On 25/11/16 09:57, Thierry Reding wrote:

* PGP Signed by an unknown key

On Thu, Nov 24, 2016 at 02:08:54PM +0530, Laxman Dewangan wrote:

quoted

NVIDIA Tegra124 and later SoCs support the multi-voltage level and
low power state of some of its IO pads. The IO pads can work in
the voltage of the 1.8V and 3.3V of IO voltage from IO power rail
sources. When IO interfaces are not used then IO pads can be
configure in low power state to reduce the power consumption from
that IO pads.

On Tegra124, the voltage level of IO power rail source is auto
detected by hardware(SoC) and hence it is only require to configure
in low power mode if IO pads are not used.

On T210 onwards, the auto-detection of voltage level from IO power
rail is removed from SoC and hence SW need to configure the PMC
register explicitly to set proper voltage in IO pads based on
IO rail power source voltage.

This driver adds the IO pad driver to configure the power state and
IO pad voltage based on the usage and power tree via pincontrol
framework. The configuration can be static and dynamic.

Signed-off-by: Laxman Dewangan <redacted>

---
Changes from V1:
- Dropped the custom properties to set pad voltage and use regulator.
- Added support for regulator to get vottage in boot and configure IO
  pad voltage.
- Add support for callback to handle regulator notification and configure
  IO pad voltage based on voltage change.

Changes from V2:
 Mostly nit changes per Jon's feedback i.e. use macros for voltage, added
 comment on macros, reduce the structure and variable name size, optimise
 number of variables, and allocate memory for regulator info when it needed.

Changes from V3:
 Use the devm_regulator_get() instead of devm_regulator_get_optional().

 drivers/pinctrl/tegra/Kconfig                |  12 +
 drivers/pinctrl/tegra/Makefile               |   1 +
 drivers/pinctrl/tegra/pinctrl-tegra-io-pad.c | 530 +++++++++++++++++++++++++++
 3 files changed, 543 insertions(+)
 create mode 100644 drivers/pinctrl/tegra/pinctrl-tegra-io-pad.c

...

quoted

diff --git a/drivers/pinctrl/tegra/pinctrl-tegra-io-pad.c b/drivers/pinctrl/tegra/pinctrl-tegra-io-pad.c
new file mode 100644
index 0000000..aab02d0
--- /dev/null
+++ b/drivers/pinctrl/tegra/pinctrl-tegra-io-pad.c

@@ -0,0 +1,530 @@
+/*
+ * pinctrl-tegra-io-pad: IO PAD driver for configuration of IO rail and deep
+ *			 Power Down mode via pinctrl framework.
+ *
+ * Copyright (C) 2016 NVIDIA CORPORATION. All rights reserved.
+ *
+ * Author: Laxman Dewangan <ldewangan-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/pinctrl/pinctrl.h>
+#include <linux/pinctrl/pinconf-generic.h>
+#include <linux/pinctrl/pinconf.h>
+#include <linux/pinctrl/pinmux.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <soc/tegra/pmc.h>

Have you considered moving this code into the PMC driver? It seems a
little over the top to go through all of the platform device creation
and driver registration dance only to call into a public API later on.

I would prefer moving this under driver/soc/tegra as well (even if it is
not in the same source file) so we don't need all this public APIs.

Cheers
Jon

-- 
nvpublic
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