| Message ID | 1558354817-12034-4-git-send-email-sagar.kadam@sifive.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Extend dt bindings to support I2C on sifive devices and a fix broken IRQ in polling mode. | expand |
> @@ -406,7 +416,7 @@ static int ocores_xfer(struct i2c_adapter *adap, > { > struct ocores_i2c *i2c = i2c_get_adapdata(adap); > > - if (i2c->flags & OCORES_FLAG_POLL) > + if ((i2c->flags & (OCORES_FLAG_POLL | OCORES_FLAG_BROKEN_IRQ))) > return ocores_xfer_polling(adap, msgs, num); > return ocores_xfer_core(i2c, msgs, num, false); > } You are not listening to what i said. All you need to know here is that you must poll. It does not matter if the IRQ is broken or not. > irq = platform_get_irq(pdev, 0); > if (irq == -ENXIO) { > - i2c->flags |= OCORES_FLAG_POLL; If there is no interrupt, you need to poll. So keep this line. > + /* > + * Set a OCORES_FLAG_BROKEN_IRQ to enable workaround for > + * FU540-C000 SoC in polling mode interface of i2c-ocore driver. > + * Else enable default polling mode interface for SIFIVE/OCORE > + * device types. > + */ > + match = of_match_node(ocores_i2c_match, pdev->dev.of_node); > + if (match && (long)match->data == TYPE_SIFIVE_REV0) > + i2c->flags |= OCORES_FLAG_BROKEN_IRQ; If it is a OCORE, IRQ is broken, so OR in OCORES_FLAG_BROKEN_IRQ. > > - if (!(i2c->flags & OCORES_FLAG_POLL)) { > + if (!(i2c->flags & (OCORES_FLAG_POLL | OCORES_FLAG_BROKEN_IRQ))) { > ret = devm_request_irq(&pdev->dev, irq, ocores_isr, 0, > pdev->name, i2c); Here you just need to know if you are polling. Broken IRQ does not matter. Andrew
Hi Andrew, On Mon, May 20, 2019 at 6:11 PM Andrew Lunn <andrew@lunn.ch> wrote: > > > @@ -406,7 +416,7 @@ static int ocores_xfer(struct i2c_adapter *adap, > > { > > struct ocores_i2c *i2c = i2c_get_adapdata(adap); > > > > - if (i2c->flags & OCORES_FLAG_POLL) > > + if ((i2c->flags & (OCORES_FLAG_POLL | OCORES_FLAG_BROKEN_IRQ))) > > return ocores_xfer_polling(adap, msgs, num); > > return ocores_xfer_core(i2c, msgs, num, false); > > } > > You are not listening to what i said. All you need to know here is > that you must poll. It does not matter if the IRQ is broken or not. > Apologies for my miss-understanding. I will rectify this and submit a v5. > > irq = platform_get_irq(pdev, 0); > > if (irq == -ENXIO) { > > - i2c->flags |= OCORES_FLAG_POLL; > > If there is no interrupt, you need to poll. So keep this line. Will retain this. > > + /* > > + * Set a OCORES_FLAG_BROKEN_IRQ to enable workaround for > > + * FU540-C000 SoC in polling mode interface of i2c-ocore driver. > > + * Else enable default polling mode interface for SIFIVE/OCORE > > + * device types. > > + */ > > + match = of_match_node(ocores_i2c_match, pdev->dev.of_node); > > + if (match && (long)match->data == TYPE_SIFIVE_REV0) > > + i2c->flags |= OCORES_FLAG_BROKEN_IRQ; > > If it is a OCORE, IRQ is broken, so OR in OCORES_FLAG_BROKEN_IRQ. Got it, as device type SIFIVE is based on OCORE's re-implementation, will OR in the broken IRQ flag and submit a v5. > > > > - if (!(i2c->flags & OCORES_FLAG_POLL)) { > > + if (!(i2c->flags & (OCORES_FLAG_POLL | OCORES_FLAG_BROKEN_IRQ))) { > > ret = devm_request_irq(&pdev->dev, irq, ocores_isr, 0, > > pdev->name, i2c); > > Here you just need to know if you are polling. Broken IRQ does not > matter. > > Andrew Thanks & Regards, Sagar
diff --git a/drivers/i2c/busses/i2c-ocores.c b/drivers/i2c/busses/i2c-ocores.c index aee1d86..e0d7f24 100644 --- a/drivers/i2c/busses/i2c-ocores.c +++ b/drivers/i2c/busses/i2c-ocores.c @@ -27,6 +27,7 @@ #include <linux/jiffies.h> #define OCORES_FLAG_POLL BIT(0) +#define OCORES_FLAG_BROKEN_IRQ BIT(1) /* Broken IRQ for FU540-C000 SoC */ /* * 'process_lock' exists because ocores_process() and ocores_process_timeout() @@ -239,9 +240,13 @@ static irqreturn_t ocores_isr(int irq, void *dev_id) struct ocores_i2c *i2c = dev_id; u8 stat = oc_getreg(i2c, OCI2C_STATUS); - if (!(stat & OCI2C_STAT_IF)) + if (i2c->flags & OCORES_FLAG_BROKEN_IRQ) { + if (stat & OCI2C_STAT_IF) + if (!(stat & OCI2C_STAT_BUSY)) + return IRQ_NONE; + } else if (!(stat & OCI2C_STAT_IF)) { return IRQ_NONE; - + } ocores_process(i2c, stat); return IRQ_HANDLED; @@ -356,6 +361,11 @@ static void ocores_process_polling(struct ocores_i2c *i2c) ret = ocores_isr(-1, i2c); if (ret == IRQ_NONE) break; /* all messages have been transferred */ + else { + if (i2c->flags & OCORES_FLAG_BROKEN_IRQ) + if (i2c->state == STATE_DONE) + break; + } } } @@ -406,7 +416,7 @@ static int ocores_xfer(struct i2c_adapter *adap, { struct ocores_i2c *i2c = i2c_get_adapdata(adap); - if (i2c->flags & OCORES_FLAG_POLL) + if ((i2c->flags & (OCORES_FLAG_POLL | OCORES_FLAG_BROKEN_IRQ))) return ocores_xfer_polling(adap, msgs, num); return ocores_xfer_core(i2c, msgs, num, false); } @@ -601,6 +611,7 @@ static int ocores_i2c_probe(struct platform_device *pdev) { struct ocores_i2c *i2c; struct ocores_i2c_platform_data *pdata; + const struct of_device_id *match; struct resource *res; int irq; int ret; @@ -682,13 +693,23 @@ static int ocores_i2c_probe(struct platform_device *pdev) irq = platform_get_irq(pdev, 0); if (irq == -ENXIO) { - i2c->flags |= OCORES_FLAG_POLL; + /* + * Set a OCORES_FLAG_BROKEN_IRQ to enable workaround for + * FU540-C000 SoC in polling mode interface of i2c-ocore driver. + * Else enable default polling mode interface for SIFIVE/OCORE + * device types. + */ + match = of_match_node(ocores_i2c_match, pdev->dev.of_node); + if (match && (long)match->data == TYPE_SIFIVE_REV0) + i2c->flags |= OCORES_FLAG_BROKEN_IRQ; + else + i2c->flags |= OCORES_FLAG_POLL; } else { if (irq < 0) return irq; } - if (!(i2c->flags & OCORES_FLAG_POLL)) { + if (!(i2c->flags & (OCORES_FLAG_POLL | OCORES_FLAG_BROKEN_IRQ))) { ret = devm_request_irq(&pdev->dev, irq, ocores_isr, 0, pdev->name, i2c); if (ret) {
The i2c-ocore driver already has a polling mode interface.But it needs a workaround for FU540 Chipset on HiFive unleashed board (RevA00). There is an erratum in FU540 chip that prevents interrupt driven i2c transfers from working, and also the I2C controller's interrupt bit cannot be cleared if set, due to this the existing i2c polling mode interface added in mainline earlier doesn't work, and CPU stall's infinitely, when-ever i2c transfer is initiated. Ref:previous polling mode support in mainline commit 69c8c0c0efa8 ("i2c: ocores: add polling interface") The workaround / fix under OCORES_FLAG_BROKEN_IRQ is particularly for FU540-COOO SoC. Signed-off-by: Sagar Shrikant Kadam <sagar.kadam@sifive.com> --- drivers/i2c/busses/i2c-ocores.c | 31 ++++++++++++++++++++++++++----- 1 file changed, 26 insertions(+), 5 deletions(-)