| 1 | // SPDX-License-Identifier: GPL-2.0 |
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| 2 | /* |
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| 3 | * Copyright (C) 2018 Spreadtrum Communications Inc. |
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| 4 | * Copyright (C) 2018 Linaro Ltd. |
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| 5 | */ |
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| 6 | |
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| 7 | #include <linux/cpu.h> |
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| 8 | #include <linux/kernel.h> |
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| 9 | #include <linux/module.h> |
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| 10 | #include <linux/platform_device.h> |
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| 11 | #include <linux/pm.h> |
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| 12 | #include <linux/regmap.h> |
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| 13 | #include <linux/syscore_ops.h> |
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| 14 | |
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| 15 | #define SC27XX_PWR_PD_HW 0xc2c |
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| 16 | #define SC27XX_PWR_OFF_EN BIT(0) |
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| 17 | #define SC27XX_SLP_CTRL 0xdf0 |
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| 18 | #define SC27XX_LDO_XTL_EN BIT(3) |
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| 19 | |
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| 20 | static struct regmap *regmap; |
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| 21 | |
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| 22 | /* |
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| 23 | * On Spreadtrum platform, we need power off system through external SC27xx |
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| 24 | * series PMICs, and it is one similar SPI bus mapped by regmap to access PMIC, |
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| 25 | * which is not fast io access. |
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| 26 | * |
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| 27 | * So before stopping other cores, we need release other cores' resource by |
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| 28 | * taking cpus down to avoid racing regmap or spi mutex lock when poweroff |
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| 29 | * system through PMIC. |
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| 30 | */ |
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| 31 | static void sc27xx_poweroff_shutdown(void) |
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| 32 | { |
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| 33 | #ifdef CONFIG_HOTPLUG_CPU |
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| 34 | int cpu; |
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| 35 | |
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| 36 | for_each_online_cpu(cpu) { |
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| 37 | if (cpu != smp_processor_id()) |
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| 38 | remove_cpu(cpu); |
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| 39 | } |
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| 40 | #endif |
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| 41 | } |
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| 42 | |
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| 43 | static struct syscore_ops poweroff_syscore_ops = { |
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| 44 | .shutdown = sc27xx_poweroff_shutdown, |
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| 45 | }; |
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| 46 | |
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| 47 | static void sc27xx_poweroff_do_poweroff(void) |
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| 48 | { |
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| 49 | /* Disable the external subsys connection's power firstly */ |
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| 50 | regmap_write(map: regmap, SC27XX_SLP_CTRL, SC27XX_LDO_XTL_EN); |
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| 51 | |
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| 52 | regmap_write(map: regmap, SC27XX_PWR_PD_HW, SC27XX_PWR_OFF_EN); |
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| 53 | } |
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| 54 | |
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| 55 | static int sc27xx_poweroff_probe(struct platform_device *pdev) |
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| 56 | { |
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| 57 | if (regmap) |
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| 58 | return -EINVAL; |
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| 59 | |
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| 60 | regmap = dev_get_regmap(dev: pdev->dev.parent, NULL); |
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| 61 | if (!regmap) |
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| 62 | return -ENODEV; |
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| 63 | |
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| 64 | pm_power_off = sc27xx_poweroff_do_poweroff; |
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| 65 | register_syscore_ops(ops: &poweroff_syscore_ops); |
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| 66 | return 0; |
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| 67 | } |
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| 68 | |
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| 69 | static struct platform_driver sc27xx_poweroff_driver = { |
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| 70 | .probe = sc27xx_poweroff_probe, |
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| 71 | .driver = { |
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| 72 | .name = "sc27xx-poweroff" , |
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| 73 | }, |
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| 74 | }; |
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| 75 | module_platform_driver(sc27xx_poweroff_driver); |
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| 76 | |
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| 77 | MODULE_DESCRIPTION("Power off driver for SC27XX PMIC Device" ); |
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| 78 | MODULE_AUTHOR("Baolin Wang <baolin.wang@unisoc.com>" ); |
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| 79 | MODULE_LICENSE("GPL v2" ); |
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| 80 | |
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