| Message ID | 1398802790-29287-2-git-send-email-dmurphy@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tuesday 29 April 2014 15:19:40 Dan Murphy wrote: > +#ifndef _RESET_TI_H_ > +#define _RESET_TI_H_ > + > +#ifdef CONFIG_RESET_TI > +void ti_dt_reset_init(void); > +#else > +static inline void ti_dt_reset_init(void){ return; }; > +#endif Why can't this be a regular platform device driver that gets initialized through an initcall rather than get called from platform code? Arnd
Hi Dan, Am Dienstag, den 29.04.2014, 15:19 -0500 schrieb Dan Murphy: > The TI SoC reset controller support utilizes the > reset controller framework to give device drivers or > function drivers a common set of APIs to call to reset > a module. > > The reset-ti is a common interface to the reset framework. > The register data is retrieved during initialization > of the reset driver through the reset-ti-data > file. The array of data is associated with the compatible from the > respective DT entry. > > Once the data is available then this is derefenced within the common > interface. > > The device driver has the ability to assert, deassert or perform a > complete reset. > > This code was derived from previous work by Rajendra Nayak and Afzal Mohammed. > The code was changed to adopt to the reset core and abstract away the SoC information. > > Signed-off-by: Dan Murphy <dmurphy@ti.com> > --- > drivers/reset/Kconfig | 1 + > drivers/reset/Makefile | 1 + > drivers/reset/ti/Kconfig | 8 ++ > drivers/reset/ti/Makefile | 1 + > drivers/reset/ti/reset-ti-data.h | 58 ++++++++++++ > drivers/reset/ti/reset-ti.c | 195 ++++++++++++++++++++++++++++++++++++++ > include/linux/reset_ti.h | 25 +++++ > 7 files changed, 289 insertions(+) > create mode 100644 drivers/reset/ti/Kconfig > create mode 100644 drivers/reset/ti/Makefile > create mode 100644 drivers/reset/ti/reset-ti-data.h > create mode 100644 drivers/reset/ti/reset-ti.c > create mode 100644 include/linux/reset_ti.h > > diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig > index 0615f50..a58d789 100644 > --- a/drivers/reset/Kconfig > +++ b/drivers/reset/Kconfig > @@ -13,3 +13,4 @@ menuconfig RESET_CONTROLLER > If unsure, say no. > > source "drivers/reset/sti/Kconfig" > +source "drivers/reset/ti/Kconfig" > diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile > index 4f60caf..1c8c444 100644 > --- a/drivers/reset/Makefile > +++ b/drivers/reset/Makefile > @@ -1,3 +1,4 @@ > obj-$(CONFIG_RESET_CONTROLLER) += core.o > obj-$(CONFIG_ARCH_SUNXI) += reset-sunxi.o > obj-$(CONFIG_ARCH_STI) += sti/ > +obj-$(CONFIG_RESET_TI) += ti/ > diff --git a/drivers/reset/ti/Kconfig b/drivers/reset/ti/Kconfig > new file mode 100644 > index 0000000..dcdce90 > --- /dev/null > +++ b/drivers/reset/ti/Kconfig > @@ -0,0 +1,8 @@ > +config RESET_TI > + depends on RESET_CONTROLLER > + bool "TI reset controller" > + help > + Reset controller support for TI SoC's > + > + Reset controller found in TI's AM series of SoC's like > + AM335x and AM43x and OMAP SoC's like OMAP5 and DRA7 > diff --git a/drivers/reset/ti/Makefile b/drivers/reset/ti/Makefile > new file mode 100644 > index 0000000..55ab3f5 > --- /dev/null > +++ b/drivers/reset/ti/Makefile > @@ -0,0 +1 @@ > +obj-$(CONFIG_RESET_TI) += reset-ti.o > diff --git a/drivers/reset/ti/reset-ti-data.h b/drivers/reset/ti/reset-ti-data.h > new file mode 100644 > index 0000000..6afdf37 > --- /dev/null > +++ b/drivers/reset/ti/reset-ti-data.h > @@ -0,0 +1,58 @@ > +/* > + * PRCM reset driver for TI SoC's > + * > + * Copyright 2014 Texas Instruments Inc. > + * > + * Author: Dan Murphy <dmurphy@ti.com> > + * > + * 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. > + */ > + > +#ifndef _RESET_TI_DATA_H_ > +#define _RESET_TI_DATA_H_ > + > +#include <linux/kernel.h> > +#include <linux/of_device.h> > +#include <linux/reset-controller.h> > + > +/** > + * struct ti_reset_reg_data - Structure of the reset register information > + * for a particular SoC. > + * @rstctrl_offs: This is the reset control offset value from > + * from the parent reset node. > + * @rstst_offs: This is the reset status offset value from > + * from the parent reset node. > + * @rstctrl_bit: This is the reset control bit for the module. > + * @rstst_bit: This is the reset status bit for the module. > + * > + * This structure describes the reset register control and status offsets. > + * The bits are also defined for the same. > + */ > +struct ti_reset_reg_data { > + u32 rstctrl_offs; > + u32 rstst_offs; > + u8 rstctrl_bit; > + u8 rstst_bit; You are only ever using these as (1 << rstctrl_bit) and as (1 << rstst_bit). You could store the mask here directly, like the regulator framework does. > +}; > + > +/** > + * struct ti_reset_data - Structure that contains the reset register data > + * as well as the total number of resets for a particular SoC. > + * @reg_data: Pointer to the register data structure. > + * @nr_resets: Total number of resets for the SoC in the reset array. > + * > + * This structure contains a pointer to the register data and the modules > + * register base. The number of resets and reset controller device data is > + * stored within this structure. > + * trailing whitespace > + */ > +struct ti_reset_data { > + struct ti_reset_reg_data *reg_data; > + struct reset_controller_dev rcdev; > + void __iomem *reg_base; > + u8 nr_resets; > +}; > + > +#endif > diff --git a/drivers/reset/ti/reset-ti.c b/drivers/reset/ti/reset-ti.c > new file mode 100644 > index 0000000..1d38069 > --- /dev/null > +++ b/drivers/reset/ti/reset-ti.c > @@ -0,0 +1,195 @@ > +/* > + * PRCM reset driver for TI SoC's > + * > + * Copyright 2014 Texas Instruments Inc. > + * > + * Author: Dan Murphy <dmurphy@ti.com> > + * > + * 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/device.h> > +#include <linux/err.h> > +#include <linux/io.h> > +#include <linux/kernel.h> > +#include <linux/of_address.h> > +#include <linux/of_device.h> > +#include <linux/slab.h> > + > +#include <linux/reset_ti.h> > +#include <linux/reset.h> > + > +#include "reset-ti-data.h" > + > +static void ti_reset_wait_on_reset(struct reset_controller_dev *rcdev, > + unsigned long id) > +{ > + struct ti_reset_data *reset_data = container_of(rcdev, > + struct ti_reset_data, > + rcdev); Please consider taking a few steps to the left. > + void __iomem *status_reg; > + u32 val = 0; > + u8 status_bit = 0; > + > + if (id < 0) { > + pr_err("%s: ID passed is invalid\n", __func__); > + return; > + } > + > + /* Clear the reset status bit to reflect the current status */ > + status_reg = reset_data->reg_base + reset_data->reg_data[id].rstst_offs; > + status_bit = reset_data->reg_data[id].rstst_bit; > + do { > + val = readl(status_reg); > + if (!(val & (1 << status_bit))) > + break; > + } while (1); Is the status bit guaranteed to clear after a few cycles? > +} > + > +static int ti_reset_assert(struct reset_controller_dev *rcdev, > + unsigned long id) > +{ > + struct ti_reset_data *reset_data = container_of(rcdev, > + struct ti_reset_data, > + rcdev); Very long lines again. > + void __iomem *reg; > + void __iomem *status_reg; > + u32 val = 0; > + u8 bit = 0; > + u8 status_bit = 0; > + > + if (id < 0) { The id parameter is _unsigned_ long. > + pr_err("%s: ID passed is invalid\n", __func__); > + return -ENODEV; > + } > + > + /* Clear the reset status bit to reflect the current status */ > + status_reg = reset_data->reg_base + reset_data->reg_data[id].rstst_offs; > + status_bit = reset_data->reg_data[id].rstst_bit; > + writel(1 << status_bit, status_reg); See the first comment, all the left shifts could be done by the compiler if you store the bit mask instead of the bit offset. > + reg = reset_data->reg_base + reset_data->reg_data[id].rstctrl_offs; > + bit = reset_data->reg_data[id].rstctrl_bit; > + val = readl(reg); > + if (!(val & (1 << bit))) { > + val |= (1 << bit); > + writel(val, reg); > + } > + > + return 0; > +} > + > +static int ti_reset_deassert(struct reset_controller_dev *rcdev, > + unsigned long id) > +{ > + > + struct ti_reset_data *reset_data; > + void __iomem *reg; > + void __iomem *status_reg; > + u32 val = 0; > + u8 bit = 0; > + u8 status_bit = 0; > + > + if (id < 0) { Again, unsigned. > + pr_err("%s: reset ID passed is invalid\n", __func__); > + return -ENODEV; > + } > + > + reset_data = container_of(rcdev, struct ti_reset_data, rcdev); > + > + /* Clear the reset status bit to reflect the current status */ > + status_reg = reset_data->reg_base + reset_data->reg_data[id].rstst_offs; > + status_bit = reset_data->reg_data[id].rstst_bit; > + writel(1 << status_bit, status_reg); > + > + reg = reset_data->reg_base + reset_data->reg_data[id].rstctrl_offs; > + bit = reset_data->reg_data[id].rstctrl_bit; > + val = readl(reg); > + if (val & (1 << bit)) { > + val &= ~(1 << bit); > + writel(val, reg); > + } > + > + return 0; > +} > + > +static int ti_reset_reset(struct reset_controller_dev *rcdev, > + unsigned long id) > +{ > + ti_reset_assert(rcdev, id); > + ti_reset_deassert(rcdev, id); > + ti_reset_wait_on_reset(rcdev, id); > + > + return 0; > +} > + > +static struct reset_control_ops ti_reset_ops = { > + .reset = ti_reset_reset, > + .assert = ti_reset_assert, > + .deassert = ti_reset_deassert, > +}; > + > +static const struct of_device_id ti_reset_of_match[] = { > + {}, > +}; > + > +const struct of_device_id *ti_reset_get_data(struct device_node *parent) > +{ > + const struct of_device_id *dev_node; > + > + dev_node = of_match_node(ti_reset_of_match, parent); > + if (!dev_node) { > + pr_err("%s: No compatible for resets for %s\n", > + __func__, parent->name); > + return NULL; > + } > + > + return dev_node; > +} > + > +void __init ti_dt_reset_init(void) Is there a reason not to just register this as a platform device? > +{ > + struct ti_reset_data *ti_data; > + struct device_node *parent; > + struct device_node *resets; > + const struct of_device_id *dev_node; > + > + resets = of_find_node_by_name(NULL, "resets"); > + if (!resets) { > + pr_err("%s: missing 'resets' child node.\n", __func__); > + return; > + } > + > + parent = of_get_parent(resets); > + if (!parent) { > + pr_err("%s: Cannot find parent reset node\n", __func__); > + return; > + } > + > + ti_data = kzalloc(sizeof(*ti_data), GFP_KERNEL); > + if (!ti_data) > + return; > + > + dev_node = ti_reset_get_data(resets); > + if (!dev_node) { > + pr_err("%s: Cannot find data for node\n", __func__); > + return; > + } > + > + ti_data = (struct ti_reset_data *) dev_node->data; > + > + ti_data->reg_base = of_iomap(parent, 0); > + if (!ti_data->reg_base) { > + pr_err("%s: Cannot map reset parent.\n", __func__); > + return; > + } > + > + ti_data->rcdev.owner = THIS_MODULE; > + ti_data->rcdev.nr_resets = ti_data->nr_resets; > + ti_data->rcdev.of_node = resets; > + ti_data->rcdev.ops = &ti_reset_ops; > + > + reset_controller_register(&ti_data->rcdev); > +} > diff --git a/include/linux/reset_ti.h b/include/linux/reset_ti.h > new file mode 100644 > index 0000000..d18f47f > --- /dev/null > +++ b/include/linux/reset_ti.h > @@ -0,0 +1,25 @@ > +/* > + * TI reset driver support > + * > + * Copyright (C) 2014 Texas Instruments, Inc. > + * > + * 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 "as is" WITHOUT ANY WARRANTY of any > + * kind, whether express or implied; without even the implied warranty > + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + */ > + > +#ifndef _RESET_TI_H_ > +#define _RESET_TI_H_ > + > +#ifdef CONFIG_RESET_TI > +void ti_dt_reset_init(void); > +#else > +static inline void ti_dt_reset_init(void){ return; }; > +#endif > + > +#endif regards Philipp
Philipp and Arnd Thank you for the comments On 04/30/2014 03:20 AM, Philipp Zabel wrote: > Hi Dan, > > Am Dienstag, den 29.04.2014, 15:19 -0500 schrieb Dan Murphy: >> The TI SoC reset controller support utilizes the >> reset controller framework to give device drivers or >> function drivers a common set of APIs to call to reset >> a module. >> >> The reset-ti is a common interface to the reset framework. >> The register data is retrieved during initialization >> of the reset driver through the reset-ti-data >> file. The array of data is associated with the compatible from the >> respective DT entry. >> >> Once the data is available then this is derefenced within the common >> interface. >> >> The device driver has the ability to assert, deassert or perform a >> complete reset. >> >> This code was derived from previous work by Rajendra Nayak and Afzal Mohammed. >> The code was changed to adopt to the reset core and abstract away the SoC information. >> >> Signed-off-by: Dan Murphy <dmurphy@ti.com> >> --- >> drivers/reset/Kconfig | 1 + >> drivers/reset/Makefile | 1 + >> drivers/reset/ti/Kconfig | 8 ++ >> drivers/reset/ti/Makefile | 1 + >> drivers/reset/ti/reset-ti-data.h | 58 ++++++++++++ >> drivers/reset/ti/reset-ti.c | 195 ++++++++++++++++++++++++++++++++++++++ >> include/linux/reset_ti.h | 25 +++++ >> 7 files changed, 289 insertions(+) >> create mode 100644 drivers/reset/ti/Kconfig >> create mode 100644 drivers/reset/ti/Makefile >> create mode 100644 drivers/reset/ti/reset-ti-data.h >> create mode 100644 drivers/reset/ti/reset-ti.c >> create mode 100644 include/linux/reset_ti.h >> >> diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig >> index 0615f50..a58d789 100644 >> --- a/drivers/reset/Kconfig >> +++ b/drivers/reset/Kconfig >> @@ -13,3 +13,4 @@ menuconfig RESET_CONTROLLER >> If unsure, say no. >> >> source "drivers/reset/sti/Kconfig" >> +source "drivers/reset/ti/Kconfig" >> diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile >> index 4f60caf..1c8c444 100644 >> --- a/drivers/reset/Makefile >> +++ b/drivers/reset/Makefile >> @@ -1,3 +1,4 @@ >> obj-$(CONFIG_RESET_CONTROLLER) += core.o >> obj-$(CONFIG_ARCH_SUNXI) += reset-sunxi.o >> obj-$(CONFIG_ARCH_STI) += sti/ >> +obj-$(CONFIG_RESET_TI) += ti/ >> diff --git a/drivers/reset/ti/Kconfig b/drivers/reset/ti/Kconfig >> new file mode 100644 >> index 0000000..dcdce90 >> --- /dev/null >> +++ b/drivers/reset/ti/Kconfig >> @@ -0,0 +1,8 @@ >> +config RESET_TI >> + depends on RESET_CONTROLLER >> + bool "TI reset controller" >> + help >> + Reset controller support for TI SoC's >> + >> + Reset controller found in TI's AM series of SoC's like >> + AM335x and AM43x and OMAP SoC's like OMAP5 and DRA7 >> diff --git a/drivers/reset/ti/Makefile b/drivers/reset/ti/Makefile >> new file mode 100644 >> index 0000000..55ab3f5 >> --- /dev/null >> +++ b/drivers/reset/ti/Makefile >> @@ -0,0 +1 @@ >> +obj-$(CONFIG_RESET_TI) += reset-ti.o >> diff --git a/drivers/reset/ti/reset-ti-data.h b/drivers/reset/ti/reset-ti-data.h >> new file mode 100644 >> index 0000000..6afdf37 >> --- /dev/null >> +++ b/drivers/reset/ti/reset-ti-data.h >> @@ -0,0 +1,58 @@ >> +/* >> + * PRCM reset driver for TI SoC's >> + * >> + * Copyright 2014 Texas Instruments Inc. >> + * >> + * Author: Dan Murphy <dmurphy@ti.com> >> + * >> + * 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. >> + */ >> + >> +#ifndef _RESET_TI_DATA_H_ >> +#define _RESET_TI_DATA_H_ >> + >> +#include <linux/kernel.h> >> +#include <linux/of_device.h> >> +#include <linux/reset-controller.h> >> + >> +/** >> + * struct ti_reset_reg_data - Structure of the reset register information >> + * for a particular SoC. >> + * @rstctrl_offs: This is the reset control offset value from >> + * from the parent reset node. >> + * @rstst_offs: This is the reset status offset value from >> + * from the parent reset node. >> + * @rstctrl_bit: This is the reset control bit for the module. >> + * @rstst_bit: This is the reset status bit for the module. >> + * >> + * This structure describes the reset register control and status offsets. >> + * The bits are also defined for the same. >> + */ >> +struct ti_reset_reg_data { >> + u32 rstctrl_offs; >> + u32 rstst_offs; >> + u8 rstctrl_bit; >> + u8 rstst_bit; > You are only ever using these as (1 << rstctrl_bit) and as > (1 << rstst_bit). You could store the mask here directly, > like the regulator framework does. > Yes we can store the mask as opposed to the bit. I will look into it for v2. >> +}; >> + >> +/** >> + * struct ti_reset_data - Structure that contains the reset register data >> + * as well as the total number of resets for a particular SoC. >> + * @reg_data: Pointer to the register data structure. >> + * @nr_resets: Total number of resets for the SoC in the reset array. >> + * >> + * This structure contains a pointer to the register data and the modules >> + * register base. The number of resets and reset controller device data is >> + * stored within this structure. >> + * > trailing whitespace Got it will fix v2. >> + */ >> +struct ti_reset_data { >> + struct ti_reset_reg_data *reg_data; >> + struct reset_controller_dev rcdev; >> + void __iomem *reg_base; >> + u8 nr_resets; >> +}; >> + >> +#endif >> diff --git a/drivers/reset/ti/reset-ti.c b/drivers/reset/ti/reset-ti.c >> new file mode 100644 >> index 0000000..1d38069 >> --- /dev/null >> +++ b/drivers/reset/ti/reset-ti.c >> @@ -0,0 +1,195 @@ >> +/* >> + * PRCM reset driver for TI SoC's >> + * >> + * Copyright 2014 Texas Instruments Inc. >> + * >> + * Author: Dan Murphy <dmurphy@ti.com> >> + * >> + * 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/device.h> >> +#include <linux/err.h> >> +#include <linux/io.h> >> +#include <linux/kernel.h> >> +#include <linux/of_address.h> >> +#include <linux/of_device.h> >> +#include <linux/slab.h> >> + >> +#include <linux/reset_ti.h> >> +#include <linux/reset.h> >> + >> +#include "reset-ti-data.h" >> + >> +static void ti_reset_wait_on_reset(struct reset_controller_dev *rcdev, >> + unsigned long id) >> +{ >> + struct ti_reset_data *reset_data = container_of(rcdev, >> + struct ti_reset_data, >> + rcdev); > Please consider taking a few steps to the left. Got it will fix v2. > >> + void __iomem *status_reg; >> + u32 val = 0; >> + u8 status_bit = 0; >> + >> + if (id < 0) { >> + pr_err("%s: ID passed is invalid\n", __func__); >> + return; >> + } >> + >> + /* Clear the reset status bit to reflect the current status */ >> + status_reg = reset_data->reg_base + reset_data->reg_data[id].rstst_offs; >> + status_bit = reset_data->reg_data[id].rstst_bit; >> + do { >> + val = readl(status_reg); >> + if (!(val & (1 << status_bit))) >> + break; >> + } while (1); > Is the status bit guaranteed to clear after a few cycles? I will look into this question >> +} >> + >> +static int ti_reset_assert(struct reset_controller_dev *rcdev, >> + unsigned long id) >> +{ >> + struct ti_reset_data *reset_data = container_of(rcdev, >> + struct ti_reset_data, >> + rcdev); > Very long lines again. Yep. Will fix v2 copy/paste problem > >> + void __iomem *reg; >> + void __iomem *status_reg; >> + u32 val = 0; >> + u8 bit = 0; >> + u8 status_bit = 0; >> + >> + if (id < 0) { > The id parameter is _unsigned_ long. OK got it. > >> + pr_err("%s: ID passed is invalid\n", __func__); >> + return -ENODEV; >> + } >> + >> + /* Clear the reset status bit to reflect the current status */ >> + status_reg = reset_data->reg_base + reset_data->reg_data[id].rstst_offs; >> + status_bit = reset_data->reg_data[id].rstst_bit; >> + writel(1 << status_bit, status_reg); > See the first comment, all the left shifts could be done by the compiler > if you store the bit mask instead of the bit offset. Per my reply I will look into this > >> + reg = reset_data->reg_base + reset_data->reg_data[id].rstctrl_offs; >> + bit = reset_data->reg_data[id].rstctrl_bit; >> + val = readl(reg); >> + if (!(val & (1 << bit))) { >> + val |= (1 << bit); >> + writel(val, reg); >> + } >> + >> + return 0; >> +} >> + >> +static int ti_reset_deassert(struct reset_controller_dev *rcdev, >> + unsigned long id) >> +{ >> + >> + struct ti_reset_data *reset_data; >> + void __iomem *reg; >> + void __iomem *status_reg; >> + u32 val = 0; >> + u8 bit = 0; >> + u8 status_bit = 0; >> + >> + if (id < 0) { > Again, unsigned. > >> + pr_err("%s: reset ID passed is invalid\n", __func__); >> + return -ENODEV; >> + } >> + >> + reset_data = container_of(rcdev, struct ti_reset_data, rcdev); >> + >> + /* Clear the reset status bit to reflect the current status */ >> + status_reg = reset_data->reg_base + reset_data->reg_data[id].rstst_offs; >> + status_bit = reset_data->reg_data[id].rstst_bit; >> + writel(1 << status_bit, status_reg); >> + >> + reg = reset_data->reg_base + reset_data->reg_data[id].rstctrl_offs; >> + bit = reset_data->reg_data[id].rstctrl_bit; >> + val = readl(reg); >> + if (val & (1 << bit)) { >> + val &= ~(1 << bit); >> + writel(val, reg); >> + } >> + >> + return 0; >> +} >> + >> +static int ti_reset_reset(struct reset_controller_dev *rcdev, >> + unsigned long id) >> +{ >> + ti_reset_assert(rcdev, id); >> + ti_reset_deassert(rcdev, id); >> + ti_reset_wait_on_reset(rcdev, id); >> + >> + return 0; >> +} >> + >> +static struct reset_control_ops ti_reset_ops = { >> + .reset = ti_reset_reset, >> + .assert = ti_reset_assert, >> + .deassert = ti_reset_deassert, >> +}; >> + >> +static const struct of_device_id ti_reset_of_match[] = { >> + {}, >> +}; >> + >> +const struct of_device_id *ti_reset_get_data(struct device_node *parent) >> +{ >> + const struct of_device_id *dev_node; >> + >> + dev_node = of_match_node(ti_reset_of_match, parent); >> + if (!dev_node) { >> + pr_err("%s: No compatible for resets for %s\n", >> + __func__, parent->name); >> + return NULL; >> + } >> + >> + return dev_node; >> +} >> + >> +void __init ti_dt_reset_init(void) > Is there a reason not to just register this as a platform device? To answer this comment as well as Arnd's. To be honest this was a remnant of my development. You are both correct and this can be called during the init as a platform driver. I will fix this in v2. Which will in turn remove one patch as well as a header file. Dan <snip>
diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig index 0615f50..a58d789 100644 --- a/drivers/reset/Kconfig +++ b/drivers/reset/Kconfig @@ -13,3 +13,4 @@ menuconfig RESET_CONTROLLER If unsure, say no. source "drivers/reset/sti/Kconfig" +source "drivers/reset/ti/Kconfig" diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile index 4f60caf..1c8c444 100644 --- a/drivers/reset/Makefile +++ b/drivers/reset/Makefile @@ -1,3 +1,4 @@ obj-$(CONFIG_RESET_CONTROLLER) += core.o obj-$(CONFIG_ARCH_SUNXI) += reset-sunxi.o obj-$(CONFIG_ARCH_STI) += sti/ +obj-$(CONFIG_RESET_TI) += ti/ diff --git a/drivers/reset/ti/Kconfig b/drivers/reset/ti/Kconfig new file mode 100644 index 0000000..dcdce90 --- /dev/null +++ b/drivers/reset/ti/Kconfig @@ -0,0 +1,8 @@ +config RESET_TI + depends on RESET_CONTROLLER + bool "TI reset controller" + help + Reset controller support for TI SoC's + + Reset controller found in TI's AM series of SoC's like + AM335x and AM43x and OMAP SoC's like OMAP5 and DRA7 diff --git a/drivers/reset/ti/Makefile b/drivers/reset/ti/Makefile new file mode 100644 index 0000000..55ab3f5 --- /dev/null +++ b/drivers/reset/ti/Makefile @@ -0,0 +1 @@ +obj-$(CONFIG_RESET_TI) += reset-ti.o diff --git a/drivers/reset/ti/reset-ti-data.h b/drivers/reset/ti/reset-ti-data.h new file mode 100644 index 0000000..6afdf37 --- /dev/null +++ b/drivers/reset/ti/reset-ti-data.h @@ -0,0 +1,58 @@ +/* + * PRCM reset driver for TI SoC's + * + * Copyright 2014 Texas Instruments Inc. + * + * Author: Dan Murphy <dmurphy@ti.com> + * + * 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. + */ + +#ifndef _RESET_TI_DATA_H_ +#define _RESET_TI_DATA_H_ + +#include <linux/kernel.h> +#include <linux/of_device.h> +#include <linux/reset-controller.h> + +/** + * struct ti_reset_reg_data - Structure of the reset register information + * for a particular SoC. + * @rstctrl_offs: This is the reset control offset value from + * from the parent reset node. + * @rstst_offs: This is the reset status offset value from + * from the parent reset node. + * @rstctrl_bit: This is the reset control bit for the module. + * @rstst_bit: This is the reset status bit for the module. + * + * This structure describes the reset register control and status offsets. + * The bits are also defined for the same. + */ +struct ti_reset_reg_data { + u32 rstctrl_offs; + u32 rstst_offs; + u8 rstctrl_bit; + u8 rstst_bit; +}; + +/** + * struct ti_reset_data - Structure that contains the reset register data + * as well as the total number of resets for a particular SoC. + * @reg_data: Pointer to the register data structure. + * @nr_resets: Total number of resets for the SoC in the reset array. + * + * This structure contains a pointer to the register data and the modules + * register base. The number of resets and reset controller device data is + * stored within this structure. + * + */ +struct ti_reset_data { + struct ti_reset_reg_data *reg_data; + struct reset_controller_dev rcdev; + void __iomem *reg_base; + u8 nr_resets; +}; + +#endif diff --git a/drivers/reset/ti/reset-ti.c b/drivers/reset/ti/reset-ti.c new file mode 100644 index 0000000..1d38069 --- /dev/null +++ b/drivers/reset/ti/reset-ti.c @@ -0,0 +1,195 @@ +/* + * PRCM reset driver for TI SoC's + * + * Copyright 2014 Texas Instruments Inc. + * + * Author: Dan Murphy <dmurphy@ti.com> + * + * 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/device.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/of_address.h> +#include <linux/of_device.h> +#include <linux/slab.h> + +#include <linux/reset_ti.h> +#include <linux/reset.h> + +#include "reset-ti-data.h" + +static void ti_reset_wait_on_reset(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct ti_reset_data *reset_data = container_of(rcdev, + struct ti_reset_data, + rcdev); + void __iomem *status_reg; + u32 val = 0; + u8 status_bit = 0; + + if (id < 0) { + pr_err("%s: ID passed is invalid\n", __func__); + return; + } + + /* Clear the reset status bit to reflect the current status */ + status_reg = reset_data->reg_base + reset_data->reg_data[id].rstst_offs; + status_bit = reset_data->reg_data[id].rstst_bit; + do { + val = readl(status_reg); + if (!(val & (1 << status_bit))) + break; + } while (1); +} + +static int ti_reset_assert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct ti_reset_data *reset_data = container_of(rcdev, + struct ti_reset_data, + rcdev); + void __iomem *reg; + void __iomem *status_reg; + u32 val = 0; + u8 bit = 0; + u8 status_bit = 0; + + if (id < 0) { + pr_err("%s: ID passed is invalid\n", __func__); + return -ENODEV; + } + + /* Clear the reset status bit to reflect the current status */ + status_reg = reset_data->reg_base + reset_data->reg_data[id].rstst_offs; + status_bit = reset_data->reg_data[id].rstst_bit; + writel(1 << status_bit, status_reg); + + reg = reset_data->reg_base + reset_data->reg_data[id].rstctrl_offs; + bit = reset_data->reg_data[id].rstctrl_bit; + val = readl(reg); + if (!(val & (1 << bit))) { + val |= (1 << bit); + writel(val, reg); + } + + return 0; +} + +static int ti_reset_deassert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + + struct ti_reset_data *reset_data; + void __iomem *reg; + void __iomem *status_reg; + u32 val = 0; + u8 bit = 0; + u8 status_bit = 0; + + if (id < 0) { + pr_err("%s: reset ID passed is invalid\n", __func__); + return -ENODEV; + } + + reset_data = container_of(rcdev, struct ti_reset_data, rcdev); + + /* Clear the reset status bit to reflect the current status */ + status_reg = reset_data->reg_base + reset_data->reg_data[id].rstst_offs; + status_bit = reset_data->reg_data[id].rstst_bit; + writel(1 << status_bit, status_reg); + + reg = reset_data->reg_base + reset_data->reg_data[id].rstctrl_offs; + bit = reset_data->reg_data[id].rstctrl_bit; + val = readl(reg); + if (val & (1 << bit)) { + val &= ~(1 << bit); + writel(val, reg); + } + + return 0; +} + +static int ti_reset_reset(struct reset_controller_dev *rcdev, + unsigned long id) +{ + ti_reset_assert(rcdev, id); + ti_reset_deassert(rcdev, id); + ti_reset_wait_on_reset(rcdev, id); + + return 0; +} + +static struct reset_control_ops ti_reset_ops = { + .reset = ti_reset_reset, + .assert = ti_reset_assert, + .deassert = ti_reset_deassert, +}; + +static const struct of_device_id ti_reset_of_match[] = { + {}, +}; + +const struct of_device_id *ti_reset_get_data(struct device_node *parent) +{ + const struct of_device_id *dev_node; + + dev_node = of_match_node(ti_reset_of_match, parent); + if (!dev_node) { + pr_err("%s: No compatible for resets for %s\n", + __func__, parent->name); + return NULL; + } + + return dev_node; +} + +void __init ti_dt_reset_init(void) +{ + struct ti_reset_data *ti_data; + struct device_node *parent; + struct device_node *resets; + const struct of_device_id *dev_node; + + resets = of_find_node_by_name(NULL, "resets"); + if (!resets) { + pr_err("%s: missing 'resets' child node.\n", __func__); + return; + } + + parent = of_get_parent(resets); + if (!parent) { + pr_err("%s: Cannot find parent reset node\n", __func__); + return; + } + + ti_data = kzalloc(sizeof(*ti_data), GFP_KERNEL); + if (!ti_data) + return; + + dev_node = ti_reset_get_data(resets); + if (!dev_node) { + pr_err("%s: Cannot find data for node\n", __func__); + return; + } + + ti_data = (struct ti_reset_data *) dev_node->data; + + ti_data->reg_base = of_iomap(parent, 0); + if (!ti_data->reg_base) { + pr_err("%s: Cannot map reset parent.\n", __func__); + return; + } + + ti_data->rcdev.owner = THIS_MODULE; + ti_data->rcdev.nr_resets = ti_data->nr_resets; + ti_data->rcdev.of_node = resets; + ti_data->rcdev.ops = &ti_reset_ops; + + reset_controller_register(&ti_data->rcdev); +} diff --git a/include/linux/reset_ti.h b/include/linux/reset_ti.h new file mode 100644 index 0000000..d18f47f --- /dev/null +++ b/include/linux/reset_ti.h @@ -0,0 +1,25 @@ +/* + * TI reset driver support + * + * Copyright (C) 2014 Texas Instruments, Inc. + * + * 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 "as is" WITHOUT ANY WARRANTY of any + * kind, whether express or implied; without even the implied warranty + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#ifndef _RESET_TI_H_ +#define _RESET_TI_H_ + +#ifdef CONFIG_RESET_TI +void ti_dt_reset_init(void); +#else +static inline void ti_dt_reset_init(void){ return; }; +#endif + +#endif
The TI SoC reset controller support utilizes the reset controller framework to give device drivers or function drivers a common set of APIs to call to reset a module. The reset-ti is a common interface to the reset framework. The register data is retrieved during initialization of the reset driver through the reset-ti-data file. The array of data is associated with the compatible from the respective DT entry. Once the data is available then this is derefenced within the common interface. The device driver has the ability to assert, deassert or perform a complete reset. This code was derived from previous work by Rajendra Nayak and Afzal Mohammed. The code was changed to adopt to the reset core and abstract away the SoC information. Signed-off-by: Dan Murphy <dmurphy@ti.com> --- drivers/reset/Kconfig | 1 + drivers/reset/Makefile | 1 + drivers/reset/ti/Kconfig | 8 ++ drivers/reset/ti/Makefile | 1 + drivers/reset/ti/reset-ti-data.h | 58 ++++++++++++ drivers/reset/ti/reset-ti.c | 195 ++++++++++++++++++++++++++++++++++++++ include/linux/reset_ti.h | 25 +++++ 7 files changed, 289 insertions(+) create mode 100644 drivers/reset/ti/Kconfig create mode 100644 drivers/reset/ti/Makefile create mode 100644 drivers/reset/ti/reset-ti-data.h create mode 100644 drivers/reset/ti/reset-ti.c create mode 100644 include/linux/reset_ti.h