_spinlock_t lock;
u8 channel;
+ int irq;
+ u8 ee;
+ u8 min_apid;
+ u8 max_apid;
+ u32 mapping_table[SPMI_MAPPING_TABLE_LEN];
+ 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)
@@ -306,12 +325,316 @@ static int pmic_arb_write_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid,
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, buf, len))
+ 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, buf, len))
+ 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;
+ u32 status;
+ int i, id;
+
+ chained_irq_enter(chip, desc);
+
+ for (i = first; i <= last; ++i) {
+ status = readl_relaxed(intr +
+ SPMI_PIC_OWNER_ACC_STATUS(pa->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;
+
+ raw_spin_lock_irqsave(&pa->lock, flags);
+ writel_relaxed(1 << irq, pa->intr + SPMI_PIC_IRQ_CLEAR(apid));
+ raw_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;
+
+ raw_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));
+ }
+ raw_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;
+
+ raw_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));
+ }
+ raw_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)
+{
+ u8 irq = d->hwirq >> 8;
+ u8 data;
+
+ 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_qpnpint_type type;
+ u8 irq = d->hwirq >> 8;
+
+ qpnpint_spmi_read(d, QPNPINT_REG_SET_TYPE, &type, sizeof(type));
+
+ 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, sizeof(type));
+ 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);
+ irq_set_noprobe(virq);
+ 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;
- u32 channel;
+ u32 channel, ee;
int err, i;

ctrl = spmi_controller_alloc(&pdev->dev, sizeof(*pa));
@@ -319,6 +642,7 @@ static int spmi_pmic_arb_probe(struct platform_device *pdev)
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);
@@ -341,6 +665,12 @@ static int spmi_pmic_arb_probe(struct platform_device *pdev)
goto err_put_ctrl;
}

+ pa->irq = platform_get_irq_byname(pdev, "periph_irq");
+ if (pa->irq < 0) {
+ err = pa->irq;
+ goto err_put_ctrl;
+ }
+
err = of_property_read_u32(pdev->dev.of_node, "qcom,channel", &channel);
if (err) {
dev_err(&pdev->dev, "channel unspecified.\n");
@@ -355,6 +685,29 @@ static int spmi_pmic_arb_probe(struct platform_device *pdev)

pa->channel = channel;

+ err = of_property_read_u32(pdev->dev.of_node, "qcom,ee", &ee);
+ if (err) {
+ dev_err(&pdev->dev, "EE unspecified.\n");
+ goto err_put_ctrl;
+ }
+
+ if (ee > 5) {
+ dev_err(&pdev->dev, "invalid EE (%u) specified\n", ee);
+ err = -EINVAL;
+ goto err_put_ctrl;
+ }
+
+ pa->ee = ee;
+
+ for (i = 0; i < ARRAY_SIZE(pa->mapping_table); ++i)
+ pa->mapping_table[i] = readl_relaxed(
+ pa->cnfg + SPMI_MAPPING_TABLE_REG(i));
+
+ /* Initialize max_apid/min_apid to the opposite bounds, during
+ * the irq domain translation, we are sure to update these */
+ pa->max_apid = 0;
+ pa->min_apid = PMIC_ARB_MAX_PERIPHS - 1;
+
platform_set_drvdata(pdev, ctrl);
raw_spin_lock_init(&pa->lock);

@@ -362,15 +715,31 @@ 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");
+ err = -ENOMEM;
+ 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;
@@ -379,7 +748,11 @@ err_put_ctrl:
static int 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);
spmi_controller_remove(ctrl);
+ irq_set_chained_handler(pa->irq, NULL);
+ irq_set_handler_data(pa->irq, NULL);
+ irq_domain_remove(pa->domain);
spmi_controller_put(ctrl);
return 0;
}
--
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