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From 61f87edd9a522d70d979f679d11849d1dc20cedb Mon Sep 17 00:00:00 2001
From: Phil Elwell <phil@raspberrypi.org>
Date: Thu, 23 Mar 2017 16:34:46 +0000
Subject: [PATCH 108/454] bcm2835-aux: Add aux interrupt controller
The AUX block has a shared interrupt line with a register indicating
which devices have active IRQs. Expose this as a nested interrupt
controller to avoid sharing problems.
See: https://github.com/raspberrypi/linux/issues/1484
https://github.com/raspberrypi/linux/issues/1573
Signed-off-by: Phil Elwell <phil@raspberrypi.org>
---
drivers/clk/bcm/clk-bcm2835-aux.c | 120 ++++++++++++++++++++++++++++++
1 file changed, 120 insertions(+)
--- a/drivers/clk/bcm/clk-bcm2835-aux.c
+++ b/drivers/clk/bcm/clk-bcm2835-aux.c
@@ -17,17 +17,107 @@
#include <linux/clk/bcm2835.h>
#include <linux/module.h>
#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/irqdomain.h>
+#include <linux/of_irq.h>
#include <dt-bindings/clock/bcm2835-aux.h>
#define BCM2835_AUXIRQ 0x00
#define BCM2835_AUXENB 0x04
+#define BCM2835_AUXIRQ_NUM_IRQS 3
+
+#define BCM2835_AUXIRQ_UART_IRQ 0
+#define BCM2835_AUXIRQ_SPI1_IRQ 1
+#define BCM2835_AUXIRQ_SPI2_IRQ 2
+
+#define BCM2835_AUXIRQ_UART_MASK 0x01
+#define BCM2835_AUXIRQ_SPI1_MASK 0x02
+#define BCM2835_AUXIRQ_SPI2_MASK 0x04
+
+#define BCM2835_AUXIRQ_ALL_MASK \
+ (BCM2835_AUXIRQ_UART_MASK | \
+ BCM2835_AUXIRQ_SPI1_MASK | \
+ BCM2835_AUXIRQ_SPI2_MASK)
+
+struct auxirq_state {
+ void __iomem *status;
+ u32 enables;
+ struct irq_domain *domain;
+ struct regmap *local_regmap;
+};
+
+static struct auxirq_state auxirq __read_mostly;
+
+static irqreturn_t bcm2835_auxirq_handler(int irq, void *dev_id)
+{
+ u32 stat = readl_relaxed(auxirq.status);
+ u32 masked = stat & auxirq.enables;
+
+ if (masked & BCM2835_AUXIRQ_UART_MASK)
+ generic_handle_irq(irq_linear_revmap(auxirq.domain,
+ BCM2835_AUXIRQ_UART_IRQ));
+
+ if (masked & BCM2835_AUXIRQ_SPI1_MASK)
+ generic_handle_irq(irq_linear_revmap(auxirq.domain,
+ BCM2835_AUXIRQ_SPI1_IRQ));
+
+ if (masked & BCM2835_AUXIRQ_SPI2_MASK)
+ generic_handle_irq(irq_linear_revmap(auxirq.domain,
+ BCM2835_AUXIRQ_SPI2_IRQ));
+
+ return (masked & BCM2835_AUXIRQ_ALL_MASK) ? IRQ_HANDLED : IRQ_NONE;
+}
+
+static int bcm2835_auxirq_xlate(struct irq_domain *d,
+ struct device_node *ctrlr,
+ const u32 *intspec, unsigned int intsize,
+ unsigned long *out_hwirq,
+ unsigned int *out_type)
+{
+ if (WARN_ON(intsize != 1))
+ return -EINVAL;
+
+ if (WARN_ON(intspec[0] >= BCM2835_AUXIRQ_NUM_IRQS))
+ return -EINVAL;
+
+ *out_hwirq = intspec[0];
+ *out_type = IRQ_TYPE_NONE;
+ return 0;
+}
+
+static void bcm2835_auxirq_mask(struct irq_data *data)
+{
+ irq_hw_number_t hwirq = irqd_to_hwirq(data);
+
+ auxirq.enables &= ~(1 << hwirq);
+}
+
+static void bcm2835_auxirq_unmask(struct irq_data *data)
+{
+ irq_hw_number_t hwirq = irqd_to_hwirq(data);
+
+ auxirq.enables |= (1 << hwirq);
+}
+
+static struct irq_chip bcm2835_auxirq_chip = {
+ .name = "bcm2835-auxirq",
+ .irq_mask = bcm2835_auxirq_mask,
+ .irq_unmask = bcm2835_auxirq_unmask,
+};
+
+static const struct irq_domain_ops bcm2835_auxirq_ops = {
+ .xlate = bcm2835_auxirq_xlate//irq_domain_xlate_onecell
+};
+
static int bcm2835_aux_clk_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
+ struct device_node *node = dev->of_node;
struct clk_hw_onecell_data *onecell;
const char *parent;
struct clk *parent_clk;
+ int parent_irq;
struct resource *res;
void __iomem *reg, *gate;
@@ -41,6 +131,36 @@ static int bcm2835_aux_clk_probe(struct
if (IS_ERR(reg))
return PTR_ERR(reg);
+ parent_irq = irq_of_parse_and_map(node, 0);
+ if (parent_irq) {
+ int ret;
+ int i;
+
+ /* Manage the AUX irq as well */
+ auxirq.status = reg + BCM2835_AUXIRQ;
+ auxirq.domain = irq_domain_add_linear(node,
+ BCM2835_AUXIRQ_NUM_IRQS,
+ &bcm2835_auxirq_ops,
+ NULL);
+ if (!auxirq.domain)
+ return -ENXIO;
+
+ for (i = 0; i < BCM2835_AUXIRQ_NUM_IRQS; i++) {
+ unsigned int irq = irq_create_mapping(auxirq.domain, i);
+
+ if (irq == 0)
+ return -ENXIO;
+
+ irq_set_chip_and_handler(irq, &bcm2835_auxirq_chip,
+ handle_level_irq);
+ }
+
+ ret = devm_request_irq(dev, parent_irq, bcm2835_auxirq_handler,
+ 0, "bcm2835-auxirq", NULL);
+ if (ret)
+ return ret;
+ }
+
onecell = devm_kmalloc(dev, sizeof(*onecell) + sizeof(*onecell->hws) *
BCM2835_AUX_CLOCK_COUNT, GFP_KERNEL);
if (!onecell)
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