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https://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson
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81312ea9b8
Use syscon_regmap_lookup_by_phandle_args() which is a wrapper over syscon_regmap_lookup_by_phandle() combined with getting the syscon argument. Except simpler code this annotates within one line that given phandle has arguments, so grepping for code would be easier. There is also no real benefit in printing errors on missing syscon argument, because this is done just too late: runtime check on static/build-time data. Dtschema and Devicetree bindings offer the static/build-time check for this already. Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Link: https://lore.kernel.org/r/20250111185358.183725-1-krzysztof.kozlowski@linaro.org Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
162 lines
3.8 KiB
C
162 lines
3.8 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* TI keystone reboot driver
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*
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* Copyright (C) 2014 Texas Instruments Incorporated. https://www.ti.com/
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*
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* Author: Ivan Khoronzhuk <ivan.khoronzhuk@ti.com>
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*/
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#include <linux/io.h>
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#include <linux/module.h>
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#include <linux/notifier.h>
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#include <linux/platform_device.h>
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#include <linux/reboot.h>
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#include <linux/regmap.h>
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#include <linux/mfd/syscon.h>
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#include <linux/of.h>
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#define RSCTRL_RG 0x4
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#define RSCFG_RG 0x8
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#define RSISO_RG 0xc
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#define RSCTRL_KEY_MASK 0x0000ffff
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#define RSCTRL_RESET_MASK BIT(16)
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#define RSCTRL_KEY 0x5a69
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#define RSMUX_OMODE_MASK 0xe
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#define RSMUX_OMODE_RESET_ON 0xa
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#define RSMUX_OMODE_RESET_OFF 0x0
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#define RSMUX_LOCK_SET 0x1
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#define RSCFG_RSTYPE_SOFT 0x300f
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#define RSCFG_RSTYPE_HARD 0x0
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#define WDT_MUX_NUMBER 0x4
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static int rspll_offset;
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static struct regmap *pllctrl_regs;
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/**
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* rsctrl_enable_rspll_write - enable access to RSCTRL, RSCFG
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* To be able to access to RSCTRL, RSCFG registers
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* we have to write a key before
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*/
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static inline int rsctrl_enable_rspll_write(void)
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{
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return regmap_update_bits(pllctrl_regs, rspll_offset + RSCTRL_RG,
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RSCTRL_KEY_MASK, RSCTRL_KEY);
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}
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static int rsctrl_restart_handler(struct notifier_block *this,
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unsigned long mode, void *cmd)
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{
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/* enable write access to RSTCTRL */
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rsctrl_enable_rspll_write();
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/* reset the SOC */
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regmap_update_bits(pllctrl_regs, rspll_offset + RSCTRL_RG,
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RSCTRL_RESET_MASK, 0);
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return NOTIFY_DONE;
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}
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static struct notifier_block rsctrl_restart_nb = {
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.notifier_call = rsctrl_restart_handler,
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.priority = 128,
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};
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static const struct of_device_id rsctrl_of_match[] = {
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{.compatible = "ti,keystone-reset", },
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{},
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};
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MODULE_DEVICE_TABLE(of, rsctrl_of_match);
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static int rsctrl_probe(struct platform_device *pdev)
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{
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int i;
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int ret;
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u32 val;
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unsigned int rg;
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u32 rsmux_offset;
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struct regmap *devctrl_regs;
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struct device *dev = &pdev->dev;
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struct device_node *np = dev->of_node;
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if (!np)
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return -ENODEV;
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/* get regmaps */
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pllctrl_regs = syscon_regmap_lookup_by_phandle_args(np, "ti,syscon-pll",
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1, &rspll_offset);
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if (IS_ERR(pllctrl_regs))
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return PTR_ERR(pllctrl_regs);
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devctrl_regs = syscon_regmap_lookup_by_phandle_args(np, "ti,syscon-dev",
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1, &rsmux_offset);
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if (IS_ERR(devctrl_regs))
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return PTR_ERR(devctrl_regs);
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/* set soft/hard reset */
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val = of_property_read_bool(np, "ti,soft-reset");
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val = val ? RSCFG_RSTYPE_SOFT : RSCFG_RSTYPE_HARD;
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ret = rsctrl_enable_rspll_write();
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if (ret)
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return ret;
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ret = regmap_write(pllctrl_regs, rspll_offset + RSCFG_RG, val);
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if (ret)
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return ret;
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/* disable a reset isolation for all module clocks */
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ret = regmap_write(pllctrl_regs, rspll_offset + RSISO_RG, 0);
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if (ret)
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return ret;
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/* enable a reset for watchdogs from wdt-list */
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for (i = 0; i < WDT_MUX_NUMBER; i++) {
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ret = of_property_read_u32_index(np, "ti,wdt-list", i, &val);
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if (ret == -EOVERFLOW && !i) {
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dev_err(dev, "ti,wdt-list property has to contain at"
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"least one entry\n");
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return -EINVAL;
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} else if (ret) {
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break;
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}
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if (val >= WDT_MUX_NUMBER) {
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dev_err(dev, "ti,wdt-list property can contain "
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"only numbers < 4\n");
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return -EINVAL;
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}
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rg = rsmux_offset + val * 4;
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ret = regmap_update_bits(devctrl_regs, rg, RSMUX_OMODE_MASK,
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RSMUX_OMODE_RESET_ON |
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RSMUX_LOCK_SET);
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if (ret)
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return ret;
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}
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ret = register_restart_handler(&rsctrl_restart_nb);
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if (ret)
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dev_err(dev, "cannot register restart handler (err=%d)\n", ret);
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return ret;
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}
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static struct platform_driver rsctrl_driver = {
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.probe = rsctrl_probe,
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.driver = {
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.name = KBUILD_MODNAME,
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.of_match_table = rsctrl_of_match,
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},
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};
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module_platform_driver(rsctrl_driver);
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MODULE_AUTHOR("Ivan Khoronzhuk <ivan.khoronzhuk@ti.com>");
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MODULE_DESCRIPTION("Texas Instruments keystone reset driver");
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MODULE_ALIAS("platform:" KBUILD_MODNAME);
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