|  | /* | 
|  | * ECAP PWM driver | 
|  | * | 
|  | * Copyright (C) 2012 Texas Instruments, Inc. - http://www.ti.com/ | 
|  | * | 
|  | * This program is free software; you can redistribute it and/or modify | 
|  | * it under the terms of the GNU General Public License as published by | 
|  | * the Free Software Foundation; either version 2 of the License, or | 
|  | * (at your option) any later version. | 
|  | * | 
|  | * This program is distributed in the hope that it will be useful, | 
|  | * but WITHOUT ANY WARRANTY; without even the implied warranty of | 
|  | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | 
|  | * GNU General Public License for more details. | 
|  | * | 
|  | * You should have received a copy of the GNU General Public License | 
|  | * along with this program; if not, write to the Free Software | 
|  | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | 
|  | */ | 
|  |  | 
|  | #include <linux/module.h> | 
|  | #include <linux/platform_device.h> | 
|  | #include <linux/io.h> | 
|  | #include <linux/err.h> | 
|  | #include <linux/clk.h> | 
|  | #include <linux/pm_runtime.h> | 
|  | #include <linux/pwm.h> | 
|  | #include <linux/of_device.h> | 
|  |  | 
|  | #include "pwm-tipwmss.h" | 
|  |  | 
|  | /* ECAP registers and bits definitions */ | 
|  | #define CAP1			0x08 | 
|  | #define CAP2			0x0C | 
|  | #define CAP3			0x10 | 
|  | #define CAP4			0x14 | 
|  | #define ECCTL2			0x2A | 
|  | #define ECCTL2_APWM_POL_LOW	BIT(10) | 
|  | #define ECCTL2_APWM_MODE	BIT(9) | 
|  | #define ECCTL2_SYNC_SEL_DISA	(BIT(7) | BIT(6)) | 
|  | #define ECCTL2_TSCTR_FREERUN	BIT(4) | 
|  |  | 
|  | struct ecap_context { | 
|  | u32	cap3; | 
|  | u32	cap4; | 
|  | u16	ecctl2; | 
|  | }; | 
|  |  | 
|  | struct ecap_pwm_chip { | 
|  | struct pwm_chip	chip; | 
|  | unsigned int	clk_rate; | 
|  | void __iomem	*mmio_base; | 
|  | struct ecap_context ctx; | 
|  | }; | 
|  |  | 
|  | static inline struct ecap_pwm_chip *to_ecap_pwm_chip(struct pwm_chip *chip) | 
|  | { | 
|  | return container_of(chip, struct ecap_pwm_chip, chip); | 
|  | } | 
|  |  | 
|  | /* | 
|  | * period_ns = 10^9 * period_cycles / PWM_CLK_RATE | 
|  | * duty_ns   = 10^9 * duty_cycles / PWM_CLK_RATE | 
|  | */ | 
|  | static int ecap_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, | 
|  | int duty_ns, int period_ns) | 
|  | { | 
|  | struct ecap_pwm_chip *pc = to_ecap_pwm_chip(chip); | 
|  | unsigned long long c; | 
|  | unsigned long period_cycles, duty_cycles; | 
|  | unsigned int reg_val; | 
|  |  | 
|  | if (period_ns > NSEC_PER_SEC) | 
|  | return -ERANGE; | 
|  |  | 
|  | c = pc->clk_rate; | 
|  | c = c * period_ns; | 
|  | do_div(c, NSEC_PER_SEC); | 
|  | period_cycles = (unsigned long)c; | 
|  |  | 
|  | if (period_cycles < 1) { | 
|  | period_cycles = 1; | 
|  | duty_cycles = 1; | 
|  | } else { | 
|  | c = pc->clk_rate; | 
|  | c = c * duty_ns; | 
|  | do_div(c, NSEC_PER_SEC); | 
|  | duty_cycles = (unsigned long)c; | 
|  | } | 
|  |  | 
|  | pm_runtime_get_sync(pc->chip.dev); | 
|  |  | 
|  | reg_val = readw(pc->mmio_base + ECCTL2); | 
|  |  | 
|  | /* Configure APWM mode & disable sync option */ | 
|  | reg_val |= ECCTL2_APWM_MODE | ECCTL2_SYNC_SEL_DISA; | 
|  |  | 
|  | writew(reg_val, pc->mmio_base + ECCTL2); | 
|  |  | 
|  | if (!test_bit(PWMF_ENABLED, &pwm->flags)) { | 
|  | /* Update active registers if not running */ | 
|  | writel(duty_cycles, pc->mmio_base + CAP2); | 
|  | writel(period_cycles, pc->mmio_base + CAP1); | 
|  | } else { | 
|  | /* | 
|  | * Update shadow registers to configure period and | 
|  | * compare values. This helps current PWM period to | 
|  | * complete on reconfiguring | 
|  | */ | 
|  | writel(duty_cycles, pc->mmio_base + CAP4); | 
|  | writel(period_cycles, pc->mmio_base + CAP3); | 
|  | } | 
|  |  | 
|  | if (!test_bit(PWMF_ENABLED, &pwm->flags)) { | 
|  | reg_val = readw(pc->mmio_base + ECCTL2); | 
|  | /* Disable APWM mode to put APWM output Low */ | 
|  | reg_val &= ~ECCTL2_APWM_MODE; | 
|  | writew(reg_val, pc->mmio_base + ECCTL2); | 
|  | } | 
|  |  | 
|  | pm_runtime_put_sync(pc->chip.dev); | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static int ecap_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm, | 
|  | enum pwm_polarity polarity) | 
|  | { | 
|  | struct ecap_pwm_chip *pc = to_ecap_pwm_chip(chip); | 
|  | unsigned short reg_val; | 
|  |  | 
|  | pm_runtime_get_sync(pc->chip.dev); | 
|  | reg_val = readw(pc->mmio_base + ECCTL2); | 
|  | if (polarity == PWM_POLARITY_INVERSED) | 
|  | /* Duty cycle defines LOW period of PWM */ | 
|  | reg_val |= ECCTL2_APWM_POL_LOW; | 
|  | else | 
|  | /* Duty cycle defines HIGH period of PWM */ | 
|  | reg_val &= ~ECCTL2_APWM_POL_LOW; | 
|  |  | 
|  | writew(reg_val, pc->mmio_base + ECCTL2); | 
|  | pm_runtime_put_sync(pc->chip.dev); | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static int ecap_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) | 
|  | { | 
|  | struct ecap_pwm_chip *pc = to_ecap_pwm_chip(chip); | 
|  | unsigned int reg_val; | 
|  |  | 
|  | /* Leave clock enabled on enabling PWM */ | 
|  | pm_runtime_get_sync(pc->chip.dev); | 
|  |  | 
|  | /* | 
|  | * Enable 'Free run Time stamp counter mode' to start counter | 
|  | * and  'APWM mode' to enable APWM output | 
|  | */ | 
|  | reg_val = readw(pc->mmio_base + ECCTL2); | 
|  | reg_val |= ECCTL2_TSCTR_FREERUN | ECCTL2_APWM_MODE; | 
|  | writew(reg_val, pc->mmio_base + ECCTL2); | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static void ecap_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) | 
|  | { | 
|  | struct ecap_pwm_chip *pc = to_ecap_pwm_chip(chip); | 
|  | unsigned int reg_val; | 
|  |  | 
|  | /* | 
|  | * Disable 'Free run Time stamp counter mode' to stop counter | 
|  | * and 'APWM mode' to put APWM output to low | 
|  | */ | 
|  | reg_val = readw(pc->mmio_base + ECCTL2); | 
|  | reg_val &= ~(ECCTL2_TSCTR_FREERUN | ECCTL2_APWM_MODE); | 
|  | writew(reg_val, pc->mmio_base + ECCTL2); | 
|  |  | 
|  | /* Disable clock on PWM disable */ | 
|  | pm_runtime_put_sync(pc->chip.dev); | 
|  | } | 
|  |  | 
|  | static void ecap_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) | 
|  | { | 
|  | if (test_bit(PWMF_ENABLED, &pwm->flags)) { | 
|  | dev_warn(chip->dev, "Removing PWM device without disabling\n"); | 
|  | pm_runtime_put_sync(chip->dev); | 
|  | } | 
|  | } | 
|  |  | 
|  | static const struct pwm_ops ecap_pwm_ops = { | 
|  | .free		= ecap_pwm_free, | 
|  | .config		= ecap_pwm_config, | 
|  | .set_polarity	= ecap_pwm_set_polarity, | 
|  | .enable		= ecap_pwm_enable, | 
|  | .disable	= ecap_pwm_disable, | 
|  | .owner		= THIS_MODULE, | 
|  | }; | 
|  |  | 
|  | static const struct of_device_id ecap_of_match[] = { | 
|  | { .compatible	= "ti,am33xx-ecap" }, | 
|  | {}, | 
|  | }; | 
|  | MODULE_DEVICE_TABLE(of, ecap_of_match); | 
|  |  | 
|  | static int ecap_pwm_probe(struct platform_device *pdev) | 
|  | { | 
|  | int ret; | 
|  | struct resource *r; | 
|  | struct clk *clk; | 
|  | struct ecap_pwm_chip *pc; | 
|  | u16 status; | 
|  |  | 
|  | pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL); | 
|  | if (!pc) | 
|  | return -ENOMEM; | 
|  |  | 
|  | clk = devm_clk_get(&pdev->dev, "fck"); | 
|  | if (IS_ERR(clk)) { | 
|  | dev_err(&pdev->dev, "failed to get clock\n"); | 
|  | return PTR_ERR(clk); | 
|  | } | 
|  |  | 
|  | pc->clk_rate = clk_get_rate(clk); | 
|  | if (!pc->clk_rate) { | 
|  | dev_err(&pdev->dev, "failed to get clock rate\n"); | 
|  | return -EINVAL; | 
|  | } | 
|  |  | 
|  | pc->chip.dev = &pdev->dev; | 
|  | pc->chip.ops = &ecap_pwm_ops; | 
|  | pc->chip.of_xlate = of_pwm_xlate_with_flags; | 
|  | pc->chip.of_pwm_n_cells = 3; | 
|  | pc->chip.base = -1; | 
|  | pc->chip.npwm = 1; | 
|  |  | 
|  | r = platform_get_resource(pdev, IORESOURCE_MEM, 0); | 
|  | pc->mmio_base = devm_ioremap_resource(&pdev->dev, r); | 
|  | if (IS_ERR(pc->mmio_base)) | 
|  | return PTR_ERR(pc->mmio_base); | 
|  |  | 
|  | ret = pwmchip_add(&pc->chip); | 
|  | if (ret < 0) { | 
|  | dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret); | 
|  | return ret; | 
|  | } | 
|  |  | 
|  | pm_runtime_enable(&pdev->dev); | 
|  | pm_runtime_get_sync(&pdev->dev); | 
|  |  | 
|  | status = pwmss_submodule_state_change(pdev->dev.parent, | 
|  | PWMSS_ECAPCLK_EN); | 
|  | if (!(status & PWMSS_ECAPCLK_EN_ACK)) { | 
|  | dev_err(&pdev->dev, "PWMSS config space clock enable failed\n"); | 
|  | ret = -EINVAL; | 
|  | goto pwmss_clk_failure; | 
|  | } | 
|  |  | 
|  | pm_runtime_put_sync(&pdev->dev); | 
|  |  | 
|  | platform_set_drvdata(pdev, pc); | 
|  | return 0; | 
|  |  | 
|  | pwmss_clk_failure: | 
|  | pm_runtime_put_sync(&pdev->dev); | 
|  | pm_runtime_disable(&pdev->dev); | 
|  | pwmchip_remove(&pc->chip); | 
|  | return ret; | 
|  | } | 
|  |  | 
|  | static int ecap_pwm_remove(struct platform_device *pdev) | 
|  | { | 
|  | struct ecap_pwm_chip *pc = platform_get_drvdata(pdev); | 
|  |  | 
|  | pm_runtime_get_sync(&pdev->dev); | 
|  | /* | 
|  | * Due to hardware misbehaviour, acknowledge of the stop_req | 
|  | * is missing. Hence checking of the status bit skipped. | 
|  | */ | 
|  | pwmss_submodule_state_change(pdev->dev.parent, PWMSS_ECAPCLK_STOP_REQ); | 
|  | pm_runtime_put_sync(&pdev->dev); | 
|  |  | 
|  | pm_runtime_disable(&pdev->dev); | 
|  | return pwmchip_remove(&pc->chip); | 
|  | } | 
|  |  | 
|  | #ifdef CONFIG_PM_SLEEP | 
|  | static void ecap_pwm_save_context(struct ecap_pwm_chip *pc) | 
|  | { | 
|  | pm_runtime_get_sync(pc->chip.dev); | 
|  | pc->ctx.ecctl2 = readw(pc->mmio_base + ECCTL2); | 
|  | pc->ctx.cap4 = readl(pc->mmio_base + CAP4); | 
|  | pc->ctx.cap3 = readl(pc->mmio_base + CAP3); | 
|  | pm_runtime_put_sync(pc->chip.dev); | 
|  | } | 
|  |  | 
|  | static void ecap_pwm_restore_context(struct ecap_pwm_chip *pc) | 
|  | { | 
|  | writel(pc->ctx.cap3, pc->mmio_base + CAP3); | 
|  | writel(pc->ctx.cap4, pc->mmio_base + CAP4); | 
|  | writew(pc->ctx.ecctl2, pc->mmio_base + ECCTL2); | 
|  | } | 
|  |  | 
|  | static int ecap_pwm_suspend(struct device *dev) | 
|  | { | 
|  | struct ecap_pwm_chip *pc = dev_get_drvdata(dev); | 
|  | struct pwm_device *pwm = pc->chip.pwms; | 
|  |  | 
|  | ecap_pwm_save_context(pc); | 
|  |  | 
|  | /* Disable explicitly if PWM is running */ | 
|  | if (test_bit(PWMF_ENABLED, &pwm->flags)) | 
|  | pm_runtime_put_sync(dev); | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static int ecap_pwm_resume(struct device *dev) | 
|  | { | 
|  | struct ecap_pwm_chip *pc = dev_get_drvdata(dev); | 
|  | struct pwm_device *pwm = pc->chip.pwms; | 
|  |  | 
|  | /* Enable explicitly if PWM was running */ | 
|  | if (test_bit(PWMF_ENABLED, &pwm->flags)) | 
|  | pm_runtime_get_sync(dev); | 
|  |  | 
|  | ecap_pwm_restore_context(pc); | 
|  | return 0; | 
|  | } | 
|  | #endif | 
|  |  | 
|  | static SIMPLE_DEV_PM_OPS(ecap_pwm_pm_ops, ecap_pwm_suspend, ecap_pwm_resume); | 
|  |  | 
|  | static struct platform_driver ecap_pwm_driver = { | 
|  | .driver = { | 
|  | .name	= "ecap", | 
|  | .owner	= THIS_MODULE, | 
|  | .of_match_table = ecap_of_match, | 
|  | .pm	= &ecap_pwm_pm_ops, | 
|  | }, | 
|  | .probe = ecap_pwm_probe, | 
|  | .remove = ecap_pwm_remove, | 
|  | }; | 
|  |  | 
|  | module_platform_driver(ecap_pwm_driver); | 
|  |  | 
|  | MODULE_DESCRIPTION("ECAP PWM driver"); | 
|  | MODULE_AUTHOR("Texas Instruments"); | 
|  | MODULE_LICENSE("GPL"); |