[PATCH v8 1/5] pwm: dwc: split pci out of core driver

From: Ben Dooks
Date: Wed Jun 14 2023 - 14:36:40 EST

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Moving towards adding non-pci support for the driver, move the pci
parts out of the core into their own module. This is partly due to
the module_driver() code only being allowed once in a module and also
to avoid a number of #ifdef if we build a single file in a system
without pci support.

Signed-off-by: Ben Dooks <ben.dooks@xxxxxxxxxx>
---
v8:
- add module namespace
- remove compile-test for pci case, doesn't make sense
- fix makefile, missed config symbol changes
v7:
- re-order kconfig to make dwc core be selected by PCI driver
v6:
- put DWC_PERIOD_NS back to avoid bisect issues
v4:
- removed DWC_PERIOD_NS as not needed
---
drivers/pwm/Kconfig | 14 ++-
drivers/pwm/Makefile | 1 +
drivers/pwm/pwm-dwc-core.c | 176 +++++++++++++++++++++++++++++++++
drivers/pwm/pwm-dwc.c | 197 +------------------------------------
drivers/pwm/pwm-dwc.h | 60 +++++++++++
5 files changed, 253 insertions(+), 195 deletions(-)
create mode 100644 drivers/pwm/pwm-dwc-core.c
create mode 100644 drivers/pwm/pwm-dwc.h

diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 8df861b1f4a3..7c54cdcb97a0 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -186,9 +186,19 @@ config PWM_CROS_EC
PWM driver for exposing a PWM attached to the ChromeOS Embedded
Controller.

+config PWM_DWC_CORE
+ tristate
+ depends on HAS_IOMEM
+ help
+ PWM driver for Synopsys DWC PWM Controller.
+
+ To compile this driver as a module, build the dependecies as
+ modules, this will be called pwm-dwc-core.
+
config PWM_DWC
- tristate "DesignWare PWM Controller"
- depends on PCI
+ tristate "DesignWare PWM Controller (PCI bus)"
+ depends on HAS_IOMEM && PCI
+ select PWM_DWC_CORE
help
PWM driver for Synopsys DWC PWM Controller attached to a PCI bus.

diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
index 19899b912e00..de3ed77e8d7c 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_PWM_CLK) += pwm-clk.o
obj-$(CONFIG_PWM_CLPS711X) += pwm-clps711x.o
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-$(CONFIG_PWM_EP93XX) += pwm-ep93xx.o
obj-$(CONFIG_PWM_FSL_FTM) += pwm-fsl-ftm.o
diff --git a/drivers/pwm/pwm-dwc-core.c b/drivers/pwm/pwm-dwc-core.c
new file mode 100644
index 000000000000..b693cb7fa812
--- /dev/null
+++ b/drivers/pwm/pwm-dwc-core.c
@@ -0,0 +1,176 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * DesignWare PWM Controller driver core
+ *
+ * Copyright (C) 2018-2020 Intel Corporation
+ *
+ * Author: Felipe Balbi (Intel)
+ * Author: Jarkko Nikula <jarkko.nikula@xxxxxxxxxxxxxxx>
+ * Author: Raymond Tan <raymond.tan@xxxxxxxxx>
+ */
+
+#define DEFAULT_SYMBOL_NAMESPACE dwc_pwm
+
+#include <linux/bitops.h>
+#include <linux/export.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/pm_runtime.h>
+#include <linux/pwm.h>
+
+#include "pwm-dwc.h"
+
+static void __dwc_pwm_set_enable(struct dwc_pwm *dwc, int pwm, int enabled)
+{
+ u32 reg;
+
+ reg = dwc_pwm_readl(dwc, DWC_TIM_CTRL(pwm));
+
+ if (enabled)
+ reg |= DWC_TIM_CTRL_EN;
+ else
+ reg &= ~DWC_TIM_CTRL_EN;
+
+ dwc_pwm_writel(dwc, reg, DWC_TIM_CTRL(pwm));
+}
+
+static int __dwc_pwm_configure_timer(struct dwc_pwm *dwc,
+ struct pwm_device *pwm,
+ const struct pwm_state *state)
+{
+ u64 tmp;
+ u32 ctrl;
+ u32 high;
+ u32 low;
+
+ /*
+ * Calculate width of low and high period in terms of input clock
+ * periods and check are the result within HW limits between 1 and
+ * 2^32 periods.
+ */
+ tmp = DIV_ROUND_CLOSEST_ULL(state->duty_cycle, DWC_CLK_PERIOD_NS);
+ if (tmp < 1 || tmp > (1ULL << 32))
+ return -ERANGE;
+ low = tmp - 1;
+
+ tmp = DIV_ROUND_CLOSEST_ULL(state->period - state->duty_cycle,
+ DWC_CLK_PERIOD_NS);
+ if (tmp < 1 || tmp > (1ULL << 32))
+ return -ERANGE;
+ high = tmp - 1;
+
+ /*
+ * Specification says timer usage flow is to disable timer, then
+ * program it followed by enable. It also says Load Count is loaded
+ * into timer after it is enabled - either after a disable or
+ * a reset. Based on measurements it happens also without disable
+ * whenever Load Count is updated. But follow the specification.
+ */
+ __dwc_pwm_set_enable(dwc, pwm->hwpwm, false);
+
+ /*
+ * Write Load Count and Load Count 2 registers. Former defines the
+ * width of low period and latter the width of high period in terms
+ * multiple of input clock periods:
+ * Width = ((Count + 1) * input clock period).
+ */
+ dwc_pwm_writel(dwc, low, DWC_TIM_LD_CNT(pwm->hwpwm));
+ dwc_pwm_writel(dwc, high, DWC_TIM_LD_CNT2(pwm->hwpwm));
+
+ /*
+ * Set user-defined mode, timer reloads from Load Count registers
+ * when it counts down to 0.
+ * Set PWM mode, it makes output to toggle and width of low and high
+ * periods are set by Load Count registers.
+ */
+ ctrl = DWC_TIM_CTRL_MODE_USER | DWC_TIM_CTRL_PWM;
+ dwc_pwm_writel(dwc, ctrl, DWC_TIM_CTRL(pwm->hwpwm));
+
+ /*
+ * Enable timer. Output starts from low period.
+ */
+ __dwc_pwm_set_enable(dwc, pwm->hwpwm, state->enabled);
+
+ return 0;
+}
+
+static int dwc_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+ const struct pwm_state *state)
+{
+ struct dwc_pwm *dwc = to_dwc_pwm(chip);
+
+ if (state->polarity != PWM_POLARITY_INVERSED)
+ return -EINVAL;
+
+ if (state->enabled) {
+ if (!pwm->state.enabled)
+ pm_runtime_get_sync(chip->dev);
+ return __dwc_pwm_configure_timer(dwc, pwm, state);
+ } else {
+ if (pwm->state.enabled) {
+ __dwc_pwm_set_enable(dwc, pwm->hwpwm, false);
+ pm_runtime_put_sync(chip->dev);
+ }
+ }
+
+ return 0;
+}
+
+static int dwc_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
+ struct pwm_state *state)
+{
+ struct dwc_pwm *dwc = to_dwc_pwm(chip);
+ u64 duty, period;
+
+ pm_runtime_get_sync(chip->dev);
+
+ state->enabled = !!(dwc_pwm_readl(dwc,
+ DWC_TIM_CTRL(pwm->hwpwm)) & DWC_TIM_CTRL_EN);
+
+ duty = dwc_pwm_readl(dwc, DWC_TIM_LD_CNT(pwm->hwpwm));
+ duty += 1;
+ duty *= DWC_CLK_PERIOD_NS;
+ state->duty_cycle = duty;
+
+ period = dwc_pwm_readl(dwc, DWC_TIM_LD_CNT2(pwm->hwpwm));
+ period += 1;
+ period *= DWC_CLK_PERIOD_NS;
+ period += duty;
+ state->period = period;
+
+ state->polarity = PWM_POLARITY_INVERSED;
+
+ pm_runtime_put_sync(chip->dev);
+
+ return 0;
+}
+
+static const struct pwm_ops dwc_pwm_ops = {
+ .apply = dwc_pwm_apply,
+ .get_state = dwc_pwm_get_state,
+ .owner = THIS_MODULE,
+};
+
+struct dwc_pwm *dwc_pwm_alloc(struct device *dev)
+{
+ struct dwc_pwm *dwc;
+
+ dwc = devm_kzalloc(dev, sizeof(*dwc), GFP_KERNEL);
+ if (!dwc)
+ return NULL;
+
+ dwc->chip.dev = dev;
+ dwc->chip.ops = &dwc_pwm_ops;
+ dwc->chip.npwm = DWC_TIMERS_TOTAL;
+
+ dev_set_drvdata(dev, dwc);
+ return dwc;
+}
+EXPORT_SYMBOL_GPL(dwc_pwm_alloc);
+
+MODULE_AUTHOR("Felipe Balbi (Intel)");
+MODULE_AUTHOR("Jarkko Nikula <jarkko.nikula@xxxxxxxxxxxxxxx>");
+MODULE_AUTHOR("Raymond Tan <raymond.tan@xxxxxxxxx>");
+MODULE_DESCRIPTION("DesignWare PWM Controller");
+MODULE_LICENSE("GPL");
diff --git a/drivers/pwm/pwm-dwc.c b/drivers/pwm/pwm-dwc.c
index 3bbb26c862c3..bd9cadb497d7 100644
--- a/drivers/pwm/pwm-dwc.c
+++ b/drivers/pwm/pwm-dwc.c
@@ -1,6 +1,6 @@
// SPDX-License-Identifier: GPL-2.0
/*
- * DesignWare PWM Controller driver
+ * DesignWare PWM Controller driver (PCI part)
*
* Copyright (C) 2018-2020 Intel Corporation
*
@@ -13,6 +13,8 @@
* periods are one or more input clock periods long.
*/

+#define DEFAULT_MOUDLE_NAMESPACE dwc_pwm
+
#include <linux/bitops.h>
#include <linux/export.h>
#include <linux/kernel.h>
@@ -21,198 +23,7 @@
#include <linux/pm_runtime.h>
#include <linux/pwm.h>

-#define DWC_TIM_LD_CNT(n) ((n) * 0x14)
-#define DWC_TIM_LD_CNT2(n) (((n) * 4) + 0xb0)
-#define DWC_TIM_CUR_VAL(n) (((n) * 0x14) + 0x04)
-#define DWC_TIM_CTRL(n) (((n) * 0x14) + 0x08)
-#define DWC_TIM_EOI(n) (((n) * 0x14) + 0x0c)
-#define DWC_TIM_INT_STS(n) (((n) * 0x14) + 0x10)
-
-#define DWC_TIMERS_INT_STS 0xa0
-#define DWC_TIMERS_EOI 0xa4
-#define DWC_TIMERS_RAW_INT_STS 0xa8
-#define DWC_TIMERS_COMP_VERSION 0xac
-
-#define DWC_TIMERS_TOTAL 8
-#define DWC_CLK_PERIOD_NS 10
-
-/* Timer Control Register */
-#define DWC_TIM_CTRL_EN BIT(0)
-#define DWC_TIM_CTRL_MODE BIT(1)
-#define DWC_TIM_CTRL_MODE_FREE (0 << 1)
-#define DWC_TIM_CTRL_MODE_USER (1 << 1)
-#define DWC_TIM_CTRL_INT_MASK BIT(2)
-#define DWC_TIM_CTRL_PWM BIT(3)
-
-struct dwc_pwm_ctx {
- u32 cnt;
- u32 cnt2;
- u32 ctrl;
-};
-
-struct dwc_pwm {
- struct pwm_chip chip;
- void __iomem *base;
- struct dwc_pwm_ctx ctx[DWC_TIMERS_TOTAL];
-};
-#define to_dwc_pwm(p) (container_of((p), struct dwc_pwm, chip))
-
-static inline u32 dwc_pwm_readl(struct dwc_pwm *dwc, u32 offset)
-{
- return readl(dwc->base + offset);
-}
-
-static inline void dwc_pwm_writel(struct dwc_pwm *dwc, u32 value, u32 offset)
-{
- writel(value, dwc->base + offset);
-}
-
-static void __dwc_pwm_set_enable(struct dwc_pwm *dwc, int pwm, int enabled)
-{
- u32 reg;
-
- reg = dwc_pwm_readl(dwc, DWC_TIM_CTRL(pwm));
-
- if (enabled)
- reg |= DWC_TIM_CTRL_EN;
- else
- reg &= ~DWC_TIM_CTRL_EN;
-
- dwc_pwm_writel(dwc, reg, DWC_TIM_CTRL(pwm));
-}
-
-static int __dwc_pwm_configure_timer(struct dwc_pwm *dwc,
- struct pwm_device *pwm,
- const struct pwm_state *state)
-{
- u64 tmp;
- u32 ctrl;
- u32 high;
- u32 low;
-
- /*
- * Calculate width of low and high period in terms of input clock
- * periods and check are the result within HW limits between 1 and
- * 2^32 periods.
- */
- tmp = DIV_ROUND_CLOSEST_ULL(state->duty_cycle, DWC_CLK_PERIOD_NS);
- if (tmp < 1 || tmp > (1ULL << 32))
- return -ERANGE;
- low = tmp - 1;
-
- tmp = DIV_ROUND_CLOSEST_ULL(state->period - state->duty_cycle,
- DWC_CLK_PERIOD_NS);
- if (tmp < 1 || tmp > (1ULL << 32))
- return -ERANGE;
- high = tmp - 1;
-
- /*
- * Specification says timer usage flow is to disable timer, then
- * program it followed by enable. It also says Load Count is loaded
- * into timer after it is enabled - either after a disable or
- * a reset. Based on measurements it happens also without disable
- * whenever Load Count is updated. But follow the specification.
- */
- __dwc_pwm_set_enable(dwc, pwm->hwpwm, false);
-
- /*
- * Write Load Count and Load Count 2 registers. Former defines the
- * width of low period and latter the width of high period in terms
- * multiple of input clock periods:
- * Width = ((Count + 1) * input clock period).
- */
- dwc_pwm_writel(dwc, low, DWC_TIM_LD_CNT(pwm->hwpwm));
- dwc_pwm_writel(dwc, high, DWC_TIM_LD_CNT2(pwm->hwpwm));
-
- /*
- * Set user-defined mode, timer reloads from Load Count registers
- * when it counts down to 0.
- * Set PWM mode, it makes output to toggle and width of low and high
- * periods are set by Load Count registers.
- */
- ctrl = DWC_TIM_CTRL_MODE_USER | DWC_TIM_CTRL_PWM;
- dwc_pwm_writel(dwc, ctrl, DWC_TIM_CTRL(pwm->hwpwm));
-
- /*
- * Enable timer. Output starts from low period.
- */
- __dwc_pwm_set_enable(dwc, pwm->hwpwm, state->enabled);
-
- return 0;
-}
-
-static int dwc_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
- const struct pwm_state *state)
-{
- struct dwc_pwm *dwc = to_dwc_pwm(chip);
-
- if (state->polarity != PWM_POLARITY_INVERSED)
- return -EINVAL;
-
- if (state->enabled) {
- if (!pwm->state.enabled)
- pm_runtime_get_sync(chip->dev);
- return __dwc_pwm_configure_timer(dwc, pwm, state);
- } else {
- if (pwm->state.enabled) {
- __dwc_pwm_set_enable(dwc, pwm->hwpwm, false);
- pm_runtime_put_sync(chip->dev);
- }
- }
-
- return 0;
-}
-
-static int dwc_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
- struct pwm_state *state)
-{
- struct dwc_pwm *dwc = to_dwc_pwm(chip);
- u64 duty, period;
-
- pm_runtime_get_sync(chip->dev);
-
- state->enabled = !!(dwc_pwm_readl(dwc,
- DWC_TIM_CTRL(pwm->hwpwm)) & DWC_TIM_CTRL_EN);
-
- duty = dwc_pwm_readl(dwc, DWC_TIM_LD_CNT(pwm->hwpwm));
- duty += 1;
- duty *= DWC_CLK_PERIOD_NS;
- state->duty_cycle = duty;
-
- period = dwc_pwm_readl(dwc, DWC_TIM_LD_CNT2(pwm->hwpwm));
- period += 1;
- period *= DWC_CLK_PERIOD_NS;
- period += duty;
- state->period = period;
-
- state->polarity = PWM_POLARITY_INVERSED;
-
- pm_runtime_put_sync(chip->dev);
-
- return 0;
-}
-
-static const struct pwm_ops dwc_pwm_ops = {
- .apply = dwc_pwm_apply,
- .get_state = dwc_pwm_get_state,
- .owner = THIS_MODULE,
-};
-
-static struct dwc_pwm *dwc_pwm_alloc(struct device *dev)
-{
- struct dwc_pwm *dwc;
-
- dwc = devm_kzalloc(dev, sizeof(*dwc), GFP_KERNEL);
- if (!dwc)
- return NULL;
-
- dwc->chip.dev = dev;
- dwc->chip.ops = &dwc_pwm_ops;
- dwc->chip.npwm = DWC_TIMERS_TOTAL;
-
- dev_set_drvdata(dev, dwc);
- return dwc;
-}
+#include "pwm-dwc.h"

static int dwc_pwm_probe(struct pci_dev *pci, const struct pci_device_id *id)
{
diff --git a/drivers/pwm/pwm-dwc.h b/drivers/pwm/pwm-dwc.h
new file mode 100644
index 000000000000..56deab4e28ec
--- /dev/null
+++ b/drivers/pwm/pwm-dwc.h
@@ -0,0 +1,60 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * DesignWare PWM Controller driver
+ *
+ * Copyright (C) 2018-2020 Intel Corporation
+ *
+ * Author: Felipe Balbi (Intel)
+ * Author: Jarkko Nikula <jarkko.nikula@xxxxxxxxxxxxxxx>
+ * Author: Raymond Tan <raymond.tan@xxxxxxxxx>
+ */
+
+MODULE_IMPORT_NS(dwc_pwm);
+
+#define DWC_TIM_LD_CNT(n) ((n) * 0x14)
+#define DWC_TIM_LD_CNT2(n) (((n) * 4) + 0xb0)
+#define DWC_TIM_CUR_VAL(n) (((n) * 0x14) + 0x04)
+#define DWC_TIM_CTRL(n) (((n) * 0x14) + 0x08)
+#define DWC_TIM_EOI(n) (((n) * 0x14) + 0x0c)
+#define DWC_TIM_INT_STS(n) (((n) * 0x14) + 0x10)
+
+#define DWC_TIMERS_INT_STS 0xa0
+#define DWC_TIMERS_EOI 0xa4
+#define DWC_TIMERS_RAW_INT_STS 0xa8
+#define DWC_TIMERS_COMP_VERSION 0xac
+
+#define DWC_TIMERS_TOTAL 8
+#define DWC_CLK_PERIOD_NS 10
+
+/* Timer Control Register */
+#define DWC_TIM_CTRL_EN BIT(0)
+#define DWC_TIM_CTRL_MODE BIT(1)
+#define DWC_TIM_CTRL_MODE_FREE (0 << 1)
+#define DWC_TIM_CTRL_MODE_USER (1 << 1)
+#define DWC_TIM_CTRL_INT_MASK BIT(2)
+#define DWC_TIM_CTRL_PWM BIT(3)
+
+struct dwc_pwm_ctx {
+ u32 cnt;
+ u32 cnt2;
+ u32 ctrl;
+};
+
+struct dwc_pwm {
+ struct pwm_chip chip;
+ void __iomem *base;
+ struct dwc_pwm_ctx ctx[DWC_TIMERS_TOTAL];
+};
+#define to_dwc_pwm(p) (container_of((p), struct dwc_pwm, chip))
+
+static inline u32 dwc_pwm_readl(struct dwc_pwm *dwc, u32 offset)
+{
+ return readl(dwc->base + offset);
+}
+
+static inline void dwc_pwm_writel(struct dwc_pwm *dwc, u32 value, u32 offset)
+{
+ writel(value, dwc->base + offset);
+}
+
+extern struct dwc_pwm *dwc_pwm_alloc(struct device *dev);
--
2.39.2

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