Commit Graph

16 Commits

Author SHA1 Message Date
Junlin Yang 57c855f742 pinctrl: ti: fix error return code of ti_iodelay_dt_node_to_map()
when devm_kcalloc fails, use -ENOMEM instead of -EINVAL,
and consistent with other devm_kcalloc return values.

Signed-off-by: Junlin Yang <yangjunlin@yulong.com>
Link: https://lore.kernel.org/r/20210330062655.1027-1-angkery@163.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2021-04-08 15:57:14 +02:00
Jia-Ju Bai 47386ce36f pinctrl: ti: fix error return code of ti_iodelay_probe()
When ti_iodelay_pinconf_init_dev() fails, no error return code of
ti_iodelay_probe() is assigned.
To fix this bug, ret is assigned with the return value of
ti_iodelay_pinconf_init_dev(), and then ret is checked.

Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Link: https://lore.kernel.org/r/20210306125122.15043-1-baijiaju1990@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2021-03-15 16:36:45 +01:00
Souptick Joarder a5d8278375 pinctrl: ti :iodelay: Fixed inconsistent indenting
Kernel test robot throws below warning ->

smatch warnings:
drivers/pinctrl/ti/pinctrl-ti-iodelay.c:708
ti_iodelay_pinconf_group_dbg_show() warn: inconsistent indenting

Fixed the inconsistent indenting.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Link: https://lore.kernel.org/r/1610394585-4296-1-git-send-email-jrdr.linux@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2021-01-18 14:21:04 +01:00
Zheng Yongjun 502045d91a pinctrl: ti-iodelay: convert comma to semicolon
Replace a comma between expression statements by a semicolon.

Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
Link: https://lore.kernel.org/r/20201211084902.2480-1-zhengyongjun3@huawei.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2021-01-04 15:31:51 +01:00
Alexander A. Klimov 42348547ce pinctl: ti: iodelay: Replace HTTP links with HTTPS ones
Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.

Deterministic algorithm:
For each file:
  If not .svg:
    For each line:
      If doesn't contain `\bxmlns\b`:
        For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
	  If neither `\bgnu\.org/license`, nor `\bmozilla\.org/MPL\b`:
            If both the HTTP and HTTPS versions
            return 200 OK and serve the same content:
              Replace HTTP with HTTPS.

Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Link: https://lore.kernel.org/r/20200718120807.19714-1-grandmaster@al2klimov.de
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2020-07-20 16:15:59 +02:00
Colin Ian King 5ff8aca906 pinctl: ti: iodelay: fix error checking on pinctrl_count_index_with_args call
The call to pinctrl_count_index_with_args checks for a -EINVAL return
however this function calls pinctrl_get_list_and_count and this can
return -ENOENT. Rather than check for a specific error, fix this by
checking for any error return to catch the -ENOENT case.

Addresses-Coverity: ("Improper use of negative")
Fixes: 003910ebc8 ("pinctrl: Introduce TI IOdelay configuration driver")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20190920122030.14340-1-colin.king@canonical.com
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2019-10-04 23:08:47 +02:00
YueHaibing ff54d82b77 pinctrl: ti-iodelay: Fix platform_no_drv_owner.cocci warnings
Remove .owner field if calls are used which set it automatically
Generated by: scripts/coccinelle/api/platform_no_drv_owner.cocci

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2019-01-28 14:41:54 +01:00
Nishanth Menon 40e3795851 pinctrl: ti: iodelay: Lower the priority of prints
Dont print every single iodelay register configuration - this is just
plain noise. Since this is useful debug information, just lower to debug

Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2019-01-21 14:38:40 +01:00
Rob Herring 94f4e54cec pinctrl: Convert to using %pOFn instead of device_node.name
In preparation to remove the node name pointer from struct device_node,
convert printf users to use the %pOFn format specifier.

Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Dong Aisheng <aisheng.dong@nxp.com>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Stefan Agner <stefan@agner.ch>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Cc: Sean Wang <sean.wang@mediatek.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Carlo Caione <carlo@caione.org>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Gregory Clement <gregory.clement@bootlin.com>
Cc: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Haojian Zhuang <haojian.zhuang@linaro.org>
Cc: Patrice Chotard <patrice.chotard@st.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: linux-gpio@vger.kernel.org
Cc: linux-mediatek@lists.infradead.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-amlogic@lists.infradead.org
Cc: linux-rockchip@lists.infradead.org
Cc: linux-omap@vger.kernel.org
Acked-by: Dong Aisheng <aisheng.dong@nxp.com>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Sean Wang <sean.wang@mediatek.com>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2018-08-29 14:05:36 +02:00
Kees Cook a86854d0c5 treewide: devm_kzalloc() -> devm_kcalloc()
The devm_kzalloc() function has a 2-factor argument form, devm_kcalloc().
This patch replaces cases of:

        devm_kzalloc(handle, a * b, gfp)

with:
        devm_kcalloc(handle, a * b, gfp)

as well as handling cases of:

        devm_kzalloc(handle, a * b * c, gfp)

with:

        devm_kzalloc(handle, array3_size(a, b, c), gfp)

as it's slightly less ugly than:

        devm_kcalloc(handle, array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

        devm_kzalloc(handle, 4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

Some manual whitespace fixes were needed in this patch, as Coccinelle
really liked to write "=devm_kcalloc..." instead of "= devm_kcalloc...".

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
expression HANDLE;
type TYPE;
expression THING, E;
@@

(
  devm_kzalloc(HANDLE,
-	(sizeof(TYPE)) * E
+	sizeof(TYPE) * E
  , ...)
|
  devm_kzalloc(HANDLE,
-	(sizeof(THING)) * E
+	sizeof(THING) * E
  , ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression HANDLE;
expression COUNT;
typedef u8;
typedef __u8;
@@

(
  devm_kzalloc(HANDLE,
-	sizeof(u8) * (COUNT)
+	COUNT
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(__u8) * (COUNT)
+	COUNT
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(char) * (COUNT)
+	COUNT
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(unsigned char) * (COUNT)
+	COUNT
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(u8) * COUNT
+	COUNT
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(__u8) * COUNT
+	COUNT
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(char) * COUNT
+	COUNT
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(unsigned char) * COUNT
+	COUNT
  , ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
expression HANDLE;
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	sizeof(TYPE) * (COUNT_ID)
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	sizeof(TYPE) * COUNT_ID
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	sizeof(TYPE) * (COUNT_CONST)
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	sizeof(TYPE) * COUNT_CONST
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	sizeof(THING) * (COUNT_ID)
+	COUNT_ID, sizeof(THING)
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	sizeof(THING) * COUNT_ID
+	COUNT_ID, sizeof(THING)
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	sizeof(THING) * (COUNT_CONST)
+	COUNT_CONST, sizeof(THING)
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	sizeof(THING) * COUNT_CONST
+	COUNT_CONST, sizeof(THING)
  , ...)
)

// 2-factor product, only identifiers.
@@
expression HANDLE;
identifier SIZE, COUNT;
@@

- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	SIZE * COUNT
+	COUNT, SIZE
  , ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression HANDLE;
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
  devm_kzalloc(HANDLE,
-	sizeof(TYPE) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(TYPE) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(TYPE) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(TYPE) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(THING) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(THING) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(THING) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(THING) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression HANDLE;
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
  devm_kzalloc(HANDLE,
-	sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(THING1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(THING1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(TYPE1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
expression HANDLE;
identifier STRIDE, SIZE, COUNT;
@@

(
  devm_kzalloc(HANDLE,
-	(COUNT) * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  devm_kzalloc(HANDLE,
-	COUNT * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  devm_kzalloc(HANDLE,
-	COUNT * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  devm_kzalloc(HANDLE,
-	(COUNT) * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  devm_kzalloc(HANDLE,
-	COUNT * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  devm_kzalloc(HANDLE,
-	(COUNT) * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  devm_kzalloc(HANDLE,
-	(COUNT) * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  devm_kzalloc(HANDLE,
-	COUNT * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression HANDLE;
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
  devm_kzalloc(HANDLE, C1 * C2 * C3, ...)
|
  devm_kzalloc(HANDLE,
-	(E1) * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  devm_kzalloc(HANDLE,
-	(E1) * (E2) * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  devm_kzalloc(HANDLE,
-	(E1) * (E2) * (E3)
+	array3_size(E1, E2, E3)
  , ...)
|
  devm_kzalloc(HANDLE,
-	E1 * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression HANDLE;
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
  devm_kzalloc(HANDLE, sizeof(THING) * C2, ...)
|
  devm_kzalloc(HANDLE, sizeof(TYPE) * C2, ...)
|
  devm_kzalloc(HANDLE, C1 * C2 * C3, ...)
|
  devm_kzalloc(HANDLE, C1 * C2, ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	sizeof(TYPE) * (E2)
+	E2, sizeof(TYPE)
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	sizeof(TYPE) * E2
+	E2, sizeof(TYPE)
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	sizeof(THING) * (E2)
+	E2, sizeof(THING)
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	sizeof(THING) * E2
+	E2, sizeof(THING)
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	(E1) * E2
+	E1, E2
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	(E1) * (E2)
+	E1, E2
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	E1 * E2
+	E1, E2
  , ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-12 16:19:22 -07:00
Colin Ian King 13dc48a883 pinctrl: ti-iodelay: remove redundant unused variable dev
The pointer dev is being assigned but is never used, hence it is
redundant and can be removed. Cleans up clang warnings:

drivers/pinctrl/ti/pinctrl-ti-iodelay.c:582:2: warning: Value stored
to 'dev' is never read
drivers/pinctrl/ti/pinctrl-ti-iodelay.c:701:2: warning: Value stored
to 'dev' is never read

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-11-08 13:49:57 +01:00
Julia Lawall a9856ef759 pinctrl: ti-iodelay: constify pinconf_ops, pinctrl_ops, and pinmux_ops structures
These structures are only stored in fields of a pinctrl_desc
structure (confops and pctlops) that are const. Make the
structures const as well.

Done with the help of Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-08-22 14:42:48 +02:00
Tony Lindgren 6118714275 pinctrl: core: Fix pinctrl_register_and_init() with pinctrl_enable()
Recent pinctrl changes to allow dynamic allocation of pins exposed one
more issue with the pinctrl pins claimed early by the controller itself.
This caused a regression for IMX6 pinctrl hogs.

Before enabling the pin controller driver we need to wait until it has
been properly initialized, then claim the hogs, and only then enable it.

To fix the regression, split the code into pinctrl_claim_hogs() and
pinctrl_enable(). And then let's require that pinctrl_enable() is always
called by the pin controller driver when ready after calling
pinctrl_register_and_init().

Depends-on: 950b0d91dc ("pinctrl: core: Fix regression caused by delayed
work for hogs")
Fixes: df61b366af26 ("pinctrl: core: Use delayed work for hogs")
Fixes: e566fc11ea ("pinctrl: imx: use generic pinctrl helpers for
managing groups")
Cc: Haojian Zhuang <haojian.zhuang@linaro.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Nishanth Menon <nm@ti.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Stefan Agner <stefan@agner.ch>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Gary Bisson <gary.bisson@boundarydevices.com>
Tested-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-04-07 01:08:08 +02:00
Colin Ian King 731d43cd6b pinctrl: ti-iodelay: remove redundant pin < 0 check on unsigned int
pin is an unsigned int and therefore can never be < 0 so
this check is redundant. Remove the check and the associated
dev_err error message.

Fixes CoverityScan CID#1396438 ("Unsigned compared against 0")

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-01-18 10:23:37 +01:00
Tony Lindgren 950b0d91dc pinctrl: core: Fix regression caused by delayed work for hogs
Commit df61b366af26 ("pinctrl: core: Use delayed work for hogs") caused a
regression at least with sh-pfc that is also a GPIO controller as
noted by Geert Uytterhoeven <geert@linux-m68k.org>.

As the original pinctrl_register() has issues calling pin controller
driver functions early before the controller has finished registering,
we can't just revert commit df61b366af26. That would break the drivers
using GENERIC_PINCTRL_GROUPS or GENERIC_PINMUX_FUNCTIONS.

So let's fix the issue with the following steps as a single patch:

1. Revert the late_init parts of commit df61b366af26.

   The late_init clearly won't work and we have to just give up
   on fixing pinctrl_register() for GENERIC_PINCTRL_GROUPS and
   GENERIC_PINMUX_FUNCTIONS.

2. Split pinctrl_register() into two parts

   By splitting pinctrl_register() into pinctrl_init_controller()
   and pinctrl_create_and_start() we have better control over when
   it's safe to call pinctrl_create().

3. Introduce a new pinctrl_register_and_init() function

   As suggested by Linus Walleij <linus.walleij@linaro.org>, we
   can just introduce a new function for the controllers that need
   pinctrl_create() called later.

4. Convert the four known problem cases to use new function

   Let's convert pinctrl-imx, pinctrl-single, sh-pfc and ti-iodelay
   to use the new function to fix the issues. The rest of the drivers
   can be converted later. Let's also update Documentation/pinctrl.txt
   accordingly because of the known issues with pinctrl_register().

Fixes: df61b366af26 ("pinctrl: core: Use delayed work for hogs")
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Gary Bisson <gary.bisson@boundarydevices.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-01-13 16:25:17 +01:00
Nishanth Menon 003910ebc8 pinctrl: Introduce TI IOdelay configuration driver
SoC family such as DRA7 family of processors have, in addition
to the regular muxing of pins (as done by pinctrl-single), a separate
hardware module called IODelay which is also expected to be configured.
The "IODelay" module has it's own register space that is independent
of the control module and the padconf register area.

With recent changes to the pinctrl framework, we can now support
this hardware with a reasonably minimal driver by using #pinctrl-cells,
GENERIC_PINCTRL_GROUPS and GENERIC_PINMUX_FUNCTIONS.

It is advocated strongly in TI's official documentation considering
the existing design of the DRA7 family of processors during mux or
IODelay reconfiguration, there is a potential for a significant glitch
which may cause functional impairment to certain hardware. It is
hence recommended to do as little of muxing as absolutely necessary
without I/O isolation (which can only be done in initial stages of
bootloader).

NOTE: with the system wide I/O isolation scheme present in DRA7 SoC
family, it is not reasonable to do stop all I/O operations for every
such pad configuration scheme. So, we will let it glitch when used in
this mode.

Even with the above limitation, certain functionality such as MMC has
mandatory need for IODelay reconfiguration requirements, depending on
speed of transfer. In these cases, with careful examination of usecase
involved, the expected glitch can be controlled such that it does not
impact functionality.

In short, IODelay module support as a padconf driver being introduced
here is not expected to do SoC wide I/O Isolation and is meant for
a limited subset of IODelay configuration requirements that need to
be dynamic and whose glitchy behavior will not cause functionality
failure for that interface.

IMPORTANT NOTE: we take the approach of keeping LOCK_BITs cleared
to 0x0 at all times, even when configuring Manual IO Timing Modes.
This is done by eliminating the LOCK_BIT=1 setting from Step
of the Manual IO timing Mode configuration procedure. This option
leaves the CFG_* registers unprotected from unintended writes to the
CTRL_CORE_PAD_* registers while Manual IO Timing Modes are configured.

This approach is taken to allow for a generic driver to exist in kernel
world that has to be used carefully in required usecases.

Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
[tony@atomide.com: updated to use generic pinctrl functions, added
 binding documentation, updated comments]
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-01-09 19:43:21 +01:00