/* * Intel Low Power Subsystem PWM controller driver * * Copyright (C) 2014, Intel Corporation * Author: Mika Westerberg * Author: Chew Kean Ho * Author: Chang Rebecca Swee Fun * Author: Chew Chiau Ee * Author: Alan Cox * * 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 #include #include #include #include #include #include static int pci_drv, plat_drv; /* So we know which drivers registered */ #define PWM 0x00000000 #define PWM_ENABLE BIT(31) #define PWM_SW_UPDATE BIT(30) #define PWM_BASE_UNIT_SHIFT 8 #define PWM_BASE_UNIT_MASK 0x00ffff00 #define PWM_ON_TIME_DIV_MASK 0x000000ff #define PWM_DIVISION_CORRECTION 0x2 #define PWM_LIMIT (0x8000 + PWM_DIVISION_CORRECTION) #define NSECS_PER_SEC 1000000000UL struct pwm_lpss_chip { struct pwm_chip chip; void __iomem *regs; unsigned long clk_rate; }; struct pwm_lpss_boardinfo { unsigned long clk_rate; }; /* BayTrail */ static const struct pwm_lpss_boardinfo byt_info = { 25000000 }; /* Braswell */ static const struct pwm_lpss_boardinfo bsw_info = { 19200000 }; static inline struct pwm_lpss_chip *to_lpwm(struct pwm_chip *chip) { return container_of(chip, struct pwm_lpss_chip, chip); } static int pwm_lpss_config(struct pwm_chip *chip, struct pwm_device *pwm, int duty_ns, int period_ns) { struct pwm_lpss_chip *lpwm = to_lpwm(chip); u8 on_time_div; unsigned long c; unsigned long long base_unit, freq = NSECS_PER_SEC; u32 ctrl; do_div(freq, period_ns); /* The equation is: base_unit = ((freq / c) * 65536) + correction */ base_unit = freq * 65536; c = lpwm->clk_rate; if (!c) return -EINVAL; do_div(base_unit, c); base_unit += PWM_DIVISION_CORRECTION; if (base_unit > PWM_LIMIT) return -EINVAL; if (duty_ns <= 0) duty_ns = 1; on_time_div = 255 - (255 * duty_ns / period_ns); ctrl = readl(lpwm->regs + PWM); ctrl &= ~(PWM_BASE_UNIT_MASK | PWM_ON_TIME_DIV_MASK); ctrl |= (u16) base_unit << PWM_BASE_UNIT_SHIFT; ctrl |= on_time_div; /* request PWM to update on next cycle */ ctrl |= PWM_SW_UPDATE; writel(ctrl, lpwm->regs + PWM); return 0; } static int pwm_lpss_enable(struct pwm_chip *chip, struct pwm_device *pwm) { struct pwm_lpss_chip *lpwm = to_lpwm(chip); u32 ctrl; ctrl = readl(lpwm->regs + PWM); writel(ctrl | PWM_ENABLE, lpwm->regs + PWM); return 0; } static void pwm_lpss_disable(struct pwm_chip *chip, struct pwm_device *pwm) { struct pwm_lpss_chip *lpwm = to_lpwm(chip); u32 ctrl; ctrl = readl(lpwm->regs + PWM); writel(ctrl & ~PWM_ENABLE, lpwm->regs + PWM); } static const struct pwm_ops pwm_lpss_ops = { .config = pwm_lpss_config, .enable = pwm_lpss_enable, .disable = pwm_lpss_disable, .owner = THIS_MODULE, }; static struct pwm_lpss_chip *pwm_lpss_probe(struct device *dev, struct resource *r, const struct pwm_lpss_boardinfo *info) { struct pwm_lpss_chip *lpwm; int ret; lpwm = devm_kzalloc(dev, sizeof(*lpwm), GFP_KERNEL); if (!lpwm) return ERR_PTR(-ENOMEM); lpwm->regs = devm_ioremap_resource(dev, r); if (IS_ERR(lpwm->regs)) return ERR_CAST(lpwm->regs); lpwm->clk_rate = info->clk_rate; lpwm->chip.dev = dev; lpwm->chip.ops = &pwm_lpss_ops; lpwm->chip.base = -1; lpwm->chip.npwm = 1; ret = pwmchip_add(&lpwm->chip); if (ret) { dev_err(dev, "failed to add PWM chip: %d\n", ret); return ERR_PTR(ret); } return lpwm; } static int pwm_lpss_remove(struct pwm_lpss_chip *lpwm) { u32 ctrl; ctrl = readl(lpwm->regs + PWM); writel(ctrl & ~PWM_ENABLE, lpwm->regs + PWM); return pwmchip_remove(&lpwm->chip); } static int pwm_lpss_probe_pci(struct pci_dev *pdev, const struct pci_device_id *id) { const struct pwm_lpss_boardinfo *info; struct pwm_lpss_chip *lpwm; int err; err = pci_enable_device(pdev); if (err < 0) return err; info = (struct pwm_lpss_boardinfo *)id->driver_data; lpwm = pwm_lpss_probe(&pdev->dev, &pdev->resource[0], info); if (IS_ERR(lpwm)) return PTR_ERR(lpwm); pci_set_drvdata(pdev, lpwm); return 0; } static void pwm_lpss_remove_pci(struct pci_dev *pdev) { struct pwm_lpss_chip *lpwm = pci_get_drvdata(pdev); pwm_lpss_remove(lpwm); pci_disable_device(pdev); } static struct pci_device_id pwm_lpss_pci_ids[] = { { PCI_VDEVICE(INTEL, 0x0f08), (unsigned long)&byt_info}, { PCI_VDEVICE(INTEL, 0x0f09), (unsigned long)&byt_info}, { PCI_VDEVICE(INTEL, 0x2288), (unsigned long)&bsw_info}, { PCI_VDEVICE(INTEL, 0x2289), (unsigned long)&bsw_info}, { }, }; MODULE_DEVICE_TABLE(pci, pwm_lpss_pci_ids); static struct pci_driver pwm_lpss_driver_pci = { .name = "pwm-lpss", .id_table = pwm_lpss_pci_ids, .probe = pwm_lpss_probe_pci, .remove = pwm_lpss_remove_pci, }; static int pwm_lpss_probe_platform(struct platform_device *pdev) { const struct pwm_lpss_boardinfo *info; const struct acpi_device_id *id; struct pwm_lpss_chip *lpwm; struct resource *r; id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev); if (!id) return -ENODEV; r = platform_get_resource(pdev, IORESOURCE_MEM, 0); info = (struct pwm_lpss_boardinfo *)id->driver_data; lpwm = pwm_lpss_probe(&pdev->dev, r, info); if (IS_ERR(lpwm)) return PTR_ERR(lpwm); platform_set_drvdata(pdev, lpwm); return 0; } static int pwm_lpss_remove_platform(struct platform_device *pdev) { struct pwm_lpss_chip *lpwm = platform_get_drvdata(pdev); return pwm_lpss_remove(lpwm); } static const struct acpi_device_id pwm_lpss_acpi_match[] = { { "80860F09", (unsigned long)&byt_info }, { "80862288", (unsigned long)&bsw_info }, { }, }; MODULE_DEVICE_TABLE(acpi, pwm_lpss_acpi_match); static struct platform_driver pwm_lpss_driver_platform = { .driver = { .name = "pwm-lpss", .acpi_match_table = pwm_lpss_acpi_match, }, .probe = pwm_lpss_probe_platform, .remove = pwm_lpss_remove_platform, }; static int __init pwm_init(void) { pci_drv = pci_register_driver(&pwm_lpss_driver_pci); plat_drv = platform_driver_register(&pwm_lpss_driver_platform); if (pci_drv && plat_drv) return pci_drv; return 0; } module_init(pwm_init); static void __exit pwm_exit(void) { if (!pci_drv) pci_unregister_driver(&pwm_lpss_driver_pci); if (!plat_drv) platform_driver_unregister(&pwm_lpss_driver_platform); } module_exit(pwm_exit); MODULE_DESCRIPTION("PWM driver for Intel LPSS"); MODULE_AUTHOR("Mika Westerberg "); MODULE_LICENSE("GPL v2"); MODULE_ALIAS("platform:pwm-lpss");