--- /dev/null
+/*
+ * Copyright 2017 NXP.
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/slab.h>
+
+#define TPM_GLOBAL 0x8
+#define TPM_SC 0x10
+#define TPM_CNT 0x14
+#define TPM_MOD 0x18
+#define TPM_C0SC 0x20
+#define TPM_C0V 0x24
+
+#define SC_CMOD 3
+#define SC_CPWMS BIT(5)
+#define MSnB BIT(5)
+#define MSnA BIT(4)
+#define ELSnB BIT(3)
+#define ELSnA BIT(2)
+
+#define PERIOD_PERIOD_MAX 0x10000
+#define PERIOD_DIV_MAX 8
+
+struct tpm_pwm_chip {
+ struct pwm_chip chip;
+ struct clk *clk;
+ void __iomem *base;
+};
+
+static const unsigned int prediv[8] = {
+ 1, 2, 4, 8, 16, 32, 64, 128
+};
+
+#define to_tpm_pwm_chip(_chip) container_of(_chip, struct tpm_pwm_chip, chip)
+
+static int tpm_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
+ int duty_ns, int period_ns)
+{
+ struct tpm_pwm_chip *tpm = to_tpm_pwm_chip(chip);
+ int ret, div = 0;
+ unsigned int period_cycles, duty_cycles;
+ unsigned long rate;
+ u64 c;
+
+ rate = clk_get_rate(tpm->clk);
+ /* calculate the period_cycles and duty_cycles */
+ while (1) {
+ c = rate / prediv[div];
+ c = c * period_ns;
+ do_div(c, 1000000000);
+ if (c < PERIOD_PERIOD_MAX)
+ break;
+ div++;
+ if (div >= 8)
+ return -EINVAL;
+ }
+
+ /* enable the clock before writing the register */
+ if (!pwm_is_enabled(pwm)) {
+ ret = clk_prepare_enable(tpm->clk);
+ if (ret)
+ return ret;
+ }
+
+ period_cycles = c;
+ c *= duty_ns;
+ do_div(c, period_ns);
+ duty_cycles = c;
+
+ writel(period_cycles & 0xffff, tpm->base + TPM_MOD);
+ writel(duty_cycles & 0xffff, tpm->base + TPM_C0V + pwm->hwpwm * 0x8);
+
+ /* if pwm is not enabled, disable clk after setting */
+ if (!pwm_is_enabled(pwm))
+ clk_disable_unprepare(tpm->clk);
+
+ return 0;
+}
+
+static int tpm_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct tpm_pwm_chip *tpm = to_tpm_pwm_chip(chip);
+ int val;
+
+ clk_prepare_enable(tpm->clk);
+ /*
+ * To enable a tpm channel, CPWMS = 0, MSnB:MSnA = 0x0,
+ * for TPM normal polarity ELSnB:ELSnA = 2b'10,
+ * inverse ELSnB:ELSnA = 2b'01
+ */
+ val = readl(tpm->base + TPM_C0SC + pwm->hwpwm * 0x8);
+
+ val &= ~(MSnB | MSnA | ELSnB | ELSnA);
+ val |= MSnB;
+ val |= pwm->state.polarity ? ELSnA : ELSnB;
+
+ writel(val, tpm->base + TPM_C0SC + pwm->hwpwm * 0x8);
+
+ /* start the counter */
+ val = readl(tpm->base + TPM_SC);
+ val |= 0x1 << SC_CMOD;
+ writel(val, tpm->base + TPM_SC);
+
+ return 0;
+}
+
+static void tpm_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct tpm_pwm_chip *tpm = to_tpm_pwm_chip(chip);
+
+ clk_disable_unprepare(tpm->clk);
+}
+
+static int tpm_pwm_set_polarity(struct pwm_chip *chip,
+ struct pwm_device *pwm,
+ enum pwm_polarity polarity)
+{
+ struct tpm_pwm_chip *tpm = to_tpm_pwm_chip(chip);
+ int ret, val;
+
+ /* enable the clock before writing the register */
+ if (!pwm_is_enabled(pwm)) {
+ ret = clk_prepare_enable(tpm->clk);
+ if (ret)
+ return ret;
+ }
+
+ val = readl(tpm->base + TPM_C0SC + pwm->hwpwm * 0x8);
+ val &= ~(ELSnB | ELSnA);
+ val |= pwm->state.polarity ? ELSnA : ELSnB;
+ writel(val, tpm->base + TPM_C0SC + pwm->hwpwm * 0x8);
+
+ if (!pwm_is_enabled(pwm))
+ clk_disable_unprepare(tpm->clk);
+
+ return 0;
+}
+
+static const struct pwm_ops tpm_pwm_ops = {
+ .config = tpm_pwm_config,
+ .enable = tpm_pwm_enable,
+ .disable = tpm_pwm_disable,
+ .set_polarity = tpm_pwm_set_polarity,
+ .owner = THIS_MODULE,
+};
+
+static int tpm_pwm_probe(struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node;
+ struct tpm_pwm_chip *tpm;
+ struct resource *res;
+ int ret;
+
+ tpm = devm_kzalloc(&pdev->dev, sizeof(*tpm), GFP_KERNEL);
+ if (!tpm)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ tpm->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(tpm->base))
+ return PTR_ERR(tpm->base);
+
+ tpm->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(tpm->clk))
+ return PTR_ERR(tpm->clk);
+
+ tpm->chip.dev = &pdev->dev;
+ tpm->chip.ops = &tpm_pwm_ops;
+ tpm->chip.base = -1;
+ tpm->chip.can_sleep = true;
+ /*
+ * init the number of pwm in the pwm chip. if no "fsl,pwm-number"
+ * found, init the npwm to 2, as tpm module has at least two pwm channel
+ */
+ ret = of_property_read_u32(np, "nxp,pwm-number", &tpm->chip.npwm);
+ if (ret < 0) {
+ dev_info(&pdev->dev, "default two pwm channel");
+ tpm->chip.npwm = 2;
+ }
+
+ ret = pwmchip_add(&tpm->chip);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed to add pwm chip %d\n", ret);
+ return ret;
+ }
+
+ platform_set_drvdata(pdev, tpm);
+
+ return 0;
+}
+
+static int tpm_pwm_remove(struct platform_device *pdev)
+{
+ struct tpm_pwm_chip *tpm = platform_get_drvdata(pdev);
+
+ return pwmchip_remove(&tpm->chip);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int tpm_pwm_suspend(struct device *dev)
+{
+ pinctrl_pm_select_sleep_state(dev);
+
+ return 0;
+}
+
+static int tpm_pwm_resume(struct device *dev)
+{
+ pinctrl_pm_select_default_state(dev);
+
+ return 0;
+};
+#endif
+
+static SIMPLE_DEV_PM_OPS(tpm_pwm_pm, tpm_pwm_suspend, tpm_pwm_resume);
+
+static const struct of_device_id tpm_pwm_dt_ids[] = {
+ { .compatible = "nxp,tpm-pwm", },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, tpm_pwm_dt_ids);
+
+static struct platform_driver tpm_pwm_driver = {
+ .driver = {
+ .name = "tpm-pwm",
+ .of_match_table = tpm_pwm_dt_ids,
+ .pm = &tpm_pwm_pm,
+ },
+ .probe = tpm_pwm_probe,
+ .remove = tpm_pwm_remove,
+};
+module_platform_driver(tpm_pwm_driver);
+
+MODULE_ALIAS("platform:tpm-pwm");
+MODULE_AUTHOR("Jacky Bai <ping.bai@nxp.com>");
+MODULE_DESCRIPTION("NXP TPM PWM Driver");
+MODULE_LICENSE("GPL v2");
projects / linux.git / commitdiff