* [PATCH v8 3/3] i2c-ocores: sifive: add polling mode workaround for FU540-C000 SoC.
@ 2019-05-29 4:26 Sagar Shrikant Kadam
0 siblings, 0 replies; 4+ messages in thread
From: Sagar Shrikant Kadam @ 2019-05-29 4:26 UTC (permalink / raw)
To: robh+dt, mark.rutland, peter, andrew, palmer, paul.walmsley,
sagar.kadam, linux-i2c, devicetree, linux-riscv, linux-kernel
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:
commit dd7dbf0eb090 ("i2c: ocores: refactor setup for polling")
The workaround / fix under OCORES_FLAG_BROKEN_IRQ is particularly for
FU540-COOO SoC.
The polling function identifies a SiFive device based on the device node
and enables the workaround.
Signed-off-by: Sagar Shrikant Kadam <sagar.kadam@sifive.com>
---
drivers/i2c/busses/i2c-ocores.c | 24 ++++++++++++++++++++++--
1 file changed, 22 insertions(+), 2 deletions(-)
diff --git a/drivers/i2c/busses/i2c-ocores.c b/drivers/i2c/busses/i2c-ocores.c
index b334fa2..4117f1a 100644
--- a/drivers/i2c/busses/i2c-ocores.c
+++ b/drivers/i2c/busses/i2c-ocores.c
@@ -35,6 +35,7 @@ struct ocores_i2c {
int iobase;
u32 reg_shift;
u32 reg_io_width;
+ unsigned long flags;
wait_queue_head_t wait;
struct i2c_adapter adap;
struct i2c_msg *msg;
@@ -84,6 +85,8 @@ struct ocores_i2c {
#define TYPE_GRLIB 1
#define TYPE_SIFIVE_REV0 2
+#define OCORES_FLAG_BROKEN_IRQ BIT(1) /* Broken IRQ for FU540-C000 SoC */
+
static void oc_setreg_8(struct ocores_i2c *i2c, int reg, u8 value)
{
iowrite8(value, i2c->base + (reg << i2c->reg_shift));
@@ -236,9 +239,12 @@ 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) && !(stat & OCI2C_STAT_BUSY))
+ return IRQ_NONE;
+ } else if (!(stat & OCI2C_STAT_IF)) {
return IRQ_NONE;
-
+ }
ocores_process(i2c, stat);
return IRQ_HANDLED;
@@ -353,6 +359,11 @@ 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;
+ }
}
}
@@ -595,6 +606,7 @@ 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;
@@ -677,6 +689,14 @@ static int ocores_i2c_probe(struct platform_device *pdev)
irq = platform_get_irq(pdev, 0);
if (irq == -ENXIO) {
ocores_algorithm.master_xfer = ocores_xfer_polling;
+
+ /*
+ * Set in OCORES_FLAG_BROKEN_IRQ to enable workaround for
+ * FU540-C000 SoC in polling mode.
+ */
+ 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 {
if (irq < 0)
return irq;
--
1.9.1
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^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v8 3/3] i2c-ocores: sifive: add polling mode workaround for FU540-C000 SoC.
2019-05-29 15:53 ` Andrew Lunn
@ 2019-05-30 3:55 ` Sagar Kadam
0 siblings, 0 replies; 4+ messages in thread
From: Sagar Kadam @ 2019-05-30 3:55 UTC (permalink / raw)
To: Andrew Lunn
Cc: Mark Rutland, devicetree, peter, Palmer Dabbelt, linux-kernel,
Rob Herring, Linux I2C, Paul Walmsley, linux-riscv
On Wed, May 29, 2019 at 9:23 PM Andrew Lunn <andrew@lunn.ch> wrote:
>
> On Wed, May 29, 2019 at 09:57:27AM +0530, Sagar Shrikant Kadam wrote:
> > 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:
> > commit dd7dbf0eb090 ("i2c: ocores: refactor setup for polling")
> >
> > The workaround / fix under OCORES_FLAG_BROKEN_IRQ is particularly for
> > FU540-COOO SoC.
> >
> > The polling function identifies a SiFive device based on the device node
> > and enables the workaround.
> >
> > Signed-off-by: Sagar Shrikant Kadam <sagar.kadam@sifive.com>
>
> Hi Sagar
>
> When you repost, you are supposed to add any reviewed-by, or acked-by
> tags you received.
Sorry Andrew, I missed it.
I will repost it, with acked by Andrew Lunn as you had Acknowledged it earlier
>
> Andrew
Thanks,
Sagar
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^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v8 3/3] i2c-ocores: sifive: add polling mode workaround for FU540-C000 SoC.
2019-05-29 4:27 ` [PATCH v8 3/3] i2c-ocores: sifive: add polling mode workaround for FU540-C000 SoC Sagar Shrikant Kadam
@ 2019-05-29 15:53 ` Andrew Lunn
2019-05-30 3:55 ` Sagar Kadam
0 siblings, 1 reply; 4+ messages in thread
From: Andrew Lunn @ 2019-05-29 15:53 UTC (permalink / raw)
To: Sagar Shrikant Kadam
Cc: mark.rutland, devicetree, peter, palmer, linux-kernel, robh+dt,
linux-i2c, paul.walmsley, linux-riscv
On Wed, May 29, 2019 at 09:57:27AM +0530, Sagar Shrikant Kadam wrote:
> 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:
> commit dd7dbf0eb090 ("i2c: ocores: refactor setup for polling")
>
> The workaround / fix under OCORES_FLAG_BROKEN_IRQ is particularly for
> FU540-COOO SoC.
>
> The polling function identifies a SiFive device based on the device node
> and enables the workaround.
>
> Signed-off-by: Sagar Shrikant Kadam <sagar.kadam@sifive.com>
Hi Sagar
When you repost, you are supposed to add any reviewed-by, or acked-by
tags you received.
Andrew
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linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH v8 3/3] i2c-ocores: sifive: add polling mode workaround for FU540-C000 SoC.
2019-05-29 4:27 [PATCH v8 0/3] Extend dt bindings to support I2C on sifive devices and a fix broken IRQ in polling mode Sagar Shrikant Kadam
@ 2019-05-29 4:27 ` Sagar Shrikant Kadam
2019-05-29 15:53 ` Andrew Lunn
0 siblings, 1 reply; 4+ messages in thread
From: Sagar Shrikant Kadam @ 2019-05-29 4:27 UTC (permalink / raw)
To: robh+dt, mark.rutland, peter, andrew, palmer, paul.walmsley,
sagar.kadam, linux-i2c, devicetree, linux-riscv, linux-kernel
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:
commit dd7dbf0eb090 ("i2c: ocores: refactor setup for polling")
The workaround / fix under OCORES_FLAG_BROKEN_IRQ is particularly for
FU540-COOO SoC.
The polling function identifies a SiFive device based on the device node
and enables the workaround.
Signed-off-by: Sagar Shrikant Kadam <sagar.kadam@sifive.com>
---
drivers/i2c/busses/i2c-ocores.c | 24 ++++++++++++++++++++++--
1 file changed, 22 insertions(+), 2 deletions(-)
diff --git a/drivers/i2c/busses/i2c-ocores.c b/drivers/i2c/busses/i2c-ocores.c
index b334fa2..4117f1a 100644
--- a/drivers/i2c/busses/i2c-ocores.c
+++ b/drivers/i2c/busses/i2c-ocores.c
@@ -35,6 +35,7 @@ struct ocores_i2c {
int iobase;
u32 reg_shift;
u32 reg_io_width;
+ unsigned long flags;
wait_queue_head_t wait;
struct i2c_adapter adap;
struct i2c_msg *msg;
@@ -84,6 +85,8 @@ struct ocores_i2c {
#define TYPE_GRLIB 1
#define TYPE_SIFIVE_REV0 2
+#define OCORES_FLAG_BROKEN_IRQ BIT(1) /* Broken IRQ for FU540-C000 SoC */
+
static void oc_setreg_8(struct ocores_i2c *i2c, int reg, u8 value)
{
iowrite8(value, i2c->base + (reg << i2c->reg_shift));
@@ -236,9 +239,12 @@ 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) && !(stat & OCI2C_STAT_BUSY))
+ return IRQ_NONE;
+ } else if (!(stat & OCI2C_STAT_IF)) {
return IRQ_NONE;
-
+ }
ocores_process(i2c, stat);
return IRQ_HANDLED;
@@ -353,6 +359,11 @@ 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;
+ }
}
}
@@ -595,6 +606,7 @@ 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;
@@ -677,6 +689,14 @@ static int ocores_i2c_probe(struct platform_device *pdev)
irq = platform_get_irq(pdev, 0);
if (irq == -ENXIO) {
ocores_algorithm.master_xfer = ocores_xfer_polling;
+
+ /*
+ * Set in OCORES_FLAG_BROKEN_IRQ to enable workaround for
+ * FU540-C000 SoC in polling mode.
+ */
+ 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 {
if (irq < 0)
return irq;
--
1.9.1
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^ permalink raw reply related [flat|nested] 4+ messages in thread
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2019-05-29 4:26 [PATCH v8 3/3] i2c-ocores: sifive: add polling mode workaround for FU540-C000 SoC Sagar Shrikant Kadam
2019-05-29 4:27 [PATCH v8 0/3] Extend dt bindings to support I2C on sifive devices and a fix broken IRQ in polling mode Sagar Shrikant Kadam
2019-05-29 4:27 ` [PATCH v8 3/3] i2c-ocores: sifive: add polling mode workaround for FU540-C000 SoC Sagar Shrikant Kadam
2019-05-29 15:53 ` Andrew Lunn
2019-05-30 3:55 ` Sagar Kadam
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