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authorLinus Torvalds <torvalds@linux-foundation.org>2017-02-22 12:14:01 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-02-22 12:14:01 -0800
commitcaa59428971d5ad81d19512365c9ba580d83268c (patch)
treecd9615719bad9a97f02bb5bc1021396a1b484762 /drivers/pwm/pwm-stm32.c
parentb2064617c74f301dab1448f1f9c8dbb3c8021058 (diff)
parent0a441275018b69deffd35bc22a84fd51c54d7d85 (diff)
Merge tag 'staging-4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
Pull staging/iio driver updates from Greg KH: "Here is the big staging and iio driver patchsets for 4.11-rc1. We almost broke even this time around, with only a few thousand lines added overall, as we removed the old and obsolete i4l code, but added some new drivers for the RPi platform, as well as adding some new IIO drivers. All of these have been in linux-next for a while with no reported issues" * tag 'staging-4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (669 commits) Staging: vc04_services: Fix the "space prohibited" code style errors Staging: vc04_services: Fix the "wrong indent" code style errors staging: octeon: Use net_device_stats from struct net_device Staging: rtl8192u: ieee80211: ieee80211.h - style fix Staging: rtl8192u: ieee80211: ieee80211_tx.c - style fix Staging: rtl8192u: ieee80211: rtl819x_BAProc.c - style fix Staging: rtl8192u: ieee80211: ieee80211_module.c - style fix Staging: rtl8192u: ieee80211: rtl819x_TSProc.c - style fix Staging: rtl8192u: r8192U.h - style fix Staging: rtl8192u: r8192U_core.c - style fix Staging: rtl8192u: r819xU_cmdpkt.c - style fix staging: rtl8192u: blank lines aren't necessary before a close brace '}' staging: rtl8192u: Adding space after enum and struct definition staging: rtl8192u: Adding space after struct definition Staging: ks7010: Add required and preferred spaces around operators Staging: ks7010: ks*: Remove redundant blank lines Staging: ks7010: ks*: Add missing blank lines after declarations staging: visorbus, replace init_timer with setup_timer staging: vt6656: rxtx.c Removed multiple dereferencing staging: vt6656: Alignment match open parenthesis ...
Diffstat (limited to 'drivers/pwm/pwm-stm32.c')
-rw-r--r--drivers/pwm/pwm-stm32.c397
1 files changed, 397 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-stm32.c b/drivers/pwm/pwm-stm32.c
new file mode 100644
index 000000000000..6139512aab7b
--- /dev/null
+++ b/drivers/pwm/pwm-stm32.c
@@ -0,0 +1,397 @@
+/*
+ * Copyright (C) STMicroelectronics 2016
+ *
+ * Author: Gerald Baeza <gerald.baeza@st.com>
+ *
+ * License terms: GNU General Public License (GPL), version 2
+ *
+ * Inspired by timer-stm32.c from Maxime Coquelin
+ * pwm-atmel.c from Bo Shen
+ */
+
+#include <linux/mfd/stm32-timers.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+
+#define CCMR_CHANNEL_SHIFT 8
+#define CCMR_CHANNEL_MASK 0xFF
+#define MAX_BREAKINPUT 2
+
+struct stm32_pwm {
+ struct pwm_chip chip;
+ struct device *dev;
+ struct clk *clk;
+ struct regmap *regmap;
+ u32 max_arr;
+ bool have_complementary_output;
+};
+
+struct stm32_breakinput {
+ u32 index;
+ u32 level;
+ u32 filter;
+};
+
+static inline struct stm32_pwm *to_stm32_pwm_dev(struct pwm_chip *chip)
+{
+ return container_of(chip, struct stm32_pwm, chip);
+}
+
+static u32 active_channels(struct stm32_pwm *dev)
+{
+ u32 ccer;
+
+ regmap_read(dev->regmap, TIM_CCER, &ccer);
+
+ return ccer & TIM_CCER_CCXE;
+}
+
+static int write_ccrx(struct stm32_pwm *dev, int ch, u32 value)
+{
+ switch (ch) {
+ case 0:
+ return regmap_write(dev->regmap, TIM_CCR1, value);
+ case 1:
+ return regmap_write(dev->regmap, TIM_CCR2, value);
+ case 2:
+ return regmap_write(dev->regmap, TIM_CCR3, value);
+ case 3:
+ return regmap_write(dev->regmap, TIM_CCR4, value);
+ }
+ return -EINVAL;
+}
+
+static int stm32_pwm_config(struct stm32_pwm *priv, int ch,
+ int duty_ns, int period_ns)
+{
+ unsigned long long prd, div, dty;
+ unsigned int prescaler = 0;
+ u32 ccmr, mask, shift;
+
+ /* Period and prescaler values depends on clock rate */
+ div = (unsigned long long)clk_get_rate(priv->clk) * period_ns;
+
+ do_div(div, NSEC_PER_SEC);
+ prd = div;
+
+ while (div > priv->max_arr) {
+ prescaler++;
+ div = prd;
+ do_div(div, prescaler + 1);
+ }
+
+ prd = div;
+
+ if (prescaler > MAX_TIM_PSC)
+ return -EINVAL;
+
+ /*
+ * All channels share the same prescaler and counter so when two
+ * channels are active at the same time we can't change them
+ */
+ if (active_channels(priv) & ~(1 << ch * 4)) {
+ u32 psc, arr;
+
+ regmap_read(priv->regmap, TIM_PSC, &psc);
+ regmap_read(priv->regmap, TIM_ARR, &arr);
+
+ if ((psc != prescaler) || (arr != prd - 1))
+ return -EBUSY;
+ }
+
+ regmap_write(priv->regmap, TIM_PSC, prescaler);
+ regmap_write(priv->regmap, TIM_ARR, prd - 1);
+ regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_ARPE, TIM_CR1_ARPE);
+
+ /* Calculate the duty cycles */
+ dty = prd * duty_ns;
+ do_div(dty, period_ns);
+
+ write_ccrx(priv, ch, dty);
+
+ /* Configure output mode */
+ shift = (ch & 0x1) * CCMR_CHANNEL_SHIFT;
+ ccmr = (TIM_CCMR_PE | TIM_CCMR_M1) << shift;
+ mask = CCMR_CHANNEL_MASK << shift;
+
+ if (ch < 2)
+ regmap_update_bits(priv->regmap, TIM_CCMR1, mask, ccmr);
+ else
+ regmap_update_bits(priv->regmap, TIM_CCMR2, mask, ccmr);
+
+ regmap_update_bits(priv->regmap, TIM_BDTR,
+ TIM_BDTR_MOE | TIM_BDTR_AOE,
+ TIM_BDTR_MOE | TIM_BDTR_AOE);
+
+ return 0;
+}
+
+static int stm32_pwm_set_polarity(struct stm32_pwm *priv, int ch,
+ enum pwm_polarity polarity)
+{
+ u32 mask;
+
+ mask = TIM_CCER_CC1P << (ch * 4);
+ if (priv->have_complementary_output)
+ mask |= TIM_CCER_CC1NP << (ch * 4);
+
+ regmap_update_bits(priv->regmap, TIM_CCER, mask,
+ polarity == PWM_POLARITY_NORMAL ? 0 : mask);
+
+ return 0;
+}
+
+static int stm32_pwm_enable(struct stm32_pwm *priv, int ch)
+{
+ u32 mask;
+ int ret;
+
+ ret = clk_enable(priv->clk);
+ if (ret)
+ return ret;
+
+ /* Enable channel */
+ mask = TIM_CCER_CC1E << (ch * 4);
+ if (priv->have_complementary_output)
+ mask |= TIM_CCER_CC1NE << (ch * 4);
+
+ regmap_update_bits(priv->regmap, TIM_CCER, mask, mask);
+
+ /* Make sure that registers are updated */
+ regmap_update_bits(priv->regmap, TIM_EGR, TIM_EGR_UG, TIM_EGR_UG);
+
+ /* Enable controller */
+ regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, TIM_CR1_CEN);
+
+ return 0;
+}
+
+static void stm32_pwm_disable(struct stm32_pwm *priv, int ch)
+{
+ u32 mask;
+
+ /* Disable channel */
+ mask = TIM_CCER_CC1E << (ch * 4);
+ if (priv->have_complementary_output)
+ mask |= TIM_CCER_CC1NE << (ch * 4);
+
+ regmap_update_bits(priv->regmap, TIM_CCER, mask, 0);
+
+ /* When all channels are disabled, we can disable the controller */
+ if (!active_channels(priv))
+ regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, 0);
+
+ clk_disable(priv->clk);
+}
+
+static int stm32_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+ struct pwm_state *state)
+{
+ bool enabled;
+ struct stm32_pwm *priv = to_stm32_pwm_dev(chip);
+ int ret;
+
+ enabled = pwm->state.enabled;
+
+ if (enabled && !state->enabled) {
+ stm32_pwm_disable(priv, pwm->hwpwm);
+ return 0;
+ }
+
+ if (state->polarity != pwm->state.polarity)
+ stm32_pwm_set_polarity(priv, pwm->hwpwm, state->polarity);
+
+ ret = stm32_pwm_config(priv, pwm->hwpwm,
+ state->duty_cycle, state->period);
+ if (ret)
+ return ret;
+
+ if (!enabled && state->enabled)
+ ret = stm32_pwm_enable(priv, pwm->hwpwm);
+
+ return ret;
+}
+
+static const struct pwm_ops stm32pwm_ops = {
+ .owner = THIS_MODULE,
+ .apply = stm32_pwm_apply,
+};
+
+static int stm32_pwm_set_breakinput(struct stm32_pwm *priv,
+ int index, int level, int filter)
+{
+ u32 bke = (index == 0) ? TIM_BDTR_BKE : TIM_BDTR_BK2E;
+ int shift = (index == 0) ? TIM_BDTR_BKF_SHIFT : TIM_BDTR_BK2F_SHIFT;
+ u32 mask = (index == 0) ? TIM_BDTR_BKE | TIM_BDTR_BKP | TIM_BDTR_BKF
+ : TIM_BDTR_BK2E | TIM_BDTR_BK2P | TIM_BDTR_BK2F;
+ u32 bdtr = bke;
+
+ /*
+ * The both bits could be set since only one will be wrote
+ * due to mask value.
+ */
+ if (level)
+ bdtr |= TIM_BDTR_BKP | TIM_BDTR_BK2P;
+
+ bdtr |= (filter & TIM_BDTR_BKF_MASK) << shift;
+
+ regmap_update_bits(priv->regmap, TIM_BDTR, mask, bdtr);
+
+ regmap_read(priv->regmap, TIM_BDTR, &bdtr);
+
+ return (bdtr & bke) ? 0 : -EINVAL;
+}
+
+static int stm32_pwm_apply_breakinputs(struct stm32_pwm *priv,
+ struct device_node *np)
+{
+ struct stm32_breakinput breakinput[MAX_BREAKINPUT];
+ int nb, ret, i, array_size;
+
+ nb = of_property_count_elems_of_size(np, "st,breakinput",
+ sizeof(struct stm32_breakinput));
+
+ /*
+ * Because "st,breakinput" parameter is optional do not make probe
+ * failed if it doesn't exist.
+ */
+ if (nb <= 0)
+ return 0;
+
+ if (nb > MAX_BREAKINPUT)
+ return -EINVAL;
+
+ array_size = nb * sizeof(struct stm32_breakinput) / sizeof(u32);
+ ret = of_property_read_u32_array(np, "st,breakinput",
+ (u32 *)breakinput, array_size);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < nb && !ret; i++) {
+ ret = stm32_pwm_set_breakinput(priv,
+ breakinput[i].index,
+ breakinput[i].level,
+ breakinput[i].filter);
+ }
+
+ return ret;
+}
+
+static void stm32_pwm_detect_complementary(struct stm32_pwm *priv)
+{
+ u32 ccer;
+
+ /*
+ * If complementary bit doesn't exist writing 1 will have no
+ * effect so we can detect it.
+ */
+ regmap_update_bits(priv->regmap,
+ TIM_CCER, TIM_CCER_CC1NE, TIM_CCER_CC1NE);
+ regmap_read(priv->regmap, TIM_CCER, &ccer);
+ regmap_update_bits(priv->regmap, TIM_CCER, TIM_CCER_CC1NE, 0);
+
+ priv->have_complementary_output = (ccer != 0);
+}
+
+static int stm32_pwm_detect_channels(struct stm32_pwm *priv)
+{
+ u32 ccer;
+ int npwm = 0;
+
+ /*
+ * If channels enable bits don't exist writing 1 will have no
+ * effect so we can detect and count them.
+ */
+ regmap_update_bits(priv->regmap,
+ TIM_CCER, TIM_CCER_CCXE, TIM_CCER_CCXE);
+ regmap_read(priv->regmap, TIM_CCER, &ccer);
+ regmap_update_bits(priv->regmap, TIM_CCER, TIM_CCER_CCXE, 0);
+
+ if (ccer & TIM_CCER_CC1E)
+ npwm++;
+
+ if (ccer & TIM_CCER_CC2E)
+ npwm++;
+
+ if (ccer & TIM_CCER_CC3E)
+ npwm++;
+
+ if (ccer & TIM_CCER_CC4E)
+ npwm++;
+
+ return npwm;
+}
+
+static int stm32_pwm_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ struct stm32_timers *ddata = dev_get_drvdata(pdev->dev.parent);
+ struct stm32_pwm *priv;
+ int ret;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->regmap = ddata->regmap;
+ priv->clk = ddata->clk;
+ priv->max_arr = ddata->max_arr;
+
+ if (!priv->regmap || !priv->clk)
+ return -EINVAL;
+
+ ret = stm32_pwm_apply_breakinputs(priv, np);
+ if (ret)
+ return ret;
+
+ stm32_pwm_detect_complementary(priv);
+
+ priv->chip.base = -1;
+ priv->chip.dev = dev;
+ priv->chip.ops = &stm32pwm_ops;
+ priv->chip.npwm = stm32_pwm_detect_channels(priv);
+
+ ret = pwmchip_add(&priv->chip);
+ if (ret < 0)
+ return ret;
+
+ platform_set_drvdata(pdev, priv);
+
+ return 0;
+}
+
+static int stm32_pwm_remove(struct platform_device *pdev)
+{
+ struct stm32_pwm *priv = platform_get_drvdata(pdev);
+ unsigned int i;
+
+ for (i = 0; i < priv->chip.npwm; i++)
+ pwm_disable(&priv->chip.pwms[i]);
+
+ pwmchip_remove(&priv->chip);
+
+ return 0;
+}
+
+static const struct of_device_id stm32_pwm_of_match[] = {
+ { .compatible = "st,stm32-pwm", },
+ { /* end node */ },
+};
+MODULE_DEVICE_TABLE(of, stm32_pwm_of_match);
+
+static struct platform_driver stm32_pwm_driver = {
+ .probe = stm32_pwm_probe,
+ .remove = stm32_pwm_remove,
+ .driver = {
+ .name = "stm32-pwm",
+ .of_match_table = stm32_pwm_of_match,
+ },
+};
+module_platform_driver(stm32_pwm_driver);
+
+MODULE_ALIAS("platform:stm32-pwm");
+MODULE_DESCRIPTION("STMicroelectronics STM32 PWM driver");
+MODULE_LICENSE("GPL v2");