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Subject[PATCH] irqchip: stm32: use a platform driver for stm32mp1-exti device
Date
This irqchip driver uses the hwspinlock framework (coprocessor HW regs
access concurrency) for the stm32mp1-exti device.
Hence, this driver needs to handle the hwspinlock driver dependency
using the deferred probe mechanism which requires to move this driver
into a platform one with a probe() ops.
This applies only for the device which is "st,stm32mp1-exti" compatible,
the management of the other devices (st,stm32h7-exti / st,stm32-exti) is
kept unchanged (use IRQCHIP_DECLARE)

Signed-off-by: Fabien Dessenne <fabien.dessenne@st.com>
---
drivers/irqchip/irq-stm32-exti.c | 233 +++++++++++++++++++++++----------------
1 file changed, 140 insertions(+), 93 deletions(-)

diff --git a/drivers/irqchip/irq-stm32-exti.c b/drivers/irqchip/irq-stm32-exti.c
index 6b19bff..528be78 100644
--- a/drivers/irqchip/irq-stm32-exti.c
+++ b/drivers/irqchip/irq-stm32-exti.c
@@ -14,8 +14,10 @@
#include <linux/irqchip.h>
#include <linux/irqchip/chained_irq.h>
#include <linux/irqdomain.h>
+#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
+#include <linux/of_platform.h>
#include <linux/syscore_ops.h>

#include <dt-bindings/interrupt-controller/arm-gic.h>
@@ -37,12 +39,6 @@ struct stm32_exti_bank {

#define UNDEF_REG ~0

-enum stm32_exti_hwspinlock {
- HWSPINLOCK_UNKNOWN,
- HWSPINLOCK_NONE,
- HWSPINLOCK_READY,
-};
-
struct stm32_desc_irq {
u32 exti;
u32 irq_parent;
@@ -69,8 +65,6 @@ struct stm32_exti_host_data {
void __iomem *base;
struct stm32_exti_chip_data *chips_data;
const struct stm32_exti_drv_data *drv_data;
- struct device_node *node;
- enum stm32_exti_hwspinlock hwlock_state;
struct hwspinlock *hwlock;
};

@@ -285,49 +279,27 @@ static int stm32_exti_set_type(struct irq_data *d,

static int stm32_exti_hwspin_lock(struct stm32_exti_chip_data *chip_data)
{
- struct stm32_exti_host_data *host_data = chip_data->host_data;
- struct hwspinlock *hwlock;
- int id, ret = 0, timeout = 0;
-
- /* first time, check for hwspinlock availability */
- if (unlikely(host_data->hwlock_state == HWSPINLOCK_UNKNOWN)) {
- id = of_hwspin_lock_get_id(host_data->node, 0);
- if (id >= 0) {
- hwlock = hwspin_lock_request_specific(id);
- if (hwlock) {
- /* found valid hwspinlock */
- host_data->hwlock_state = HWSPINLOCK_READY;
- host_data->hwlock = hwlock;
- pr_debug("%s hwspinlock = %d\n", __func__, id);
- } else {
- host_data->hwlock_state = HWSPINLOCK_NONE;
- }
- } else if (id != -EPROBE_DEFER) {
- host_data->hwlock_state = HWSPINLOCK_NONE;
- } else {
- /* hwspinlock driver shall be ready at that stage */
- ret = -EPROBE_DEFER;
- }
- }
+ int ret, timeout = 0;

- if (likely(host_data->hwlock_state == HWSPINLOCK_READY)) {
- /*
- * Use the x_raw API since we are under spin_lock protection.
- * Do not use the x_timeout API because we are under irq_disable
- * mode (see __setup_irq())
- */
- do {
- ret = hwspin_trylock_raw(host_data->hwlock);
- if (!ret)
- return 0;
-
- udelay(HWSPNLCK_RETRY_DELAY);
- timeout += HWSPNLCK_RETRY_DELAY;
- } while (timeout < HWSPNLCK_TIMEOUT);
-
- if (ret == -EBUSY)
- ret = -ETIMEDOUT;
- }
+ if (!chip_data->host_data->hwlock)
+ return 0;
+
+ /*
+ * Use the x_raw API since we are under spin_lock protection.
+ * Do not use the x_timeout API because we are under irq_disable
+ * mode (see __setup_irq())
+ */
+ do {
+ ret = hwspin_trylock_raw(chip_data->host_data->hwlock);
+ if (!ret)
+ return 0;
+
+ udelay(HWSPNLCK_RETRY_DELAY);
+ timeout += HWSPNLCK_RETRY_DELAY;
+ } while (timeout < HWSPNLCK_TIMEOUT);
+
+ if (ret == -EBUSY)
+ ret = -ETIMEDOUT;

if (ret)
pr_err("%s can't get hwspinlock (%d)\n", __func__, ret);
@@ -337,7 +309,7 @@ static int stm32_exti_hwspin_lock(struct stm32_exti_chip_data *chip_data)

static void stm32_exti_hwspin_unlock(struct stm32_exti_chip_data *chip_data)
{
- if (likely(chip_data->host_data->hwlock_state == HWSPINLOCK_READY))
+ if (chip_data->host_data->hwlock)
hwspin_unlock_raw(chip_data->host_data->hwlock);
}

@@ -586,8 +558,7 @@ static int stm32_exti_h_set_affinity(struct irq_data *d,
return -EINVAL;
}

-#ifdef CONFIG_PM
-static int stm32_exti_h_suspend(void)
+static int __maybe_unused stm32_exti_h_suspend(void)
{
struct stm32_exti_chip_data *chip_data;
int i;
@@ -602,7 +573,7 @@ static int stm32_exti_h_suspend(void)
return 0;
}

-static void stm32_exti_h_resume(void)
+static void __maybe_unused stm32_exti_h_resume(void)
{
struct stm32_exti_chip_data *chip_data;
int i;
@@ -616,17 +587,22 @@ static void stm32_exti_h_resume(void)
}

static struct syscore_ops stm32_exti_h_syscore_ops = {
+#ifdef CONFIG_PM_SLEEP
.suspend = stm32_exti_h_suspend,
.resume = stm32_exti_h_resume,
+#endif
};

-static void stm32_exti_h_syscore_init(void)
+static void stm32_exti_h_syscore_init(struct stm32_exti_host_data *host_data)
{
+ stm32_host_data = host_data;
register_syscore_ops(&stm32_exti_h_syscore_ops);
}
-#else
-static inline void stm32_exti_h_syscore_init(void) {}
-#endif
+
+static void stm32_exti_h_syscore_deinit(void)
+{
+ unregister_syscore_ops(&stm32_exti_h_syscore_ops);
+}

static struct irq_chip stm32_exti_h_chip = {
.name = "stm32-exti-h",
@@ -683,8 +659,6 @@ stm32_exti_host_data *stm32_exti_host_init(const struct stm32_exti_drv_data *dd,
return NULL;

host_data->drv_data = dd;
- host_data->node = node;
- host_data->hwlock_state = HWSPINLOCK_UNKNOWN;
host_data->chips_data = kcalloc(dd->bank_nr,
sizeof(struct stm32_exti_chip_data),
GFP_KERNEL);
@@ -711,7 +685,8 @@ stm32_exti_host_data *stm32_exti_host_init(const struct stm32_exti_drv_data *dd,

static struct
stm32_exti_chip_data *stm32_exti_chip_init(struct stm32_exti_host_data *h_data,
- u32 bank_idx)
+ u32 bank_idx,
+ struct device_node *node)
{
const struct stm32_exti_bank *stm32_bank;
struct stm32_exti_chip_data *chip_data;
@@ -731,7 +706,7 @@ stm32_exti_chip_data *stm32_exti_chip_init(struct stm32_exti_host_data *h_data,
writel_relaxed(0, base + stm32_bank->imr_ofst);
writel_relaxed(0, base + stm32_bank->emr_ofst);

- pr_info("%pOF: bank%d\n", h_data->node, bank_idx);
+ pr_info("%pOF: bank%d\n", node, bank_idx);

return chip_data;
}
@@ -771,7 +746,7 @@ static int __init stm32_exti_init(const struct stm32_exti_drv_data *drv_data,
struct stm32_exti_chip_data *chip_data;

stm32_bank = drv_data->exti_banks[i];
- chip_data = stm32_exti_chip_init(host_data, i);
+ chip_data = stm32_exti_chip_init(host_data, i, node);

gc = irq_get_domain_generic_chip(domain, i * IRQS_PER_BANK);

@@ -814,50 +789,130 @@ static const struct irq_domain_ops stm32_exti_h_domain_ops = {
.free = irq_domain_free_irqs_common,
};

-static int
-__init stm32_exti_hierarchy_init(const struct stm32_exti_drv_data *drv_data,
- struct device_node *node,
- struct device_node *parent)
+static void stm32_exti_remove_irq(void *data)
+{
+ struct irq_domain *domain = data;
+
+ irq_domain_remove(domain);
+}
+
+static int stm32_exti_remove(struct platform_device *pdev)
+{
+ stm32_exti_h_syscore_deinit();
+ return 0;
+}
+
+static int stm32_exti_probe(struct platform_device *pdev)
{
+ int ret, i;
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
struct irq_domain *parent_domain, *domain;
struct stm32_exti_host_data *host_data;
- int ret, i;
+ const struct stm32_exti_drv_data *drv_data;
+ struct resource *res;

- parent_domain = irq_find_host(parent);
- if (!parent_domain) {
- pr_err("interrupt-parent not found\n");
- return -EINVAL;
+ host_data = devm_kzalloc(dev, sizeof(*host_data), GFP_KERNEL);
+ if (!host_data)
+ return -ENOMEM;
+
+ /* check for optional hwspinlock which may be not available yet */
+ ret = of_hwspin_lock_get_id(np, 0);
+ if (ret == -EPROBE_DEFER)
+ /* hwspinlock framework not yet ready */
+ return ret;
+
+ if (ret >= 0) {
+ host_data->hwlock = devm_hwspin_lock_request_specific(dev, ret);
+ if (!host_data->hwlock) {
+ dev_err(dev, "Failed to request hwspinlock\n");
+ return -EINVAL;
+ }
+ } else if (ret != -ENOENT) {
+ /* note: ENOENT is a valid case (means 'no hwspinlock') */
+ dev_err(dev, "Failed to get hwspinlock\n");
+ return ret;
}

- host_data = stm32_exti_host_init(drv_data, node);
- if (!host_data)
+ /* initialize host_data */
+ drv_data = of_device_get_match_data(dev);
+ if (!drv_data) {
+ dev_err(dev, "no of match data\n");
+ return -ENODEV;
+ }
+ host_data->drv_data = drv_data;
+
+ host_data->chips_data = devm_kcalloc(dev, drv_data->bank_nr,
+ sizeof(*host_data->chips_data),
+ GFP_KERNEL);
+ if (!host_data->chips_data)
return -ENOMEM;

+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ host_data->base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(host_data->base)) {
+ dev_err(dev, "Unable to map registers\n");
+ return PTR_ERR(host_data->base);
+ }
+
for (i = 0; i < drv_data->bank_nr; i++)
- stm32_exti_chip_init(host_data, i);
+ stm32_exti_chip_init(host_data, i, np);
+
+ parent_domain = irq_find_host(of_irq_find_parent(np));
+ if (!parent_domain) {
+ dev_err(dev, "GIC interrupt-parent not found\n");
+ return -EINVAL;
+ }

domain = irq_domain_add_hierarchy(parent_domain, 0,
drv_data->bank_nr * IRQS_PER_BANK,
- node, &stm32_exti_h_domain_ops,
+ np, &stm32_exti_h_domain_ops,
host_data);

if (!domain) {
- pr_err("%pOFn: Could not register exti domain.\n", node);
- ret = -ENOMEM;
- goto out_unmap;
+ dev_err(dev, "Could not register exti domain\n");
+ return -ENOMEM;
}

- stm32_exti_h_syscore_init();
+ ret = devm_add_action_or_reset(dev, stm32_exti_remove_irq, domain);
+ if (ret)
+ return ret;
+
+ stm32_exti_h_syscore_init(host_data);

return 0;
+}

-out_unmap:
- iounmap(host_data->base);
- kfree(host_data->chips_data);
- kfree(host_data);
- return ret;
+/* platform driver only for MP1 */
+static const struct of_device_id stm32_exti_ids[] = {
+ { .compatible = "st,stm32mp1-exti", .data = &stm32mp1_drv_data},
+ {},
+};
+MODULE_DEVICE_TABLE(of, stm32_exti_ids);
+
+static struct platform_driver stm32_exti_driver = {
+ .probe = stm32_exti_probe,
+ .remove = stm32_exti_remove,
+ .driver = {
+ .name = "stm32_exti",
+ .of_match_table = stm32_exti_ids,
+ },
+};
+
+static int __init stm32_exti_arch_init(void)
+{
+ return platform_driver_register(&stm32_exti_driver);
}

+static void __exit stm32_exti_arch_exit(void)
+{
+ return platform_driver_unregister(&stm32_exti_driver);
+}
+
+arch_initcall(stm32_exti_arch_init);
+module_exit(stm32_exti_arch_exit);
+
+/* no platform driver for F4 and H7 */
static int __init stm32f4_exti_of_init(struct device_node *np,
struct device_node *parent)
{
@@ -873,11 +928,3 @@ static int __init stm32h7_exti_of_init(struct device_node *np,
}

IRQCHIP_DECLARE(stm32h7_exti, "st,stm32h7-exti", stm32h7_exti_of_init);
-
-static int __init stm32mp1_exti_of_init(struct device_node *np,
- struct device_node *parent)
-{
- return stm32_exti_hierarchy_init(&stm32mp1_drv_data, np, parent);
-}
-
-IRQCHIP_DECLARE(stm32mp1_exti, "st,stm32mp1-exti", stm32mp1_exti_of_init);
--
2.7.4
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