Hi Dan, On 07/17/2014 11:45 AM, Murphy, Dan wrote: > 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. Outdated commit description, this is no longer correct. > > 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@xxxxxx> > --- > > v3 - Resolved comments from v2. To many to call out here - https://patchwork.kernel.org/patch/4116941/ Please add a cover letter for the series next time and make sure you cc the reset driver maintainer. > > drivers/reset/Kconfig | 9 ++ > drivers/reset/Makefile | 1 + > drivers/reset/reset-ti.c | 373 ++++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 383 insertions(+) > create mode 100644 drivers/reset/reset-ti.c > > diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig > index 0615f50..31a5a79 100644 > --- a/drivers/reset/Kconfig > +++ b/drivers/reset/Kconfig > @@ -12,4 +12,13 @@ menuconfig RESET_CONTROLLER > > If unsure, say no. > > +config RESET_TI > + depends on RESET_CONTROLLER && ARCH_OMAP || COMPILE_TEST > + 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 > + > source "drivers/reset/sti/Kconfig" > diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile > index 60fed3d..a5986b9 100644 > --- a/drivers/reset/Makefile > +++ b/drivers/reset/Makefile > @@ -1,4 +1,5 @@ > obj-$(CONFIG_RESET_CONTROLLER) += core.o > obj-$(CONFIG_ARCH_SOCFPGA) += reset-socfpga.o > obj-$(CONFIG_ARCH_SUNXI) += reset-sunxi.o > +obj-$(CONFIG_RESET_TI) += reset-ti.o > obj-$(CONFIG_ARCH_STI) += sti/ > diff --git a/drivers/reset/reset-ti.c b/drivers/reset/reset-ti.c > new file mode 100644 > index 0000000..e9d4039 > --- /dev/null > +++ b/drivers/reset/reset-ti.c > @@ -0,0 +1,373 @@ > +/* > + * reset-ti.c - PRCM reset driver for TI SoC's > + * > + * Copyright (C) 2014 Texas Instruments Incorporated - http://www.ti.com > + * > + * Author: Dan Murphy <dmurphy@xxxxxx> > + * > + * 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/device.h> > +#include <linux/err.h> > +#include <linux/io.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/of_address.h> This header is no longer needed, now that you are not using of_iomap. > +#include <linux/of_device.h> > +#include <linux/platform_device.h> > +#include <linux/reset.h> > +#include <linux/reset-controller.h> > +#include <linux/slab.h> > +#include <linux/spinlock.h> > + > +#define DRIVER_NAME "prcm_reset_ti" > +#define MAX_RESET_SIGNALS 255 This sounds like a lot, I think you should reduce this to not waste memory. Start with a small number, and add a trace for increasing this if you run out of the current slots. > + > +/** > + * 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. > + * > + * Longer description of this structure. > + */ > +struct ti_reset_reg_data { > + phandle handle; > + u32 rstctrl_offs; > + u32 rstst_offs; > + u32 rstctrl_bit; > + u32 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. > + * @ti_data: Pointer to this structure to be dereferenced > + * @reg_data: Pointer to the register data structure. > + * @rcdev: Reset controller device instance > + * @dev: Pointer to the devive structure > + * @ti_reg_data: Array of register data. Only reset signal with valid > + * phandles will be stored in this array. > + * @reg_base: Parent register base address > + * @lock: Spinlock for accessing the registers > + * @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_data *ti_data; I initially thought this was for list management to deal with multiple reset nodes, but why do we need this self-referencing pointer? > + struct ti_reset_reg_data *reg_data; What do you need this for? I haven't seen it getting used anywhere, and ti_reg_data looks very similar. > + struct reset_controller_dev rcdev; > + struct device *dev; > + struct ti_reset_reg_data ti_reg_data[MAX_RESET_SIGNALS]; > + void __iomem *reg_base; > + spinlock_t lock; > + int nr_resets; > +}; > + > +static int 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 = reset_data->reg_base; > + u32 bit_mask = 0; > + u32 val = 0; > + unsigned long flags; > + int i = 1000; > + int ret = 0; > + > + spin_lock_irqsave(&reset_data->lock, flags); > + /* Clear the reset status bit to reflect the current status */ > + status_reg = reset_data->reg_base + reset_data->ti_reg_data[id].rstst_offs; > + bit_mask = reset_data->ti_reg_data[id].rstst_bit; > + > + do { > + val = readl(status_reg); > + } while (--i && (val & (1 << bit_mask))); Others have already pointed this out, I believe you want something equivalent to omap_test_timeout here. Please check with Tero if that would be available, otherwise, you can define the same in this file. > + > + if (i == 0 && val & (1 << bit_mask)) { > + dev_err(reset_data->dev, "%s: Reset failed\n", __func__); > + ret = -EIO; > + } > + > + spin_unlock_irqrestore(&reset_data->lock, flags); > + return ret; > +} > + > +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 status_bit = 0; > + u32 bit_mask = 0; > + u32 val = 0; > + unsigned long flags; > + > + spin_lock_irqsave(&reset_data->lock, flags); > + > + /* Clear the reset status bit to reflect the current status */ > + status_reg = reset_data->reg_base + reset_data->ti_reg_data[id].rstst_offs; > + status_bit = reset_data->ti_reg_data[id].rstst_bit; > + writel(1 << status_bit, status_reg); > + > + reg = reset_data->reg_base + reset_data->ti_reg_data[id].rstctrl_offs; > + bit_mask = reset_data->ti_reg_data[id].rstctrl_bit; > + val = readl(reg); > + if (!(val & bit_mask)) { > + val |= bit_mask; > + writel(val, reg); > + } > + > + spin_unlock_irqrestore(&reset_data->lock, flags); > + return 0; > +} > + > +static int ti_reset_deassert(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 status_bit = 0; > + u32 bit_mask = 0; > + u32 val = 0; > + unsigned long flags; > + > + spin_lock_irqsave(&reset_data->lock, flags); > + > + /* Clear the reset status bit to reflect the current status */ > + status_reg = reset_data->reg_base + reset_data->ti_reg_data[id].rstst_offs; > + status_bit = reset_data->ti_reg_data[id].rstst_bit; > + writel(1 << status_bit, status_reg); Is there a need for clearing the reset status both in assert and deassert? > + > + reg = reset_data->reg_base + reset_data->ti_reg_data[id].rstctrl_offs; > + bit_mask = reset_data->ti_reg_data[id].rstctrl_bit; > + val = readl(reg); > + if (val & bit_mask) { > + val &= ~bit_mask; > + writel(val, reg); > + } > + > + spin_unlock_irqrestore(&reset_data->lock, flags); > + > + 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); > + > + return ti_reset_wait_on_reset(rcdev, id); > +} > + > +static int ti_reset_xlate(struct reset_controller_dev *rcdev, > + const struct of_phandle_args *reset_spec) > +{ > + > + struct ti_reset_data *reset_data = container_of(rcdev, > + struct ti_reset_data, > + rcdev); > + struct device_node *dev_node; > + int i; > + > + if (WARN_ON(reset_spec->args_count != rcdev->of_reset_n_cells)) > + return -EINVAL; > + > + /* Verify that the phandle exists */ > + dev_node = of_find_node_by_phandle((phandle) reset_spec->args[0]); > + if (!dev_node) { > + dev_err(reset_data->dev, > + "%s: Cannot find phandle node\n", > + __func__); > + return -EINVAL; > + } > + > + for (i = 0; i <= reset_data->nr_resets; i++) { > + if (reset_data->ti_reg_data[i].handle == dev_node->phandle) > + return i; > + } > + > + return -EINVAL; > +} > + > +static struct reset_control_ops ti_reset_ops = { > + .reset = ti_reset_reset, > + .assert = ti_reset_assert, > + .deassert = ti_reset_deassert, > +}; > + > +static int ti_reset_populate_child(struct ti_reset_data *reset_data, > + struct device_node *reset_child, > + u32 ctrl_offs, u32 status_offs) > +{ > + struct device_node *next_reset_child = NULL; > + int i = reset_data->nr_resets; > + int ret; > + u32 ctrl_bit; > + > + while ((next_reset_child = of_get_next_child(reset_child, next_reset_child))) { Add a check for array bounds on the ti_reg_data array here, rather than choosing a large number to begin with. > + if (next_reset_child->phandle) { > + /* Get the bits of each sub-reset */ > + ret = of_property_read_u32(next_reset_child, "control-bit", > + &ctrl_bit); > + if (ret < 0) { > + dev_err(reset_data->dev, > + "%s: No entry in %s for rstctrl_offs\n", > + __func__, next_reset_child->name); > + > + return -ENODEV; > + } > + > + ret = of_property_read_u32(next_reset_child, "status-bit", > + &reset_data->ti_reg_data[i].rstst_bit); > + if (ret < 0) { > + dev_err(reset_data->dev, > + "%s: No entry in %s for rstst_offs\n", > + __func__, next_reset_child->name); > + > + return -ENODEV; > + } > + > + reset_data->ti_reg_data[i].rstctrl_offs = ctrl_offs; > + reset_data->ti_reg_data[i].rstst_offs = status_offs; > + reset_data->ti_reg_data[i].handle = next_reset_child->phandle; > + i++; > + } > + }; > + > + reset_data->nr_resets = i; > + > + return 0; > +} > + > +static int ti_reset_get_of_data(struct ti_reset_data *reset_data, > + struct device_node *dev_node) > +{ > + struct device_node *reset_child = NULL; > + int ret = -EINVAL; > + u32 ctrl_offs, status_offs; > + > + /* Loop through all the children and populate a lookup array */ > + while ((reset_child = of_get_next_child(dev_node, reset_child))) { > + ret = of_property_read_u32_index(reset_child, "reg", 0, > + &ctrl_offs); > + if (ret) > + return ret; > + > + ret = of_property_read_u32_index(reset_child, "reg", 1, > + &status_offs); > + if (ret) > + return ret; > + > + ret = ti_reset_populate_child(reset_data, reset_child, > + ctrl_offs, status_offs); > + if (ret) > + return ret; > + }; > + > + return 0; > +} > + > +static int ti_reset_probe(struct platform_device *pdev) > +{ > + struct device_node *resets; > + struct ti_reset_data *reset_data; > + struct resource *res; > + int ret; > + > + reset_data = devm_kzalloc(&pdev->dev, sizeof(*reset_data), GFP_KERNEL); > + if (!reset_data) > + return -ENOMEM; > + > + resets = of_find_node_by_name(NULL, "resets"); > + if (!resets) { > + dev_err(&pdev->dev, "%s: missing 'resets' child node.\n", > + __func__); > + return -EINVAL; > + } > + > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + reset_data->reg_base = devm_ioremap_resource(&pdev->dev, res); > + if (IS_ERR(reset_data->reg_base)) { > + dev_err(&pdev->dev, "%s: Cannot map reset parent.\n", __func__); > + return -ENODEV; > + } If the PRM node address is accessed by someone else as well, then this will always fail. > + > + spin_lock_init(&reset_data->lock); > + reset_data->dev = &pdev->dev; > + ret = ti_reset_get_of_data(reset_data, resets); > + if (ret) > + return -EINVAL; > + > + reset_data->rcdev.owner = THIS_MODULE; > + reset_data->rcdev.of_node = resets; > + reset_data->rcdev.ops = &ti_reset_ops; > + > + reset_data->rcdev.of_reset_n_cells = 1; > + reset_data->rcdev.of_xlate = &ti_reset_xlate; > + > + reset_data->ti_data = reset_data; > + > + platform_set_drvdata(pdev, reset_data); > + > + reset_controller_register(&reset_data->rcdev); > + > + return 0; > +} > + > +static int ti_reset_remove(struct platform_device *pdev) > +{ > + struct ti_reset_data *reset_data; > + > + reset_data = platform_get_drvdata(pdev); > + reset_controller_unregister(&reset_data->rcdev); > + > + return 0; > +} > + > +static const struct of_device_id ti_reset_of_match[] = { > + { .compatible = "ti,omap5-prm" }, > + { .compatible = "ti,omap4-prm" }, > + { .compatible = "ti,omap5-prm" }, Duplicate entry > + { .compatible = "ti,dra7-prm" }, > + { .compatible = "ti,am4-prcm" }, > + { .compatible = "ti,am3-prcm" }, > + {}, > +}; You are using the parent SoC parent nodes as the compatibles, but this has to restricted to just the resets. I believe this driver is designed only to deal with the reset nodes under those PRM/PRCM nodes - we won't be handling all the other nodes under these PRM/PRCM nodes. Please also see Tony's comment about working with Tero's PRM cleanup. regards Suman > + > +static struct platform_driver ti_reset_driver = { > + .probe = ti_reset_probe, > + .remove = ti_reset_remove, > + .driver = { > + .name = DRIVER_NAME, > + .owner = THIS_MODULE, > + .of_match_table = of_match_ptr(ti_reset_of_match), > + }, > +}; > +module_platform_driver(ti_reset_driver); > + > +MODULE_DESCRIPTION("PRCM reset driver for TI SoCs"); > +MODULE_LICENSE("GPL v2"); > +MODULE_ALIAS("platform:" DRIVER_NAME); > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
