[PATCHv7 20/24] i2c: omap: switch to threaded IRQ support
From: Shubhrajyoti D <hidden>
Date: 2012-08-16 14:03:51
Also in:
linux-i2c, linux-omap
Subsystem:
i2c subsystem, i2c subsystem host drivers, omap i2c driver, omap1 support, omap2+ support, the rest · Maintainers:
Andi Shyti, Vignesh R, Aaro Koskinen, Janusz Krzysztofik, Andreas Kemnade, Kevin Hilman, Roger Quadros, Tony Lindgren, Linus Torvalds
From: Felipe Balbi <redacted> for OMAP2, we can easily switch over to threaded IRQs on the I2C driver. This will allow us to spend less time in hardirq context. Signed-off-by: Felipe Balbi <redacted> [Trivial formating changes] Signed-off-by: Shubhrajyoti D <redacted> --- drivers/i2c/busses/i2c-omap.c | 43 +++++++++++++++++++++++++++++++++++----- 1 files changed, 37 insertions(+), 6 deletions(-)
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index f5eafb7..39e5d36 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c@@ -176,6 +176,7 @@ enum { #define I2C_OMAP_ERRATA_I462 (1 << 1) struct omap_i2c_dev { + spinlock_t lock; /* IRQ synchronization */ struct device *dev; void __iomem *base; /* virtual */ int irq;
@@ -854,9 +855,30 @@ static int omap_i2c_transmit_data(struct omap_i2c_dev *dev, u8 num_bytes, } static irqreturn_t -omap_i2c_isr(int this_irq, void *dev_id) +omap_i2c_isr(int irq, void *dev_id) { struct omap_i2c_dev *dev = dev_id; + irqreturn_t ret = IRQ_HANDLED; + u16 mask; + u16 stat; + + spin_lock(&dev->lock); + mask = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG); + stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG); + + if (stat & mask) + ret = IRQ_WAKE_THREAD; + + spin_unlock(&dev->lock); + + return ret; +} + +static irqreturn_t +omap_i2c_isr_thread(int this_irq, void *dev_id) +{ + struct omap_i2c_dev *dev = dev_id; + unsigned long flags; u16 bits; u16 stat; int err = 0, count = 0;
@@ -864,6 +886,7 @@ omap_i2c_isr(int this_irq, void *dev_id) if (pm_runtime_suspended(dev->dev)) return IRQ_HANDLED; + spin_lock_irqsave(&dev->lock, flags); do { bits = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG); stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
@@ -877,6 +900,7 @@ omap_i2c_isr(int this_irq, void *dev_id) if (!stat) { /* my work here is done */ + spin_unlock_irqrestore(&dev->lock, flags); return IRQ_HANDLED; }
@@ -985,6 +1009,8 @@ omap_i2c_isr(int this_irq, void *dev_id) out: omap_i2c_complete_cmd(dev, err); + spin_unlock_irqrestore(&dev->lock, flags); + return IRQ_HANDLED; }
@@ -1028,7 +1054,6 @@ omap_i2c_probe(struct platform_device *pdev) struct omap_i2c_bus_platform_data *pdata = pdev->dev.platform_data; struct device_node *node = pdev->dev.of_node; const struct of_device_id *match; - irq_handler_t isr; int irq; int r;
@@ -1078,6 +1103,8 @@ omap_i2c_probe(struct platform_device *pdev) dev->dev = &pdev->dev; dev->irq = irq; + spin_lock_init(&dev->lock); + platform_set_drvdata(pdev, dev); init_completion(&dev->cmd_complete);
@@ -1130,10 +1157,14 @@ omap_i2c_probe(struct platform_device *pdev) /* reset ASAP, clearing any IRQs */ omap_i2c_init(dev); - isr = (dev->rev < OMAP_I2C_OMAP1_REV_2) ? omap_i2c_omap1_isr : - omap_i2c_isr; - r = devm_request_irq(&pdev->dev, dev->irq, isr, IRQF_NO_SUSPEND, - pdev->name, dev); + if (dev->rev < OMAP_I2C_OMAP1_REV_2) + r = devm_request_irq(&pdev->dev, dev->irq, omap_i2c_omap1_isr, + IRQF_NO_SUSPEND, pdev->name, dev); + else + r = devm_request_threaded_irq(&pdev->dev, dev->irq, + omap_i2c_isr, omap_i2c_isr_thread, + IRQF_NO_SUSPEND | IRQF_ONESHOT, + pdev->name, dev); if (r) { dev_err(dev->dev, "failure requesting irq %i\n", dev->irq);
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1.7.5.4