From: Hugo Villeneuve <[email protected]>
Hello,
this patch series mainly fixes a GPIO regression and improve RS485 flags and properties
detection from DT.
It now also includes various small fixes and improvements that were previously
sent as separate patches, but that made testing everything difficult.
Patches 1 and 2 are simple comments fix/improvements.
Patch 3 fixes an issue when debugging IOcontrol register. After testing the GPIO
regression patches (patches 6 and 7, tests done by Lech Perczak), it appers that
this patch is also necessary for having the correct IOcontrol register values.
Patch 4 introduces a delay after a reset operation to respect datasheet
timing recommandations.
Patch 5 fixes an issue with init of first port during probing. This commit
brings some questions and I appreciate if people from the serial subsystem could
comment on my proposed solution.
Patch 6 fixes a bug with the output value when first setting the GPIO direction.
Patch 7, 8 and 9 fix a GPIO regression by (re)allowing to choose GPIO function for
GPIO pins shared with modem status lines.
Patch 10 allows to read common rs485 device-tree flags and properties.
Patch 11 add a custom dump function as relying on regmal debugfs is not really
practical for this driver.
I have tested the changes on a custom board with two SC16IS752 DUART using a
Variscite IMX8MN NANO SOM.
Thank you.
Link: [v1] https://lkml.org/lkml/2023/5/17/967
[v1] https://lkml.org/lkml/2023/5/17/777
[v1] https://lkml.org/lkml/2023/5/17/780
[v1] https://lkml.org/lkml/2023/5/17/785
[v1] https://lkml.org/lkml/2023/5/17/1311
[v2] https://lkml.org/lkml/2023/5/18/516
Changes for V3:
- Integrated all patches into single serie to facilitate debugging and tests.
- Reduce number of exported GPIOs depending on new property nxp,modem-control-line-ports
- Added additional example in DT bindings
Hugo Villeneuve (11):
serial: sc16is7xx: fix syntax error in comments
serial: sc16is7xx: improve comments about variants
serial: sc16is7xx: mark IOCONTROL register as volatile
serial: sc16is7xx: add post reset delay
serial: sc16is7xx: fix broken port 0 uart init
serial: sc16is7xx: fix bug when first setting GPIO direction
dt-bindings: sc16is7xx: Add property to change GPIO function
serial: sc16is7xx: fix regression with GPIO configuration
serial: sc16is7xx: add I/O register translation offset
serial: sc16is7xx: add call to get rs485 DT flags and properties
serial: sc16is7xx: add dump registers function
.../bindings/serial/nxp,sc16is7xx.txt | 46 +++++
drivers/tty/serial/sc16is7xx.c | 180 +++++++++++++++---
2 files changed, 199 insertions(+), 27 deletions(-)
base-commit: 933174ae28ba72ab8de5b35cb7c98fc211235096
--
2.30.2
From: Hugo Villeneuve <[email protected]>
Commit 679875d1d880 ("sc16is7xx: Separate GPIOs from modem control lines")
and commit 21144bab4f11 ("sc16is7xx: Handle modem status lines")
changed the function of the GPIOs pins to act as modem control
lines without any possibility of selecting GPIO function.
As a consequence, applications that depends on GPIO lines configured
by default as GPIO pins no longer work as expected.
Also, the change to select modem control lines function was done only
for channel A of dual UART variants (752/762). This was not documented
in the log message.
This new patch allows to specify GPIO or modem control line function
in the device tree, and for each of the ports (A or B).
This is done by using the new device-tree property named
"modem-control-line-ports" (property added in separate patch).
We also now reduce the number of exported GPIOs according to the
modem-status-line-port DT property.
Boards that need to have GPIOS configured as modem control lines
should add that property to their device tree. Here is a list of
boards using the sc16is7xx driver in their device tree and that may
need to be modified:
arm64/boot/dts/freescale/fsl-ls1012a-frdm.dts
mips/boot/dts/ingenic/cu1830-neo.dts
mips/boot/dts/ingenic/cu1000-neo.dts
Fixes: 679875d1d880 ("sc16is7xx: Separate GPIOs from modem control lines")
Fixes: 21144bab4f11 ("sc16is7xx: Handle modem status lines")
Signed-off-by: Hugo Villeneuve <[email protected]>
---
drivers/tty/serial/sc16is7xx.c | 65 +++++++++++++++++++++++-----------
1 file changed, 44 insertions(+), 21 deletions(-)
diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index a5d8af0f6da0..97ec532a0a19 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -236,7 +236,8 @@
/* IOControl register bits (Only 75x/76x) */
#define SC16IS7XX_IOCONTROL_LATCH_BIT (1 << 0) /* Enable input latching */
-#define SC16IS7XX_IOCONTROL_MODEM_BIT (1 << 1) /* Enable GPIO[7:4] as modem pins */
+#define SC16IS7XX_IOCONTROL_MODEM_A_BIT (1 << 1) /* Enable GPIO[7:4] as modem A pins */
+#define SC16IS7XX_IOCONTROL_MODEM_B_BIT (1 << 2) /* Enable GPIO[3:0] as modem B pins */
#define SC16IS7XX_IOCONTROL_SRESET_BIT (1 << 3) /* Software Reset */
/* EFCR register bits */
@@ -301,12 +302,12 @@
/* Misc definitions */
#define SC16IS7XX_FIFO_SIZE (64)
#define SC16IS7XX_REG_SHIFT 2
+#define SC16IS7XX_GPIOS_PER_BANK 4
struct sc16is7xx_devtype {
char name[10];
int nr_gpio;
int nr_uart;
- int has_mctrl;
};
#define SC16IS7XX_RECONF_MD (1 << 0)
@@ -336,6 +337,7 @@ struct sc16is7xx_port {
struct clk *clk;
#ifdef CONFIG_GPIOLIB
struct gpio_chip gpio;
+ int gpio_configured;
#endif
unsigned char buf[SC16IS7XX_FIFO_SIZE];
struct kthread_worker kworker;
@@ -447,35 +449,30 @@ static const struct sc16is7xx_devtype sc16is74x_devtype = {
.name = "SC16IS74X",
.nr_gpio = 0,
.nr_uart = 1,
- .has_mctrl = 0,
};
static const struct sc16is7xx_devtype sc16is750_devtype = {
.name = "SC16IS750",
- .nr_gpio = 4,
+ .nr_gpio = 8,
.nr_uart = 1,
- .has_mctrl = 1,
};
static const struct sc16is7xx_devtype sc16is752_devtype = {
.name = "SC16IS752",
- .nr_gpio = 0,
+ .nr_gpio = 8,
.nr_uart = 2,
- .has_mctrl = 1,
};
static const struct sc16is7xx_devtype sc16is760_devtype = {
.name = "SC16IS760",
- .nr_gpio = 4,
+ .nr_gpio = 8,
.nr_uart = 1,
- .has_mctrl = 1,
};
static const struct sc16is7xx_devtype sc16is762_devtype = {
.name = "SC16IS762",
- .nr_gpio = 0,
+ .nr_gpio = 8,
.nr_uart = 2,
- .has_mctrl = 1,
};
static bool sc16is7xx_regmap_volatile(struct device *dev, unsigned int reg)
@@ -1396,6 +1393,10 @@ static int sc16is7xx_probe(struct device *dev,
return -ENOMEM;
}
+#ifdef CONFIG_GPIOLIB
+ s->gpio_configured = devtype->nr_gpio;
+#endif /* CONFIG_GPIOLIB */
+
/* Always ask for fixed clock rate from a property. */
device_property_read_u32(dev, "clock-frequency", &uartclk);
@@ -1473,12 +1474,6 @@ static int sc16is7xx_probe(struct device *dev,
SC16IS7XX_EFCR_RXDISABLE_BIT |
SC16IS7XX_EFCR_TXDISABLE_BIT);
- /* Use GPIO lines as modem status registers */
- if (devtype->has_mctrl)
- sc16is7xx_port_write(&s->p[i].port,
- SC16IS7XX_IOCONTROL_REG,
- SC16IS7XX_IOCONTROL_MODEM_BIT);
-
/* Initialize kthread work structs */
kthread_init_work(&s->p[i].tx_work, sc16is7xx_tx_proc);
kthread_init_work(&s->p[i].reg_work, sc16is7xx_reg_proc);
@@ -1514,10 +1509,38 @@ static int sc16is7xx_probe(struct device *dev,
prop, p, u)
if (u < devtype->nr_uart)
s->p[u].irda_mode = true;
+
+ val = 0;
+
+ of_property_for_each_u32(dev->of_node, "nxp,modem-control-line-ports",
+ prop, p, u)
+ if (u < devtype->nr_uart) {
+ /* Use GPIO lines as modem control lines */
+ if (u == 0)
+ val |= SC16IS7XX_IOCONTROL_MODEM_A_BIT;
+ else if (u == 1)
+ val |= SC16IS7XX_IOCONTROL_MODEM_B_BIT;
+
+#ifdef CONFIG_GPIOLIB
+ if (s->gpio_configured >=
+ SC16IS7XX_GPIOS_PER_BANK)
+ s->gpio_configured -=
+ SC16IS7XX_GPIOS_PER_BANK;
+#endif /* CONFIG_GPIOLIB */
+ }
+
+ if (val)
+ regmap_update_bits(
+ s->regmap,
+ SC16IS7XX_IOCONTROL_REG << SC16IS7XX_REG_SHIFT,
+ SC16IS7XX_IOCONTROL_MODEM_A_BIT |
+ SC16IS7XX_IOCONTROL_MODEM_B_BIT, val);
}
#ifdef CONFIG_GPIOLIB
- if (devtype->nr_gpio) {
+ dev_dbg(dev, "GPIOs to configure: %d\n", s->gpio_configured);
+
+ if (s->gpio_configured) {
/* Setup GPIO controller */
s->gpio.owner = THIS_MODULE;
s->gpio.parent = dev;
@@ -1527,7 +1550,7 @@ static int sc16is7xx_probe(struct device *dev,
s->gpio.direction_output = sc16is7xx_gpio_direction_output;
s->gpio.set = sc16is7xx_gpio_set;
s->gpio.base = -1;
- s->gpio.ngpio = devtype->nr_gpio;
+ s->gpio.ngpio = s->gpio_configured;
s->gpio.can_sleep = 1;
ret = gpiochip_add_data(&s->gpio, s);
if (ret)
@@ -1555,7 +1578,7 @@ static int sc16is7xx_probe(struct device *dev,
return 0;
#ifdef CONFIG_GPIOLIB
- if (devtype->nr_gpio)
+ if (s->gpio_configured)
gpiochip_remove(&s->gpio);
out_thread:
@@ -1581,7 +1604,7 @@ static void sc16is7xx_remove(struct device *dev)
int i;
#ifdef CONFIG_GPIOLIB
- if (s->devtype->nr_gpio)
+ if (s->gpio_configured)
gpiochip_remove(&s->gpio);
#endif
--
2.30.2
From: Hugo Villeneuve <[email protected]>
When we want to configure a pin as an output pin with a value of logic
0, we end up as having a value of logic 1 on the output pin. Setting a
logic 0 a second time (or more) after that will correctly output a
logic 0 on the output pin.
By default, all GPIO pins are configured as inputs. When we enter
c16is7xx_gpio_direction_output() for the first time, we first set the
desired value in IOSTATE, and then we configure the pin as an output.
The datasheet states that writing to IOSTATE register will trigger a
transfer of the value to the I/O pin configured as output, so if the
pin is configured as an input, nothing will be transferred.
Therefore, set the direction first in IODIR, and then set the desired
value in IOSTATE.
This is what is done in NXP application note AN10587.
Fixes: dfeae619d781 ("serial: sc16is7xx")
Signed-off-by: Hugo Villeneuve <[email protected]>
---
drivers/tty/serial/sc16is7xx.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index 8a2fc6f89d36..a5d8af0f6da0 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -1343,9 +1343,18 @@ static int sc16is7xx_gpio_direction_output(struct gpio_chip *chip,
state |= BIT(offset);
else
state &= ~BIT(offset);
- sc16is7xx_port_write(port, SC16IS7XX_IOSTATE_REG, state);
+
+ /*
+ * If we write IOSTATE first, and then IODIR, the output value is not
+ * transferred to the corresponding I/O pin.
+ * The datasheet states that each register bit will be transferred to
+ * the corresponding I/O pin programmed as output when writing to
+ * IOSTATE. Therefore, configure direction first with IODIR, and then
+ * set value after with IOSTATE.
+ */
sc16is7xx_port_update(port, SC16IS7XX_IODIR_REG, BIT(offset),
BIT(offset));
+ sc16is7xx_port_write(port, SC16IS7XX_IOSTATE_REG, state);
return 0;
}
--
2.30.2
From: Hugo Villeneuve <[email protected]>
cotroller -> controller
Signed-off-by: Hugo Villeneuve <[email protected]>
---
drivers/tty/serial/sc16is7xx.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index abad091baeea..5bd98e4316f5 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -1501,7 +1501,7 @@ static int sc16is7xx_probe(struct device *dev,
#ifdef CONFIG_GPIOLIB
if (devtype->nr_gpio) {
- /* Setup GPIO cotroller */
+ /* Setup GPIO controller */
s->gpio.owner = THIS_MODULE;
s->gpio.parent = dev;
s->gpio.label = dev_name(dev);
--
2.30.2
From: Hugo Villeneuve <[email protected]>
Add call to uart_get_rs485_mode() to probe for RS485 flags and
properties from device tree.
Signed-off-by: Hugo Villeneuve <[email protected]>
---
drivers/tty/serial/sc16is7xx.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index c2cfd057ed9a..03d00b144304 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -1511,6 +1511,10 @@ static int sc16is7xx_probe(struct device *dev,
goto out_ports;
}
+ ret = uart_get_rs485_mode(&s->p[i].port);
+ if (ret)
+ goto out_ports;
+
/* Disable all interrupts */
sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_IER_REG, 0);
/* Disable TX/RX */
--
2.30.2
From: Hugo Villeneuve <[email protected]>
Replace 740/750/760 with generic terms like 74x/75x/76x to account for
variants like 741, 752 and 762.
Signed-off-by: Hugo Villeneuve <[email protected]>
---
drivers/tty/serial/sc16is7xx.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index 5bd98e4316f5..00054bb49780 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -223,7 +223,7 @@
* trigger levels. Trigger levels from 4 characters to 60 characters are
* available with a granularity of four.
*
- * When the trigger level setting in TLR is zero, the SC16IS740/750/760 uses the
+ * When the trigger level setting in TLR is zero, the SC16IS74x/75x/76x uses the
* trigger level setting defined in FCR. If TLR has non-zero trigger level value
* the trigger level defined in FCR is discarded. This applies to both transmit
* FIFO and receive FIFO trigger level setting.
@@ -234,7 +234,7 @@
#define SC16IS7XX_TLR_TX_TRIGGER(words) ((((words) / 4) & 0x0f) << 0)
#define SC16IS7XX_TLR_RX_TRIGGER(words) ((((words) / 4) & 0x0f) << 4)
-/* IOControl register bits (Only 750/760) */
+/* IOControl register bits (Only 75x/76x) */
#define SC16IS7XX_IOCONTROL_LATCH_BIT (1 << 0) /* Enable input latching */
#define SC16IS7XX_IOCONTROL_MODEM_BIT (1 << 1) /* Enable GPIO[7:4] as modem pins */
#define SC16IS7XX_IOCONTROL_SRESET_BIT (1 << 3) /* Software Reset */
@@ -248,9 +248,9 @@
#define SC16IS7XX_EFCR_RTS_INVERT_BIT (1 << 5) /* RTS output inversion */
#define SC16IS7XX_EFCR_IRDA_MODE_BIT (1 << 7) /* IrDA mode
* 0 = rate upto 115.2 kbit/s
- * - Only 750/760
+ * - Only 75x/76x
* 1 = rate upto 1.152 Mbit/s
- * - Only 760
+ * - Only 76x
*/
/* EFR register bits */
--
2.30.2
From: Hugo Villeneuve <[email protected]>
Make sure we wait at least 3us before initiating communication with
the device after reset.
Signed-off-by: Hugo Villeneuve <[email protected]>
---
drivers/tty/serial/sc16is7xx.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index a7c4da3cfd2b..af7e66db54b4 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -1428,6 +1428,12 @@ static int sc16is7xx_probe(struct device *dev,
regmap_write(s->regmap, SC16IS7XX_IOCONTROL_REG << SC16IS7XX_REG_SHIFT,
SC16IS7XX_IOCONTROL_SRESET_BIT);
+ /*
+ * After reset, the host must wait at least 3us before initializing a
+ * communication with the device.
+ */
+ usleep_range(3, 5);
+
for (i = 0; i < devtype->nr_uart; ++i) {
s->p[i].line = i;
/* Initialize port data */
--
2.30.2
Thu, May 25, 2023 at 12:03:17AM -0400, Hugo Villeneuve kirjoitti:
> From: Hugo Villeneuve <[email protected]>
>
> Make sure we wait at least 3us before initiating communication with
> the device after reset.
...
> + usleep_range(3, 5);
I would put (5, 10) instead to relax a bit the scheduler.
--
With Best Regards,
Andy Shevchenko
Thu, May 25, 2023 at 12:03:13AM -0400, Hugo Villeneuve kirjoitti:
> From: Hugo Villeneuve <[email protected]>
>
> Hello,
> this patch series mainly fixes a GPIO regression and improve RS485 flags and properties
> detection from DT.
>
> It now also includes various small fixes and improvements that were previously
> sent as separate patches, but that made testing everything difficult.
> Patches 1 and 2 are simple comments fix/improvements.
Usually we put fixes at the beginning of the series, but these patches are
missing Fixed tag. Are they really fixes or can be simply moved to the end of
the series?
> Patch 3 fixes an issue when debugging IOcontrol register. After testing the GPIO
> regression patches (patches 6 and 7, tests done by Lech Perczak), it appers that
> this patch is also necessary for having the correct IOcontrol register values.
>
> Patch 4 introduces a delay after a reset operation to respect datasheet
> timing recommandations.
>
> Patch 5 fixes an issue with init of first port during probing. This commit
> brings some questions and I appreciate if people from the serial subsystem could
> comment on my proposed solution.
>
> Patch 6 fixes a bug with the output value when first setting the GPIO direction.
>
> Patch 7, 8 and 9 fix a GPIO regression by (re)allowing to choose GPIO function for
> GPIO pins shared with modem status lines.
>
> Patch 10 allows to read common rs485 device-tree flags and properties.
>
> Patch 11 add a custom dump function as relying on regmal debugfs is not really
> practical for this driver.
>
> I have tested the changes on a custom board with two SC16IS752 DUART using a
> Variscite IMX8MN NANO SOM.
Other comments are per individual emails.
--
With Best Regards,
Andy Shevchenko
Thu, May 25, 2023 at 12:03:20AM -0400, Hugo Villeneuve kirjoitti:
> From: Hugo Villeneuve <[email protected]>
>
> When we want to configure a pin as an output pin with a value of logic
> 0, we end up as having a value of logic 1 on the output pin. Setting a
> logic 0 a second time (or more) after that will correctly output a
> logic 0 on the output pin.
>
> By default, all GPIO pins are configured as inputs. When we enter
> c16is7xx_gpio_direction_output() for the first time, we first set the
Missing 's'.
> desired value in IOSTATE, and then we configure the pin as an output.
> The datasheet states that writing to IOSTATE register will trigger a
> transfer of the value to the I/O pin configured as output, so if the
> pin is configured as an input, nothing will be transferred.
>
> Therefore, set the direction first in IODIR, and then set the desired
> value in IOSTATE.
>
> This is what is done in NXP application note AN10587.
--
With Best Regards,
Andy Shevchenko
On Thu, 25 May 2023, Hugo Villeneuve wrote:
> From: Hugo Villeneuve <[email protected]>
>
> Make sure we wait at least 3us before initiating communication with
> the device after reset.
>
> Signed-off-by: Hugo Villeneuve <[email protected]>
> ---
> drivers/tty/serial/sc16is7xx.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
> index a7c4da3cfd2b..af7e66db54b4 100644
> --- a/drivers/tty/serial/sc16is7xx.c
> +++ b/drivers/tty/serial/sc16is7xx.c
> @@ -1428,6 +1428,12 @@ static int sc16is7xx_probe(struct device *dev,
> regmap_write(s->regmap, SC16IS7XX_IOCONTROL_REG << SC16IS7XX_REG_SHIFT,
> SC16IS7XX_IOCONTROL_SRESET_BIT);
>
> + /*
> + * After reset, the host must wait at least 3us before initializing a
> + * communication with the device.
> + */
> + usleep_range(3, 5);
> +
> for (i = 0; i < devtype->nr_uart; ++i) {
> s->p[i].line = i;
> /* Initialize port data */
Does this fix a problem? You don't have a Fixes tag nor did you describe
a problem that arises if the is not there in the changelog.
--
i.
Thu, May 25, 2023 at 12:03:22AM -0400, Hugo Villeneuve kirjoitti:
> From: Hugo Villeneuve <[email protected]>
>
> Commit 679875d1d880 ("sc16is7xx: Separate GPIOs from modem control lines")
> and commit 21144bab4f11 ("sc16is7xx: Handle modem status lines")
> changed the function of the GPIOs pins to act as modem control
> lines without any possibility of selecting GPIO function.
>
> As a consequence, applications that depends on GPIO lines configured
> by default as GPIO pins no longer work as expected.
>
> Also, the change to select modem control lines function was done only
> for channel A of dual UART variants (752/762). This was not documented
> in the log message.
> This new patch allows to specify GPIO or modem control line function
> in the device tree, and for each of the ports (A or B).
Imperative mood as stated in documentation, please.
Like "Allow to specify...".
> This is done by using the new device-tree property named
> "modem-control-line-ports" (property added in separate patch).
>
> We also now reduce the number of exported GPIOs according to the
> modem-status-line-port DT property.
>
> Boards that need to have GPIOS configured as modem control lines
> should add that property to their device tree. Here is a list of
> boards using the sc16is7xx driver in their device tree and that may
> need to be modified:
> arm64/boot/dts/freescale/fsl-ls1012a-frdm.dts
> mips/boot/dts/ingenic/cu1830-neo.dts
> mips/boot/dts/ingenic/cu1000-neo.dts
...
> +#ifdef CONFIG_GPIOLIB
I'm wondering if we can avoid adding new ifdefferies...
> + s->gpio_configured = devtype->nr_gpio;
The name of the variable is a bit vague WRT its content.
Shouldn't be as simple as the rvalue, i.e. s->nr_gpio?
> +#endif /* CONFIG_GPIOLIB */
...
> + of_property_for_each_u32(dev->of_node, "nxp,modem-control-line-ports",
> + prop, p, u)
The driver so far is agnostic to property provider. Please keep it that way,
i.e. no of_ APIs.
> + if (u < devtype->nr_uart) {
Hmm... What other can it be?
> + /* Use GPIO lines as modem control lines */
> + if (u == 0)
> + val |= SC16IS7XX_IOCONTROL_MODEM_A_BIT;
> + else if (u == 1)
> + val |= SC16IS7XX_IOCONTROL_MODEM_B_BIT;
> +
> +#ifdef CONFIG_GPIOLIB
> + if (s->gpio_configured >=
> + SC16IS7XX_GPIOS_PER_BANK)
On one line it will be better to read. Esp. taking into account the above remark.
> + s->gpio_configured -=
> + SC16IS7XX_GPIOS_PER_BANK;
Ditto.
> +#endif /* CONFIG_GPIOLIB */
> + }
--
With Best Regards,
Andy Shevchenko
On Thu, 25 May 2023, Hugo Villeneuve wrote:
> From: Hugo Villeneuve <[email protected]>
>
> Commit 679875d1d880 ("sc16is7xx: Separate GPIOs from modem control lines")
> and commit 21144bab4f11 ("sc16is7xx: Handle modem status lines")
> changed the function of the GPIOs pins to act as modem control
> lines without any possibility of selecting GPIO function.
>
> As a consequence, applications that depends on GPIO lines configured
> by default as GPIO pins no longer work as expected.
>
> Also, the change to select modem control lines function was done only
> for channel A of dual UART variants (752/762). This was not documented
> in the log message.
>
> This new patch allows to specify GPIO or modem control line function
> in the device tree, and for each of the ports (A or B).
>
> This is done by using the new device-tree property named
> "modem-control-line-ports" (property added in separate patch).
>
> We also now reduce the number of exported GPIOs according to the
> modem-status-line-port DT property.
>
> Boards that need to have GPIOS configured as modem control lines
> should add that property to their device tree. Here is a list of
> boards using the sc16is7xx driver in their device tree and that may
> need to be modified:
> arm64/boot/dts/freescale/fsl-ls1012a-frdm.dts
> mips/boot/dts/ingenic/cu1830-neo.dts
> mips/boot/dts/ingenic/cu1000-neo.dts
>
> Fixes: 679875d1d880 ("sc16is7xx: Separate GPIOs from modem control lines")
> Fixes: 21144bab4f11 ("sc16is7xx: Handle modem status lines")
> Signed-off-by: Hugo Villeneuve <[email protected]>
> ---
> drivers/tty/serial/sc16is7xx.c | 65 +++++++++++++++++++++++-----------
> 1 file changed, 44 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
> index a5d8af0f6da0..97ec532a0a19 100644
> --- a/drivers/tty/serial/sc16is7xx.c
> +++ b/drivers/tty/serial/sc16is7xx.c
> @@ -236,7 +236,8 @@
>
> /* IOControl register bits (Only 75x/76x) */
> #define SC16IS7XX_IOCONTROL_LATCH_BIT (1 << 0) /* Enable input latching */
> -#define SC16IS7XX_IOCONTROL_MODEM_BIT (1 << 1) /* Enable GPIO[7:4] as modem pins */
> +#define SC16IS7XX_IOCONTROL_MODEM_A_BIT (1 << 1) /* Enable GPIO[7:4] as modem A pins */
> +#define SC16IS7XX_IOCONTROL_MODEM_B_BIT (1 << 2) /* Enable GPIO[3:0] as modem B pins */
> #define SC16IS7XX_IOCONTROL_SRESET_BIT (1 << 3) /* Software Reset */
>
> /* EFCR register bits */
> @@ -301,12 +302,12 @@
> /* Misc definitions */
> #define SC16IS7XX_FIFO_SIZE (64)
> #define SC16IS7XX_REG_SHIFT 2
> +#define SC16IS7XX_GPIOS_PER_BANK 4
>
> struct sc16is7xx_devtype {
> char name[10];
> int nr_gpio;
> int nr_uart;
> - int has_mctrl;
> };
>
> #define SC16IS7XX_RECONF_MD (1 << 0)
> @@ -336,6 +337,7 @@ struct sc16is7xx_port {
> struct clk *clk;
> #ifdef CONFIG_GPIOLIB
> struct gpio_chip gpio;
> + int gpio_configured;
> #endif
> unsigned char buf[SC16IS7XX_FIFO_SIZE];
> struct kthread_worker kworker;
> @@ -447,35 +449,30 @@ static const struct sc16is7xx_devtype sc16is74x_devtype = {
> .name = "SC16IS74X",
> .nr_gpio = 0,
> .nr_uart = 1,
> - .has_mctrl = 0,
> };
>
> static const struct sc16is7xx_devtype sc16is750_devtype = {
> .name = "SC16IS750",
> - .nr_gpio = 4,
> + .nr_gpio = 8,
> .nr_uart = 1,
> - .has_mctrl = 1,
> };
>
> static const struct sc16is7xx_devtype sc16is752_devtype = {
> .name = "SC16IS752",
> - .nr_gpio = 0,
> + .nr_gpio = 8,
> .nr_uart = 2,
> - .has_mctrl = 1,
> };
>
> static const struct sc16is7xx_devtype sc16is760_devtype = {
> .name = "SC16IS760",
> - .nr_gpio = 4,
> + .nr_gpio = 8,
> .nr_uart = 1,
> - .has_mctrl = 1,
> };
>
> static const struct sc16is7xx_devtype sc16is762_devtype = {
> .name = "SC16IS762",
> - .nr_gpio = 0,
> + .nr_gpio = 8,
> .nr_uart = 2,
> - .has_mctrl = 1,
> };
>
> static bool sc16is7xx_regmap_volatile(struct device *dev, unsigned int reg)
> @@ -1396,6 +1393,10 @@ static int sc16is7xx_probe(struct device *dev,
> return -ENOMEM;
> }
>
> +#ifdef CONFIG_GPIOLIB
> + s->gpio_configured = devtype->nr_gpio;
> +#endif /* CONFIG_GPIOLIB */
> +
> /* Always ask for fixed clock rate from a property. */
> device_property_read_u32(dev, "clock-frequency", &uartclk);
>
> @@ -1473,12 +1474,6 @@ static int sc16is7xx_probe(struct device *dev,
> SC16IS7XX_EFCR_RXDISABLE_BIT |
> SC16IS7XX_EFCR_TXDISABLE_BIT);
>
> - /* Use GPIO lines as modem status registers */
> - if (devtype->has_mctrl)
> - sc16is7xx_port_write(&s->p[i].port,
> - SC16IS7XX_IOCONTROL_REG,
> - SC16IS7XX_IOCONTROL_MODEM_BIT);
> -
> /* Initialize kthread work structs */
> kthread_init_work(&s->p[i].tx_work, sc16is7xx_tx_proc);
> kthread_init_work(&s->p[i].reg_work, sc16is7xx_reg_proc);
> @@ -1514,10 +1509,38 @@ static int sc16is7xx_probe(struct device *dev,
> prop, p, u)
> if (u < devtype->nr_uart)
> s->p[u].irda_mode = true;
> +
> + val = 0;
> +
> + of_property_for_each_u32(dev->of_node, "nxp,modem-control-line-ports",
> + prop, p, u)
> + if (u < devtype->nr_uart) {
Reverse logic + use continue. It will help with the indentation levels.
> + /* Use GPIO lines as modem control lines */
> + if (u == 0)
> + val |= SC16IS7XX_IOCONTROL_MODEM_A_BIT;
> + else if (u == 1)
> + val |= SC16IS7XX_IOCONTROL_MODEM_B_BIT;
> +
> +#ifdef CONFIG_GPIOLIB
> + if (s->gpio_configured >=
> + SC16IS7XX_GPIOS_PER_BANK)
> + s->gpio_configured -=
> + SC16IS7XX_GPIOS_PER_BANK;
> +#endif /* CONFIG_GPIOLIB */
> + }
Please use braces for of_property_for_each_u32 block.
> +
> + if (val)
> + regmap_update_bits(
> + s->regmap,
> + SC16IS7XX_IOCONTROL_REG << SC16IS7XX_REG_SHIFT,
> + SC16IS7XX_IOCONTROL_MODEM_A_BIT |
> + SC16IS7XX_IOCONTROL_MODEM_B_BIT, val);
> }
>
> #ifdef CONFIG_GPIOLIB
> - if (devtype->nr_gpio) {
> + dev_dbg(dev, "GPIOs to configure: %d\n", s->gpio_configured);
> +
> + if (s->gpio_configured) {
> /* Setup GPIO controller */
> s->gpio.owner = THIS_MODULE;
> s->gpio.parent = dev;
> @@ -1527,7 +1550,7 @@ static int sc16is7xx_probe(struct device *dev,
> s->gpio.direction_output = sc16is7xx_gpio_direction_output;
> s->gpio.set = sc16is7xx_gpio_set;
> s->gpio.base = -1;
> - s->gpio.ngpio = devtype->nr_gpio;
> + s->gpio.ngpio = s->gpio_configured;
> s->gpio.can_sleep = 1;
> ret = gpiochip_add_data(&s->gpio, s);
> if (ret)
> @@ -1555,7 +1578,7 @@ static int sc16is7xx_probe(struct device *dev,
> return 0;
>
> #ifdef CONFIG_GPIOLIB
> - if (devtype->nr_gpio)
> + if (s->gpio_configured)
> gpiochip_remove(&s->gpio);
>
> out_thread:
> @@ -1581,7 +1604,7 @@ static void sc16is7xx_remove(struct device *dev)
> int i;
>
> #ifdef CONFIG_GPIOLIB
> - if (s->devtype->nr_gpio)
> + if (s->gpio_configured)
> gpiochip_remove(&s->gpio);
> #endif
>
>
--
i.
On Thu, 25 May 2023, Hugo Villeneuve wrote:
> From: Hugo Villeneuve <[email protected]>
>
> Add call to uart_get_rs485_mode() to probe for RS485 flags and
> properties from device tree.
>
> Signed-off-by: Hugo Villeneuve <[email protected]>
> ---
> drivers/tty/serial/sc16is7xx.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
> index c2cfd057ed9a..03d00b144304 100644
> --- a/drivers/tty/serial/sc16is7xx.c
> +++ b/drivers/tty/serial/sc16is7xx.c
> @@ -1511,6 +1511,10 @@ static int sc16is7xx_probe(struct device *dev,
> goto out_ports;
> }
>
> + ret = uart_get_rs485_mode(&s->p[i].port);
> + if (ret)
> + goto out_ports;
> +
> /* Disable all interrupts */
> sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_IER_REG, 0);
> /* Disable TX/RX */
>
Reviewed-by: Ilpo J?rvinen <[email protected]>
--
i.
On Thu, 25 May 2023 13:30:06 +0300
[email protected] wrote:
> Thu, May 25, 2023 at 12:03:17AM -0400, Hugo Villeneuve kirjoitti:
> > From: Hugo Villeneuve <[email protected]>
> >
> > Make sure we wait at least 3us before initiating communication with
> > the device after reset.
>
> ...
>
> > + usleep_range(3, 5);
>
> I would put (5, 10) instead to relax a bit the scheduler.
Hi,
Ok, done.
On Thu, 25 May 2023 16:37:17 +0300
Andy Shevchenko <[email protected]> wrote:
> On Thu, May 25, 2023 at 4:26 PM Hugo Villeneuve <[email protected]> wrote:
> > On Thu, 25 May 2023 13:27:52 +0300
> > [email protected] wrote:
> > > Thu, May 25, 2023 at 12:03:13AM -0400, Hugo Villeneuve kirjoitti:
> > > > From: Hugo Villeneuve <[email protected]>
> > > >
> > > > Hello,
> > > > this patch series mainly fixes a GPIO regression and improve RS485 flags and properties
> > > > detection from DT.
> > > >
> > > > It now also includes various small fixes and improvements that were previously
> > > > sent as separate patches, but that made testing everything difficult.
> > >
> > > > Patches 1 and 2 are simple comments fix/improvements.
> > >
> > > Usually we put fixes at the beginning of the series, but these patches are
> > > missing Fixed tag. Are they really fixes or can be simply moved to the end of
> > > the series?
> >
> > these are not code fixes, they are comments improvements. I was not aware that you need to put a Fixes tag for correcting syntax errors in comments, or adding comments to improve clarity.
> >
> > I often submit such comments patches but was never asked to put a Fixes tag before. Seems strange to me...
>
> In this case there are probably no conflicts, but the usual grouping
> of patches is following
> 1) fixes that may be backported;
> 2) cleanups / refactoring /etc;
> 3) new features.
> 4) additional light-weit cleanups, such as whitespace cleaning (it's a
> radical, we probably do not accept pure whitespace cleaning patches,
> but you got the idea).
>
> Seems patches 1 and 2 fall into category 4).
Ok, I changed the order to put these two patches at the end.
Hugo.
On Thu, 25 May 2023 13:27:52 +0300
[email protected] wrote:
> Thu, May 25, 2023 at 12:03:13AM -0400, Hugo Villeneuve kirjoitti:
> > From: Hugo Villeneuve <[email protected]>
> >
> > Hello,
> > this patch series mainly fixes a GPIO regression and improve RS485 flags and properties
> > detection from DT.
> >
> > It now also includes various small fixes and improvements that were previously
> > sent as separate patches, but that made testing everything difficult.
>
> > Patches 1 and 2 are simple comments fix/improvements.
>
> Usually we put fixes at the beginning of the series, but these patches are
> missing Fixed tag. Are they really fixes or can be simply moved to the end of
> the series?
Hi,
these are not code fixes, they are comments improvements. I was not aware that you need to put a Fixes tag for correcting syntax errors in comments, or adding comments to improve clarity.
I often submit such comments patches but was never asked to put a Fixes tag before. Seems strange to me...
Hugo.
> > Patch 3 fixes an issue when debugging IOcontrol register. After testing the GPIO
> > regression patches (patches 6 and 7, tests done by Lech Perczak), it appers that
> > this patch is also necessary for having the correct IOcontrol register values.
> >
> > Patch 4 introduces a delay after a reset operation to respect datasheet
> > timing recommandations.
> >
> > Patch 5 fixes an issue with init of first port during probing. This commit
> > brings some questions and I appreciate if people from the serial subsystem could
> > comment on my proposed solution.
> >
> > Patch 6 fixes a bug with the output value when first setting the GPIO direction.
> >
> > Patch 7, 8 and 9 fix a GPIO regression by (re)allowing to choose GPIO function for
> > GPIO pins shared with modem status lines.
> >
> > Patch 10 allows to read common rs485 device-tree flags and properties.
> >
> > Patch 11 add a custom dump function as relying on regmal debugfs is not really
> > practical for this driver.
> >
> > I have tested the changes on a custom board with two SC16IS752 DUART using a
> > Variscite IMX8MN NANO SOM.
>
> Other comments are per individual emails.
>
> --
> With Best Regards,
> Andy Shevchenko
>
>
>
On Thu, May 25, 2023 at 4:26 PM Hugo Villeneuve <[email protected]> wrote:
> On Thu, 25 May 2023 13:27:52 +0300
> [email protected] wrote:
> > Thu, May 25, 2023 at 12:03:13AM -0400, Hugo Villeneuve kirjoitti:
> > > From: Hugo Villeneuve <[email protected]>
> > >
> > > Hello,
> > > this patch series mainly fixes a GPIO regression and improve RS485 flags and properties
> > > detection from DT.
> > >
> > > It now also includes various small fixes and improvements that were previously
> > > sent as separate patches, but that made testing everything difficult.
> >
> > > Patches 1 and 2 are simple comments fix/improvements.
> >
> > Usually we put fixes at the beginning of the series, but these patches are
> > missing Fixed tag. Are they really fixes or can be simply moved to the end of
> > the series?
>
> these are not code fixes, they are comments improvements. I was not aware that you need to put a Fixes tag for correcting syntax errors in comments, or adding comments to improve clarity.
>
> I often submit such comments patches but was never asked to put a Fixes tag before. Seems strange to me...
In this case there are probably no conflicts, but the usual grouping
of patches is following
1) fixes that may be backported;
2) cleanups / refactoring /etc;
3) new features.
4) additional light-weit cleanups, such as whitespace cleaning (it's a
radical, we probably do not accept pure whitespace cleaning patches,
but you got the idea).
Seems patches 1 and 2 fall into category 4).
--
With Best Regards,
Andy Shevchenko
On Thu, 25 May 2023 14:05:35 +0300 (EEST)
Ilpo J?rvinen <[email protected]> wrote:
> On Thu, 25 May 2023, Hugo Villeneuve wrote:
>
> > From: Hugo Villeneuve <[email protected]>
> >
> > Make sure we wait at least 3us before initiating communication with
> > the device after reset.
> >
> > Signed-off-by: Hugo Villeneuve <[email protected]>
> > ---
> > drivers/tty/serial/sc16is7xx.c | 6 ++++++
> > 1 file changed, 6 insertions(+)
> >
> > diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
> > index a7c4da3cfd2b..af7e66db54b4 100644
> > --- a/drivers/tty/serial/sc16is7xx.c
> > +++ b/drivers/tty/serial/sc16is7xx.c
> > @@ -1428,6 +1428,12 @@ static int sc16is7xx_probe(struct device *dev,
> > regmap_write(s->regmap, SC16IS7XX_IOCONTROL_REG << SC16IS7XX_REG_SHIFT,
> > SC16IS7XX_IOCONTROL_SRESET_BIT);
> >
> > + /*
> > + * After reset, the host must wait at least 3us before initializing a
> > + * communication with the device.
> > + */
> > + usleep_range(3, 5);
> > +
> > for (i = 0; i < devtype->nr_uart; ++i) {
> > s->p[i].line = i;
> > /* Initialize port data */
>
> Does this fix a problem? You don't have a Fixes tag nor did you describe
> a problem that arises if the is not there in the changelog.
Not for the moment, that is why I didn't put a Fixes tag.
A potential problem that can arise is that on a much faster processor, there is a chance that we could reach the first instruction that request a read/write before the reset post-delay.
Hugo.
On Thu, 25 May 2023 14:10:27 +0300
[email protected] wrote:
> Thu, May 25, 2023 at 12:03:20AM -0400, Hugo Villeneuve kirjoitti:
> > From: Hugo Villeneuve <[email protected]>
> >
> > When we want to configure a pin as an output pin with a value of logic
> > 0, we end up as having a value of logic 1 on the output pin. Setting a
> > logic 0 a second time (or more) after that will correctly output a
> > logic 0 on the output pin.
> >
> > By default, all GPIO pins are configured as inputs. When we enter
> > c16is7xx_gpio_direction_output() for the first time, we first set the
>
> Missing 's'.
Fixed.
> > desired value in IOSTATE, and then we configure the pin as an output.
> > The datasheet states that writing to IOSTATE register will trigger a
> > transfer of the value to the I/O pin configured as output, so if the
> > pin is configured as an input, nothing will be transferred.
> >
> > Therefore, set the direction first in IODIR, and then set the desired
> > value in IOSTATE.
> >
> > This is what is done in NXP application note AN10587.
>
> --
> With Best Regards,
> Andy Shevchenko
>
>
>
On Thu, 25 May 2023 14:19:52 +0300
[email protected] wrote:
> Thu, May 25, 2023 at 12:03:22AM -0400, Hugo Villeneuve kirjoitti:
> > From: Hugo Villeneuve <[email protected]>
> >
> > Commit 679875d1d880 ("sc16is7xx: Separate GPIOs from modem control lines")
> > and commit 21144bab4f11 ("sc16is7xx: Handle modem status lines")
> > changed the function of the GPIOs pins to act as modem control
> > lines without any possibility of selecting GPIO function.
> >
> > As a consequence, applications that depends on GPIO lines configured
> > by default as GPIO pins no longer work as expected.
> >
> > Also, the change to select modem control lines function was done only
> > for channel A of dual UART variants (752/762). This was not documented
> > in the log message.
>
> > This new patch allows to specify GPIO or modem control line function
> > in the device tree, and for each of the ports (A or B).
>
> Imperative mood as stated in documentation, please.
> Like "Allow to specify...".
>
> > This is done by using the new device-tree property named
> > "modem-control-line-ports" (property added in separate patch).
> >
> > We also now reduce the number of exported GPIOs according to the
> > modem-status-line-port DT property.
Just noticed a mistake:
s/modem-status-line-port/modem-control-line-ports
> >
> > Boards that need to have GPIOS configured as modem control lines
> > should add that property to their device tree. Here is a list of
> > boards using the sc16is7xx driver in their device tree and that may
> > need to be modified:
> > arm64/boot/dts/freescale/fsl-ls1012a-frdm.dts
> > mips/boot/dts/ingenic/cu1830-neo.dts
> > mips/boot/dts/ingenic/cu1000-neo.dts
>
> ...
>
> > +#ifdef CONFIG_GPIOLIB
>
> I'm wondering if we can avoid adding new ifdefferies...
I am simply following waht was already done in the existing driver.
Are you suggesting that we need to remove all these #defines? If not, what exactly do you suggest?
> > + s->gpio_configured = devtype->nr_gpio;
>
> The name of the variable is a bit vague WRT its content.
> Shouldn't be as simple as the rvalue, i.e. s->nr_gpio?
Maybe the name could be improved (and/or comments).
devtype->nr_gpio is the maximum "theoretical" number of GPIOs supported by the chip.
s->gpio_configured is the number of GPIOs that are configured or requested according to the presence (or not) of the modem-control-line-ports property.
I wanted to avoid using the same name to avoid potential confusion.
Maybe devtype->nr_gpio could be renamed to devtype->nr_gpio_max and s->gpio_configured to s->nr_gpio_requested or s->nr_gpio_configured?
> > +#endif /* CONFIG_GPIOLIB */
>
> ...
>
> > + of_property_for_each_u32(dev->of_node, "nxp,modem-control-line-ports",
> > + prop, p, u)
>
> The driver so far is agnostic to property provider. Please keep it that way,
> i.e. no of_ APIs.
The driver, before my patches, was already using the exact same function of_property_for_each_u32() to process the irda-mode-ports property, so I don't understand your comment.
But what do you suggest instead of of_property_for_each_u32()? And do we need to change it also for processing the irda-mode-ports property?
> > + if (u < devtype->nr_uart) {
>
> Hmm... What other can it be?
Again, this is similar to the handling of the irda-mode-ports property.
But I am not sure I understand your question/concern?
I think this check is important, because if someone puts the following property in a DT:
nxp,modem-control-line-ports = <0 1>;
but the variant only supports 1 port, then the check is usefull, no?
>
> > + /* Use GPIO lines as modem control lines */
> > + if (u == 0)
> > + val |= SC16IS7XX_IOCONTROL_MODEM_A_BIT;
> > + else if (u == 1)
> > + val |= SC16IS7XX_IOCONTROL_MODEM_B_BIT;
> > +
> > +#ifdef CONFIG_GPIOLIB
> > + if (s->gpio_configured >=
> > + SC16IS7XX_GPIOS_PER_BANK)
>
> On one line it will be better to read. Esp. taking into account the above remark.
Fixed.
> > + s->gpio_configured -=
> > + SC16IS7XX_GPIOS_PER_BANK;
>
> Ditto.
Fixed.
>
> > +#endif /* CONFIG_GPIOLIB */
> > + }
>
> --
> With Best Regards,
> Andy Shevchenko
>
>
>
On Thu, 25 May 2023 15:03:41 +0300 (EEST)
Ilpo J?rvinen <[email protected]> wrote:
> On Thu, 25 May 2023, Hugo Villeneuve wrote:
>
> > From: Hugo Villeneuve <[email protected]>
> >
> > Commit 679875d1d880 ("sc16is7xx: Separate GPIOs from modem control lines")
> > and commit 21144bab4f11 ("sc16is7xx: Handle modem status lines")
> > changed the function of the GPIOs pins to act as modem control
> > lines without any possibility of selecting GPIO function.
> >
> > As a consequence, applications that depends on GPIO lines configured
> > by default as GPIO pins no longer work as expected.
> >
> > Also, the change to select modem control lines function was done only
> > for channel A of dual UART variants (752/762). This was not documented
> > in the log message.
> >
> > This new patch allows to specify GPIO or modem control line function
> > in the device tree, and for each of the ports (A or B).
> >
> > This is done by using the new device-tree property named
> > "modem-control-line-ports" (property added in separate patch).
> >
> > We also now reduce the number of exported GPIOs according to the
> > modem-status-line-port DT property.
> >
> > Boards that need to have GPIOS configured as modem control lines
> > should add that property to their device tree. Here is a list of
> > boards using the sc16is7xx driver in their device tree and that may
> > need to be modified:
> > arm64/boot/dts/freescale/fsl-ls1012a-frdm.dts
> > mips/boot/dts/ingenic/cu1830-neo.dts
> > mips/boot/dts/ingenic/cu1000-neo.dts
> >
> > Fixes: 679875d1d880 ("sc16is7xx: Separate GPIOs from modem control lines")
> > Fixes: 21144bab4f11 ("sc16is7xx: Handle modem status lines")
> > Signed-off-by: Hugo Villeneuve <[email protected]>
> > ---
> > drivers/tty/serial/sc16is7xx.c | 65 +++++++++++++++++++++++-----------
> > 1 file changed, 44 insertions(+), 21 deletions(-)
> >
> > diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
> > index a5d8af0f6da0..97ec532a0a19 100644
> > --- a/drivers/tty/serial/sc16is7xx.c
> > +++ b/drivers/tty/serial/sc16is7xx.c
> > @@ -236,7 +236,8 @@
> >
> > /* IOControl register bits (Only 75x/76x) */
> > #define SC16IS7XX_IOCONTROL_LATCH_BIT (1 << 0) /* Enable input latching */
> > -#define SC16IS7XX_IOCONTROL_MODEM_BIT (1 << 1) /* Enable GPIO[7:4] as modem pins */
> > +#define SC16IS7XX_IOCONTROL_MODEM_A_BIT (1 << 1) /* Enable GPIO[7:4] as modem A pins */
> > +#define SC16IS7XX_IOCONTROL_MODEM_B_BIT (1 << 2) /* Enable GPIO[3:0] as modem B pins */
> > #define SC16IS7XX_IOCONTROL_SRESET_BIT (1 << 3) /* Software Reset */
> >
> > /* EFCR register bits */
> > @@ -301,12 +302,12 @@
> > /* Misc definitions */
> > #define SC16IS7XX_FIFO_SIZE (64)
> > #define SC16IS7XX_REG_SHIFT 2
> > +#define SC16IS7XX_GPIOS_PER_BANK 4
> >
> > struct sc16is7xx_devtype {
> > char name[10];
> > int nr_gpio;
> > int nr_uart;
> > - int has_mctrl;
> > };
> >
> > #define SC16IS7XX_RECONF_MD (1 << 0)
> > @@ -336,6 +337,7 @@ struct sc16is7xx_port {
> > struct clk *clk;
> > #ifdef CONFIG_GPIOLIB
> > struct gpio_chip gpio;
> > + int gpio_configured;
> > #endif
> > unsigned char buf[SC16IS7XX_FIFO_SIZE];
> > struct kthread_worker kworker;
> > @@ -447,35 +449,30 @@ static const struct sc16is7xx_devtype sc16is74x_devtype = {
> > .name = "SC16IS74X",
> > .nr_gpio = 0,
> > .nr_uart = 1,
> > - .has_mctrl = 0,
> > };
> >
> > static const struct sc16is7xx_devtype sc16is750_devtype = {
> > .name = "SC16IS750",
> > - .nr_gpio = 4,
> > + .nr_gpio = 8,
> > .nr_uart = 1,
> > - .has_mctrl = 1,
> > };
> >
> > static const struct sc16is7xx_devtype sc16is752_devtype = {
> > .name = "SC16IS752",
> > - .nr_gpio = 0,
> > + .nr_gpio = 8,
> > .nr_uart = 2,
> > - .has_mctrl = 1,
> > };
> >
> > static const struct sc16is7xx_devtype sc16is760_devtype = {
> > .name = "SC16IS760",
> > - .nr_gpio = 4,
> > + .nr_gpio = 8,
> > .nr_uart = 1,
> > - .has_mctrl = 1,
> > };
> >
> > static const struct sc16is7xx_devtype sc16is762_devtype = {
> > .name = "SC16IS762",
> > - .nr_gpio = 0,
> > + .nr_gpio = 8,
> > .nr_uart = 2,
> > - .has_mctrl = 1,
> > };
> >
> > static bool sc16is7xx_regmap_volatile(struct device *dev, unsigned int reg)
> > @@ -1396,6 +1393,10 @@ static int sc16is7xx_probe(struct device *dev,
> > return -ENOMEM;
> > }
> >
> > +#ifdef CONFIG_GPIOLIB
> > + s->gpio_configured = devtype->nr_gpio;
> > +#endif /* CONFIG_GPIOLIB */
> > +
> > /* Always ask for fixed clock rate from a property. */
> > device_property_read_u32(dev, "clock-frequency", &uartclk);
> >
> > @@ -1473,12 +1474,6 @@ static int sc16is7xx_probe(struct device *dev,
> > SC16IS7XX_EFCR_RXDISABLE_BIT |
> > SC16IS7XX_EFCR_TXDISABLE_BIT);
> >
> > - /* Use GPIO lines as modem status registers */
> > - if (devtype->has_mctrl)
> > - sc16is7xx_port_write(&s->p[i].port,
> > - SC16IS7XX_IOCONTROL_REG,
> > - SC16IS7XX_IOCONTROL_MODEM_BIT);
> > -
> > /* Initialize kthread work structs */
> > kthread_init_work(&s->p[i].tx_work, sc16is7xx_tx_proc);
> > kthread_init_work(&s->p[i].reg_work, sc16is7xx_reg_proc);
> > @@ -1514,10 +1509,38 @@ static int sc16is7xx_probe(struct device *dev,
> > prop, p, u)
> > if (u < devtype->nr_uart)
> > s->p[u].irda_mode = true;
> > +
> > + val = 0;
> > +
> > + of_property_for_each_u32(dev->of_node, "nxp,modem-control-line-ports",
> > + prop, p, u)
> > + if (u < devtype->nr_uart) {
>
> Reverse logic + use continue. It will help with the indentation levels.
Good suggestion, done.
> > + /* Use GPIO lines as modem control lines */
> > + if (u == 0)
> > + val |= SC16IS7XX_IOCONTROL_MODEM_A_BIT;
> > + else if (u == 1)
> > + val |= SC16IS7XX_IOCONTROL_MODEM_B_BIT;
> > +
> > +#ifdef CONFIG_GPIOLIB
> > + if (s->gpio_configured >=
> > + SC16IS7XX_GPIOS_PER_BANK)
> > + s->gpio_configured -=
> > + SC16IS7XX_GPIOS_PER_BANK;
> > +#endif /* CONFIG_GPIOLIB */
> > + }
>
> Please use braces for of_property_for_each_u32 block.
Done
> > +
> > + if (val)
> > + regmap_update_bits(
> > + s->regmap,
> > + SC16IS7XX_IOCONTROL_REG << SC16IS7XX_REG_SHIFT,
> > + SC16IS7XX_IOCONTROL_MODEM_A_BIT |
> > + SC16IS7XX_IOCONTROL_MODEM_B_BIT, val);
> > }
> >
> > #ifdef CONFIG_GPIOLIB
> > - if (devtype->nr_gpio) {
> > + dev_dbg(dev, "GPIOs to configure: %d\n", s->gpio_configured);
> > +
> > + if (s->gpio_configured) {
> > /* Setup GPIO controller */
> > s->gpio.owner = THIS_MODULE;
> > s->gpio.parent = dev;
> > @@ -1527,7 +1550,7 @@ static int sc16is7xx_probe(struct device *dev,
> > s->gpio.direction_output = sc16is7xx_gpio_direction_output;
> > s->gpio.set = sc16is7xx_gpio_set;
> > s->gpio.base = -1;
> > - s->gpio.ngpio = devtype->nr_gpio;
> > + s->gpio.ngpio = s->gpio_configured;
> > s->gpio.can_sleep = 1;
> > ret = gpiochip_add_data(&s->gpio, s);
> > if (ret)
> > @@ -1555,7 +1578,7 @@ static int sc16is7xx_probe(struct device *dev,
> > return 0;
> >
> > #ifdef CONFIG_GPIOLIB
> > - if (devtype->nr_gpio)
> > + if (s->gpio_configured)
> > gpiochip_remove(&s->gpio);
> >
> > out_thread:
> > @@ -1581,7 +1604,7 @@ static void sc16is7xx_remove(struct device *dev)
> > int i;
> >
> > #ifdef CONFIG_GPIOLIB
> > - if (s->devtype->nr_gpio)
> > + if (s->gpio_configured)
> > gpiochip_remove(&s->gpio);
> > #endif
> >
> >
>
> --
> i.
>
>
Thu, May 25, 2023 at 11:02:55AM -0400, Hugo Villeneuve kirjoitti:
> On Thu, 25 May 2023 14:19:52 +0300
> [email protected] wrote:
> > Thu, May 25, 2023 at 12:03:22AM -0400, Hugo Villeneuve kirjoitti:
...
> > I'm wondering if we can avoid adding new ifdefferies...
>
> I am simply following waht was already done in the existing driver.
>
> Are you suggesting that we need to remove all these #defines? If not, what
> exactly do you suggest?
I was wondering and have nothing to suggest here. It seems a burden we have to
cope with for now.
> > > + s->gpio_configured = devtype->nr_gpio;
> >
> > The name of the variable is a bit vague WRT its content.
> > Shouldn't be as simple as the rvalue, i.e. s->nr_gpio?
>
> Maybe the name could be improved (and/or comments).
>
> devtype->nr_gpio is the maximum "theoretical" number of GPIOs supported by
> the chip.
>
> s->gpio_configured is the number of GPIOs that are configured or requested
> according to the presence (or not) of the modem-control-line-ports property.
>
> I wanted to avoid using the same name to avoid potential confusion.
>
> Maybe devtype->nr_gpio could be renamed to devtype->nr_gpio_max and
> s->gpio_configured to s->nr_gpio_requested or s->nr_gpio_configured?
Maybe, but first try the approach with valid mask being involved. It may be
that we won't need this variable at all.
...
> > > + of_property_for_each_u32(dev->of_node, "nxp,modem-control-line-ports",
> > > + prop, p, u)
> >
> > The driver so far is agnostic to property provider. Please keep it that way,
> > i.e. no of_ APIs.
>
> The driver, before my patches, was already using the exact same function
> of_property_for_each_u32() to process the irda-mode-ports property, so I
> don't understand your comment.
This is unfortunate. I missed that one, but i don't care about IrDA so much.
> But what do you suggest instead of of_property_for_each_u32()? And do we need
> to change it also for processing the irda-mode-ports property?
device_property_read_u32_array().
Independently on the IrDA case, this one is more important and would have
consequences if we avoid agnostic APIs.
...
> > > + if (u < devtype->nr_uart) {
> >
> > Hmm... What other can it be?
>
> Again, this is similar to the handling of the irda-mode-ports property.
>
> But I am not sure I understand your question/concern?
>
> I think this check is important, because if someone puts the following
> property in a DT:
>
> nxp,modem-control-line-ports = <0 1>;
>
> but the variant only supports 1 port, then the check is usefull, no?
But you have below checks for u value. Wouldn't be enough?
> > > + /* Use GPIO lines as modem control lines */
> > > + if (u == 0)
> > > + val |= SC16IS7XX_IOCONTROL_MODEM_A_BIT;
> > > + else if (u == 1)
> > > + val |= SC16IS7XX_IOCONTROL_MODEM_B_BIT;
> > > +
--
With Best Regards,
Andy Shevchenko