From: Stefan Lengfeld <contact@stefanchrist.eu>
To: Marco Felsch <m.felsch@pengutronix.de>
Cc: Stefan Riedmueller <s.riedmueller@phytec.de>,
shawnguo@kernel.org, s.hauer@pengutronix.de, stefan@agner.ch,
linux@rempel-privat.de, Oleksij Rempel <o.rempel@pengutronix.de>,
linux-imx@nxp.com, kernel@pengutronix.de, festevam@gmail.com,
linux-arm-kernel@lists.infradead.org, linux-i2c@vger.kernel.org
Subject: Re: [PATCH] i2c: imx: implement master_xfer_atomic callback
Date: Sun, 26 Jan 2020 18:53:01 +0100 [thread overview]
Message-ID: <20200126175301.upbrn5bx46wangbc@porty> (raw)
In-Reply-To: <20200120093650.12911-1-m.felsch@pengutronix.de>
Hi Marco,
On Mon, Jan 20, 2020 at 10:36:50AM +0100, Marco Felsch wrote:
> From: Stefan Lengfeld <contact@stefanchrist.eu>
>
> Rework the read and write code paths in the driver to support operation
> in atomic contexts. To achieve this, the driver must not rely on IRQs
> and not call schedule(), e.g. via a sleep routine, in these cases.
>
> With this patch the driver supports normal operation, DMA transfers and
> now the polling mode or also called sleep-free or IRQ-less operation. It
> makes the code not simpler or easier to read, but atomic I2C transfers
> are needed on some hardware configurations, e.g. to trigger reboots on
> an external PMIC chip.
>
> Signed-off-by: Stefan Lengfeld <contact@stefanchrist.eu>
> [m.felsch@pengutronix.de: integrate https://patchwork.ozlabs.org/patch/1085943/ review feedback]
nitpick(personal taste): This line can be wrapped to make the commit
message more readable in the output of 'git log'.
> [m.felsch@pengutronix.de: adapt commit message]
> Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
> Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Tested-by: Stefan Lengfeld <contact@stefanchrist.eu>
on a phyCORE-i.MX6 Quad with baseboard phyBOARD-Mira.
> ---
> Hi,
>
> I picked Stefan Lengfeld RFC patch [1] and added Stefan Agner's review
> feedback [1]. Checkpatch complains about a few 80 char violations. I
> kept those to gain readability.
>
> Regards,
> Marco
>
> [1] https://patchwork.ozlabs.org/patch/1085943/
>
> Changes:
> - general: adapt commit message
> - general: fix some 80char line issues
> - general: s/if(!atomic)/if(atomic)/
+1 avoiding negations are good for readability.
> - i2c_imx_trx_complete: use readb_poll_timeout_atomic()
> - i2c_imx_trx_complete: adapt poll_timeout and add poll_timeout calc comment
> - i2c_imx_start: simplify irq disable
> - i2c_imx_xfer_common: don't allow bus recovery within atomic context
> - i2c_imx_probe: drop pm_runtime_irq_safe usage and instead:
> * i2c_imx_xfer_common: move rpm calls into i2c_imx_xfer
> * i2c_imx_xfer_common: add clk_enable/disable for i2c_imx_xfer_atomic
Ack and thanks.
If you like, you can take over the authorship of this patch, because you
improved it substantially. To take the fame and the blame ;-) Otherwise
I'm also still fine being the author.
One additionally nitpick below.
> ---
> drivers/i2c/busses/i2c-imx.c | 146 +++++++++++++++++++++++++----------
> 1 file changed, 105 insertions(+), 41 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
> index a3b61336fe55..79d5b37fd8a1 100644
> --- a/drivers/i2c/busses/i2c-imx.c
> +++ b/drivers/i2c/busses/i2c-imx.c
> @@ -34,6 +34,7 @@
> #include <linux/init.h>
> #include <linux/interrupt.h>
> #include <linux/io.h>
> +#include <linux/iopoll.h>
> #include <linux/kernel.h>
> #include <linux/module.h>
> #include <linux/of.h>
> @@ -414,7 +415,7 @@ static void i2c_imx_dma_free(struct imx_i2c_struct *i2c_imx)
> dma->chan_using = NULL;
> }
>
> -static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy)
> +static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy, bool atomic)
> {
> unsigned long orig_jiffies = jiffies;
> unsigned int temp;
> @@ -444,15 +445,37 @@ static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy)
> "<%s> I2C bus is busy\n", __func__);
> return -ETIMEDOUT;
> }
> - schedule();
> + if (atomic)
> + udelay(100);
> + else
> + schedule();
> }
>
> return 0;
> }
>
> -static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx)
> +static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx, bool atomic)
> {
> - wait_event_timeout(i2c_imx->queue, i2c_imx->i2csr & I2SR_IIF, HZ / 10);
> + if (atomic) {
> + void __iomem *addr = i2c_imx->base + (IMX_I2C_I2SR << i2c_imx->hwdata->regshift);
> + unsigned int regval;
> +
> + /*
> + * The formula for the poll timeout is documented in the RM
> + * Rev.5 on page 1878:
> + * T_min = 10/F_scl
> + * Set the value hard as it is done for the non-atomic use-case.
> + * Use 10 kHz for the calculation since this is the minimum
> + * allowed SMBus frequency. Also add an offset of 100us since it
> + * turned out that the I2SR_IIF bit isn't set correctly within
> + * the minimum timeout in polling mode.
> + */
> + readb_poll_timeout_atomic(addr, regval, regval & I2SR_IIF, 5, 1000 + 100);
Nice.
> + i2c_imx->i2csr = regval;
> + imx_i2c_write_reg(0, i2c_imx, IMX_I2C_I2SR);
> + } else {
> + wait_event_timeout(i2c_imx->queue, i2c_imx->i2csr & I2SR_IIF, HZ / 10);
> + }
>
> if (unlikely(!(i2c_imx->i2csr & I2SR_IIF))) {
> dev_dbg(&i2c_imx->adapter.dev, "<%s> Timeout\n", __func__);
> @@ -530,7 +553,7 @@ static int i2c_imx_clk_notifier_call(struct notifier_block *nb,
> return NOTIFY_OK;
> }
>
> -static int i2c_imx_start(struct imx_i2c_struct *i2c_imx)
> +static int i2c_imx_start(struct imx_i2c_struct *i2c_imx, bool atomic)
> {
> unsigned int temp = 0;
> int result;
> @@ -543,23 +566,29 @@ static int i2c_imx_start(struct imx_i2c_struct *i2c_imx)
> imx_i2c_write_reg(i2c_imx->hwdata->i2cr_ien_opcode, i2c_imx, IMX_I2C_I2CR);
>
> /* Wait controller to be stable */
> - usleep_range(50, 150);
> + if (atomic)
> + udelay(50);
> + else
> + usleep_range(50, 150);
>
> /* Start I2C transaction */
> temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
> temp |= I2CR_MSTA;
> imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
> - result = i2c_imx_bus_busy(i2c_imx, 1);
> + result = i2c_imx_bus_busy(i2c_imx, 1, atomic);
> if (result)
> return result;
>
> temp |= I2CR_IIEN | I2CR_MTX | I2CR_TXAK;
> + if (atomic)
> + temp &= ~I2CR_IIEN; /* Disable interrupt */
> +
> temp &= ~I2CR_DMAEN;
> imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
> return result;
> }
>
> -static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx)
> +static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx, bool atomic)
> {
> unsigned int temp = 0;
>
> @@ -581,7 +610,7 @@ static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx)
> }
>
> if (!i2c_imx->stopped)
> - i2c_imx_bus_busy(i2c_imx, 0);
> + i2c_imx_bus_busy(i2c_imx, 0, atomic);
>
> /* Disable I2C controller */
> temp = i2c_imx->hwdata->i2cr_ien_opcode ^ I2CR_IEN,
> @@ -662,7 +691,7 @@ static int i2c_imx_dma_write(struct imx_i2c_struct *i2c_imx,
> /* The last data byte must be transferred by the CPU. */
> imx_i2c_write_reg(msgs->buf[msgs->len-1],
> i2c_imx, IMX_I2C_I2DR);
> - result = i2c_imx_trx_complete(i2c_imx);
> + result = i2c_imx_trx_complete(i2c_imx, false);
> if (result)
> return result;
>
> @@ -721,7 +750,7 @@ static int i2c_imx_dma_read(struct imx_i2c_struct *i2c_imx,
>
> msgs->buf[msgs->len-2] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
> /* read n byte data */
> - result = i2c_imx_trx_complete(i2c_imx);
> + result = i2c_imx_trx_complete(i2c_imx, false);
> if (result)
> return result;
>
> @@ -734,7 +763,7 @@ static int i2c_imx_dma_read(struct imx_i2c_struct *i2c_imx,
> temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
> temp &= ~(I2CR_MSTA | I2CR_MTX);
> imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
> - i2c_imx_bus_busy(i2c_imx, 0);
> + i2c_imx_bus_busy(i2c_imx, 0, false);
> } else {
> /*
> * For i2c master receiver repeat restart operation like:
> @@ -752,7 +781,8 @@ static int i2c_imx_dma_read(struct imx_i2c_struct *i2c_imx,
> return 0;
> }
>
> -static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
> +static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs,
> + bool atomic)
> {
> int i, result;
>
> @@ -761,7 +791,7 @@ static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
>
> /* write slave address */
> imx_i2c_write_reg(i2c_8bit_addr_from_msg(msgs), i2c_imx, IMX_I2C_I2DR);
> - result = i2c_imx_trx_complete(i2c_imx);
> + result = i2c_imx_trx_complete(i2c_imx, atomic);
> if (result)
> return result;
> result = i2c_imx_acked(i2c_imx);
> @@ -775,7 +805,7 @@ static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
> "<%s> write byte: B%d=0x%X\n",
> __func__, i, msgs->buf[i]);
> imx_i2c_write_reg(msgs->buf[i], i2c_imx, IMX_I2C_I2DR);
> - result = i2c_imx_trx_complete(i2c_imx);
> + result = i2c_imx_trx_complete(i2c_imx, atomic);
> if (result)
> return result;
> result = i2c_imx_acked(i2c_imx);
> @@ -785,7 +815,8 @@ static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
> return 0;
> }
>
> -static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, bool is_lastmsg)
> +static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs,
> + bool is_lastmsg, bool atomic)
> {
> int i, result;
> unsigned int temp;
> @@ -798,7 +829,7 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, bo
>
> /* write slave address */
> imx_i2c_write_reg(i2c_8bit_addr_from_msg(msgs), i2c_imx, IMX_I2C_I2DR);
> - result = i2c_imx_trx_complete(i2c_imx);
> + result = i2c_imx_trx_complete(i2c_imx, atomic);
> if (result)
> return result;
> result = i2c_imx_acked(i2c_imx);
> @@ -831,7 +862,7 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, bo
> for (i = 0; i < msgs->len; i++) {
> u8 len = 0;
>
> - result = i2c_imx_trx_complete(i2c_imx);
> + result = i2c_imx_trx_complete(i2c_imx, atomic);
> if (result)
> return result;
> /*
> @@ -859,7 +890,7 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, bo
> temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
> temp &= ~(I2CR_MSTA | I2CR_MTX);
> imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
> - i2c_imx_bus_busy(i2c_imx, 0);
> + i2c_imx_bus_busy(i2c_imx, 0, atomic);
> } else {
> /*
> * For i2c master receiver repeat restart operation like:
> @@ -890,8 +921,8 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, bo
> return 0;
> }
>
> -static int i2c_imx_xfer(struct i2c_adapter *adapter,
> - struct i2c_msg *msgs, int num)
> +static int i2c_imx_xfer_common(struct i2c_adapter *adapter,
> + struct i2c_msg *msgs, int num, bool atomic)
nitpick(cleanup): The function argument 'struct i2c_adapter *adapter'
can be replaced with 'struct imx_i2c_struct *i2c_imx'. The adapter
pointer is already 'dereferenced' in the calling functions
i2c_imx_xfer() and
i2c_imx_xfer_atomic()
This avoids the second call 'i2c_get_adapdata(adapter)' some lines
below.
Kind regards,
Stefan
WARNING: multiple messages have this Message-ID (diff)
From: Stefan Lengfeld <contact@stefanchrist.eu>
To: Marco Felsch <m.felsch@pengutronix.de>
Cc: Stefan Riedmueller <s.riedmueller@phytec.de>,
shawnguo@kernel.org, s.hauer@pengutronix.de, stefan@agner.ch,
linux@rempel-privat.de, Oleksij Rempel <o.rempel@pengutronix.de>,
linux-imx@nxp.com, kernel@pengutronix.de, festevam@gmail.com,
linux-arm-kernel@lists.infradead.org, linux-i2c@vger.kernel.org
Subject: Re: [PATCH] i2c: imx: implement master_xfer_atomic callback
Date: Sun, 26 Jan 2020 18:53:01 +0100 [thread overview]
Message-ID: <20200126175301.upbrn5bx46wangbc@porty> (raw)
In-Reply-To: <20200120093650.12911-1-m.felsch@pengutronix.de>
Hi Marco,
On Mon, Jan 20, 2020 at 10:36:50AM +0100, Marco Felsch wrote:
> From: Stefan Lengfeld <contact@stefanchrist.eu>
>
> Rework the read and write code paths in the driver to support operation
> in atomic contexts. To achieve this, the driver must not rely on IRQs
> and not call schedule(), e.g. via a sleep routine, in these cases.
>
> With this patch the driver supports normal operation, DMA transfers and
> now the polling mode or also called sleep-free or IRQ-less operation. It
> makes the code not simpler or easier to read, but atomic I2C transfers
> are needed on some hardware configurations, e.g. to trigger reboots on
> an external PMIC chip.
>
> Signed-off-by: Stefan Lengfeld <contact@stefanchrist.eu>
> [m.felsch@pengutronix.de: integrate https://patchwork.ozlabs.org/patch/1085943/ review feedback]
nitpick(personal taste): This line can be wrapped to make the commit
message more readable in the output of 'git log'.
> [m.felsch@pengutronix.de: adapt commit message]
> Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
> Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Tested-by: Stefan Lengfeld <contact@stefanchrist.eu>
on a phyCORE-i.MX6 Quad with baseboard phyBOARD-Mira.
> ---
> Hi,
>
> I picked Stefan Lengfeld RFC patch [1] and added Stefan Agner's review
> feedback [1]. Checkpatch complains about a few 80 char violations. I
> kept those to gain readability.
>
> Regards,
> Marco
>
> [1] https://patchwork.ozlabs.org/patch/1085943/
>
> Changes:
> - general: adapt commit message
> - general: fix some 80char line issues
> - general: s/if(!atomic)/if(atomic)/
+1 avoiding negations are good for readability.
> - i2c_imx_trx_complete: use readb_poll_timeout_atomic()
> - i2c_imx_trx_complete: adapt poll_timeout and add poll_timeout calc comment
> - i2c_imx_start: simplify irq disable
> - i2c_imx_xfer_common: don't allow bus recovery within atomic context
> - i2c_imx_probe: drop pm_runtime_irq_safe usage and instead:
> * i2c_imx_xfer_common: move rpm calls into i2c_imx_xfer
> * i2c_imx_xfer_common: add clk_enable/disable for i2c_imx_xfer_atomic
Ack and thanks.
If you like, you can take over the authorship of this patch, because you
improved it substantially. To take the fame and the blame ;-) Otherwise
I'm also still fine being the author.
One additionally nitpick below.
> ---
> drivers/i2c/busses/i2c-imx.c | 146 +++++++++++++++++++++++++----------
> 1 file changed, 105 insertions(+), 41 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
> index a3b61336fe55..79d5b37fd8a1 100644
> --- a/drivers/i2c/busses/i2c-imx.c
> +++ b/drivers/i2c/busses/i2c-imx.c
> @@ -34,6 +34,7 @@
> #include <linux/init.h>
> #include <linux/interrupt.h>
> #include <linux/io.h>
> +#include <linux/iopoll.h>
> #include <linux/kernel.h>
> #include <linux/module.h>
> #include <linux/of.h>
> @@ -414,7 +415,7 @@ static void i2c_imx_dma_free(struct imx_i2c_struct *i2c_imx)
> dma->chan_using = NULL;
> }
>
> -static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy)
> +static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy, bool atomic)
> {
> unsigned long orig_jiffies = jiffies;
> unsigned int temp;
> @@ -444,15 +445,37 @@ static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy)
> "<%s> I2C bus is busy\n", __func__);
> return -ETIMEDOUT;
> }
> - schedule();
> + if (atomic)
> + udelay(100);
> + else
> + schedule();
> }
>
> return 0;
> }
>
> -static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx)
> +static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx, bool atomic)
> {
> - wait_event_timeout(i2c_imx->queue, i2c_imx->i2csr & I2SR_IIF, HZ / 10);
> + if (atomic) {
> + void __iomem *addr = i2c_imx->base + (IMX_I2C_I2SR << i2c_imx->hwdata->regshift);
> + unsigned int regval;
> +
> + /*
> + * The formula for the poll timeout is documented in the RM
> + * Rev.5 on page 1878:
> + * T_min = 10/F_scl
> + * Set the value hard as it is done for the non-atomic use-case.
> + * Use 10 kHz for the calculation since this is the minimum
> + * allowed SMBus frequency. Also add an offset of 100us since it
> + * turned out that the I2SR_IIF bit isn't set correctly within
> + * the minimum timeout in polling mode.
> + */
> + readb_poll_timeout_atomic(addr, regval, regval & I2SR_IIF, 5, 1000 + 100);
Nice.
> + i2c_imx->i2csr = regval;
> + imx_i2c_write_reg(0, i2c_imx, IMX_I2C_I2SR);
> + } else {
> + wait_event_timeout(i2c_imx->queue, i2c_imx->i2csr & I2SR_IIF, HZ / 10);
> + }
>
> if (unlikely(!(i2c_imx->i2csr & I2SR_IIF))) {
> dev_dbg(&i2c_imx->adapter.dev, "<%s> Timeout\n", __func__);
> @@ -530,7 +553,7 @@ static int i2c_imx_clk_notifier_call(struct notifier_block *nb,
> return NOTIFY_OK;
> }
>
> -static int i2c_imx_start(struct imx_i2c_struct *i2c_imx)
> +static int i2c_imx_start(struct imx_i2c_struct *i2c_imx, bool atomic)
> {
> unsigned int temp = 0;
> int result;
> @@ -543,23 +566,29 @@ static int i2c_imx_start(struct imx_i2c_struct *i2c_imx)
> imx_i2c_write_reg(i2c_imx->hwdata->i2cr_ien_opcode, i2c_imx, IMX_I2C_I2CR);
>
> /* Wait controller to be stable */
> - usleep_range(50, 150);
> + if (atomic)
> + udelay(50);
> + else
> + usleep_range(50, 150);
>
> /* Start I2C transaction */
> temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
> temp |= I2CR_MSTA;
> imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
> - result = i2c_imx_bus_busy(i2c_imx, 1);
> + result = i2c_imx_bus_busy(i2c_imx, 1, atomic);
> if (result)
> return result;
>
> temp |= I2CR_IIEN | I2CR_MTX | I2CR_TXAK;
> + if (atomic)
> + temp &= ~I2CR_IIEN; /* Disable interrupt */
> +
> temp &= ~I2CR_DMAEN;
> imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
> return result;
> }
>
> -static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx)
> +static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx, bool atomic)
> {
> unsigned int temp = 0;
>
> @@ -581,7 +610,7 @@ static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx)
> }
>
> if (!i2c_imx->stopped)
> - i2c_imx_bus_busy(i2c_imx, 0);
> + i2c_imx_bus_busy(i2c_imx, 0, atomic);
>
> /* Disable I2C controller */
> temp = i2c_imx->hwdata->i2cr_ien_opcode ^ I2CR_IEN,
> @@ -662,7 +691,7 @@ static int i2c_imx_dma_write(struct imx_i2c_struct *i2c_imx,
> /* The last data byte must be transferred by the CPU. */
> imx_i2c_write_reg(msgs->buf[msgs->len-1],
> i2c_imx, IMX_I2C_I2DR);
> - result = i2c_imx_trx_complete(i2c_imx);
> + result = i2c_imx_trx_complete(i2c_imx, false);
> if (result)
> return result;
>
> @@ -721,7 +750,7 @@ static int i2c_imx_dma_read(struct imx_i2c_struct *i2c_imx,
>
> msgs->buf[msgs->len-2] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
> /* read n byte data */
> - result = i2c_imx_trx_complete(i2c_imx);
> + result = i2c_imx_trx_complete(i2c_imx, false);
> if (result)
> return result;
>
> @@ -734,7 +763,7 @@ static int i2c_imx_dma_read(struct imx_i2c_struct *i2c_imx,
> temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
> temp &= ~(I2CR_MSTA | I2CR_MTX);
> imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
> - i2c_imx_bus_busy(i2c_imx, 0);
> + i2c_imx_bus_busy(i2c_imx, 0, false);
> } else {
> /*
> * For i2c master receiver repeat restart operation like:
> @@ -752,7 +781,8 @@ static int i2c_imx_dma_read(struct imx_i2c_struct *i2c_imx,
> return 0;
> }
>
> -static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
> +static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs,
> + bool atomic)
> {
> int i, result;
>
> @@ -761,7 +791,7 @@ static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
>
> /* write slave address */
> imx_i2c_write_reg(i2c_8bit_addr_from_msg(msgs), i2c_imx, IMX_I2C_I2DR);
> - result = i2c_imx_trx_complete(i2c_imx);
> + result = i2c_imx_trx_complete(i2c_imx, atomic);
> if (result)
> return result;
> result = i2c_imx_acked(i2c_imx);
> @@ -775,7 +805,7 @@ static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
> "<%s> write byte: B%d=0x%X\n",
> __func__, i, msgs->buf[i]);
> imx_i2c_write_reg(msgs->buf[i], i2c_imx, IMX_I2C_I2DR);
> - result = i2c_imx_trx_complete(i2c_imx);
> + result = i2c_imx_trx_complete(i2c_imx, atomic);
> if (result)
> return result;
> result = i2c_imx_acked(i2c_imx);
> @@ -785,7 +815,8 @@ static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
> return 0;
> }
>
> -static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, bool is_lastmsg)
> +static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs,
> + bool is_lastmsg, bool atomic)
> {
> int i, result;
> unsigned int temp;
> @@ -798,7 +829,7 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, bo
>
> /* write slave address */
> imx_i2c_write_reg(i2c_8bit_addr_from_msg(msgs), i2c_imx, IMX_I2C_I2DR);
> - result = i2c_imx_trx_complete(i2c_imx);
> + result = i2c_imx_trx_complete(i2c_imx, atomic);
> if (result)
> return result;
> result = i2c_imx_acked(i2c_imx);
> @@ -831,7 +862,7 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, bo
> for (i = 0; i < msgs->len; i++) {
> u8 len = 0;
>
> - result = i2c_imx_trx_complete(i2c_imx);
> + result = i2c_imx_trx_complete(i2c_imx, atomic);
> if (result)
> return result;
> /*
> @@ -859,7 +890,7 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, bo
> temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
> temp &= ~(I2CR_MSTA | I2CR_MTX);
> imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
> - i2c_imx_bus_busy(i2c_imx, 0);
> + i2c_imx_bus_busy(i2c_imx, 0, atomic);
> } else {
> /*
> * For i2c master receiver repeat restart operation like:
> @@ -890,8 +921,8 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, bo
> return 0;
> }
>
> -static int i2c_imx_xfer(struct i2c_adapter *adapter,
> - struct i2c_msg *msgs, int num)
> +static int i2c_imx_xfer_common(struct i2c_adapter *adapter,
> + struct i2c_msg *msgs, int num, bool atomic)
nitpick(cleanup): The function argument 'struct i2c_adapter *adapter'
can be replaced with 'struct imx_i2c_struct *i2c_imx'. The adapter
pointer is already 'dereferenced' in the calling functions
i2c_imx_xfer() and
i2c_imx_xfer_atomic()
This avoids the second call 'i2c_get_adapdata(adapter)' some lines
below.
Kind regards,
Stefan
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next prev parent reply other threads:[~2020-01-26 17:53 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-20 9:36 [PATCH] i2c: imx: implement master_xfer_atomic callback Marco Felsch
2020-01-20 9:36 ` Marco Felsch
2020-01-20 10:03 ` Stefan Agner
2020-01-20 10:03 ` Stefan Agner
2020-01-20 10:39 ` Marco Felsch
2020-01-20 10:39 ` Marco Felsch
2020-01-26 17:53 ` Stefan Lengfeld [this message]
2020-01-26 17:53 ` Stefan Lengfeld
2020-02-18 14:04 ` Marco Felsch
2020-02-18 14:04 ` Marco Felsch
2020-02-22 11:55 ` Wolfram Sang
2020-02-22 11:55 ` Wolfram Sang
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