pwm: Add PWM driver for HiSilicon BVT SOCs
authoryuanjian <yuanjian12@hisilicon.com>
Mon, 28 Nov 2016 09:42:46 +0000 (17:42 +0800)
committerThierry Reding <thierry.reding@gmail.com>
Tue, 29 Nov 2016 15:50:12 +0000 (16:50 +0100)
Add PWM driver for the PWM controller found on HiSilicon BVT SoCs such
as Hi3519V100, Hi3516CV300, etc. The PWM controller is primarily in
charge of controlling the P-Iris lens.

Reviewed-by: Jiancheng Xue <xuejiancheng@hisilicon.com>
Signed-off-by: Jian Yuan <yuanjian12@hisilicon.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Documentation/devicetree/bindings/pwm/pwm-hibvt.txt [new file with mode: 0644]
drivers/pwm/Kconfig
drivers/pwm/Makefile
drivers/pwm/pwm-hibvt.c [new file with mode: 0644]

diff --git a/Documentation/devicetree/bindings/pwm/pwm-hibvt.txt b/Documentation/devicetree/bindings/pwm/pwm-hibvt.txt
new file mode 100644 (file)
index 0000000..fa7849d
--- /dev/null
@@ -0,0 +1,21 @@
+Hisilicon PWM controller
+
+Required properties:
+-compatible: should contain one SoC specific compatible string
+ The SoC specific strings supported including:
+       "hisilicon,hi3516cv300-pwm"
+       "hisilicon,hi3519v100-pwm"
+- reg: physical base address and length of the controller's registers.
+- clocks: phandle and clock specifier of the PWM reference clock.
+- resets: phandle and reset specifier for the PWM controller reset.
+- #pwm-cells: Should be 3. See pwm.txt in this directory for a description of
+  the cells format.
+
+Example:
+       pwm: pwm@12130000 {
+               compatible = "hisilicon,hi3516cv300-pwm";
+               reg = <0x12130000 0x10000>;
+               clocks = <&crg_ctrl HI3516CV300_PWM_CLK>;
+               resets = <&crg_ctrl 0x38 0>;
+               #pwm-cells = <3>;
+       };
index bf0128899c094801f2b35c453725c02aae0fea39..f92dd41b0395f2621d188969a3a249cc5cfbd122 100644 (file)
@@ -175,6 +175,15 @@ config PWM_FSL_FTM
          To compile this driver as a module, choose M here: the module
          will be called pwm-fsl-ftm.
 
+config PWM_HIBVT
+       tristate "HiSilicon BVT PWM support"
+       depends on ARCH_HISI || COMPILE_TEST
+       help
+         Generic PWM framework driver for HiSilicon BVT SoCs.
+
+         To compile this driver as a module, choose M here: the module
+         will be called pwm-hibvt.
+
 config PWM_IMG
        tristate "Imagination Technologies PWM driver"
        depends on HAS_IOMEM
index 1194c54efcc2571cd9bfa7cfe976d22c06d44ca6..a48bdb517792d30dc580811dde7b62bf4364f6a9 100644 (file)
@@ -15,6 +15,7 @@ obj-$(CONFIG_PWM_CRC)         += pwm-crc.o
 obj-$(CONFIG_PWM_CROS_EC)      += pwm-cros-ec.o
 obj-$(CONFIG_PWM_EP93XX)       += pwm-ep93xx.o
 obj-$(CONFIG_PWM_FSL_FTM)      += pwm-fsl-ftm.o
+obj-$(CONFIG_PWM_HIBVT)                += pwm-hibvt.o
 obj-$(CONFIG_PWM_IMG)          += pwm-img.o
 obj-$(CONFIG_PWM_IMX)          += pwm-imx.o
 obj-$(CONFIG_PWM_JZ4740)       += pwm-jz4740.o
diff --git a/drivers/pwm/pwm-hibvt.c b/drivers/pwm/pwm-hibvt.c
new file mode 100644 (file)
index 0000000..d0e8f85
--- /dev/null
@@ -0,0 +1,271 @@
+/*
+ * PWM Controller Driver for HiSilicon BVT SoCs
+ *
+ * Copyright (c) 2016 HiSilicon Technologies Co., Ltd.
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/reset.h>
+
+#define PWM_CFG0_ADDR(x)    (((x) * 0x20) + 0x0)
+#define PWM_CFG1_ADDR(x)    (((x) * 0x20) + 0x4)
+#define PWM_CFG2_ADDR(x)    (((x) * 0x20) + 0x8)
+#define PWM_CTRL_ADDR(x)    (((x) * 0x20) + 0xC)
+
+#define PWM_ENABLE_SHIFT    0
+#define PWM_ENABLE_MASK     BIT(0)
+
+#define PWM_POLARITY_SHIFT  1
+#define PWM_POLARITY_MASK   BIT(1)
+
+#define PWM_KEEP_SHIFT      2
+#define PWM_KEEP_MASK       BIT(2)
+
+#define PWM_PERIOD_MASK     GENMASK(31, 0)
+#define PWM_DUTY_MASK       GENMASK(31, 0)
+
+struct hibvt_pwm_chip {
+       struct pwm_chip chip;
+       struct clk *clk;
+       void __iomem *base;
+       struct reset_control *rstc;
+};
+
+struct hibvt_pwm_soc {
+       u32 num_pwms;
+};
+
+static const struct hibvt_pwm_soc pwm_soc[2] = {
+       { .num_pwms = 4 },
+       { .num_pwms = 8 },
+};
+
+static inline struct hibvt_pwm_chip *to_hibvt_pwm_chip(struct pwm_chip *chip)
+{
+       return container_of(chip, struct hibvt_pwm_chip, chip);
+}
+
+static void hibvt_pwm_set_bits(void __iomem *base, u32 offset,
+                                       u32 mask, u32 data)
+{
+       void __iomem *address = base + offset;
+       u32 value;
+
+       value = readl(address);
+       value &= ~mask;
+       value |= (data & mask);
+       writel(value, address);
+}
+
+static void hibvt_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+       struct hibvt_pwm_chip *hi_pwm_chip = to_hibvt_pwm_chip(chip);
+
+       hibvt_pwm_set_bits(hi_pwm_chip->base, PWM_CTRL_ADDR(pwm->hwpwm),
+                       PWM_ENABLE_MASK, 0x1);
+}
+
+static void hibvt_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+       struct hibvt_pwm_chip *hi_pwm_chip = to_hibvt_pwm_chip(chip);
+
+       hibvt_pwm_set_bits(hi_pwm_chip->base, PWM_CTRL_ADDR(pwm->hwpwm),
+                       PWM_ENABLE_MASK, 0x0);
+}
+
+static void hibvt_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
+                                       int duty_cycle_ns, int period_ns)
+{
+       struct hibvt_pwm_chip *hi_pwm_chip = to_hibvt_pwm_chip(chip);
+       u32 freq, period, duty;
+
+       freq = div_u64(clk_get_rate(hi_pwm_chip->clk), 1000000);
+
+       period = div_u64(freq * period_ns, 1000);
+       duty = div_u64(period * duty_cycle_ns, period_ns);
+
+       hibvt_pwm_set_bits(hi_pwm_chip->base, PWM_CFG0_ADDR(pwm->hwpwm),
+                       PWM_PERIOD_MASK, period);
+
+       hibvt_pwm_set_bits(hi_pwm_chip->base, PWM_CFG1_ADDR(pwm->hwpwm),
+                       PWM_DUTY_MASK, duty);
+}
+
+static void hibvt_pwm_set_polarity(struct pwm_chip *chip,
+                                       struct pwm_device *pwm,
+                                       enum pwm_polarity polarity)
+{
+       struct hibvt_pwm_chip *hi_pwm_chip = to_hibvt_pwm_chip(chip);
+
+       if (polarity == PWM_POLARITY_INVERSED)
+               hibvt_pwm_set_bits(hi_pwm_chip->base, PWM_CTRL_ADDR(pwm->hwpwm),
+                               PWM_POLARITY_MASK, (0x1 << PWM_POLARITY_SHIFT));
+       else
+               hibvt_pwm_set_bits(hi_pwm_chip->base, PWM_CTRL_ADDR(pwm->hwpwm),
+                               PWM_POLARITY_MASK, (0x0 << PWM_POLARITY_SHIFT));
+}
+
+static void hibvt_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
+                               struct pwm_state *state)
+{
+       struct hibvt_pwm_chip *hi_pwm_chip = to_hibvt_pwm_chip(chip);
+       void __iomem *base;
+       u32 freq, value;
+
+       freq = div_u64(clk_get_rate(hi_pwm_chip->clk), 1000000);
+       base = hi_pwm_chip->base;
+
+       value = readl(base + PWM_CFG0_ADDR(pwm->hwpwm));
+       state->period = div_u64(value * 1000, freq);
+
+       value = readl(base + PWM_CFG1_ADDR(pwm->hwpwm));
+       state->duty_cycle = div_u64(value * 1000, freq);
+
+       value = readl(base + PWM_CTRL_ADDR(pwm->hwpwm));
+       state->enabled = (PWM_ENABLE_MASK & value);
+}
+
+static int hibvt_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+                               struct pwm_state *state)
+{
+       if (state->polarity != pwm->state.polarity)
+               hibvt_pwm_set_polarity(chip, pwm, state->polarity);
+
+       if (state->period != pwm->state.period ||
+               state->duty_cycle != pwm->state.duty_cycle)
+               hibvt_pwm_config(chip, pwm, state->duty_cycle, state->period);
+
+       if (state->enabled != pwm->state.enabled) {
+               if (state->enabled)
+                       hibvt_pwm_enable(chip, pwm);
+               else
+                       hibvt_pwm_disable(chip, pwm);
+       }
+
+       return 0;
+}
+
+static struct pwm_ops hibvt_pwm_ops = {
+       .get_state = hibvt_pwm_get_state,
+       .apply = hibvt_pwm_apply,
+
+       .owner = THIS_MODULE,
+};
+
+static int hibvt_pwm_probe(struct platform_device *pdev)
+{
+       const struct hibvt_pwm_soc *soc =
+                               of_device_get_match_data(&pdev->dev);
+       struct hibvt_pwm_chip *pwm_chip;
+       struct resource *res;
+       int ret;
+       int i;
+
+       pwm_chip = devm_kzalloc(&pdev->dev, sizeof(*pwm_chip), GFP_KERNEL);
+       if (pwm_chip == NULL)
+               return -ENOMEM;
+
+       pwm_chip->clk = devm_clk_get(&pdev->dev, NULL);
+       if (IS_ERR(pwm_chip->clk)) {
+               dev_err(&pdev->dev, "getting clock failed with %ld\n",
+                               PTR_ERR(pwm_chip->clk));
+               return PTR_ERR(pwm_chip->clk);
+       }
+
+       pwm_chip->chip.ops = &hibvt_pwm_ops;
+       pwm_chip->chip.dev = &pdev->dev;
+       pwm_chip->chip.base = -1;
+       pwm_chip->chip.npwm = soc->num_pwms;
+       pwm_chip->chip.of_xlate = of_pwm_xlate_with_flags;
+       pwm_chip->chip.of_pwm_n_cells = 3;
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       pwm_chip->base = devm_ioremap_resource(&pdev->dev, res);
+       if (IS_ERR(pwm_chip->base))
+               return PTR_ERR(pwm_chip->base);
+
+       ret = clk_prepare_enable(pwm_chip->clk);
+       if (ret < 0)
+               return ret;
+
+       pwm_chip->rstc = devm_reset_control_get(&pdev->dev, NULL);
+       if (IS_ERR(pwm_chip->rstc)) {
+               clk_disable_unprepare(pwm_chip->clk);
+               return PTR_ERR(pwm_chip->rstc);
+       }
+
+       reset_control_assert(pwm_chip->rstc);
+       msleep(30);
+       reset_control_deassert(pwm_chip->rstc);
+
+       ret = pwmchip_add(&pwm_chip->chip);
+       if (ret < 0) {
+               clk_disable_unprepare(pwm_chip->clk);
+               return ret;
+       }
+
+       for (i = 0; i < pwm_chip->chip.npwm; i++) {
+               hibvt_pwm_set_bits(pwm_chip->base, PWM_CTRL_ADDR(i),
+                               PWM_KEEP_MASK, (0x1 << PWM_KEEP_SHIFT));
+       }
+
+       platform_set_drvdata(pdev, pwm_chip);
+
+       return 0;
+}
+
+static int hibvt_pwm_remove(struct platform_device *pdev)
+{
+       struct hibvt_pwm_chip *pwm_chip;
+
+       pwm_chip = platform_get_drvdata(pdev);
+
+       reset_control_assert(pwm_chip->rstc);
+       msleep(30);
+       reset_control_deassert(pwm_chip->rstc);
+
+       clk_disable_unprepare(pwm_chip->clk);
+
+       return pwmchip_remove(&pwm_chip->chip);
+}
+
+static const struct of_device_id hibvt_pwm_of_match[] = {
+       { .compatible = "hisilicon,hi3516cv300-pwm", .data = &pwm_soc[0] },
+       { .compatible = "hisilicon,hi3519v100-pwm", .data = &pwm_soc[1] },
+       {  }
+};
+MODULE_DEVICE_TABLE(of, hibvt_pwm_of_match);
+
+static struct platform_driver hibvt_pwm_driver = {
+       .driver = {
+               .name = "hibvt-pwm",
+               .of_match_table = hibvt_pwm_of_match,
+       },
+       .probe = hibvt_pwm_probe,
+       .remove = hibvt_pwm_remove,
+};
+module_platform_driver(hibvt_pwm_driver);
+
+MODULE_AUTHOR("Jian Yuan");
+MODULE_DESCRIPTION("HiSilicon BVT SoCs PWM driver");
+MODULE_LICENSE("GPL");