Hi Konstantin,
On Wed, Jul 25, 2012 at 16:35:16, Konstantin Baydarov wrote:
> This patch introduces a MFD core device driver for
> OMAP system control module.
>
> The control module allows software control of
> various static modes supported by the device. It is
> composed of two control submodules: general control
> module and device (padconfiguration) control
> module.
>
> Device driver is probed with postcore_initcall.
> Control module register CONTROL_STATUS that is needed
> by omap_type() is early mapped by postcore_initcall_sync.
>
> Signed-off-by: J Keerthy <j-keerthy@xxxxxx>
> Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
> Signed-off-by: Eduardo Valentin <eduardo.valentin@xxxxxx>
> Signed-off-by: Konstantin Baydarov <kbaidarov@xxxxxxxxxxxxx>
> ---
> .../devicetree/bindings/mfd/omap_control.txt | 32 ++++
> arch/arm/mach-omap2/Kconfig | 1 +
> arch/arm/plat-omap/Kconfig | 4 +
> drivers/mfd/Kconfig | 6 +
> drivers/mfd/Makefile | 1 +
> drivers/mfd/omap-control-core.c | 162 ++++++++++++++++++++
> include/linux/mfd/omap_control.h | 35 +++++
> 7 files changed, 241 insertions(+), 0 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/mfd/omap_control.txt
> create mode 100644 drivers/mfd/omap-control-core.c
> create mode 100644 include/linux/mfd/omap_control.h
>
> diff --git a/Documentation/devicetree/bindings/mfd/omap_control.txt b/Documentation/devicetree/bindings/mfd/omap_control.txt
> new file mode 100644
> index 0000000..a9dca9e
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mfd/omap_control.txt
> @@ -0,0 +1,32 @@
> +* Texas Instrument OMAP System Control Module (SCM) bindings
> +
> +The control module allows software control of various static modes supported by
> +the device. The control module controls the settings of various device modules
> +through register configuration and internal signals. It also controls the pad
> +configuration, pin functional multiplexing, and the routing of internal signals
> +(such as PRCM signals or DMA requests) to output pins configured for hardware
> +observability.
> +
> +Required properties:
> +- compatible : Should be:
> + - "ti,omap3-control" for OMAP3 support
> + - "ti,omap4-control" for OMAP4 support
> + - "ti,omap5-control" for OMAP5 support
> +
> +OMAP specific properties:
> +- ti,hwmods: Name of the hwmod associated to the control module:
> + Should be "ctrl_module_core";
> +
> +OMAP CONTROL_STATUS register:
> +reg = <0x4A0022C4 0x4>; /* CONTROL_STATUS register */
> +
> +Examples:
> +ctrl_module_core: ctrl_module_core@4A0022C4 {
> + compatible = "ti,omap4-control";
> + #address-cells = <1>;
> + #size-cells = <1>;
> + /* ranges; */
> + ti,hwmods = "ctrl_module_core";
> + reg = <0x4A0022C4 0x4>; /* CONTROL_STATUS register */
> +};
> +
> diff --git a/arch/arm/mach-omap2/Kconfig b/arch/arm/mach-omap2/Kconfig
> index dd0fbf7..1235576 100644
> --- a/arch/arm/mach-omap2/Kconfig
> +++ b/arch/arm/mach-omap2/Kconfig
> @@ -59,6 +59,7 @@ config ARCH_OMAP4
> select ARM_ERRATA_720789
> select ARCH_HAS_OPP
> select PM_RUNTIME if CPU_IDLE
> + select ARCH_HAS_CONTROL_MODULE
> select PM_OPP if PM
> select USB_ARCH_HAS_EHCI if USB_SUPPORT
> select ARM_CPU_SUSPEND if PM
> diff --git a/arch/arm/plat-omap/Kconfig b/arch/arm/plat-omap/Kconfig
> index dd36eba..2b2c9d8 100644
> --- a/arch/arm/plat-omap/Kconfig
> +++ b/arch/arm/plat-omap/Kconfig
> @@ -5,6 +5,10 @@ menu "TI OMAP Common Features"
> config ARCH_OMAP_OTG
> bool
>
> +config ARCH_HAS_CONTROL_MODULE
> + bool
> + select MFD_OMAP_CONTROL
> +
> choice
> prompt "OMAP System Type"
> default ARCH_OMAP2PLUS
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index 92144ed..530ac60 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -823,6 +823,12 @@ config MFD_WL1273_CORE
> driver connects the radio-wl1273 V4L2 module and the wl1273
> audio codec.
>
> +config MFD_OMAP_CONTROL
> + bool "Texas Instruments OMAP System control module"
> + depends on ARCH_HAS_CONTROL_MODULE
> + help
> + This is the core driver for system control module.
> +
> config MFD_OMAP_USB_HOST
> bool "Support OMAP USBHS core driver"
> depends on USB_EHCI_HCD_OMAP || USB_OHCI_HCD_OMAP3
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index 75f6ed6..b037443 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -107,6 +107,7 @@ obj-$(CONFIG_MFD_TPS6586X) += tps6586x.o
> obj-$(CONFIG_MFD_VX855) += vx855.o
> obj-$(CONFIG_MFD_WL1273_CORE) += wl1273-core.o
> obj-$(CONFIG_MFD_CS5535) += cs5535-mfd.o
> +obj-$(CONFIG_MFD_OMAP_CONTROL) += omap-control-core.o
> obj-$(CONFIG_MFD_OMAP_USB_HOST) += omap-usb-host.o
> obj-$(CONFIG_MFD_PM8921_CORE) += pm8921-core.o
> obj-$(CONFIG_MFD_PM8XXX_IRQ) += pm8xxx-irq.o
> diff --git a/drivers/mfd/omap-control-core.c b/drivers/mfd/omap-control-core.c
> new file mode 100644
> index 0000000..cefbc5a
> --- /dev/null
> +++ b/drivers/mfd/omap-control-core.c
> @@ -0,0 +1,162 @@
> +/*
> + * OMAP system control module driver file
> + *
> + * Copyright (C) 2011-2012 Texas Instruments Incorporated - http://www.ti.com/
> + * Contacts:
> + * Based on original code written by:
> + * J Keerthy <j-keerthy@xxxxxx>
> + * Moiz Sonasath <m-sonasath@xxxxxx>
> + * MFD clean up and re-factoring:
> + * Eduardo Valentin <eduardo.valentin@xxxxxx>
> + * Konstantin Baydarov <kbaidarov@xxxxxxxxxxxxx>
> + *
> + * 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.
> + *
> + * This program is distributed in the hope that it will be useful, but
> + * WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + * General Public License for more details.
> + *
> + */
> +
> +#include <linux/module.h>
> +#include <linux/export.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +#include <linux/io.h>
> +#include <linux/err.h>
> +#include <linux/of_platform.h>
> +#include <linux/of_address.h>
> +#include <linux/mfd/core.h>
> +#include <linux/mfd/omap_control.h>
> +
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +
> +void __iomem *omap_control_base;
> +unsigned long omap_control_phys_base;
> +size_t omap_control_mapsize;
> +
> +u32 omap_control_status_read(void)
> +{
> + return __raw_readl(omap_control_base);
> +}
In AM335X, D_CAN IP uses single CONTROL module register to
initialize D_CAN ram (D_CAN_RAMINIT). In order to enable
D_CAN RAM we have to write to that register in sync with
clock enable/disable.
How can I use this driver to handle this usecase? Similar to
above API?
Currently this is handled using platform call back (example below)
In arch/arm/mach-omap2/devices.c:
static void d_can_hw_raminit(unsigned int instance, unsigned int enable)
{
u32 val;
/* Read the value */
val = readl(AM33XX_CTRL_REGADDR(AM33XX_DCAN_RAMINIT_OFFSET));
if (enable) {
/* Set to "1" */
val &= ~AM33XX_DCAN_RAMINIT_START(instance);
val |= AM33XX_DCAN_RAMINIT_START(instance);
writel(val, AM33XX_CTRL_REGADDR(AM33XX_DCAN_RAMINIT_OFFSET));
} else {
/* Set to "0" */
val &= ~AM33XX_DCAN_RAMINIT_START(instance);
writel(val, AM33XX_CTRL_REGADDR(AM33XX_DCAN_RAMINIT_OFFSET));
}
}
In drivers/net/can/c_can/c_can.c:
void d_can_reset_ram(struct d_can_priv *d_can, unsigned int instance,
unsigned int enable)
{
if (d_can->ram_init)
d_can->ram_init(instance, enable);
}
Thanks
AnilKumar
