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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/pwm/pwm-pxa.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r--drivers/pwm/pwm-pxa.c227
1 files changed, 227 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-pxa.c b/drivers/pwm/pwm-pxa.c
new file mode 100644
index 000000000..0bcaa58c6
--- /dev/null
+++ b/drivers/pwm/pwm-pxa.c
@@ -0,0 +1,227 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * drivers/pwm/pwm-pxa.c
+ *
+ * simple driver for PWM (Pulse Width Modulator) controller
+ *
+ * 2008-02-13 initial version
+ * eric miao <eric.miao@marvell.com>
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/pwm.h>
+#include <linux/of_device.h>
+
+#include <asm/div64.h>
+
+#define HAS_SECONDARY_PWM 0x10
+
+static const struct platform_device_id pwm_id_table[] = {
+ /* PWM has_secondary_pwm? */
+ { "pxa25x-pwm", 0 },
+ { "pxa27x-pwm", HAS_SECONDARY_PWM },
+ { "pxa168-pwm", 0 },
+ { "pxa910-pwm", 0 },
+ { },
+};
+MODULE_DEVICE_TABLE(platform, pwm_id_table);
+
+/* PWM registers and bits definitions */
+#define PWMCR (0x00)
+#define PWMDCR (0x04)
+#define PWMPCR (0x08)
+
+#define PWMCR_SD (1 << 6)
+#define PWMDCR_FD (1 << 10)
+
+struct pxa_pwm_chip {
+ struct pwm_chip chip;
+ struct device *dev;
+
+ struct clk *clk;
+ void __iomem *mmio_base;
+};
+
+static inline struct pxa_pwm_chip *to_pxa_pwm_chip(struct pwm_chip *chip)
+{
+ return container_of(chip, struct pxa_pwm_chip, chip);
+}
+
+/*
+ * period_ns = 10^9 * (PRESCALE + 1) * (PV + 1) / PWM_CLK_RATE
+ * duty_ns = 10^9 * (PRESCALE + 1) * DC / PWM_CLK_RATE
+ */
+static int pxa_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
+ u64 duty_ns, u64 period_ns)
+{
+ struct pxa_pwm_chip *pc = to_pxa_pwm_chip(chip);
+ unsigned long long c;
+ unsigned long period_cycles, prescale, pv, dc;
+ unsigned long offset;
+ int rc;
+
+ offset = pwm->hwpwm ? 0x10 : 0;
+
+ c = clk_get_rate(pc->clk);
+ c = c * period_ns;
+ do_div(c, 1000000000);
+ period_cycles = c;
+
+ if (period_cycles < 1)
+ period_cycles = 1;
+ prescale = (period_cycles - 1) / 1024;
+ pv = period_cycles / (prescale + 1) - 1;
+
+ if (prescale > 63)
+ return -EINVAL;
+
+ if (duty_ns == period_ns)
+ dc = PWMDCR_FD;
+ else
+ dc = mul_u64_u64_div_u64(pv + 1, duty_ns, period_ns);
+
+ /* NOTE: the clock to PWM has to be enabled first
+ * before writing to the registers
+ */
+ rc = clk_prepare_enable(pc->clk);
+ if (rc < 0)
+ return rc;
+
+ writel(prescale, pc->mmio_base + offset + PWMCR);
+ writel(dc, pc->mmio_base + offset + PWMDCR);
+ writel(pv, pc->mmio_base + offset + PWMPCR);
+
+ clk_disable_unprepare(pc->clk);
+ return 0;
+}
+
+static int pxa_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct pxa_pwm_chip *pc = to_pxa_pwm_chip(chip);
+
+ return clk_prepare_enable(pc->clk);
+}
+
+static void pxa_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct pxa_pwm_chip *pc = to_pxa_pwm_chip(chip);
+
+ clk_disable_unprepare(pc->clk);
+}
+
+static int pxa_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+ const struct pwm_state *state)
+{
+ int err;
+
+ if (state->polarity != PWM_POLARITY_NORMAL)
+ return -EINVAL;
+
+ if (!state->enabled) {
+ if (pwm->state.enabled)
+ pxa_pwm_disable(chip, pwm);
+
+ return 0;
+ }
+
+ err = pxa_pwm_config(chip, pwm, state->duty_cycle, state->period);
+ if (err)
+ return err;
+
+ if (!pwm->state.enabled)
+ return pxa_pwm_enable(chip, pwm);
+
+ return 0;
+}
+
+static const struct pwm_ops pxa_pwm_ops = {
+ .apply = pxa_pwm_apply,
+ .owner = THIS_MODULE,
+};
+
+#ifdef CONFIG_OF
+/*
+ * Device tree users must create one device instance for each PWM channel.
+ * Hence we dispense with the HAS_SECONDARY_PWM and "tell" the original driver
+ * code that this is a single channel pxa25x-pwm. Currently all devices are
+ * supported identically.
+ */
+static const struct of_device_id pwm_of_match[] = {
+ { .compatible = "marvell,pxa250-pwm", .data = &pwm_id_table[0]},
+ { .compatible = "marvell,pxa270-pwm", .data = &pwm_id_table[0]},
+ { .compatible = "marvell,pxa168-pwm", .data = &pwm_id_table[0]},
+ { .compatible = "marvell,pxa910-pwm", .data = &pwm_id_table[0]},
+ { }
+};
+MODULE_DEVICE_TABLE(of, pwm_of_match);
+#else
+#define pwm_of_match NULL
+#endif
+
+static const struct platform_device_id *pxa_pwm_get_id_dt(struct device *dev)
+{
+ const struct of_device_id *id = of_match_device(pwm_of_match, dev);
+
+ return id ? id->data : NULL;
+}
+
+static int pwm_probe(struct platform_device *pdev)
+{
+ const struct platform_device_id *id = platform_get_device_id(pdev);
+ struct pxa_pwm_chip *pc;
+ int ret = 0;
+
+ if (IS_ENABLED(CONFIG_OF) && id == NULL)
+ id = pxa_pwm_get_id_dt(&pdev->dev);
+
+ if (id == NULL)
+ return -EINVAL;
+
+ pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
+ if (pc == NULL)
+ return -ENOMEM;
+
+ pc->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(pc->clk))
+ return PTR_ERR(pc->clk);
+
+ pc->chip.dev = &pdev->dev;
+ pc->chip.ops = &pxa_pwm_ops;
+ pc->chip.npwm = (id->driver_data & HAS_SECONDARY_PWM) ? 2 : 1;
+
+ if (IS_ENABLED(CONFIG_OF)) {
+ pc->chip.of_xlate = of_pwm_single_xlate;
+ pc->chip.of_pwm_n_cells = 1;
+ }
+
+ pc->mmio_base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(pc->mmio_base))
+ return PTR_ERR(pc->mmio_base);
+
+ ret = devm_pwmchip_add(&pdev->dev, &pc->chip);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static struct platform_driver pwm_driver = {
+ .driver = {
+ .name = "pxa25x-pwm",
+ .of_match_table = pwm_of_match,
+ },
+ .probe = pwm_probe,
+ .id_table = pwm_id_table,
+};
+
+module_platform_driver(pwm_driver);
+
+MODULE_LICENSE("GPL v2");