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Message-Id: <20230907161242.67190-7-ben.dooks@codethink.co.uk>
Date: Thu, 7 Sep 2023 17:12:42 +0100
From: Ben Dooks <ben.dooks@...ethink.co.uk>
To: linux-pwm@...r.kernel.org
Cc: devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
ben.dooks@...ethink.co.uk, u.kleine-koenig@...gutronix.de,
Thierry Reding <thierry.reding@...il.com>,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
Greentime Hu <greentime.hu@...ive.com>,
jarkko.nikula@...ux.intel.com,
William Salmon <william.salmon@...ive.com>,
Jude Onyenegecha <jude.onyenegecha@...ive.com>
Subject: [PATCH v9 6/6] pwm: dwc: add of/platform support
The dwc pwm controller can be used in non-PCI systems, so allow
either platform or OF based probing.
Signed-off-by: Ben Dooks <ben.dooks@...ethink.co.uk>
---
v9:
- add clk_rate_exclusive_get() to lock clock rate for now
- fix email address from sifive to codethink
- fix module namespace
v8:
- add compile test for of-case
- add module namespace
- move later in the series
v7:
- fixup kconfig from previous pcie changes
v5:
- fix missing " in kconfig
- remove .remove method, devm already sorts this.
- merge pwm-number code
- split the of code out of the core
- get bus clock
v4:
- moved the compile test code earlier
- fixed review comments
- used NS_PER_SEC
- use devm_clk_get_enabled
- ensure we get the bus clock
v3:
- changed compatible name
---
drivers/pwm/Kconfig | 10 ++++
drivers/pwm/Makefile | 1 +
drivers/pwm/pwm-dwc-core.c | 6 +++
drivers/pwm/pwm-dwc-of.c | 93 ++++++++++++++++++++++++++++++++++++++
drivers/pwm/pwm-dwc.c | 1 +
drivers/pwm/pwm-dwc.h | 1 +
6 files changed, 112 insertions(+)
create mode 100644 drivers/pwm/pwm-dwc-of.c
diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 507c8b8547a5..22d58cb334e7 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -205,6 +205,16 @@ config PWM_DWC
To compile this driver as a module, choose M here: the module
will be called pwm-dwc.
+config PWM_DWC_OF
+ tristate "DesignWare PWM Controller (OF bus)"
+ depends on HAS_IOMEM && (OF || COMPILE_TEST)
+ select PWM_DWC_CORE
+ help
+ PWM driver for Synopsys DWC PWM Controller on an OF bus.
+
+ To compile this driver as a module, choose M here: the module
+ will be called pwm-dwc-of.
+
config PWM_EP93XX
tristate "Cirrus Logic EP93xx PWM support"
depends on ARCH_EP93XX || COMPILE_TEST
diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
index c5ec9e168ee7..e3c867cb13d1 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -17,6 +17,7 @@ obj-$(CONFIG_PWM_CRC) += pwm-crc.o
obj-$(CONFIG_PWM_CROS_EC) += pwm-cros-ec.o
obj-$(CONFIG_PWM_DWC_CORE) += pwm-dwc-core.o
obj-$(CONFIG_PWM_DWC) += pwm-dwc.o
+obj-$(CONFIG_PWM_DWC_OF) += pwm-dwc-of.o
obj-$(CONFIG_PWM_EP93XX) += pwm-ep93xx.o
obj-$(CONFIG_PWM_FSL_FTM) += pwm-fsl-ftm.o
obj-$(CONFIG_PWM_HIBVT) += pwm-hibvt.o
diff --git a/drivers/pwm/pwm-dwc-core.c b/drivers/pwm/pwm-dwc-core.c
index 6358e3345210..8b4d96d655c7 100644
--- a/drivers/pwm/pwm-dwc-core.c
+++ b/drivers/pwm/pwm-dwc-core.c
@@ -16,6 +16,7 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
+#include <linux/clk.h>
#include <linux/pm_runtime.h>
#include <linux/pwm.h>
@@ -44,6 +45,9 @@ static int __dwc_pwm_configure_timer(struct dwc_pwm *dwc,
u32 high;
u32 low;
+ if (dwc->clk)
+ dwc->clk_rate = clk_get_rate(dwc->clk);
+
/*
* Calculate width of low and high period in terms of input clock
* periods and check are the result within HW limits between 1 and
@@ -128,6 +132,8 @@ static int dwc_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
pm_runtime_get_sync(chip->dev);
+ if (dwc->clk)
+ dwc->clk_rate = clk_get_rate(dwc->clk);
clk_rate = dwc->clk_rate;
ctrl = dwc_pwm_readl(dwc, DWC_TIM_CTRL(pwm->hwpwm));
diff --git a/drivers/pwm/pwm-dwc-of.c b/drivers/pwm/pwm-dwc-of.c
new file mode 100644
index 000000000000..30b860484895
--- /dev/null
+++ b/drivers/pwm/pwm-dwc-of.c
@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * DesignWare PWM Controller driver OF
+ *
+ * Copyright (C) 2022 SiFive, Inc.
+ */
+
+#define DEFAULT_MODULE_NAMESPACE dwc_pwm
+
+#include <linux/bitops.h>
+#include <linux/export.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/clk.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/pwm.h>
+#include <linux/io.h>
+
+#include "pwm-dwc.h"
+
+static int dwc_pwm_plat_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct dwc_pwm *dwc;
+ struct clk *bus;
+ u32 nr_pwm;
+ int ret;
+
+ dwc = dwc_pwm_alloc(dev);
+ if (!dwc)
+ return -ENOMEM;
+
+ if (!device_property_read_u32(dev, "snps,pwm-number", &nr_pwm)) {
+ if (nr_pwm > DWC_TIMERS_TOTAL)
+ dev_err(dev, "too many PWMs (%d) specified, capping at %d\n",
+ nr_pwm, dwc->chip.npwm);
+ else
+ dwc->chip.npwm = nr_pwm;
+ }
+
+ dwc->base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(dwc->base))
+ return PTR_ERR(dwc->base);
+
+ bus = devm_clk_get_enabled(dev, NULL);
+ if (IS_ERR(bus))
+ return dev_err_probe(dev, PTR_ERR(bus),
+ "failed to get clock\n");
+
+ dwc->clk = devm_clk_get_enabled(dev, "timer");
+ if (IS_ERR(dwc->clk))
+ return dev_err_probe(dev, PTR_ERR(dwc->clk),
+ "failed to get timer clock\n");
+
+ ret = clk_rate_exclusive_get(dwc->clk);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "clk_rate_exclusive_get() failed\n");
+
+ dwc->clk_rate = clk_get_rate(dwc->clk);
+ return devm_pwmchip_add(dev, &dwc->chip);
+}
+
+static int dwc_pwm_plat_remove(struct platform_device *pdev)
+{
+ struct dwc_pwm *dwc = dev_get_drvdata(&pdev->dev);
+
+ clk_rate_exclusive_put(dwc->clk);
+ return 0;
+}
+
+static const struct of_device_id dwc_pwm_dt_ids[] = {
+ { .compatible = "snps,dw-apb-timers-pwm2" },
+ { },
+};
+MODULE_DEVICE_TABLE(of, dwc_pwm_dt_ids);
+
+static struct platform_driver dwc_pwm_plat_driver = {
+ .driver = {
+ .name = "dwc-pwm",
+ .of_match_table = dwc_pwm_dt_ids,
+ },
+ .probe = dwc_pwm_plat_probe,
+ .remove = dwc_pwm_plat_remove,
+};
+
+module_platform_driver(dwc_pwm_plat_driver);
+
+MODULE_ALIAS("platform:dwc-pwm-of");
+MODULE_AUTHOR("Ben Dooks <ben.dooks@...ethink.co.uk>");
+MODULE_DESCRIPTION("DesignWare PWM Controller");
+MODULE_LICENSE("GPL");
diff --git a/drivers/pwm/pwm-dwc.c b/drivers/pwm/pwm-dwc.c
index bd9cadb497d7..7c32bd06ed33 100644
--- a/drivers/pwm/pwm-dwc.c
+++ b/drivers/pwm/pwm-dwc.c
@@ -20,6 +20,7 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
+#include <linux/clk.h>
#include <linux/pm_runtime.h>
#include <linux/pwm.h>
diff --git a/drivers/pwm/pwm-dwc.h b/drivers/pwm/pwm-dwc.h
index e0a940fd6e87..18e98c2c07d7 100644
--- a/drivers/pwm/pwm-dwc.h
+++ b/drivers/pwm/pwm-dwc.h
@@ -42,6 +42,7 @@ struct dwc_pwm_ctx {
struct dwc_pwm {
struct pwm_chip chip;
void __iomem *base;
+ struct clk *clk;
unsigned long clk_rate;
struct dwc_pwm_ctx ctx[DWC_TIMERS_TOTAL];
};
--
2.40.1
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