* [PATCH 0/3] i2c:imx: Deliver a timely stop on slave side, fix recv @ 2021-10-05 0:32 minyard 2021-10-05 0:32 ` [PATCH 1/3] i2c:imx: Add timer for handling the stop condition minyard ` (2 more replies) 0 siblings, 3 replies; 11+ messages in thread From: minyard @ 2021-10-05 0:32 UTC (permalink / raw) To: Oleksij Rempel Cc: Pengutronix Kernel Team, linux-i2c, Andrew Manley, linux-kernel I was working on an application that needs the stop condition immediately. So this adds a timer after each byte is received/sent and if the bus is idle at the timeout, send the stop. Also, I noticed when you use the i2c-slave-eeprom, if you read some data and then read some data again, the last byte of the first read will be the first byte of the second read. This is because i2c-slave-eeprom expects a read-ahead. That's what the documentation says, at least. -corey ^ permalink raw reply [flat|nested] 11+ messages in thread
* [PATCH 1/3] i2c:imx: Add timer for handling the stop condition 2021-10-05 0:32 [PATCH 0/3] i2c:imx: Deliver a timely stop on slave side, fix recv minyard @ 2021-10-05 0:32 ` minyard 2021-11-01 17:27 ` Corey Minyard 2021-11-10 8:58 ` Oleksij Rempel 2021-10-05 0:32 ` [PATCH 2/3] i2c:imx: Add an extra read at the end of an I2C slave read minyard 2021-10-05 0:32 ` [PATCH 3/3] i2c:imx: Use an hrtimer, not a timer, for checking for bus idle minyard 2 siblings, 2 replies; 11+ messages in thread From: minyard @ 2021-10-05 0:32 UTC (permalink / raw) To: Oleksij Rempel Cc: Pengutronix Kernel Team, linux-i2c, Andrew Manley, linux-kernel, Corey Minyard, Corey Minyard From: Corey Minyard <cminyard@mvista.com> Most IMX I2C interfaces don't generate an interrupt on a stop condition, so it won't generate a timely stop event on a slave mode transfer. Some users, like IPMB, need a timely stop event to work properly. So, add a timer and add the proper handling to generate a stop event in slave mode if the interface goes idle. Signed-off-by: Corey Minyard <minyard@acm.org> Tested-by: Andrew Manley <andrew.manley@sealingtech.com> Reviewed-by: Andrew Manley <andrew.manley@sealingtech.com> --- drivers/i2c/busses/i2c-imx.c | 78 +++++++++++++++++++++++++++--------- 1 file changed, 59 insertions(+), 19 deletions(-) diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index 3576b63a6c03..97369fe48b30 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -37,6 +37,8 @@ #include <linux/io.h> #include <linux/iopoll.h> #include <linux/kernel.h> +#include <linux/spinlock.h> +#include <linux/timer.h> #include <linux/module.h> #include <linux/of.h> #include <linux/of_device.h> @@ -210,6 +212,10 @@ struct imx_i2c_struct { struct imx_i2c_dma *dma; struct i2c_client *slave; enum i2c_slave_event last_slave_event; + + /* For checking slave events. */ + spinlock_t slave_lock; + struct timer_list slave_timer; }; static const struct imx_i2c_hwdata imx1_i2c_hwdata = { @@ -680,7 +686,7 @@ static void i2c_imx_slave_event(struct imx_i2c_struct *i2c_imx, static void i2c_imx_slave_finish_op(struct imx_i2c_struct *i2c_imx) { - u8 val; + u8 val = 0; while (i2c_imx->last_slave_event != I2C_SLAVE_STOP) { switch (i2c_imx->last_slave_event) { @@ -701,10 +707,11 @@ static void i2c_imx_slave_finish_op(struct imx_i2c_struct *i2c_imx) } } -static irqreturn_t i2c_imx_slave_isr(struct imx_i2c_struct *i2c_imx, - unsigned int status, unsigned int ctl) +/* Returns true if the timer should be restarted, false if not. */ +static irqreturn_t i2c_imx_slave_handle(struct imx_i2c_struct *i2c_imx, + unsigned int status, unsigned int ctl) { - u8 value; + u8 value = 0; if (status & I2SR_IAL) { /* Arbitration lost */ i2c_imx_clear_irq(i2c_imx, I2SR_IAL); @@ -712,6 +719,16 @@ static irqreturn_t i2c_imx_slave_isr(struct imx_i2c_struct *i2c_imx, return IRQ_HANDLED; } + if (!(status & I2SR_IBB)) { + /* No master on the bus, that could mean a stop condition. */ + i2c_imx_slave_finish_op(i2c_imx); + return IRQ_HANDLED; + } + + if (!(status & I2SR_ICF)) + /* Data transfer still in progress, ignore this. */ + goto out; + if (status & I2SR_IAAS) { /* Addressed as a slave */ i2c_imx_slave_finish_op(i2c_imx); if (status & I2SR_SRW) { /* Master wants to read from us*/ @@ -737,16 +754,9 @@ static irqreturn_t i2c_imx_slave_isr(struct imx_i2c_struct *i2c_imx, imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); } } else if (!(ctl & I2CR_MTX)) { /* Receive mode */ - if (status & I2SR_IBB) { /* No STOP signal detected */ - value = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); - i2c_imx_slave_event(i2c_imx, - I2C_SLAVE_WRITE_RECEIVED, &value); - } else { /* STOP signal is detected */ - dev_dbg(&i2c_imx->adapter.dev, - "STOP signal detected"); - i2c_imx_slave_event(i2c_imx, - I2C_SLAVE_STOP, &value); - } + value = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); + i2c_imx_slave_event(i2c_imx, + I2C_SLAVE_WRITE_RECEIVED, &value); } else if (!(status & I2SR_RXAK)) { /* Transmit mode received ACK */ ctl |= I2CR_MTX; imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR); @@ -755,15 +765,32 @@ static irqreturn_t i2c_imx_slave_isr(struct imx_i2c_struct *i2c_imx, I2C_SLAVE_READ_PROCESSED, &value); imx_i2c_write_reg(value, i2c_imx, IMX_I2C_I2DR); - } else { /* Transmit mode received NAK */ + } else { /* Transmit mode received NAK, operation is done */ ctl &= ~I2CR_MTX; imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR); imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); + i2c_imx_slave_finish_op(i2c_imx); + return IRQ_HANDLED; } +out: + mod_timer(&i2c_imx->slave_timer, jiffies + 1); return IRQ_HANDLED; } +static void i2c_imx_slave_timeout(struct timer_list *t) +{ + struct imx_i2c_struct *i2c_imx = from_timer(i2c_imx, t, slave_timer); + unsigned int ctl, status; + unsigned long flags; + + spin_lock_irqsave(&i2c_imx->slave_lock, flags); + status = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR); + ctl = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); + i2c_imx_slave_handle(i2c_imx, status, ctl); + spin_unlock_irqrestore(&i2c_imx->slave_lock, flags); +} + static void i2c_imx_slave_init(struct imx_i2c_struct *i2c_imx) { int temp; @@ -843,7 +870,9 @@ static irqreturn_t i2c_imx_isr(int irq, void *dev_id) { struct imx_i2c_struct *i2c_imx = dev_id; unsigned int ctl, status; + unsigned long flags; + spin_lock_irqsave(&i2c_imx->slave_lock, flags); status = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR); ctl = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); @@ -851,14 +880,20 @@ static irqreturn_t i2c_imx_isr(int irq, void *dev_id) i2c_imx_clear_irq(i2c_imx, I2SR_IIF); if (i2c_imx->slave) { if (!(ctl & I2CR_MSTA)) { - return i2c_imx_slave_isr(i2c_imx, status, ctl); - } else if (i2c_imx->last_slave_event != - I2C_SLAVE_STOP) { - i2c_imx_slave_finish_op(i2c_imx); + irqreturn_t ret; + + ret = i2c_imx_slave_handle(i2c_imx, + status, ctl); + spin_unlock_irqrestore(&i2c_imx->slave_lock, + flags); + return ret; } + i2c_imx_slave_finish_op(i2c_imx); } + spin_unlock_irqrestore(&i2c_imx->slave_lock, flags); return i2c_imx_master_isr(i2c_imx, status); } + spin_unlock_irqrestore(&i2c_imx->slave_lock, flags); return IRQ_NONE; } @@ -1378,6 +1413,9 @@ static int i2c_imx_probe(struct platform_device *pdev) if (!i2c_imx) return -ENOMEM; + spin_lock_init(&i2c_imx->slave_lock); + timer_setup(&i2c_imx->slave_timer, i2c_imx_slave_timeout, 0); + match = device_get_match_data(&pdev->dev); if (match) i2c_imx->hwdata = match; @@ -1491,6 +1529,8 @@ static int i2c_imx_remove(struct platform_device *pdev) if (ret < 0) return ret; + del_timer_sync(&i2c_imx->slave_timer); + /* remove adapter */ dev_dbg(&i2c_imx->adapter.dev, "adapter removed\n"); i2c_del_adapter(&i2c_imx->adapter); -- 2.25.1 ^ permalink raw reply related [flat|nested] 11+ messages in thread
* Re: [PATCH 1/3] i2c:imx: Add timer for handling the stop condition 2021-10-05 0:32 ` [PATCH 1/3] i2c:imx: Add timer for handling the stop condition minyard @ 2021-11-01 17:27 ` Corey Minyard 2021-11-10 8:58 ` Oleksij Rempel 1 sibling, 0 replies; 11+ messages in thread From: Corey Minyard @ 2021-11-01 17:27 UTC (permalink / raw) To: Oleksij Rempel Cc: Pengutronix Kernel Team, linux-i2c, Andrew Manley, linux-kernel, Corey Minyard On Mon, Oct 04, 2021 at 07:32:14PM -0500, minyard@acm.org wrote: > From: Corey Minyard <cminyard@mvista.com> Any comments for this patch series? -corey > > Most IMX I2C interfaces don't generate an interrupt on a stop condition, > so it won't generate a timely stop event on a slave mode transfer. > Some users, like IPMB, need a timely stop event to work properly. > > So, add a timer and add the proper handling to generate a stop event in > slave mode if the interface goes idle. > > Signed-off-by: Corey Minyard <minyard@acm.org> > Tested-by: Andrew Manley <andrew.manley@sealingtech.com> > Reviewed-by: Andrew Manley <andrew.manley@sealingtech.com> > --- > drivers/i2c/busses/i2c-imx.c | 78 +++++++++++++++++++++++++++--------- > 1 file changed, 59 insertions(+), 19 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c > index 3576b63a6c03..97369fe48b30 100644 > --- a/drivers/i2c/busses/i2c-imx.c > +++ b/drivers/i2c/busses/i2c-imx.c > @@ -37,6 +37,8 @@ > #include <linux/io.h> > #include <linux/iopoll.h> > #include <linux/kernel.h> > +#include <linux/spinlock.h> > +#include <linux/timer.h> > #include <linux/module.h> > #include <linux/of.h> > #include <linux/of_device.h> > @@ -210,6 +212,10 @@ struct imx_i2c_struct { > struct imx_i2c_dma *dma; > struct i2c_client *slave; > enum i2c_slave_event last_slave_event; > + > + /* For checking slave events. */ > + spinlock_t slave_lock; > + struct timer_list slave_timer; > }; > > static const struct imx_i2c_hwdata imx1_i2c_hwdata = { > @@ -680,7 +686,7 @@ static void i2c_imx_slave_event(struct imx_i2c_struct *i2c_imx, > > static void i2c_imx_slave_finish_op(struct imx_i2c_struct *i2c_imx) > { > - u8 val; > + u8 val = 0; > > while (i2c_imx->last_slave_event != I2C_SLAVE_STOP) { > switch (i2c_imx->last_slave_event) { > @@ -701,10 +707,11 @@ static void i2c_imx_slave_finish_op(struct imx_i2c_struct *i2c_imx) > } > } > > -static irqreturn_t i2c_imx_slave_isr(struct imx_i2c_struct *i2c_imx, > - unsigned int status, unsigned int ctl) > +/* Returns true if the timer should be restarted, false if not. */ > +static irqreturn_t i2c_imx_slave_handle(struct imx_i2c_struct *i2c_imx, > + unsigned int status, unsigned int ctl) > { > - u8 value; > + u8 value = 0; > > if (status & I2SR_IAL) { /* Arbitration lost */ > i2c_imx_clear_irq(i2c_imx, I2SR_IAL); > @@ -712,6 +719,16 @@ static irqreturn_t i2c_imx_slave_isr(struct imx_i2c_struct *i2c_imx, > return IRQ_HANDLED; > } > > + if (!(status & I2SR_IBB)) { > + /* No master on the bus, that could mean a stop condition. */ > + i2c_imx_slave_finish_op(i2c_imx); > + return IRQ_HANDLED; > + } > + > + if (!(status & I2SR_ICF)) > + /* Data transfer still in progress, ignore this. */ > + goto out; > + > if (status & I2SR_IAAS) { /* Addressed as a slave */ > i2c_imx_slave_finish_op(i2c_imx); > if (status & I2SR_SRW) { /* Master wants to read from us*/ > @@ -737,16 +754,9 @@ static irqreturn_t i2c_imx_slave_isr(struct imx_i2c_struct *i2c_imx, > imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); > } > } else if (!(ctl & I2CR_MTX)) { /* Receive mode */ > - if (status & I2SR_IBB) { /* No STOP signal detected */ > - value = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); > - i2c_imx_slave_event(i2c_imx, > - I2C_SLAVE_WRITE_RECEIVED, &value); > - } else { /* STOP signal is detected */ > - dev_dbg(&i2c_imx->adapter.dev, > - "STOP signal detected"); > - i2c_imx_slave_event(i2c_imx, > - I2C_SLAVE_STOP, &value); > - } > + value = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); > + i2c_imx_slave_event(i2c_imx, > + I2C_SLAVE_WRITE_RECEIVED, &value); > } else if (!(status & I2SR_RXAK)) { /* Transmit mode received ACK */ > ctl |= I2CR_MTX; > imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR); > @@ -755,15 +765,32 @@ static irqreturn_t i2c_imx_slave_isr(struct imx_i2c_struct *i2c_imx, > I2C_SLAVE_READ_PROCESSED, &value); > > imx_i2c_write_reg(value, i2c_imx, IMX_I2C_I2DR); > - } else { /* Transmit mode received NAK */ > + } else { /* Transmit mode received NAK, operation is done */ > ctl &= ~I2CR_MTX; > imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR); > imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); > + i2c_imx_slave_finish_op(i2c_imx); > + return IRQ_HANDLED; > } > > +out: > + mod_timer(&i2c_imx->slave_timer, jiffies + 1); > return IRQ_HANDLED; > } > > +static void i2c_imx_slave_timeout(struct timer_list *t) > +{ > + struct imx_i2c_struct *i2c_imx = from_timer(i2c_imx, t, slave_timer); > + unsigned int ctl, status; > + unsigned long flags; > + > + spin_lock_irqsave(&i2c_imx->slave_lock, flags); > + status = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR); > + ctl = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); > + i2c_imx_slave_handle(i2c_imx, status, ctl); > + spin_unlock_irqrestore(&i2c_imx->slave_lock, flags); > +} > + > static void i2c_imx_slave_init(struct imx_i2c_struct *i2c_imx) > { > int temp; > @@ -843,7 +870,9 @@ static irqreturn_t i2c_imx_isr(int irq, void *dev_id) > { > struct imx_i2c_struct *i2c_imx = dev_id; > unsigned int ctl, status; > + unsigned long flags; > > + spin_lock_irqsave(&i2c_imx->slave_lock, flags); > status = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR); > ctl = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); > > @@ -851,14 +880,20 @@ static irqreturn_t i2c_imx_isr(int irq, void *dev_id) > i2c_imx_clear_irq(i2c_imx, I2SR_IIF); > if (i2c_imx->slave) { > if (!(ctl & I2CR_MSTA)) { > - return i2c_imx_slave_isr(i2c_imx, status, ctl); > - } else if (i2c_imx->last_slave_event != > - I2C_SLAVE_STOP) { > - i2c_imx_slave_finish_op(i2c_imx); > + irqreturn_t ret; > + > + ret = i2c_imx_slave_handle(i2c_imx, > + status, ctl); > + spin_unlock_irqrestore(&i2c_imx->slave_lock, > + flags); > + return ret; > } > + i2c_imx_slave_finish_op(i2c_imx); > } > + spin_unlock_irqrestore(&i2c_imx->slave_lock, flags); > return i2c_imx_master_isr(i2c_imx, status); > } > + spin_unlock_irqrestore(&i2c_imx->slave_lock, flags); > > return IRQ_NONE; > } > @@ -1378,6 +1413,9 @@ static int i2c_imx_probe(struct platform_device *pdev) > if (!i2c_imx) > return -ENOMEM; > > + spin_lock_init(&i2c_imx->slave_lock); > + timer_setup(&i2c_imx->slave_timer, i2c_imx_slave_timeout, 0); > + > match = device_get_match_data(&pdev->dev); > if (match) > i2c_imx->hwdata = match; > @@ -1491,6 +1529,8 @@ static int i2c_imx_remove(struct platform_device *pdev) > if (ret < 0) > return ret; > > + del_timer_sync(&i2c_imx->slave_timer); > + > /* remove adapter */ > dev_dbg(&i2c_imx->adapter.dev, "adapter removed\n"); > i2c_del_adapter(&i2c_imx->adapter); > -- > 2.25.1 > ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 1/3] i2c:imx: Add timer for handling the stop condition 2021-10-05 0:32 ` [PATCH 1/3] i2c:imx: Add timer for handling the stop condition minyard 2021-11-01 17:27 ` Corey Minyard @ 2021-11-10 8:58 ` Oleksij Rempel 1 sibling, 0 replies; 11+ messages in thread From: Oleksij Rempel @ 2021-11-10 8:58 UTC (permalink / raw) To: minyard Cc: Pengutronix Kernel Team, linux-i2c, Andrew Manley, linux-kernel, Corey Minyard On Mon, Oct 04, 2021 at 07:32:14PM -0500, minyard@acm.org wrote: > From: Corey Minyard <cminyard@mvista.com> > > Most IMX I2C interfaces don't generate an interrupt on a stop condition, > so it won't generate a timely stop event on a slave mode transfer. > Some users, like IPMB, need a timely stop event to work properly. > > So, add a timer and add the proper handling to generate a stop event in > slave mode if the interface goes idle. > > Signed-off-by: Corey Minyard <minyard@acm.org> > Tested-by: Andrew Manley <andrew.manley@sealingtech.com> > Reviewed-by: Andrew Manley <andrew.manley@sealingtech.com> Reviewed-by: Oleksij Rempel <o.rempel@pengutronix.de> Thank you! > --- > drivers/i2c/busses/i2c-imx.c | 78 +++++++++++++++++++++++++++--------- > 1 file changed, 59 insertions(+), 19 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c > index 3576b63a6c03..97369fe48b30 100644 > --- a/drivers/i2c/busses/i2c-imx.c > +++ b/drivers/i2c/busses/i2c-imx.c > @@ -37,6 +37,8 @@ > #include <linux/io.h> > #include <linux/iopoll.h> > #include <linux/kernel.h> > +#include <linux/spinlock.h> > +#include <linux/timer.h> > #include <linux/module.h> > #include <linux/of.h> > #include <linux/of_device.h> > @@ -210,6 +212,10 @@ struct imx_i2c_struct { > struct imx_i2c_dma *dma; > struct i2c_client *slave; > enum i2c_slave_event last_slave_event; > + > + /* For checking slave events. */ > + spinlock_t slave_lock; > + struct timer_list slave_timer; > }; > > static const struct imx_i2c_hwdata imx1_i2c_hwdata = { > @@ -680,7 +686,7 @@ static void i2c_imx_slave_event(struct imx_i2c_struct *i2c_imx, > > static void i2c_imx_slave_finish_op(struct imx_i2c_struct *i2c_imx) > { > - u8 val; > + u8 val = 0; > > while (i2c_imx->last_slave_event != I2C_SLAVE_STOP) { > switch (i2c_imx->last_slave_event) { > @@ -701,10 +707,11 @@ static void i2c_imx_slave_finish_op(struct imx_i2c_struct *i2c_imx) > } > } > > -static irqreturn_t i2c_imx_slave_isr(struct imx_i2c_struct *i2c_imx, > - unsigned int status, unsigned int ctl) > +/* Returns true if the timer should be restarted, false if not. */ > +static irqreturn_t i2c_imx_slave_handle(struct imx_i2c_struct *i2c_imx, > + unsigned int status, unsigned int ctl) > { > - u8 value; > + u8 value = 0; > > if (status & I2SR_IAL) { /* Arbitration lost */ > i2c_imx_clear_irq(i2c_imx, I2SR_IAL); > @@ -712,6 +719,16 @@ static irqreturn_t i2c_imx_slave_isr(struct imx_i2c_struct *i2c_imx, > return IRQ_HANDLED; > } > > + if (!(status & I2SR_IBB)) { > + /* No master on the bus, that could mean a stop condition. */ > + i2c_imx_slave_finish_op(i2c_imx); > + return IRQ_HANDLED; > + } > + > + if (!(status & I2SR_ICF)) > + /* Data transfer still in progress, ignore this. */ > + goto out; > + > if (status & I2SR_IAAS) { /* Addressed as a slave */ > i2c_imx_slave_finish_op(i2c_imx); > if (status & I2SR_SRW) { /* Master wants to read from us*/ > @@ -737,16 +754,9 @@ static irqreturn_t i2c_imx_slave_isr(struct imx_i2c_struct *i2c_imx, > imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); > } > } else if (!(ctl & I2CR_MTX)) { /* Receive mode */ > - if (status & I2SR_IBB) { /* No STOP signal detected */ > - value = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); > - i2c_imx_slave_event(i2c_imx, > - I2C_SLAVE_WRITE_RECEIVED, &value); > - } else { /* STOP signal is detected */ > - dev_dbg(&i2c_imx->adapter.dev, > - "STOP signal detected"); > - i2c_imx_slave_event(i2c_imx, > - I2C_SLAVE_STOP, &value); > - } > + value = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); > + i2c_imx_slave_event(i2c_imx, > + I2C_SLAVE_WRITE_RECEIVED, &value); > } else if (!(status & I2SR_RXAK)) { /* Transmit mode received ACK */ > ctl |= I2CR_MTX; > imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR); > @@ -755,15 +765,32 @@ static irqreturn_t i2c_imx_slave_isr(struct imx_i2c_struct *i2c_imx, > I2C_SLAVE_READ_PROCESSED, &value); > > imx_i2c_write_reg(value, i2c_imx, IMX_I2C_I2DR); > - } else { /* Transmit mode received NAK */ > + } else { /* Transmit mode received NAK, operation is done */ > ctl &= ~I2CR_MTX; > imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR); > imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); > + i2c_imx_slave_finish_op(i2c_imx); > + return IRQ_HANDLED; > } > > +out: > + mod_timer(&i2c_imx->slave_timer, jiffies + 1); > return IRQ_HANDLED; > } > > +static void i2c_imx_slave_timeout(struct timer_list *t) > +{ > + struct imx_i2c_struct *i2c_imx = from_timer(i2c_imx, t, slave_timer); > + unsigned int ctl, status; > + unsigned long flags; > + > + spin_lock_irqsave(&i2c_imx->slave_lock, flags); > + status = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR); > + ctl = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); > + i2c_imx_slave_handle(i2c_imx, status, ctl); > + spin_unlock_irqrestore(&i2c_imx->slave_lock, flags); > +} > + > static void i2c_imx_slave_init(struct imx_i2c_struct *i2c_imx) > { > int temp; > @@ -843,7 +870,9 @@ static irqreturn_t i2c_imx_isr(int irq, void *dev_id) > { > struct imx_i2c_struct *i2c_imx = dev_id; > unsigned int ctl, status; > + unsigned long flags; > > + spin_lock_irqsave(&i2c_imx->slave_lock, flags); > status = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR); > ctl = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); > > @@ -851,14 +880,20 @@ static irqreturn_t i2c_imx_isr(int irq, void *dev_id) > i2c_imx_clear_irq(i2c_imx, I2SR_IIF); > if (i2c_imx->slave) { > if (!(ctl & I2CR_MSTA)) { > - return i2c_imx_slave_isr(i2c_imx, status, ctl); > - } else if (i2c_imx->last_slave_event != > - I2C_SLAVE_STOP) { > - i2c_imx_slave_finish_op(i2c_imx); > + irqreturn_t ret; > + > + ret = i2c_imx_slave_handle(i2c_imx, > + status, ctl); > + spin_unlock_irqrestore(&i2c_imx->slave_lock, > + flags); > + return ret; > } > + i2c_imx_slave_finish_op(i2c_imx); > } > + spin_unlock_irqrestore(&i2c_imx->slave_lock, flags); > return i2c_imx_master_isr(i2c_imx, status); > } > + spin_unlock_irqrestore(&i2c_imx->slave_lock, flags); > > return IRQ_NONE; > } > @@ -1378,6 +1413,9 @@ static int i2c_imx_probe(struct platform_device *pdev) > if (!i2c_imx) > return -ENOMEM; > > + spin_lock_init(&i2c_imx->slave_lock); > + timer_setup(&i2c_imx->slave_timer, i2c_imx_slave_timeout, 0); > + > match = device_get_match_data(&pdev->dev); > if (match) > i2c_imx->hwdata = match; > @@ -1491,6 +1529,8 @@ static int i2c_imx_remove(struct platform_device *pdev) > if (ret < 0) > return ret; > > + del_timer_sync(&i2c_imx->slave_timer); > + > /* remove adapter */ > dev_dbg(&i2c_imx->adapter.dev, "adapter removed\n"); > i2c_del_adapter(&i2c_imx->adapter); > -- > 2.25.1 > > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | ^ permalink raw reply [flat|nested] 11+ messages in thread
* [PATCH 2/3] i2c:imx: Add an extra read at the end of an I2C slave read 2021-10-05 0:32 [PATCH 0/3] i2c:imx: Deliver a timely stop on slave side, fix recv minyard 2021-10-05 0:32 ` [PATCH 1/3] i2c:imx: Add timer for handling the stop condition minyard @ 2021-10-05 0:32 ` minyard 2021-11-10 8:58 ` Oleksij Rempel 2021-10-05 0:32 ` [PATCH 3/3] i2c:imx: Use an hrtimer, not a timer, for checking for bus idle minyard 2 siblings, 1 reply; 11+ messages in thread From: minyard @ 2021-10-05 0:32 UTC (permalink / raw) To: Oleksij Rempel Cc: Pengutronix Kernel Team, linux-i2c, Andrew Manley, linux-kernel, Corey Minyard, Corey Minyard From: Corey Minyard <cminyard@mvista.com> The I2C slave interface expects that the driver will read ahead one byte. The IMX driver/device doesn't do this, but simulate it so that read operations get their index set correctly. Signed-off-by: Corey Minyard <minyard@acm.org> Tested-by: Andrew Manley <andrew.manley@sealingtech.com> Reviewed-by: Andrew Manley <andrew.manley@sealingtech.com> --- drivers/i2c/busses/i2c-imx.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index 97369fe48b30..26a04dc0590b 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -769,6 +769,15 @@ static irqreturn_t i2c_imx_slave_handle(struct imx_i2c_struct *i2c_imx, ctl &= ~I2CR_MTX; imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR); imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); + + /* + * The i2c slave interface requires one extra dummy + * read at the end to keep things in line. See the + * I2C slave docs for details. + */ + i2c_imx_slave_event(i2c_imx, + I2C_SLAVE_READ_PROCESSED, &value); + i2c_imx_slave_finish_op(i2c_imx); return IRQ_HANDLED; } -- 2.25.1 ^ permalink raw reply related [flat|nested] 11+ messages in thread
* Re: [PATCH 2/3] i2c:imx: Add an extra read at the end of an I2C slave read 2021-10-05 0:32 ` [PATCH 2/3] i2c:imx: Add an extra read at the end of an I2C slave read minyard @ 2021-11-10 8:58 ` Oleksij Rempel 0 siblings, 0 replies; 11+ messages in thread From: Oleksij Rempel @ 2021-11-10 8:58 UTC (permalink / raw) To: minyard Cc: Pengutronix Kernel Team, linux-i2c, Andrew Manley, linux-kernel, Corey Minyard On Mon, Oct 04, 2021 at 07:32:15PM -0500, minyard@acm.org wrote: > From: Corey Minyard <cminyard@mvista.com> > > The I2C slave interface expects that the driver will read ahead one > byte. The IMX driver/device doesn't do this, but simulate it so that > read operations get their index set correctly. > > Signed-off-by: Corey Minyard <minyard@acm.org> > Tested-by: Andrew Manley <andrew.manley@sealingtech.com> > Reviewed-by: Andrew Manley <andrew.manley@sealingtech.com> Reviewed-by: Oleksij Rempel <o.rempel@pengutronix.de> > --- > drivers/i2c/busses/i2c-imx.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c > index 97369fe48b30..26a04dc0590b 100644 > --- a/drivers/i2c/busses/i2c-imx.c > +++ b/drivers/i2c/busses/i2c-imx.c > @@ -769,6 +769,15 @@ static irqreturn_t i2c_imx_slave_handle(struct imx_i2c_struct *i2c_imx, > ctl &= ~I2CR_MTX; > imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR); > imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); > + > + /* > + * The i2c slave interface requires one extra dummy > + * read at the end to keep things in line. See the > + * I2C slave docs for details. > + */ > + i2c_imx_slave_event(i2c_imx, > + I2C_SLAVE_READ_PROCESSED, &value); > + > i2c_imx_slave_finish_op(i2c_imx); > return IRQ_HANDLED; > } > -- > 2.25.1 > > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | ^ permalink raw reply [flat|nested] 11+ messages in thread
* [PATCH 3/3] i2c:imx: Use an hrtimer, not a timer, for checking for bus idle 2021-10-05 0:32 [PATCH 0/3] i2c:imx: Deliver a timely stop on slave side, fix recv minyard 2021-10-05 0:32 ` [PATCH 1/3] i2c:imx: Add timer for handling the stop condition minyard 2021-10-05 0:32 ` [PATCH 2/3] i2c:imx: Add an extra read at the end of an I2C slave read minyard @ 2021-10-05 0:32 ` minyard 2021-11-02 8:58 ` Uwe Kleine-König 2021-11-10 9:03 ` Oleksij Rempel 2 siblings, 2 replies; 11+ messages in thread From: minyard @ 2021-10-05 0:32 UTC (permalink / raw) To: Oleksij Rempel Cc: Pengutronix Kernel Team, linux-i2c, Andrew Manley, linux-kernel, Corey Minyard, Corey Minyard From: Corey Minyard <cminyard@mvista.com> The timer is too slow and significantly reduces performance. Use an hrtimer to get things working faster. Signed-off-by: Corey Minyard <minyard@acm.org> Tested-by: Andrew Manley <andrew.manley@sealingtech.com> Reviewed-by: Andrew Manley <andrew.manley@sealingtech.com> --- drivers/i2c/busses/i2c-imx.c | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-) diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index 26a04dc0590b..4b0e9d1784dd 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -38,7 +38,7 @@ #include <linux/iopoll.h> #include <linux/kernel.h> #include <linux/spinlock.h> -#include <linux/timer.h> +#include <linux/hrtimer.h> #include <linux/module.h> #include <linux/of.h> #include <linux/of_device.h> @@ -53,6 +53,8 @@ /* This will be the driver name the kernel reports */ #define DRIVER_NAME "imx-i2c" +#define I2C_IMX_CHECK_DELAY 30000 /* Time to check for bus idle, in NS */ + /* * Enable DMA if transfer byte size is bigger than this threshold. * As the hardware request, it must bigger than 4 bytes.\ @@ -214,8 +216,8 @@ struct imx_i2c_struct { enum i2c_slave_event last_slave_event; /* For checking slave events. */ - spinlock_t slave_lock; - struct timer_list slave_timer; + spinlock_t slave_lock; + struct hrtimer slave_timer; }; static const struct imx_i2c_hwdata imx1_i2c_hwdata = { @@ -783,13 +785,16 @@ static irqreturn_t i2c_imx_slave_handle(struct imx_i2c_struct *i2c_imx, } out: - mod_timer(&i2c_imx->slave_timer, jiffies + 1); + hrtimer_try_to_cancel(&i2c_imx->slave_timer); + hrtimer_forward_now(&i2c_imx->slave_timer, I2C_IMX_CHECK_DELAY); + hrtimer_restart(&i2c_imx->slave_timer); return IRQ_HANDLED; } -static void i2c_imx_slave_timeout(struct timer_list *t) +static enum hrtimer_restart i2c_imx_slave_timeout(struct hrtimer *t) { - struct imx_i2c_struct *i2c_imx = from_timer(i2c_imx, t, slave_timer); + struct imx_i2c_struct *i2c_imx = container_of(t, struct imx_i2c_struct, + slave_timer); unsigned int ctl, status; unsigned long flags; @@ -798,6 +803,7 @@ static void i2c_imx_slave_timeout(struct timer_list *t) ctl = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); i2c_imx_slave_handle(i2c_imx, status, ctl); spin_unlock_irqrestore(&i2c_imx->slave_lock, flags); + return HRTIMER_NORESTART; } static void i2c_imx_slave_init(struct imx_i2c_struct *i2c_imx) @@ -1423,7 +1429,8 @@ static int i2c_imx_probe(struct platform_device *pdev) return -ENOMEM; spin_lock_init(&i2c_imx->slave_lock); - timer_setup(&i2c_imx->slave_timer, i2c_imx_slave_timeout, 0); + hrtimer_init(&i2c_imx->slave_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); + i2c_imx->slave_timer.function = i2c_imx_slave_timeout; match = device_get_match_data(&pdev->dev); if (match) @@ -1538,7 +1545,7 @@ static int i2c_imx_remove(struct platform_device *pdev) if (ret < 0) return ret; - del_timer_sync(&i2c_imx->slave_timer); + hrtimer_cancel(&i2c_imx->slave_timer); /* remove adapter */ dev_dbg(&i2c_imx->adapter.dev, "adapter removed\n"); -- 2.25.1 ^ permalink raw reply related [flat|nested] 11+ messages in thread
* Re: [PATCH 3/3] i2c:imx: Use an hrtimer, not a timer, for checking for bus idle 2021-10-05 0:32 ` [PATCH 3/3] i2c:imx: Use an hrtimer, not a timer, for checking for bus idle minyard @ 2021-11-02 8:58 ` Uwe Kleine-König 2021-11-02 11:50 ` Corey Minyard 2021-11-10 9:03 ` Oleksij Rempel 1 sibling, 1 reply; 11+ messages in thread From: Uwe Kleine-König @ 2021-11-02 8:58 UTC (permalink / raw) To: minyard Cc: Oleksij Rempel, Corey Minyard, Andrew Manley, linux-kernel, linux-i2c, Pengutronix Kernel Team [-- Attachment #1: Type: text/plain, Size: 2351 bytes --] On Mon, Oct 04, 2021 at 07:32:16PM -0500, minyard@acm.org wrote: > From: Corey Minyard <cminyard@mvista.com> > > The timer is too slow and significantly reduces performance. Use an > hrtimer to get things working faster. > > Signed-off-by: Corey Minyard <minyard@acm.org> > Tested-by: Andrew Manley <andrew.manley@sealingtech.com> > Reviewed-by: Andrew Manley <andrew.manley@sealingtech.com> > --- > drivers/i2c/busses/i2c-imx.c | 23 +++++++++++++++-------- > 1 file changed, 15 insertions(+), 8 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c > index 26a04dc0590b..4b0e9d1784dd 100644 > --- a/drivers/i2c/busses/i2c-imx.c > +++ b/drivers/i2c/busses/i2c-imx.c > @@ -38,7 +38,7 @@ > #include <linux/iopoll.h> > #include <linux/kernel.h> > #include <linux/spinlock.h> > -#include <linux/timer.h> > +#include <linux/hrtimer.h> > #include <linux/module.h> > #include <linux/of.h> > #include <linux/of_device.h> > @@ -53,6 +53,8 @@ > /* This will be the driver name the kernel reports */ > #define DRIVER_NAME "imx-i2c" > > +#define I2C_IMX_CHECK_DELAY 30000 /* Time to check for bus idle, in NS */ > + > /* > * Enable DMA if transfer byte size is bigger than this threshold. > * As the hardware request, it must bigger than 4 bytes.\ > @@ -214,8 +216,8 @@ struct imx_i2c_struct { > enum i2c_slave_event last_slave_event; > > /* For checking slave events. */ > - spinlock_t slave_lock; > - struct timer_list slave_timer; > + spinlock_t slave_lock; > + struct hrtimer slave_timer; This is unrelated to this patch, moreover it was introduced only in patch 1. > }; > > static const struct imx_i2c_hwdata imx1_i2c_hwdata = { > @@ -783,13 +785,16 @@ static irqreturn_t i2c_imx_slave_handle(struct imx_i2c_struct *i2c_imx, > } > > out: > - mod_timer(&i2c_imx->slave_timer, jiffies + 1); > + hrtimer_try_to_cancel(&i2c_imx->slave_timer); Don't you need to check the return value here? > + hrtimer_forward_now(&i2c_imx->slave_timer, I2C_IMX_CHECK_DELAY); > + hrtimer_restart(&i2c_imx->slave_timer); > return IRQ_HANDLED; > } > Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | https://www.pengutronix.de/ | [-- Attachment #2: signature.asc --] [-- Type: application/pgp-signature, Size: 488 bytes --] ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 3/3] i2c:imx: Use an hrtimer, not a timer, for checking for bus idle 2021-11-02 8:58 ` Uwe Kleine-König @ 2021-11-02 11:50 ` Corey Minyard 0 siblings, 0 replies; 11+ messages in thread From: Corey Minyard @ 2021-11-02 11:50 UTC (permalink / raw) To: Uwe Kleine-König Cc: Oleksij Rempel, Corey Minyard, Andrew Manley, linux-kernel, linux-i2c, Pengutronix Kernel Team On Tue, Nov 02, 2021 at 09:58:06AM +0100, Uwe Kleine-König wrote: > On Mon, Oct 04, 2021 at 07:32:16PM -0500, minyard@acm.org wrote: > > From: Corey Minyard <cminyard@mvista.com> > > > > The timer is too slow and significantly reduces performance. Use an > > hrtimer to get things working faster. > > > > Signed-off-by: Corey Minyard <minyard@acm.org> > > Tested-by: Andrew Manley <andrew.manley@sealingtech.com> > > Reviewed-by: Andrew Manley <andrew.manley@sealingtech.com> > > --- > > drivers/i2c/busses/i2c-imx.c | 23 +++++++++++++++-------- > > 1 file changed, 15 insertions(+), 8 deletions(-) > > > > diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c > > index 26a04dc0590b..4b0e9d1784dd 100644 > > --- a/drivers/i2c/busses/i2c-imx.c > > +++ b/drivers/i2c/busses/i2c-imx.c > > @@ -38,7 +38,7 @@ > > #include <linux/iopoll.h> > > #include <linux/kernel.h> > > #include <linux/spinlock.h> > > -#include <linux/timer.h> > > +#include <linux/hrtimer.h> > > #include <linux/module.h> > > #include <linux/of.h> > > #include <linux/of_device.h> > > @@ -53,6 +53,8 @@ > > /* This will be the driver name the kernel reports */ > > #define DRIVER_NAME "imx-i2c" > > > > +#define I2C_IMX_CHECK_DELAY 30000 /* Time to check for bus idle, in NS */ > > + > > /* > > * Enable DMA if transfer byte size is bigger than this threshold. > > * As the hardware request, it must bigger than 4 bytes.\ > > @@ -214,8 +216,8 @@ struct imx_i2c_struct { > > enum i2c_slave_event last_slave_event; > > > > /* For checking slave events. */ > > - spinlock_t slave_lock; > > - struct timer_list slave_timer; > > + spinlock_t slave_lock; > > + struct hrtimer slave_timer; > > This is unrelated to this patch, moreover it was introduced only in > patch 1. The second line is important for this patch, of course. I assume you mean the indention of the first line, which is just keeping things lined up. > > > }; > > > > static const struct imx_i2c_hwdata imx1_i2c_hwdata = { > > @@ -783,13 +785,16 @@ static irqreturn_t i2c_imx_slave_handle(struct imx_i2c_struct *i2c_imx, > > } > > > > out: > > - mod_timer(&i2c_imx->slave_timer, jiffies + 1); > > + hrtimer_try_to_cancel(&i2c_imx->slave_timer); > > Don't you need to check the return value here? Not really. The possible return values are: * * 0 when the timer was not active * * 1 when the timer was active * * -1 when the timer is currently executing the callback function and * cannot be stopped and if it returns 0 or 1, then everything is fine. If it returns -1, then the code will still work, though it may be redone (or already have been done) by the timer function. So it doesn't matter. Maybe I should add a comment about this? Thanks for reviewing. -corey > > > + hrtimer_forward_now(&i2c_imx->slave_timer, I2C_IMX_CHECK_DELAY); > > + hrtimer_restart(&i2c_imx->slave_timer); > > return IRQ_HANDLED; > > } > > > > Best regards > Uwe > > -- > Pengutronix e.K. | Uwe Kleine-König | > Industrial Linux Solutions | https://www.pengutronix.de/ | ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 3/3] i2c:imx: Use an hrtimer, not a timer, for checking for bus idle 2021-10-05 0:32 ` [PATCH 3/3] i2c:imx: Use an hrtimer, not a timer, for checking for bus idle minyard 2021-11-02 8:58 ` Uwe Kleine-König @ 2021-11-10 9:03 ` Oleksij Rempel 2021-11-10 14:45 ` Corey Minyard 1 sibling, 1 reply; 11+ messages in thread From: Oleksij Rempel @ 2021-11-10 9:03 UTC (permalink / raw) To: minyard Cc: Pengutronix Kernel Team, linux-i2c, Andrew Manley, linux-kernel, Corey Minyard On Mon, Oct 04, 2021 at 07:32:16PM -0500, minyard@acm.org wrote: > From: Corey Minyard <cminyard@mvista.com> > > The timer is too slow and significantly reduces performance. Use an > hrtimer to get things working faster. > > Signed-off-by: Corey Minyard <minyard@acm.org> > Tested-by: Andrew Manley <andrew.manley@sealingtech.com> > Reviewed-by: Andrew Manley <andrew.manley@sealingtech.com> Do we need to keep this change history? If no, please merge it to the first patch. > --- > drivers/i2c/busses/i2c-imx.c | 23 +++++++++++++++-------- > 1 file changed, 15 insertions(+), 8 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c > index 26a04dc0590b..4b0e9d1784dd 100644 > --- a/drivers/i2c/busses/i2c-imx.c > +++ b/drivers/i2c/busses/i2c-imx.c > @@ -38,7 +38,7 @@ > #include <linux/iopoll.h> > #include <linux/kernel.h> > #include <linux/spinlock.h> > -#include <linux/timer.h> > +#include <linux/hrtimer.h> > #include <linux/module.h> > #include <linux/of.h> > #include <linux/of_device.h> > @@ -53,6 +53,8 @@ > /* This will be the driver name the kernel reports */ > #define DRIVER_NAME "imx-i2c" > > +#define I2C_IMX_CHECK_DELAY 30000 /* Time to check for bus idle, in NS */ > + > /* > * Enable DMA if transfer byte size is bigger than this threshold. > * As the hardware request, it must bigger than 4 bytes.\ > @@ -214,8 +216,8 @@ struct imx_i2c_struct { > enum i2c_slave_event last_slave_event; > > /* For checking slave events. */ > - spinlock_t slave_lock; > - struct timer_list slave_timer; > + spinlock_t slave_lock; > + struct hrtimer slave_timer; > }; > > static const struct imx_i2c_hwdata imx1_i2c_hwdata = { > @@ -783,13 +785,16 @@ static irqreturn_t i2c_imx_slave_handle(struct imx_i2c_struct *i2c_imx, > } > > out: > - mod_timer(&i2c_imx->slave_timer, jiffies + 1); > + hrtimer_try_to_cancel(&i2c_imx->slave_timer); > + hrtimer_forward_now(&i2c_imx->slave_timer, I2C_IMX_CHECK_DELAY); > + hrtimer_restart(&i2c_imx->slave_timer); > return IRQ_HANDLED; > } > > -static void i2c_imx_slave_timeout(struct timer_list *t) > +static enum hrtimer_restart i2c_imx_slave_timeout(struct hrtimer *t) > { > - struct imx_i2c_struct *i2c_imx = from_timer(i2c_imx, t, slave_timer); > + struct imx_i2c_struct *i2c_imx = container_of(t, struct imx_i2c_struct, > + slave_timer); > unsigned int ctl, status; > unsigned long flags; > > @@ -798,6 +803,7 @@ static void i2c_imx_slave_timeout(struct timer_list *t) > ctl = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); > i2c_imx_slave_handle(i2c_imx, status, ctl); > spin_unlock_irqrestore(&i2c_imx->slave_lock, flags); > + return HRTIMER_NORESTART; > } > > static void i2c_imx_slave_init(struct imx_i2c_struct *i2c_imx) > @@ -1423,7 +1429,8 @@ static int i2c_imx_probe(struct platform_device *pdev) > return -ENOMEM; > > spin_lock_init(&i2c_imx->slave_lock); > - timer_setup(&i2c_imx->slave_timer, i2c_imx_slave_timeout, 0); > + hrtimer_init(&i2c_imx->slave_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); > + i2c_imx->slave_timer.function = i2c_imx_slave_timeout; > > match = device_get_match_data(&pdev->dev); > if (match) > @@ -1538,7 +1545,7 @@ static int i2c_imx_remove(struct platform_device *pdev) > if (ret < 0) > return ret; > > - del_timer_sync(&i2c_imx->slave_timer); > + hrtimer_cancel(&i2c_imx->slave_timer); > > /* remove adapter */ > dev_dbg(&i2c_imx->adapter.dev, "adapter removed\n"); > -- > 2.25.1 > > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 3/3] i2c:imx: Use an hrtimer, not a timer, for checking for bus idle 2021-11-10 9:03 ` Oleksij Rempel @ 2021-11-10 14:45 ` Corey Minyard 0 siblings, 0 replies; 11+ messages in thread From: Corey Minyard @ 2021-11-10 14:45 UTC (permalink / raw) To: Oleksij Rempel Cc: Pengutronix Kernel Team, linux-i2c, Andrew Manley, linux-kernel, Corey Minyard On Wed, Nov 10, 2021 at 10:03:38AM +0100, Oleksij Rempel wrote: > On Mon, Oct 04, 2021 at 07:32:16PM -0500, minyard@acm.org wrote: > > From: Corey Minyard <cminyard@mvista.com> > > > > The timer is too slow and significantly reduces performance. Use an > > hrtimer to get things working faster. > > > > Signed-off-by: Corey Minyard <minyard@acm.org> > > Tested-by: Andrew Manley <andrew.manley@sealingtech.com> > > Reviewed-by: Andrew Manley <andrew.manley@sealingtech.com> > > Do we need to keep this change history? If no, please merge it to the > first patch. Yeah, I can do that. It make sense. Thanks, -corey > > > --- > > drivers/i2c/busses/i2c-imx.c | 23 +++++++++++++++-------- > > 1 file changed, 15 insertions(+), 8 deletions(-) > > > > diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c > > index 26a04dc0590b..4b0e9d1784dd 100644 > > --- a/drivers/i2c/busses/i2c-imx.c > > +++ b/drivers/i2c/busses/i2c-imx.c > > @@ -38,7 +38,7 @@ > > #include <linux/iopoll.h> > > #include <linux/kernel.h> > > #include <linux/spinlock.h> > > -#include <linux/timer.h> > > +#include <linux/hrtimer.h> > > #include <linux/module.h> > > #include <linux/of.h> > > #include <linux/of_device.h> > > @@ -53,6 +53,8 @@ > > /* This will be the driver name the kernel reports */ > > #define DRIVER_NAME "imx-i2c" > > > > +#define I2C_IMX_CHECK_DELAY 30000 /* Time to check for bus idle, in NS */ > > + > > /* > > * Enable DMA if transfer byte size is bigger than this threshold. > > * As the hardware request, it must bigger than 4 bytes.\ > > @@ -214,8 +216,8 @@ struct imx_i2c_struct { > > enum i2c_slave_event last_slave_event; > > > > /* For checking slave events. */ > > - spinlock_t slave_lock; > > - struct timer_list slave_timer; > > + spinlock_t slave_lock; > > + struct hrtimer slave_timer; > > }; > > > > static const struct imx_i2c_hwdata imx1_i2c_hwdata = { > > @@ -783,13 +785,16 @@ static irqreturn_t i2c_imx_slave_handle(struct imx_i2c_struct *i2c_imx, > > } > > > > out: > > - mod_timer(&i2c_imx->slave_timer, jiffies + 1); > > + hrtimer_try_to_cancel(&i2c_imx->slave_timer); > > + hrtimer_forward_now(&i2c_imx->slave_timer, I2C_IMX_CHECK_DELAY); > > + hrtimer_restart(&i2c_imx->slave_timer); > > return IRQ_HANDLED; > > } > > > > -static void i2c_imx_slave_timeout(struct timer_list *t) > > +static enum hrtimer_restart i2c_imx_slave_timeout(struct hrtimer *t) > > { > > - struct imx_i2c_struct *i2c_imx = from_timer(i2c_imx, t, slave_timer); > > + struct imx_i2c_struct *i2c_imx = container_of(t, struct imx_i2c_struct, > > + slave_timer); > > unsigned int ctl, status; > > unsigned long flags; > > > > @@ -798,6 +803,7 @@ static void i2c_imx_slave_timeout(struct timer_list *t) > > ctl = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); > > i2c_imx_slave_handle(i2c_imx, status, ctl); > > spin_unlock_irqrestore(&i2c_imx->slave_lock, flags); > > + return HRTIMER_NORESTART; > > } > > > > static void i2c_imx_slave_init(struct imx_i2c_struct *i2c_imx) > > @@ -1423,7 +1429,8 @@ static int i2c_imx_probe(struct platform_device *pdev) > > return -ENOMEM; > > > > spin_lock_init(&i2c_imx->slave_lock); > > - timer_setup(&i2c_imx->slave_timer, i2c_imx_slave_timeout, 0); > > + hrtimer_init(&i2c_imx->slave_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); > > + i2c_imx->slave_timer.function = i2c_imx_slave_timeout; > > > > match = device_get_match_data(&pdev->dev); > > if (match) > > @@ -1538,7 +1545,7 @@ static int i2c_imx_remove(struct platform_device *pdev) > > if (ret < 0) > > return ret; > > > > - del_timer_sync(&i2c_imx->slave_timer); > > + hrtimer_cancel(&i2c_imx->slave_timer); > > > > /* remove adapter */ > > dev_dbg(&i2c_imx->adapter.dev, "adapter removed\n"); > > -- > > 2.25.1 > > > > > > -- > Pengutronix e.K. | | > Steuerwalder Str. 21 | http://www.pengutronix.de/ | > 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | > Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | ^ permalink raw reply [flat|nested] 11+ messages in thread
end of thread, other threads:[~2021-11-10 14:45 UTC | newest] Thread overview: 11+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2021-10-05 0:32 [PATCH 0/3] i2c:imx: Deliver a timely stop on slave side, fix recv minyard 2021-10-05 0:32 ` [PATCH 1/3] i2c:imx: Add timer for handling the stop condition minyard 2021-11-01 17:27 ` Corey Minyard 2021-11-10 8:58 ` Oleksij Rempel 2021-10-05 0:32 ` [PATCH 2/3] i2c:imx: Add an extra read at the end of an I2C slave read minyard 2021-11-10 8:58 ` Oleksij Rempel 2021-10-05 0:32 ` [PATCH 3/3] i2c:imx: Use an hrtimer, not a timer, for checking for bus idle minyard 2021-11-02 8:58 ` Uwe Kleine-König 2021-11-02 11:50 ` Corey Minyard 2021-11-10 9:03 ` Oleksij Rempel 2021-11-10 14:45 ` Corey Minyard
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