| /* |
| * 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 <linux/pinctrl/consumer.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; |
| struct pinctrl *pinctrl; |
| |
| pinctrl = devm_pinctrl_get_select_default(&pdev->dev); |
| if (IS_ERR(pinctrl)) |
| dev_warn(&pdev->dev, "unable to select pin group\n"); |
| |
| pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL); |
| if (!pc) { |
| dev_err(&pdev->dev, "failed to allocate memory\n"); |
| 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); |
| if (!r) { |
| dev_err(&pdev->dev, "no memory resource defined\n"); |
| return -ENODEV; |
| } |
| |
| 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_put_sync(&pdev->dev); |
| pm_runtime_disable(&pdev->dev); |
| return pwmchip_remove(&pc->chip); |
| } |
| |
| 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); |
| } |
| |
| #ifdef CONFIG_PM_SLEEP |
| 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"); |