diff mbox series

[v4,3/5] serial: sc16is7xx: split into core and I2C/SPI parts (core)

Message ID 20240409154253.3043822-4-hugo@hugovil.com
State New
Headers show
Series serial: sc16is7xx: split into core and I2C/SPI parts | expand

Commit Message

Hugo Villeneuve April 9, 2024, 3:42 p.m. UTC
From: Hugo Villeneuve <hvilleneuve@dimonoff.com>

Split the common code from sc16is7xx driver and move the I2C and SPI bus
parts into interface-specific source files.

sc16is7xx becomes the core functions which can support multiple bus
interfaces like I2C and SPI.

No functional changes intended.

Also simplify and improve Kconfig entries.
  - Capitalize SPI keyword for consistency
  - Display list of supported ICs each on a separate line (and aligned) to
    facilitate locating a specific IC model
  - Add Manufacturer name at start of description string
  - Add UART keyword to description string

Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
---
 drivers/tty/serial/Kconfig         |  47 +++---
 drivers/tty/serial/Makefile        |   2 +
 drivers/tty/serial/sc16is7xx.c     | 225 +++++------------------------
 drivers/tty/serial/sc16is7xx.h     |  41 ++++++
 drivers/tty/serial/sc16is7xx_i2c.c |  64 ++++++++
 drivers/tty/serial/sc16is7xx_spi.c |  87 +++++++++++
 6 files changed, 248 insertions(+), 218 deletions(-)
 create mode 100644 drivers/tty/serial/sc16is7xx.h
 create mode 100644 drivers/tty/serial/sc16is7xx_i2c.c
 create mode 100644 drivers/tty/serial/sc16is7xx_spi.c

Comments

Geert Uytterhoeven April 23, 2024, 10:02 a.m. UTC | #1
On Tue, Apr 23, 2024 at 12:01 PM Geert Uytterhoeven
<geert@linux-m68k.org> wrote:
> On Tue, Apr 9, 2024 at 5:48 PM Hugo Villeneuve <hugo@hugovil.com> wrote:
> > From: Hugo Villeneuve <hvilleneuve@dimonoff.com>
> >
> > Split the common code from sc16is7xx driver and move the I2C and SPI bus
> > parts into interface-specific source files.
> >
> > sc16is7xx becomes the core functions which can support multiple bus
> > interfaces like I2C and SPI.
> >
> > No functional changes intended.
> >
> > Also simplify and improve Kconfig entries.
> >   - Capitalize SPI keyword for consistency
> >   - Display list of supported ICs each on a separate line (and aligned) to
> >     facilitate locating a specific IC model
> >   - Add Manufacturer name at start of description string
> >   - Add UART keyword to description string
> >
> > Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
> > Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
>
> Thanks for your patch, which is now commit d49216438139bca0
> ("serial: sc16is7xx: split into core and I2C/SPI parts (core)")
> in tty-next (next-20240415 and later).
>
> > --- a/drivers/tty/serial/Kconfig
> > +++ b/drivers/tty/serial/Kconfig
> > @@ -1021,41 +1021,30 @@ config SERIAL_SCCNXP_CONSOLE
> >           Support for console on SCCNXP serial ports.
> >
> >  config SERIAL_SC16IS7XX_CORE
> > -       tristate
> > -
> > -config SERIAL_SC16IS7XX
> > -       tristate "SC16IS7xx serial support"
> > +       tristate "NXP SC16IS7xx UART support"
>
> Hence this replaces SERIAL_SC16IS7XX_CORE by SERIAL_SC16IS7XX,
> so arch/mips/configs/cu1??0-neo_defconfig needs to updated.

Or just rename SERIAL_SC16IS7XX_CORE back to SERIAL_SC16IS7XX.

Gr{oetje,eeting}s,

                        Geert
Andy Shevchenko April 23, 2024, 10:37 a.m. UTC | #2
On Tue, Apr 23, 2024 at 1:03 PM Geert Uytterhoeven <geert@linux-m68k.org> wrote:
> On Tue, Apr 23, 2024 at 12:01 PM Geert Uytterhoeven
> <geert@linux-m68k.org> wrote:
> > On Tue, Apr 9, 2024 at 5:48 PM Hugo Villeneuve <hugo@hugovil.com> wrote:

...

> Or just rename SERIAL_SC16IS7XX_CORE back to SERIAL_SC16IS7XX.

Since we do not know how many configurations elsewhere rely on this
and we have a real use case this suggestion seems plausible to me.
Hugo Villeneuve April 23, 2024, 1:14 p.m. UTC | #3
On Tue, 23 Apr 2024 12:01:23 +0200
Geert Uytterhoeven <geert@linux-m68k.org> wrote:

> Hi Hugo,
> 
> On Tue, Apr 9, 2024 at 5:48 PM Hugo Villeneuve <hugo@hugovil.com> wrote:
> > From: Hugo Villeneuve <hvilleneuve@dimonoff.com>
> >
> > Split the common code from sc16is7xx driver and move the I2C and SPI bus
> > parts into interface-specific source files.
> >
> > sc16is7xx becomes the core functions which can support multiple bus
> > interfaces like I2C and SPI.
> >
> > No functional changes intended.
> >
> > Also simplify and improve Kconfig entries.
> >   - Capitalize SPI keyword for consistency
> >   - Display list of supported ICs each on a separate line (and aligned) to
> >     facilitate locating a specific IC model
> >   - Add Manufacturer name at start of description string
> >   - Add UART keyword to description string
> >
> > Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
> > Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
> 
> Thanks for your patch, which is now commit d49216438139bca0
> ("serial: sc16is7xx: split into core and I2C/SPI parts (core)")
> in tty-next (next-20240415 and later).
> 
> > --- a/drivers/tty/serial/Kconfig
> > +++ b/drivers/tty/serial/Kconfig
> > @@ -1021,41 +1021,30 @@ config SERIAL_SCCNXP_CONSOLE
> >           Support for console on SCCNXP serial ports.
> >
> >  config SERIAL_SC16IS7XX_CORE
> > -       tristate
> > -
> > -config SERIAL_SC16IS7XX
> > -       tristate "SC16IS7xx serial support"
> > +       tristate "NXP SC16IS7xx UART support"
> 
> Hence this replaces SERIAL_SC16IS7XX_CORE by SERIAL_SC16IS7XX,
> so arch/mips/configs/cu1??0-neo_defconfig needs to updated.

Hi Geert,
yes you are right, sorry I missed that.

> 
> >         select SERIAL_CORE
> > -       depends on (SPI_MASTER && !I2C) || I2C
> > +       select SERIAL_SC16IS7XX_SPI if SPI_MASTER
> > +       select SERIAL_SC16IS7XX_I2C if I2C
> 
> So if SPI_MASTER or I2C is enabled, the corresponding SERIAL_SC16IS7XX_*
> subdriver can no longer be disabled?  According to
> https://lore.kernel.org/all/20240403123501.8ef5c99f65a40ca2c10f635a@hugovil.com/
> you did want to support that?

Just to clarify, SPI subdriver will be disabled if
SPI_MASTER is disabled, even if I2C is enabled, and vice versa.

It was not my original intention, V1 of the patch offered the
possibility to enable/disable each subdriver individually, but Andy
pointed out that was maybe not the standard/usual/recommended way of
defining it, and to look into what other subsystems were doing,
especially iio. After some research, I settled on this approach as a
compromise.


Hugo.

> 
> >         help
> > -         This selects support for SC16IS7xx serial ports.
> > -         Supported ICs are SC16IS740, SC16IS741, SC16IS750, SC16IS752,
> > -         SC16IS760 and SC16IS762. Select supported buses using options below.
> > +         Core driver for NXP SC16IS7xx UARTs.
> > +         Supported ICs are:
> > +
> > +           SC16IS740
> > +           SC16IS741
> > +           SC16IS750
> > +           SC16IS752
> > +           SC16IS760
> > +           SC16IS762
> > +
> > +         The driver supports both I2C and SPI interfaces.
> >
> >  config SERIAL_SC16IS7XX_I2C
> > -       bool "SC16IS7xx for I2C interface"
> > -       depends on SERIAL_SC16IS7XX
> > -       depends on I2C
> > -       select SERIAL_SC16IS7XX_CORE if SERIAL_SC16IS7XX
> > -       select REGMAP_I2C if I2C
> > -       default y
> > -       help
> > -         Enable SC16IS7xx driver on I2C bus,
> > -         If required say y, and say n to i2c if not required,
> > -         Enabled by default to support oldconfig.
> > -         You must select at least one bus for the driver to be built.
> > +       tristate
> > +       select REGMAP_I2C
> >
> >  config SERIAL_SC16IS7XX_SPI
> > -       bool "SC16IS7xx for spi interface"
> > -       depends on SERIAL_SC16IS7XX
> > -       depends on SPI_MASTER
> > -       select SERIAL_SC16IS7XX_CORE if SERIAL_SC16IS7XX
> > -       select REGMAP_SPI if SPI_MASTER
> > -       help
> > -         Enable SC16IS7xx driver on SPI bus,
> > -         If required say y, and say n to spi if not required,
> > -         This is additional support to existing driver.
> > -         You must select at least one bus for the driver to be built.
> > +       tristate
> > +       select REGMAP_SPI
> >
> >  config SERIAL_TIMBERDALE
> >         tristate "Support for timberdale UART"
> 
> Gr{oetje,eeting}s,
> 
>                         Geert
> 
> -- 
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
> 
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                 -- Linus Torvalds
>
Hugo Villeneuve April 23, 2024, 3:34 p.m. UTC | #4
On Tue, 23 Apr 2024 15:11:12 +0200
Geert Uytterhoeven <geert@linux-m68k.org> wrote:

Hi Geert,

> Hi Andy,
> 
> On Tue, Apr 23, 2024 at 12:37 PM Andy Shevchenko
> <andy.shevchenko@gmail.com> wrote:
> > On Tue, Apr 23, 2024 at 1:01 PM Geert Uytterhoeven <geert@linux-m68k.org> wrote:
> > > On Tue, Apr 9, 2024 at 5:48 PM Hugo Villeneuve <hugo@hugovil.com> wrote:
> 
> > > > -config SERIAL_SC16IS7XX
> > > > -       tristate "SC16IS7xx serial support"
> > > > +       tristate "NXP SC16IS7xx UART support"
> > >
> > > Hence this replaces SERIAL_SC16IS7XX_CORE by SERIAL_SC16IS7XX,
> > > so arch/mips/configs/cu1??0-neo_defconfig needs to updated.
> >
> >         select SERIAL_CORE
> > -       depends on (SPI_MASTER && !I2C) || I2C
> > +       select SERIAL_SC16IS7XX_SPI if SPI_MASTER
> > +       select SERIAL_SC16IS7XX_I2C if I2C
> >
> > > So if SPI_MASTER or I2C is enabled, the corresponding SERIAL_SC16IS7XX_*
> > > subdriver can no longer be disabled?  According to
> > > https://lore.kernel.org/all/20240403123501.8ef5c99f65a40ca2c10f635a@hugovil.com/
> > > you did want to support that?
> >
> > I believe it has been taken from one of the IIO drivers as an example.
> 
> Looks like a bad example to follow:
>   1. The driver question now pops up if both I2C and SPI_MASTER
>      are disabled,

True.

V3 originally had this:

>  config SERIAL_SC16IS7XX
>         tristate "SC16IS7xx serial support"
>         select SERIAL_CORE
> -       depends on (SPI_MASTER && !I2C) || I2C
> +       depends on SPI_MASTER || I2C

And Andy commented "Is it?", which I probably misinterpreted as I should
not list them as dependencies.

Reintroducing "depends on SPI_MASTER || I2C" fixes this issue.


>   2. What if SERIAL_SC16IS7XX_CORE is builtin, but I2C and/or
>      SPI_MASTER are modular?

a) SERIAL_SC16IS7XX builtin and I2C modular:
CONFIG_SERIAL_SC16IS7XX=y
CONFIG_SERIAL_SC16IS7XX_I2C=m
CONFIG_SERIAL_SC16IS7XX_SPI=y

SPI_MASTER is only boolean and cannot be modular.

Hugo.


> 
> I believe the only way to fix that is by letting the sub-drivers select the
> core driver, like before.
> 
> Gr{oetje,eeting}s,
> 
>                         Geert
> 
> -- 
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
> 
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                 -- Linus Torvalds
>
Geert Uytterhoeven May 23, 2024, 7:33 a.m. UTC | #5
On Tue, Apr 23, 2024 at 3:11 PM Geert Uytterhoeven <geert@linux-m68k.org> wrote:
> On Tue, Apr 23, 2024 at 12:37 PM Andy Shevchenko
> <andy.shevchenko@gmail.com> wrote:
> > On Tue, Apr 23, 2024 at 1:01 PM Geert Uytterhoeven <geert@linux-m68k.org> wrote:
> > > On Tue, Apr 9, 2024 at 5:48 PM Hugo Villeneuve <hugo@hugovil.com> wrote:
>
> > > > -config SERIAL_SC16IS7XX
> > > > -       tristate "SC16IS7xx serial support"
> > > > +       tristate "NXP SC16IS7xx UART support"
> > >
> > > Hence this replaces SERIAL_SC16IS7XX_CORE by SERIAL_SC16IS7XX,
> > > so arch/mips/configs/cu1??0-neo_defconfig needs to updated.
> >
> >         select SERIAL_CORE
> > -       depends on (SPI_MASTER && !I2C) || I2C
> > +       select SERIAL_SC16IS7XX_SPI if SPI_MASTER
> > +       select SERIAL_SC16IS7XX_I2C if I2C
> >
> > > So if SPI_MASTER or I2C is enabled, the corresponding SERIAL_SC16IS7XX_*
> > > subdriver can no longer be disabled?  According to
> > > https://lore.kernel.org/all/20240403123501.8ef5c99f65a40ca2c10f635a@hugovil.com/
> > > you did want to support that?
> >
> > I believe it has been taken from one of the IIO drivers as an example.
>
> Looks like a bad example to follow:
>   1. The driver question now pops up if both I2C and SPI_MASTER
>      are disabled,
>   2. What if SERIAL_SC16IS7XX_CORE is builtin, but I2C and/or
>      SPI_MASTER are modular?
>
> I believe the only way to fix that is by letting the sub-drivers select the
> core driver, like before.

FTR, this issue is now upstream.

Gr{oetje,eeting}s,

                        Geert
Hugo Villeneuve May 23, 2024, 11:56 p.m. UTC | #6
On Thu, 23 May 2024 09:33:36 +0200
Geert Uytterhoeven <geert@linux-m68k.org> wrote:

> On Tue, Apr 23, 2024 at 3:11 PM Geert Uytterhoeven <geert@linux-m68k.org> wrote:
> > On Tue, Apr 23, 2024 at 12:37 PM Andy Shevchenko
> > <andy.shevchenko@gmail.com> wrote:
> > > On Tue, Apr 23, 2024 at 1:01 PM Geert Uytterhoeven <geert@linux-m68k.org> wrote:
> > > > On Tue, Apr 9, 2024 at 5:48 PM Hugo Villeneuve <hugo@hugovil.com> wrote:
> >
> > > > > -config SERIAL_SC16IS7XX
> > > > > -       tristate "SC16IS7xx serial support"
> > > > > +       tristate "NXP SC16IS7xx UART support"
> > > >
> > > > Hence this replaces SERIAL_SC16IS7XX_CORE by SERIAL_SC16IS7XX,
> > > > so arch/mips/configs/cu1??0-neo_defconfig needs to updated.
> > >
> > >         select SERIAL_CORE
> > > -       depends on (SPI_MASTER && !I2C) || I2C
> > > +       select SERIAL_SC16IS7XX_SPI if SPI_MASTER
> > > +       select SERIAL_SC16IS7XX_I2C if I2C
> > >
> > > > So if SPI_MASTER or I2C is enabled, the corresponding SERIAL_SC16IS7XX_*
> > > > subdriver can no longer be disabled?  According to
> > > > https://lore.kernel.org/all/20240403123501.8ef5c99f65a40ca2c10f635a@hugovil.com/
> > > > you did want to support that?
> > >
> > > I believe it has been taken from one of the IIO drivers as an example.
> >
> > Looks like a bad example to follow:
> >   1. The driver question now pops up if both I2C and SPI_MASTER
> >      are disabled,
> >   2. What if SERIAL_SC16IS7XX_CORE is builtin, but I2C and/or
> >      SPI_MASTER are modular?
> >
> > I believe the only way to fix that is by letting the sub-drivers select the
> > core driver, like before.
> 
> FTR, this issue is now upstream.

Hi Geert,
I replied to you and Andy a few weeks ago about this (multiple emails with suggestions/explanations), and I even asked if you were satisfied with what I proposed, but never got anything from you, so I am still waiting on feedback to send a patch to fix this:

https://lore.kernel.org/all/20240430090333.5c5f029553cabcdf699310cb@hugovil.com/

Hugo.
Geert Uytterhoeven May 24, 2024, 7:47 a.m. UTC | #7
Hi Hugo,

On Fri, May 24, 2024 at 1:56 AM Hugo Villeneuve <hugo@hugovil.com> wrote:
> On Thu, 23 May 2024 09:33:36 +0200
> Geert Uytterhoeven <geert@linux-m68k.org> wrote:
> > On Tue, Apr 23, 2024 at 3:11 PM Geert Uytterhoeven <geert@linux-m68k.org> wrote:
> > > On Tue, Apr 23, 2024 at 12:37 PM Andy Shevchenko
> > > <andy.shevchenko@gmail.com> wrote:
> > > > On Tue, Apr 23, 2024 at 1:01 PM Geert Uytterhoeven <geert@linux-m68k.org> wrote:
> > > > > On Tue, Apr 9, 2024 at 5:48 PM Hugo Villeneuve <hugo@hugovil.com> wrote:
> > >
> > > > > > -config SERIAL_SC16IS7XX
> > > > > > -       tristate "SC16IS7xx serial support"
> > > > > > +       tristate "NXP SC16IS7xx UART support"
> > > > >
> > > > > Hence this replaces SERIAL_SC16IS7XX_CORE by SERIAL_SC16IS7XX,
> > > > > so arch/mips/configs/cu1??0-neo_defconfig needs to updated.
> > > >
> > > >         select SERIAL_CORE
> > > > -       depends on (SPI_MASTER && !I2C) || I2C
> > > > +       select SERIAL_SC16IS7XX_SPI if SPI_MASTER
> > > > +       select SERIAL_SC16IS7XX_I2C if I2C
> > > >
> > > > > So if SPI_MASTER or I2C is enabled, the corresponding SERIAL_SC16IS7XX_*
> > > > > subdriver can no longer be disabled?  According to
> > > > > https://lore.kernel.org/all/20240403123501.8ef5c99f65a40ca2c10f635a@hugovil.com/
> > > > > you did want to support that?
> > > >
> > > > I believe it has been taken from one of the IIO drivers as an example.
> > >
> > > Looks like a bad example to follow:
> > >   1. The driver question now pops up if both I2C and SPI_MASTER
> > >      are disabled,
> > >   2. What if SERIAL_SC16IS7XX_CORE is builtin, but I2C and/or
> > >      SPI_MASTER are modular?
> > >
> > > I believe the only way to fix that is by letting the sub-drivers select the
> > > core driver, like before.
> >
> > FTR, this issue is now upstream.

> I replied to you and Andy a few weeks ago about this (multiple emails with suggestions/explanations), and I even asked if you were satisfied with what I proposed, but never got anything from you, so I am still waiting on feedback to send a patch to fix this:
>
> https://lore.kernel.org/all/20240430090333.5c5f029553cabcdf699310cb@hugovil.com/

Sorry, I indeed forgot to reply there.

Please use two visible symbols (for I2C and SPI), which select
the invisible SERIAL_SC16IS7XX_CORE.
Thanks!

Gr{oetje,eeting}s,

                        Geert
diff mbox series

Patch

diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index ffcf4882b25f9..9b5a65ea8ede3 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -1021,41 +1021,30 @@  config SERIAL_SCCNXP_CONSOLE
 	  Support for console on SCCNXP serial ports.
 
 config SERIAL_SC16IS7XX_CORE
-	tristate
-
-config SERIAL_SC16IS7XX
-	tristate "SC16IS7xx serial support"
+	tristate "NXP SC16IS7xx UART support"
 	select SERIAL_CORE
-	depends on (SPI_MASTER && !I2C) || I2C
+	select SERIAL_SC16IS7XX_SPI if SPI_MASTER
+	select SERIAL_SC16IS7XX_I2C if I2C
 	help
-	  This selects support for SC16IS7xx serial ports.
-	  Supported ICs are SC16IS740, SC16IS741, SC16IS750, SC16IS752,
-	  SC16IS760 and SC16IS762. Select supported buses using options below.
+	  Core driver for NXP SC16IS7xx UARTs.
+	  Supported ICs are:
+
+	    SC16IS740
+	    SC16IS741
+	    SC16IS750
+	    SC16IS752
+	    SC16IS760
+	    SC16IS762
+
+	  The driver supports both I2C and SPI interfaces.
 
 config SERIAL_SC16IS7XX_I2C
-	bool "SC16IS7xx for I2C interface"
-	depends on SERIAL_SC16IS7XX
-	depends on I2C
-	select SERIAL_SC16IS7XX_CORE if SERIAL_SC16IS7XX
-	select REGMAP_I2C if I2C
-	default y
-	help
-	  Enable SC16IS7xx driver on I2C bus,
-	  If required say y, and say n to i2c if not required,
-	  Enabled by default to support oldconfig.
-	  You must select at least one bus for the driver to be built.
+	tristate
+	select REGMAP_I2C
 
 config SERIAL_SC16IS7XX_SPI
-	bool "SC16IS7xx for spi interface"
-	depends on SERIAL_SC16IS7XX
-	depends on SPI_MASTER
-	select SERIAL_SC16IS7XX_CORE if SERIAL_SC16IS7XX
-	select REGMAP_SPI if SPI_MASTER
-	help
-	  Enable SC16IS7xx driver on SPI bus,
-	  If required say y, and say n to spi if not required,
-	  This is additional support to existing driver.
-	  You must select at least one bus for the driver to be built.
+	tristate
+	select REGMAP_SPI
 
 config SERIAL_TIMBERDALE
 	tristate "Support for timberdale UART"
diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
index b25e9b54a6609..faa45f2b8bb05 100644
--- a/drivers/tty/serial/Makefile
+++ b/drivers/tty/serial/Makefile
@@ -76,6 +76,8 @@  obj-$(CONFIG_SERIAL_SAMSUNG)		+= samsung_tty.o
 obj-$(CONFIG_SERIAL_SB1250_DUART)	+= sb1250-duart.o
 obj-$(CONFIG_SERIAL_SCCNXP)		+= sccnxp.o
 obj-$(CONFIG_SERIAL_SC16IS7XX_CORE)	+= sc16is7xx.o
+obj-$(CONFIG_SERIAL_SC16IS7XX_SPI)	+= sc16is7xx_spi.o
+obj-$(CONFIG_SERIAL_SC16IS7XX_I2C)	+= sc16is7xx_i2c.o
 obj-$(CONFIG_SERIAL_SH_SCI)		+= sh-sci.o
 obj-$(CONFIG_SERIAL_SIFIVE)		+= sifive.o
 obj-$(CONFIG_SERIAL_SPRD)		+= sprd_serial.o
diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index b971fd2a9a77e..51fb1c95d3826 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -1,19 +1,22 @@ 
 // SPDX-License-Identifier: GPL-2.0+
 /*
- * SC16IS7xx tty serial driver - Copyright (C) 2014 GridPoint
- * Author: Jon Ringle <jringle@gridpoint.com>
+ * SC16IS7xx tty serial driver - common code
  *
- *  Based on max310x.c, by Alexander Shiyan <shc_work@mail.ru>
+ * Copyright (C) 2014 GridPoint
+ * Author: Jon Ringle <jringle@gridpoint.com>
+ * Based on max310x.c, by Alexander Shiyan <shc_work@mail.ru>
  */
 
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#undef DEFAULT_SYMBOL_NAMESPACE
+#define DEFAULT_SYMBOL_NAMESPACE SERIAL_NXP_SC16IS7XX
 
 #include <linux/bitops.h>
 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/device.h>
+#include <linux/export.h>
 #include <linux/gpio/driver.h>
-#include <linux/i2c.h>
+#include <linux/kthread.h>
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
 #include <linux/property.h>
@@ -21,15 +24,15 @@ 
 #include <linux/sched.h>
 #include <linux/serial_core.h>
 #include <linux/serial.h>
+#include <linux/string.h>
 #include <linux/tty.h>
 #include <linux/tty_flip.h>
-#include <linux/spi/spi.h>
 #include <linux/uaccess.h>
 #include <linux/units.h>
 
-#define SC16IS7XX_NAME			"sc16is7xx"
+#include "sc16is7xx.h"
+
 #define SC16IS7XX_MAX_DEVS		8
-#define SC16IS7XX_MAX_PORTS		2 /* Maximum number of UART ports per IC. */
 
 /* SC16IS7XX register definitions */
 #define SC16IS7XX_RHR_REG		(0x00) /* RX FIFO */
@@ -302,16 +305,9 @@ 
 
 
 /* Misc definitions */
-#define SC16IS7XX_SPI_READ_BIT		BIT(7)
 #define SC16IS7XX_FIFO_SIZE		(64)
 #define SC16IS7XX_GPIOS_PER_BANK	4
 
-struct sc16is7xx_devtype {
-	char	name[10];
-	int	nr_gpio;
-	int	nr_uart;
-};
-
 #define SC16IS7XX_RECONF_MD		(1 << 0)
 #define SC16IS7XX_RECONF_IER		(1 << 1)
 #define SC16IS7XX_RECONF_RS485		(1 << 2)
@@ -492,35 +488,40 @@  static void sc16is7xx_stop_rx(struct uart_port *port)
 	sc16is7xx_ier_clear(port, SC16IS7XX_IER_RDI_BIT);
 }
 
-static const struct sc16is7xx_devtype sc16is74x_devtype = {
+const struct sc16is7xx_devtype sc16is74x_devtype = {
 	.name		= "SC16IS74X",
 	.nr_gpio	= 0,
 	.nr_uart	= 1,
 };
+EXPORT_SYMBOL_GPL(sc16is74x_devtype);
 
-static const struct sc16is7xx_devtype sc16is750_devtype = {
+const struct sc16is7xx_devtype sc16is750_devtype = {
 	.name		= "SC16IS750",
 	.nr_gpio	= 8,
 	.nr_uart	= 1,
 };
+EXPORT_SYMBOL_GPL(sc16is750_devtype);
 
-static const struct sc16is7xx_devtype sc16is752_devtype = {
+const struct sc16is7xx_devtype sc16is752_devtype = {
 	.name		= "SC16IS752",
 	.nr_gpio	= 8,
 	.nr_uart	= 2,
 };
+EXPORT_SYMBOL_GPL(sc16is752_devtype);
 
-static const struct sc16is7xx_devtype sc16is760_devtype = {
+const struct sc16is7xx_devtype sc16is760_devtype = {
 	.name		= "SC16IS760",
 	.nr_gpio	= 8,
 	.nr_uart	= 1,
 };
+EXPORT_SYMBOL_GPL(sc16is760_devtype);
 
-static const struct sc16is7xx_devtype sc16is762_devtype = {
+const struct sc16is7xx_devtype sc16is762_devtype = {
 	.name		= "SC16IS762",
 	.nr_gpio	= 8,
 	.nr_uart	= 2,
 };
+EXPORT_SYMBOL_GPL(sc16is762_devtype);
 
 static bool sc16is7xx_regmap_volatile(struct device *dev, unsigned int reg)
 {
@@ -1463,9 +1464,8 @@  static const struct serial_rs485 sc16is7xx_rs485_supported = {
 	.delay_rts_after_send = 1,	/* Not supported but keep returning -EINVAL */
 };
 
-static int sc16is7xx_probe(struct device *dev,
-			   const struct sc16is7xx_devtype *devtype,
-			   struct regmap *regmaps[], int irq)
+int sc16is7xx_probe(struct device *dev, const struct sc16is7xx_devtype *devtype,
+		    struct regmap *regmaps[], int irq)
 {
 	unsigned long freq = 0, *pfreq = dev_get_platdata(dev);
 	unsigned int val;
@@ -1657,8 +1657,9 @@  static int sc16is7xx_probe(struct device *dev,
 
 	return ret;
 }
+EXPORT_SYMBOL_GPL(sc16is7xx_probe);
 
-static void sc16is7xx_remove(struct device *dev)
+void sc16is7xx_remove(struct device *dev)
 {
 	struct sc16is7xx_port *s = dev_get_drvdata(dev);
 	int i;
@@ -1680,8 +1681,9 @@  static void sc16is7xx_remove(struct device *dev)
 
 	clk_disable_unprepare(s->clk);
 }
+EXPORT_SYMBOL_GPL(sc16is7xx_remove);
 
-static const struct of_device_id __maybe_unused sc16is7xx_dt_ids[] = {
+const struct of_device_id __maybe_unused sc16is7xx_dt_ids[] = {
 	{ .compatible = "nxp,sc16is740",	.data = &sc16is74x_devtype, },
 	{ .compatible = "nxp,sc16is741",	.data = &sc16is74x_devtype, },
 	{ .compatible = "nxp,sc16is750",	.data = &sc16is750_devtype, },
@@ -1690,9 +1692,10 @@  static const struct of_device_id __maybe_unused sc16is7xx_dt_ids[] = {
 	{ .compatible = "nxp,sc16is762",	.data = &sc16is762_devtype, },
 	{ }
 };
+EXPORT_SYMBOL_GPL(sc16is7xx_dt_ids);
 MODULE_DEVICE_TABLE(of, sc16is7xx_dt_ids);
 
-static struct regmap_config regcfg = {
+struct regmap_config sc16is7xx_regcfg = {
 	.reg_bits = 5,
 	.pad_bits = 3,
 	.val_bits = 8,
@@ -1705,8 +1708,9 @@  static struct regmap_config regcfg = {
 	.max_raw_write = SC16IS7XX_FIFO_SIZE,
 	.max_register = SC16IS7XX_EFCR_REG,
 };
+EXPORT_SYMBOL_GPL(sc16is7xx_regcfg);
 
-static const char *sc16is7xx_regmap_name(u8 port_id)
+const char *sc16is7xx_regmap_name(u8 port_id)
 {
 	switch (port_id) {
 	case 0:	return "port0";
@@ -1716,184 +1720,27 @@  static const char *sc16is7xx_regmap_name(u8 port_id)
 		return NULL;
 	}
 }
+EXPORT_SYMBOL_GPL(sc16is7xx_regmap_name);
 
-static unsigned int sc16is7xx_regmap_port_mask(unsigned int port_id)
+unsigned int sc16is7xx_regmap_port_mask(unsigned int port_id)
 {
 	/* CH1,CH0 are at bits 2:1. */
 	return port_id << 1;
 }
-
-#ifdef CONFIG_SERIAL_SC16IS7XX_SPI
-static int sc16is7xx_spi_probe(struct spi_device *spi)
-{
-	const struct sc16is7xx_devtype *devtype;
-	struct regmap *regmaps[SC16IS7XX_MAX_PORTS];
-	unsigned int i;
-	int ret;
-
-	/* Setup SPI bus */
-	spi->bits_per_word	= 8;
-	/* For all variants, only mode 0 is supported */
-	if ((spi->mode & SPI_MODE_X_MASK) != SPI_MODE_0)
-		return dev_err_probe(&spi->dev, -EINVAL, "Unsupported SPI mode\n");
-
-	spi->mode		= spi->mode ? : SPI_MODE_0;
-	spi->max_speed_hz	= spi->max_speed_hz ? : 4 * HZ_PER_MHZ;
-	ret = spi_setup(spi);
-	if (ret)
-		return ret;
-
-	devtype = spi_get_device_match_data(spi);
-	if (!devtype)
-		return dev_err_probe(&spi->dev, -ENODEV, "Failed to match device\n");
-
-	for (i = 0; i < devtype->nr_uart; i++) {
-		regcfg.name = sc16is7xx_regmap_name(i);
-		/*
-		 * If read_flag_mask is 0, the regmap code sets it to a default
-		 * of 0x80. Since we specify our own mask, we must add the READ
-		 * bit ourselves:
-		 */
-		regcfg.read_flag_mask = sc16is7xx_regmap_port_mask(i) |
-			SC16IS7XX_SPI_READ_BIT;
-		regcfg.write_flag_mask = sc16is7xx_regmap_port_mask(i);
-		regmaps[i] = devm_regmap_init_spi(spi, &regcfg);
-	}
-
-	return sc16is7xx_probe(&spi->dev, devtype, regmaps, spi->irq);
-}
-
-static void sc16is7xx_spi_remove(struct spi_device *spi)
-{
-	sc16is7xx_remove(&spi->dev);
-}
-
-static const struct spi_device_id sc16is7xx_spi_id_table[] = {
-	{ "sc16is74x",	(kernel_ulong_t)&sc16is74x_devtype, },
-	{ "sc16is740",	(kernel_ulong_t)&sc16is74x_devtype, },
-	{ "sc16is741",	(kernel_ulong_t)&sc16is74x_devtype, },
-	{ "sc16is750",	(kernel_ulong_t)&sc16is750_devtype, },
-	{ "sc16is752",	(kernel_ulong_t)&sc16is752_devtype, },
-	{ "sc16is760",	(kernel_ulong_t)&sc16is760_devtype, },
-	{ "sc16is762",	(kernel_ulong_t)&sc16is762_devtype, },
-	{ }
-};
-
-MODULE_DEVICE_TABLE(spi, sc16is7xx_spi_id_table);
-
-static struct spi_driver sc16is7xx_spi_uart_driver = {
-	.driver = {
-		.name		= SC16IS7XX_NAME,
-		.of_match_table	= sc16is7xx_dt_ids,
-	},
-	.probe		= sc16is7xx_spi_probe,
-	.remove		= sc16is7xx_spi_remove,
-	.id_table	= sc16is7xx_spi_id_table,
-};
-#endif
-
-#ifdef CONFIG_SERIAL_SC16IS7XX_I2C
-static int sc16is7xx_i2c_probe(struct i2c_client *i2c)
-{
-	const struct sc16is7xx_devtype *devtype;
-	struct regmap *regmaps[SC16IS7XX_MAX_PORTS];
-	unsigned int i;
-
-	devtype = i2c_get_match_data(i2c);
-	if (!devtype)
-		return dev_err_probe(&i2c->dev, -ENODEV, "Failed to match device\n");
-
-	for (i = 0; i < devtype->nr_uart; i++) {
-		regcfg.name = sc16is7xx_regmap_name(i);
-		regcfg.read_flag_mask = sc16is7xx_regmap_port_mask(i);
-		regcfg.write_flag_mask = sc16is7xx_regmap_port_mask(i);
-		regmaps[i] = devm_regmap_init_i2c(i2c, &regcfg);
-	}
-
-	return sc16is7xx_probe(&i2c->dev, devtype, regmaps, i2c->irq);
-}
-
-static void sc16is7xx_i2c_remove(struct i2c_client *client)
-{
-	sc16is7xx_remove(&client->dev);
-}
-
-static const struct i2c_device_id sc16is7xx_i2c_id_table[] = {
-	{ "sc16is74x",	(kernel_ulong_t)&sc16is74x_devtype, },
-	{ "sc16is740",	(kernel_ulong_t)&sc16is74x_devtype, },
-	{ "sc16is741",	(kernel_ulong_t)&sc16is74x_devtype, },
-	{ "sc16is750",	(kernel_ulong_t)&sc16is750_devtype, },
-	{ "sc16is752",	(kernel_ulong_t)&sc16is752_devtype, },
-	{ "sc16is760",	(kernel_ulong_t)&sc16is760_devtype, },
-	{ "sc16is762",	(kernel_ulong_t)&sc16is762_devtype, },
-	{ }
-};
-MODULE_DEVICE_TABLE(i2c, sc16is7xx_i2c_id_table);
-
-static struct i2c_driver sc16is7xx_i2c_uart_driver = {
-	.driver = {
-		.name		= SC16IS7XX_NAME,
-		.of_match_table	= sc16is7xx_dt_ids,
-	},
-	.probe		= sc16is7xx_i2c_probe,
-	.remove		= sc16is7xx_i2c_remove,
-	.id_table	= sc16is7xx_i2c_id_table,
-};
-
-#endif
+EXPORT_SYMBOL_GPL(sc16is7xx_regmap_port_mask);
 
 static int __init sc16is7xx_init(void)
 {
-	int ret;
-
-	ret = uart_register_driver(&sc16is7xx_uart);
-	if (ret) {
-		pr_err("Registering UART driver failed\n");
-		return ret;
-	}
-
-#ifdef CONFIG_SERIAL_SC16IS7XX_I2C
-	ret = i2c_add_driver(&sc16is7xx_i2c_uart_driver);
-	if (ret < 0) {
-		pr_err("failed to init sc16is7xx i2c --> %d\n", ret);
-		goto err_i2c;
-	}
-#endif
-
-#ifdef CONFIG_SERIAL_SC16IS7XX_SPI
-	ret = spi_register_driver(&sc16is7xx_spi_uart_driver);
-	if (ret < 0) {
-		pr_err("failed to init sc16is7xx spi --> %d\n", ret);
-		goto err_spi;
-	}
-#endif
-	return ret;
-
-#ifdef CONFIG_SERIAL_SC16IS7XX_SPI
-err_spi:
-#endif
-#ifdef CONFIG_SERIAL_SC16IS7XX_I2C
-	i2c_del_driver(&sc16is7xx_i2c_uart_driver);
-err_i2c:
-#endif
-	uart_unregister_driver(&sc16is7xx_uart);
-	return ret;
+	return uart_register_driver(&sc16is7xx_uart);
 }
 module_init(sc16is7xx_init);
 
 static void __exit sc16is7xx_exit(void)
 {
-#ifdef CONFIG_SERIAL_SC16IS7XX_I2C
-	i2c_del_driver(&sc16is7xx_i2c_uart_driver);
-#endif
-
-#ifdef CONFIG_SERIAL_SC16IS7XX_SPI
-	spi_unregister_driver(&sc16is7xx_spi_uart_driver);
-#endif
 	uart_unregister_driver(&sc16is7xx_uart);
 }
 module_exit(sc16is7xx_exit);
 
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Jon Ringle <jringle@gridpoint.com>");
-MODULE_DESCRIPTION("SC16IS7XX serial driver");
+MODULE_DESCRIPTION("SC16IS7xx tty serial core driver");
diff --git a/drivers/tty/serial/sc16is7xx.h b/drivers/tty/serial/sc16is7xx.h
new file mode 100644
index 0000000000000..2ee3ce83d95a4
--- /dev/null
+++ b/drivers/tty/serial/sc16is7xx.h
@@ -0,0 +1,41 @@ 
+/* SPDX-License-Identifier: GPL-2.0+ */
+/* SC16IS7xx SPI/I2C tty serial driver */
+
+#ifndef _SC16IS7XX_H_
+#define _SC16IS7XX_H_
+
+#include <linux/mod_devicetable.h>
+#include <linux/regmap.h>
+#include <linux/types.h>
+
+#define SC16IS7XX_NAME		"sc16is7xx"
+#define SC16IS7XX_MAX_PORTS	2 /* Maximum number of UART ports per IC. */
+
+struct device;
+
+struct sc16is7xx_devtype {
+	char	name[10];
+	int	nr_gpio;
+	int	nr_uart;
+};
+
+extern struct regmap_config sc16is7xx_regcfg;
+
+extern const struct of_device_id sc16is7xx_dt_ids[];
+
+extern const struct sc16is7xx_devtype sc16is74x_devtype;
+extern const struct sc16is7xx_devtype sc16is750_devtype;
+extern const struct sc16is7xx_devtype sc16is752_devtype;
+extern const struct sc16is7xx_devtype sc16is760_devtype;
+extern const struct sc16is7xx_devtype sc16is762_devtype;
+
+const char *sc16is7xx_regmap_name(u8 port_id);
+
+unsigned int sc16is7xx_regmap_port_mask(unsigned int port_id);
+
+int sc16is7xx_probe(struct device *dev, const struct sc16is7xx_devtype *devtype,
+		    struct regmap *regmaps[], int irq);
+
+void sc16is7xx_remove(struct device *dev);
+
+#endif /* _SC16IS7XX_H_ */
diff --git a/drivers/tty/serial/sc16is7xx_i2c.c b/drivers/tty/serial/sc16is7xx_i2c.c
new file mode 100644
index 0000000000000..de51d1675abfd
--- /dev/null
+++ b/drivers/tty/serial/sc16is7xx_i2c.c
@@ -0,0 +1,64 @@ 
+// SPDX-License-Identifier: GPL-2.0+
+/* SC16IS7xx I2C interface driver */
+
+#include <linux/dev_printk.h>
+#include <linux/i2c.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/string.h>
+
+#include "sc16is7xx.h"
+
+static int sc16is7xx_i2c_probe(struct i2c_client *i2c)
+{
+	const struct sc16is7xx_devtype *devtype;
+	struct regmap *regmaps[SC16IS7XX_MAX_PORTS];
+	unsigned int i;
+
+	devtype = i2c_get_match_data(i2c);
+	if (!devtype)
+		return dev_err_probe(&i2c->dev, -ENODEV, "Failed to match device\n");
+
+	for (i = 0; i < devtype->nr_uart; i++) {
+		sc16is7xx_regcfg.name = sc16is7xx_regmap_name(i);
+		sc16is7xx_regcfg.read_flag_mask = sc16is7xx_regmap_port_mask(i);
+		sc16is7xx_regcfg.write_flag_mask = sc16is7xx_regmap_port_mask(i);
+		regmaps[i] = devm_regmap_init_i2c(i2c, &sc16is7xx_regcfg);
+	}
+
+	return sc16is7xx_probe(&i2c->dev, devtype, regmaps, i2c->irq);
+}
+
+static void sc16is7xx_i2c_remove(struct i2c_client *client)
+{
+	sc16is7xx_remove(&client->dev);
+}
+
+static const struct i2c_device_id sc16is7xx_i2c_id_table[] = {
+	{ "sc16is74x",	(kernel_ulong_t)&sc16is74x_devtype, },
+	{ "sc16is740",	(kernel_ulong_t)&sc16is74x_devtype, },
+	{ "sc16is741",	(kernel_ulong_t)&sc16is74x_devtype, },
+	{ "sc16is750",	(kernel_ulong_t)&sc16is750_devtype, },
+	{ "sc16is752",	(kernel_ulong_t)&sc16is752_devtype, },
+	{ "sc16is760",	(kernel_ulong_t)&sc16is760_devtype, },
+	{ "sc16is762",	(kernel_ulong_t)&sc16is762_devtype, },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, sc16is7xx_i2c_id_table);
+
+static struct i2c_driver sc16is7xx_i2c_driver = {
+	.driver = {
+		.name		= SC16IS7XX_NAME,
+		.of_match_table	= sc16is7xx_dt_ids,
+	},
+	.probe		= sc16is7xx_i2c_probe,
+	.remove		= sc16is7xx_i2c_remove,
+	.id_table	= sc16is7xx_i2c_id_table,
+};
+
+module_i2c_driver(sc16is7xx_i2c_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("SC16IS7xx I2C interface driver");
+MODULE_IMPORT_NS(SERIAL_NXP_SC16IS7XX);
diff --git a/drivers/tty/serial/sc16is7xx_spi.c b/drivers/tty/serial/sc16is7xx_spi.c
new file mode 100644
index 0000000000000..f110c4e6dce63
--- /dev/null
+++ b/drivers/tty/serial/sc16is7xx_spi.c
@@ -0,0 +1,87 @@ 
+// SPDX-License-Identifier: GPL-2.0+
+/* SC16IS7xx SPI interface driver */
+
+#include <linux/dev_printk.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/spi/spi.h>
+#include <linux/string.h>
+#include <linux/units.h>
+
+#include "sc16is7xx.h"
+
+/* SPI definitions */
+#define SC16IS7XX_SPI_READ_BIT	BIT(7)
+
+static int sc16is7xx_spi_probe(struct spi_device *spi)
+{
+	const struct sc16is7xx_devtype *devtype;
+	struct regmap *regmaps[SC16IS7XX_MAX_PORTS];
+	unsigned int i;
+	int ret;
+
+	/* Setup SPI bus */
+	spi->bits_per_word	= 8;
+	/* For all variants, only mode 0 is supported */
+	if ((spi->mode & SPI_MODE_X_MASK) != SPI_MODE_0)
+		return dev_err_probe(&spi->dev, -EINVAL, "Unsupported SPI mode\n");
+
+	spi->mode		= spi->mode ? : SPI_MODE_0;
+	spi->max_speed_hz	= spi->max_speed_hz ? : 4 * HZ_PER_MHZ;
+	ret = spi_setup(spi);
+	if (ret)
+		return ret;
+
+	devtype = spi_get_device_match_data(spi);
+	if (!devtype)
+		return dev_err_probe(&spi->dev, -ENODEV, "Failed to match device\n");
+
+	for (i = 0; i < devtype->nr_uart; i++) {
+		sc16is7xx_regcfg.name = sc16is7xx_regmap_name(i);
+		/*
+		 * If read_flag_mask is 0, the regmap code sets it to a default
+		 * of 0x80. Since we specify our own mask, we must add the READ
+		 * bit ourselves:
+		 */
+		sc16is7xx_regcfg.read_flag_mask = sc16is7xx_regmap_port_mask(i) |
+			SC16IS7XX_SPI_READ_BIT;
+		sc16is7xx_regcfg.write_flag_mask = sc16is7xx_regmap_port_mask(i);
+		regmaps[i] = devm_regmap_init_spi(spi, &sc16is7xx_regcfg);
+	}
+
+	return sc16is7xx_probe(&spi->dev, devtype, regmaps, spi->irq);
+}
+
+static void sc16is7xx_spi_remove(struct spi_device *spi)
+{
+	sc16is7xx_remove(&spi->dev);
+}
+
+static const struct spi_device_id sc16is7xx_spi_id_table[] = {
+	{ "sc16is74x",	(kernel_ulong_t)&sc16is74x_devtype, },
+	{ "sc16is740",	(kernel_ulong_t)&sc16is74x_devtype, },
+	{ "sc16is741",	(kernel_ulong_t)&sc16is74x_devtype, },
+	{ "sc16is750",	(kernel_ulong_t)&sc16is750_devtype, },
+	{ "sc16is752",	(kernel_ulong_t)&sc16is752_devtype, },
+	{ "sc16is760",	(kernel_ulong_t)&sc16is760_devtype, },
+	{ "sc16is762",	(kernel_ulong_t)&sc16is762_devtype, },
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, sc16is7xx_spi_id_table);
+
+static struct spi_driver sc16is7xx_spi_driver = {
+	.driver = {
+		.name		= SC16IS7XX_NAME,
+		.of_match_table	= sc16is7xx_dt_ids,
+	},
+	.probe		= sc16is7xx_spi_probe,
+	.remove		= sc16is7xx_spi_remove,
+	.id_table	= sc16is7xx_spi_id_table,
+};
+
+module_spi_driver(sc16is7xx_spi_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("SC16IS7xx SPI interface driver");
+MODULE_IMPORT_NS(SERIAL_NXP_SC16IS7XX);