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authorLinus Torvalds <torvalds@linux-foundation.org>2021-04-26 12:11:52 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-04-26 12:11:52 -0700
commit37f00ab4a003f371f81e0eae76cf372f06dec780 (patch)
treec6217483f22a0fac876f12af53f4b8948200f2fd /drivers/pwm/pwm-raspberrypi-poe.c
parent2b90506a8186df5f7c81ad1ebd250103d8469e27 (diff)
parent5ffa828534036348fa90fb3079ccc0972d202c4a (diff)
Merge tag 'arm-drivers-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc
Pull ARM SoC driver updates from Arnd Bergmann: "Updates for SoC specific drivers include a few subsystems that have their own maintainers but send them through the soc tree: TEE/OP-TEE: - Add tracepoints around calls to secure world Memory controller drivers: - Minor fixes for Renesas, Exynos, Mediatek and Tegra platforms - Add debug statistics to Tegra20 memory controller - Update Tegra bindings and convert to dtschema ARM SCMI Firmware: - Support for modular SCMI protocols and vendor specific extensions - New SCMI IIO driver - Per-cpu DVFS The other driver changes are all from the platform maintainers directly and reflect the drivers that don't fit into any other subsystem as well as treewide changes for a particular platform. SoCFPGA: - Various cleanups contributed by Krzysztof Kozlowski Mediatek: - add MT8183 support to mutex driver - MMSYS: use per SoC array to describe the possible routing - add MMSYS support for MT8183 and MT8167 - add support for PMIC wrapper with integrated arbiter - add support for MT8192/MT6873 Tegra: - Bug fixes to PMC and clock drivers NXP/i.MX: - Update SCU power domain driver to keep console domain power on. - Add missing ADC1 power domain to SCU power domain driver. - Update comments for single global power domain in SCU power domain driver. - Add i.MX51/i.MX53 unique id support to i.MX SoC driver. NXP/FSL SoC driver updates for v5.13 - Add ACPI support for RCPM driver - Use generic io{read,write} for QE drivers after performance optimized for PowerPC - Fix QBMAN probe to cleanup HW states correctly for kexec - Various cleanup and style fix for QBMAN/QE/GUTS drivers OMAP: - Preparation to use devicetree for genpd - ti-sysc needs iorange check improved when the interconnect target module has no control registers listed - ti-sysc needs to probe l4_wkup and l4_cfg interconnects first to avoid issues with missing resources and unnecessary deferred probe - ti-sysc debug option can now detect more devices - ti-sysc now warns if an old incomplete devicetree data is found as we now rely on it being complete for am3 and 4 - soc init code needs to check for prcm and prm nodes for omap4/5 and dra7 - omap-prm driver needs to enable autoidle retention support for omap4 - omap5 clocks are missing gpmc and ocmc clock registers - pci-dra7xx now needs to use builtin_platform_driver instead of using builtin_platform_driver_probe for deferred probe to work Raspberry Pi: - Fix-up all RPi firmware drivers so as for unbind to happen in an orderly fashion - Support for RPi's PoE hat PWM bus Qualcomm - Improved detection for SCM calling conventions - Support for OEM specific wifi firmware path - Added drivers for SC7280/SM8350: RPMH, LLCC< AOSS QMP" * tag 'arm-drivers-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (165 commits) soc: aspeed: fix a ternary sign expansion bug memory: mtk-smi: Add device-link between smi-larb and smi-common memory: samsung: exynos5422-dmc: handle clk_set_parent() failure memory: renesas-rpc-if: fix possible NULL pointer dereference of resource clk: socfpga: fix iomem pointer cast on 64-bit soc: aspeed: Adapt to new LPC device tree layout pinctrl: aspeed-g5: Adapt to new LPC device tree layout ipmi: kcs: aspeed: Adapt to new LPC DTS layout ARM: dts: Remove LPC BMC and Host partitions dt-bindings: aspeed-lpc: Remove LPC partitioning soc: fsl: enable acpi support in RCPM driver soc: qcom: mdt_loader: Detect truncated read of segments soc: qcom: mdt_loader: Validate that p_filesz < p_memsz soc: qcom: pdr: Fix error return code in pdr_register_listener firmware: qcom_scm: Fix kernel-doc function names to match firmware: qcom_scm: Suppress sysfs bind attributes firmware: qcom_scm: Workaround lack of "is available" call on SC7180 firmware: qcom_scm: Reduce locking section for __get_convention() firmware: qcom_scm: Make __qcom_scm_is_call_available() return bool Revert "soc: fsl: qe: introduce qe_io{read,write}* wrappers" ...
Diffstat (limited to 'drivers/pwm/pwm-raspberrypi-poe.c')
-rw-r--r--drivers/pwm/pwm-raspberrypi-poe.c206
1 files changed, 206 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-raspberrypi-poe.c b/drivers/pwm/pwm-raspberrypi-poe.c
new file mode 100644
index 000000000000..043fc32e8be8
--- /dev/null
+++ b/drivers/pwm/pwm-raspberrypi-poe.c
@@ -0,0 +1,206 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2021 Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
+ * For more information on Raspberry Pi's PoE hat see:
+ * https://www.raspberrypi.org/products/poe-hat/
+ *
+ * Limitations:
+ * - No disable bit, so a disabled PWM is simulated by duty_cycle 0
+ * - Only normal polarity
+ * - Fixed 12.5 kHz period
+ *
+ * The current period is completed when HW is reconfigured.
+ */
+
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+
+#include <soc/bcm2835/raspberrypi-firmware.h>
+#include <dt-bindings/pwm/raspberrypi,firmware-poe-pwm.h>
+
+#define RPI_PWM_MAX_DUTY 255
+#define RPI_PWM_PERIOD_NS 80000 /* 12.5 kHz */
+
+#define RPI_PWM_CUR_DUTY_REG 0x0
+
+struct raspberrypi_pwm {
+ struct rpi_firmware *firmware;
+ struct pwm_chip chip;
+ unsigned int duty_cycle;
+};
+
+struct raspberrypi_pwm_prop {
+ __le32 reg;
+ __le32 val;
+ __le32 ret;
+} __packed;
+
+static inline
+struct raspberrypi_pwm *raspberrypi_pwm_from_chip(struct pwm_chip *chip)
+{
+ return container_of(chip, struct raspberrypi_pwm, chip);
+}
+
+static int raspberrypi_pwm_set_property(struct rpi_firmware *firmware,
+ u32 reg, u32 val)
+{
+ struct raspberrypi_pwm_prop msg = {
+ .reg = cpu_to_le32(reg),
+ .val = cpu_to_le32(val),
+ };
+ int ret;
+
+ ret = rpi_firmware_property(firmware, RPI_FIRMWARE_SET_POE_HAT_VAL,
+ &msg, sizeof(msg));
+ if (ret)
+ return ret;
+ if (msg.ret)
+ return -EIO;
+
+ return 0;
+}
+
+static int raspberrypi_pwm_get_property(struct rpi_firmware *firmware,
+ u32 reg, u32 *val)
+{
+ struct raspberrypi_pwm_prop msg = {
+ .reg = reg
+ };
+ int ret;
+
+ ret = rpi_firmware_property(firmware, RPI_FIRMWARE_GET_POE_HAT_VAL,
+ &msg, sizeof(msg));
+ if (ret)
+ return ret;
+ if (msg.ret)
+ return -EIO;
+
+ *val = le32_to_cpu(msg.val);
+
+ return 0;
+}
+
+static void raspberrypi_pwm_get_state(struct pwm_chip *chip,
+ struct pwm_device *pwm,
+ struct pwm_state *state)
+{
+ struct raspberrypi_pwm *rpipwm = raspberrypi_pwm_from_chip(chip);
+
+ state->period = RPI_PWM_PERIOD_NS;
+ state->duty_cycle = DIV_ROUND_UP(rpipwm->duty_cycle * RPI_PWM_PERIOD_NS,
+ RPI_PWM_MAX_DUTY);
+ state->enabled = !!(rpipwm->duty_cycle);
+ state->polarity = PWM_POLARITY_NORMAL;
+}
+
+static int raspberrypi_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+ const struct pwm_state *state)
+{
+ struct raspberrypi_pwm *rpipwm = raspberrypi_pwm_from_chip(chip);
+ unsigned int duty_cycle;
+ int ret;
+
+ if (state->period < RPI_PWM_PERIOD_NS ||
+ state->polarity != PWM_POLARITY_NORMAL)
+ return -EINVAL;
+
+ if (!state->enabled)
+ duty_cycle = 0;
+ else if (state->duty_cycle < RPI_PWM_PERIOD_NS)
+ duty_cycle = DIV_ROUND_DOWN_ULL(state->duty_cycle * RPI_PWM_MAX_DUTY,
+ RPI_PWM_PERIOD_NS);
+ else
+ duty_cycle = RPI_PWM_MAX_DUTY;
+
+ if (duty_cycle == rpipwm->duty_cycle)
+ return 0;
+
+ ret = raspberrypi_pwm_set_property(rpipwm->firmware, RPI_PWM_CUR_DUTY_REG,
+ duty_cycle);
+ if (ret) {
+ dev_err(chip->dev, "Failed to set duty cycle: %pe\n",
+ ERR_PTR(ret));
+ return ret;
+ }
+
+ rpipwm->duty_cycle = duty_cycle;
+
+ return 0;
+}
+
+static const struct pwm_ops raspberrypi_pwm_ops = {
+ .get_state = raspberrypi_pwm_get_state,
+ .apply = raspberrypi_pwm_apply,
+ .owner = THIS_MODULE,
+};
+
+static int raspberrypi_pwm_probe(struct platform_device *pdev)
+{
+ struct device_node *firmware_node;
+ struct device *dev = &pdev->dev;
+ struct rpi_firmware *firmware;
+ struct raspberrypi_pwm *rpipwm;
+ int ret;
+
+ firmware_node = of_get_parent(dev->of_node);
+ if (!firmware_node) {
+ dev_err(dev, "Missing firmware node\n");
+ return -ENOENT;
+ }
+
+ firmware = devm_rpi_firmware_get(&pdev->dev, firmware_node);
+ of_node_put(firmware_node);
+ if (!firmware)
+ return dev_err_probe(dev, -EPROBE_DEFER,
+ "Failed to get firmware handle\n");
+
+ rpipwm = devm_kzalloc(&pdev->dev, sizeof(*rpipwm), GFP_KERNEL);
+ if (!rpipwm)
+ return -ENOMEM;
+
+ rpipwm->firmware = firmware;
+ rpipwm->chip.dev = dev;
+ rpipwm->chip.ops = &raspberrypi_pwm_ops;
+ rpipwm->chip.base = -1;
+ rpipwm->chip.npwm = RASPBERRYPI_FIRMWARE_PWM_NUM;
+
+ platform_set_drvdata(pdev, rpipwm);
+
+ ret = raspberrypi_pwm_get_property(rpipwm->firmware, RPI_PWM_CUR_DUTY_REG,
+ &rpipwm->duty_cycle);
+ if (ret) {
+ dev_err(dev, "Failed to get duty cycle: %pe\n", ERR_PTR(ret));
+ return ret;
+ }
+
+ return pwmchip_add(&rpipwm->chip);
+}
+
+static int raspberrypi_pwm_remove(struct platform_device *pdev)
+{
+ struct raspberrypi_pwm *rpipwm = platform_get_drvdata(pdev);
+
+ return pwmchip_remove(&rpipwm->chip);
+}
+
+static const struct of_device_id raspberrypi_pwm_of_match[] = {
+ { .compatible = "raspberrypi,firmware-poe-pwm", },
+ { }
+};
+MODULE_DEVICE_TABLE(of, raspberrypi_pwm_of_match);
+
+static struct platform_driver raspberrypi_pwm_driver = {
+ .driver = {
+ .name = "raspberrypi-poe-pwm",
+ .of_match_table = raspberrypi_pwm_of_match,
+ },
+ .probe = raspberrypi_pwm_probe,
+ .remove = raspberrypi_pwm_remove,
+};
+module_platform_driver(raspberrypi_pwm_driver);
+
+MODULE_AUTHOR("Nicolas Saenz Julienne <nsaenzjulienne@suse.de>");
+MODULE_DESCRIPTION("Raspberry Pi Firmware Based PWM Bus Driver");
+MODULE_LICENSE("GPL v2");