Message-Id: <20240326222844.1422948-1-prabhakar.mahadev-lad.rj@bp.renesas.com>
Date: Tue, 26 Mar 2024 22:28:31 +0000
From: Prabhakar <prabhakar.csengg@...il.com>
To: Geert Uytterhoeven <geert+renesas@...der.be>,
	Linus Walleij <linus.walleij@...aro.org>,
	Rob Herring <robh@...nel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
	Conor Dooley <conor+dt@...nel.org>,
	Magnus Damm <magnus.damm@...il.com>
Cc: linux-renesas-soc@...r.kernel.org,
	linux-gpio@...r.kernel.org,
	devicetree@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Prabhakar <prabhakar.csengg@...il.com>,
	Fabrizio Castro <fabrizio.castro.jz@...esas.com>,
	Lad Prabhakar <prabhakar.mahadev-lad.rj@...renesas.com>
Subject: [RFC PATCH 00/13] Add PFC support for Renesas RZ/V2H(P) SoC

From: Lad Prabhakar <prabhakar.mahadev-lad.rj@...renesas.com>

Hi All,

This patch series aims to add PFC (Pin Function Controller) support for
Renesas RZ/V2H(P) SoC. The PFC block on RZ/V2H(P) is almost similar to
one found on the RZ/G2L family with couple of differences. To able to
re-use the use the existing driver for RZ/V2H(P) SoC function pointers
are introduced based on the SoC changes.

Sending this patch series as an RFC mainly as we are introducing a
SoC specific 'renesas-rzv2h,output-impedance' property to configure
the output impedance on the pins. Drive strength setting on RZ/V2H(P)
depends on the different power rails which are coming out from the PMIC
(connected via i2c). These power rails (required for drive strength) can
be 1.2/1.8/3.3V. Pin are grouped into 4 groups,

Group1: Impedance
- 150/75/38/25 ohms (at 3.3 V)
- 130/65/33/22 ohms (at 1.8 V)

Group2: Impedance
- 50/40/33/25 ohms (at 1.8 V)

Group3: Impedance
- 150/75/37.5/25 ohms (at 3.3 V)
- 130/65/33/22 ohms (at 1.8 V)

Group4: Impedance
- 110/55/30/20 ohms (at 1.8 V)
- 150/75/38/25 ohms (at 1.2 V)

The existing property 'output-impedance-ohms' cannot be used to specify
the output impedance setting on the pin mainly because,
1] The regulator information will not be available very earlier in boot process
2] The power rails info will be coming from the PMIC connected to I2C chip, as
   i2c will also require configuring the PFC there will be an interdependence
   of this two nodes.
3] We cannot use 'power-source' property for each pin as DTB's dont use up all
   the pins on SoC and when dumping the pinconf-pins from debugfs we wont be
   able to print the output-impedance of pins which are unused.

Due to above cons 'renesas-rzv2h,output-impedance' property is introduced where
it allows user to specify values [ x1 x2 x4 x6 ] which internally configures
the IOLH bits to value [ 0 1 2 3 ] respectively, and does not depend on the
actual voltage setting.

Cheers,
Prabhakar

Lad Prabhakar (13):
  dt-bindings: pinctrl: renesas,rzg2l-pinctrl: Remove the check from the
    object
  dt-bindings: pinctrl: renesas: Document RZ/V2H(P) SoC
  pinctrl: renesas: pinctrl-rzg2l: Remove extra space in function
    parameter
  pinctrl: renesas: pinctrl-rzg2l: Allow more bits for pin configuration
  pinctrl: renesas: pinctrl-rzg2l: Allow parsing of variable
    configuration for all architectures
  pinctrl: renesas: pinctrl-rzg2l: Make cfg to u64 in struct
    rzg2l_variable_pin_cfg
  pinctrl: renesas: pinctrl-rzg2l: Validate power registers for SD and
    ETH
  pinctrl: renesas: pinctrl-rzg2l: Add function pointers for writing to
    PFC
  pinctrl: renesas: pinctrl-rzg2l: Add function pointer for writing to
    PMC register
  pinctrl: renesas: pinctrl-rzg2l: Add function pointers for
    reading/writing OEN register
  pinctrl: renesas: pinctrl-rzg2l: Pass pincontrol device pointer to
    pinconf_generic_parse_dt_config()
  pinctrl: renesas: pinctrl-rzg2l: Add support to pass custom params
  pinctrl: renesas: pinctrl-rzg2l: Add support for RZ/V2H SoC

 .../pinctrl/renesas,rzg2l-pinctrl.yaml        |  37 +-
 drivers/pinctrl/renesas/pinctrl-rzg2l.c       | 566 +++++++++++++++++-
 2 files changed, 560 insertions(+), 43 deletions(-)

-- 
2.34.1

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