2018-06-24 12:47:15

by Tomer Maimon

[permalink] [raw]
Subject: [PATCH v4 0/2] hwmon: Add NPCM7xx PWM and Fan driver support

This patch set adds Pulse Width Modulation (PWM) and Fan tacho
support for the Nuvoton NPCM750/730/715/705 Baseboard Management
Controller (BMC).

The Nuvoton BMC NPCM750/730/715/705 has two identical PWM controller
modules, each module has four PWM controller outputs and eight identical
Fan controller modules, each module has two Fan controller inputs.

The hwmon driver provides sysfs entries through which the user can
configure and get the duty cycle between 0 (disable the specific PWM)
to 255 of particular PWM output port.

The driver support cooling device creation, that could be bound
to a thermal zone for the thermal control.

The NPCM750 PWM and Fan driver tested on NPCM750 evaluation board.

Addressed comments from:.
- Guenter Roeck: https://www.spinics.net/lists/devicetree/msg235294.html

Changes since version 3:
- Fixing incorrect word spelling.
- Removing npcm7xx_ in variable declarations.
- All variable declarations in structure on a single line.
- Removing variable unnecessary initialization.
- dt-binding documentation haven't changed.

Changes since version 2:
- Adding hwmon documentation
- Using dev_function instead pr_function
- Removing all typecast
- Removing unused definitions
- Adding () in macros parameters.
- dt-binding documentation haven't changed

Changes since version 1:
- Rename driver name
- Adding Fan Controller support
- Adding cooling device support
- Modifying dt-binding documentation for Fan and cooling binding

Tomer Maimon (2):
dt-binding: hwmon: Add NPCM7xx PWM and Fan controller documentation
hwmon: npcm750: add NPCM7xx PWM and Fan driver

.../devicetree/bindings/hwmon/npcm750-pwm-fan.txt | 84 ++
Documentation/hwmon/npcm750-pwm-fan | 22 +
drivers/hwmon/Kconfig | 7 +
drivers/hwmon/Makefile | 1 +
drivers/hwmon/npcm750-pwm-fan.c | 1070 ++++++++++++++++++++
5 files changed, 1184 insertions(+)
create mode 100644 Documentation/devicetree/bindings/hwmon/npcm750-pwm-fan.txt
create mode 100644 Documentation/hwmon/npcm750-pwm-fan
create mode 100644 drivers/hwmon/npcm750-pwm-fan.c

--
2.14.1



2018-06-24 12:45:20

by Tomer Maimon

[permalink] [raw]
Subject: [PATCH v4 2/2] hwmon: npcm750: add NPCM7xx PWM and Fan driver

Add Nuvoton BMC NPCM750/730/715/705 Pulse Width Modulation (PWM)
and Fan tacho driver.

The Nuvoton BMC NPCM750/730/715/705 has two identical PWM controller
modules, each module has four PWM controller outputs and
eight identical Fan controller modules, each module has two
Fan controller inputs.

The driver provides a sysfs entries through which the user can
configure the duty-cycle value from 0(off) and 255(full speed)
and read the fan tacho rpm value.

The driver support cooling device creation, that could be bound
to a thermal zone for the thermal control.

Signed-off-by: Tomer Maimon <[email protected]>
---
Documentation/hwmon/npcm750-pwm-fan | 22 +
drivers/hwmon/Kconfig | 7 +
drivers/hwmon/Makefile | 1 +
drivers/hwmon/npcm750-pwm-fan.c | 1070 +++++++++++++++++++++++++++++++++++
4 files changed, 1100 insertions(+)
create mode 100644 Documentation/hwmon/npcm750-pwm-fan
create mode 100644 drivers/hwmon/npcm750-pwm-fan.c

diff --git a/Documentation/hwmon/npcm750-pwm-fan b/Documentation/hwmon/npcm750-pwm-fan
new file mode 100644
index 000000000000..3cecd4a830fe
--- /dev/null
+++ b/Documentation/hwmon/npcm750-pwm-fan
@@ -0,0 +1,22 @@
+Kernel driver npcm750-pwm-fan
+=============================
+
+Supported chip:
+ NUVOTON NPCM750/730/715/705
+
+Authors:
+ <[email protected]>
+
+Description:
+------------
+This driver implements support for NUVOTON NPCM7XX PWM and Fan Tacho
+controller. The PWM controller supports upto 8 PWM outputs. The Fan tacho
+controller supports up to 16 tachometer inputs.
+
+The driver provides the following sensor accesses in sysfs:
+
+fanX_input ro provide current fan rotation value in RPM as reported
+ by the fan to the device.
+
+pwmX rw get or set PWM fan control value. This is an integer
+ value between 0(off) and 255(full speed).
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index f10840ad465c..f6c2eff9bb7d 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1888,6 +1888,13 @@ config SENSORS_XGENE
If you say yes here you get support for the temperature
and power sensors for APM X-Gene SoC.

+config SENSORS_NPCM7XX
+ tristate "Nuvoton NPCM7XX PWM and Fan driver"
+ depends on THERMAL || THERMAL=n
+ help
+ This driver provides support for Nuvoton NPCM7XX PWM and Fan
+ controllers.
+
if ACPI

comment "ACPI drivers"
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index e7d52a36e6c4..004e2ec5b68f 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -174,6 +174,7 @@ obj-$(CONFIG_SENSORS_W83L786NG) += w83l786ng.o
obj-$(CONFIG_SENSORS_WM831X) += wm831x-hwmon.o
obj-$(CONFIG_SENSORS_WM8350) += wm8350-hwmon.o
obj-$(CONFIG_SENSORS_XGENE) += xgene-hwmon.o
+obj-$(CONFIG_SENSORS_NPCM7XX) += npcm750-pwm-fan.o

obj-$(CONFIG_PMBUS) += pmbus/

diff --git a/drivers/hwmon/npcm750-pwm-fan.c b/drivers/hwmon/npcm750-pwm-fan.c
new file mode 100644
index 000000000000..474c165c35f9
--- /dev/null
+++ b/drivers/hwmon/npcm750-pwm-fan.c
@@ -0,0 +1,1070 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2014-2018 Nuvoton Technology corporation.
+
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/spinlock.h>
+#include <linux/sysfs.h>
+#include <linux/thermal.h>
+
+/* NPCM7XX PWM registers */
+#define NPCM7XX_PWM_REG_BASE(base, n) ((base) + ((n) * 0x1000L))
+
+#define NPCM7XX_PWM_REG_PR(base, n) (NPCM7XX_PWM_REG_BASE(base, n) + 0x00)
+#define NPCM7XX_PWM_REG_CSR(base, n) (NPCM7XX_PWM_REG_BASE(base, n) + 0x04)
+#define NPCM7XX_PWM_REG_CR(base, n) (NPCM7XX_PWM_REG_BASE(base, n) + 0x08)
+#define NPCM7XX_PWM_REG_CNRx(base, n, ch) \
+ (NPCM7XX_PWM_REG_BASE(base, n) + 0x0C + (12 * (ch)))
+#define NPCM7XX_PWM_REG_CMRx(base, n, ch) \
+ (NPCM7XX_PWM_REG_BASE(base, n) + 0x10 + (12 * (ch)))
+#define NPCM7XX_PWM_REG_PDRx(base, n, ch) \
+ (NPCM7XX_PWM_REG_BASE(base, n) + 0x14 + (12 * (ch)))
+#define NPCM7XX_PWM_REG_PIER(base, n) (NPCM7XX_PWM_REG_BASE(base, n) + 0x3C)
+#define NPCM7XX_PWM_REG_PIIR(base, n) (NPCM7XX_PWM_REG_BASE(base, n) + 0x40)
+
+#define NPCM7XX_PWM_CTRL_CH0_MODE_BIT BIT(3)
+#define NPCM7XX_PWM_CTRL_CH1_MODE_BIT BIT(11)
+#define NPCM7XX_PWM_CTRL_CH2_MODE_BIT BIT(15)
+#define NPCM7XX_PWM_CTRL_CH3_MODE_BIT BIT(19)
+
+#define NPCM7XX_PWM_CTRL_CH0_INV_BIT BIT(2)
+#define NPCM7XX_PWM_CTRL_CH1_INV_BIT BIT(10)
+#define NPCM7XX_PWM_CTRL_CH2_INV_BIT BIT(14)
+#define NPCM7XX_PWM_CTRL_CH3_INV_BIT BIT(18)
+
+#define NPCM7XX_PWM_CTRL_CH0_EN_BIT BIT(0)
+#define NPCM7XX_PWM_CTRL_CH1_EN_BIT BIT(8)
+#define NPCM7XX_PWM_CTRL_CH2_EN_BIT BIT(12)
+#define NPCM7XX_PWM_CTRL_CH3_EN_BIT BIT(16)
+
+/* Define the maximum PWM channel number */
+#define NPCM7XX_PWM_MAX_CHN_NUM 8
+#define NPCM7XX_PWM_MAX_CHN_NUM_IN_A_MODULE 4
+#define NPCM7XX_PWM_MAX_MODULES 2
+
+/* Define the Counter Register, value = 100 for match 100% */
+#define NPCM7XX_PWM_COUNTER_DEFAULT_NUM 255
+#define NPCM7XX_PWM_COMPARATOR_DEFAULT_NUM 127
+
+#define NPCM7XX_PWM_COMPARATOR_MAX 255
+
+/* default all PWM channels PRESCALE2 = 1 */
+#define NPCM7XX_PWM_PRESCALE2_DEFAULT_CH0 0x4
+#define NPCM7XX_PWM_PRESCALE2_DEFAULT_CH1 0x40
+#define NPCM7XX_PWM_PRESCALE2_DEFAULT_CH2 0x400
+#define NPCM7XX_PWM_PRESCALE2_DEFAULT_CH3 0x4000
+
+#define PWM_OUTPUT_FREQ_25KHZ 25000
+#define PWN_CNT_DEFAULT 256
+#define MIN_PRESCALE1 2
+#define NPCM7XX_PWM_PRESCALE_SHIFT_CH01 8
+
+#define NPCM7XX_PWM_PRESCALE2_DEFAULT (NPCM7XX_PWM_PRESCALE2_DEFAULT_CH0 | \
+ NPCM7XX_PWM_PRESCALE2_DEFAULT_CH1 | \
+ NPCM7XX_PWM_PRESCALE2_DEFAULT_CH2 | \
+ NPCM7XX_PWM_PRESCALE2_DEFAULT_CH3)
+
+#define NPCM7XX_PWM_CTRL_MODE_DEFAULT (NPCM7XX_PWM_CTRL_CH0_MODE_BIT | \
+ NPCM7XX_PWM_CTRL_CH1_MODE_BIT | \
+ NPCM7XX_PWM_CTRL_CH2_MODE_BIT | \
+ NPCM7XX_PWM_CTRL_CH3_MODE_BIT)
+
+/* NPCM7XX FAN Tacho registers */
+#define NPCM7XX_FAN_REG_BASE(base, n) ((base) + ((n) * 0x1000L))
+
+#define NPCM7XX_FAN_REG_TCNT1(base, n) (NPCM7XX_FAN_REG_BASE(base, n) + 0x00)
+#define NPCM7XX_FAN_REG_TCRA(base, n) (NPCM7XX_FAN_REG_BASE(base, n) + 0x02)
+#define NPCM7XX_FAN_REG_TCRB(base, n) (NPCM7XX_FAN_REG_BASE(base, n) + 0x04)
+#define NPCM7XX_FAN_REG_TCNT2(base, n) (NPCM7XX_FAN_REG_BASE(base, n) + 0x06)
+#define NPCM7XX_FAN_REG_TPRSC(base, n) (NPCM7XX_FAN_REG_BASE(base, n) + 0x08)
+#define NPCM7XX_FAN_REG_TCKC(base, n) (NPCM7XX_FAN_REG_BASE(base, n) + 0x0A)
+#define NPCM7XX_FAN_REG_TMCTRL(base, n) (NPCM7XX_FAN_REG_BASE(base, n) + 0x0C)
+#define NPCM7XX_FAN_REG_TICTRL(base, n) (NPCM7XX_FAN_REG_BASE(base, n) + 0x0E)
+#define NPCM7XX_FAN_REG_TICLR(base, n) (NPCM7XX_FAN_REG_BASE(base, n) + 0x10)
+#define NPCM7XX_FAN_REG_TIEN(base, n) (NPCM7XX_FAN_REG_BASE(base, n) + 0x12)
+#define NPCM7XX_FAN_REG_TCPA(base, n) (NPCM7XX_FAN_REG_BASE(base, n) + 0x14)
+#define NPCM7XX_FAN_REG_TCPB(base, n) (NPCM7XX_FAN_REG_BASE(base, n) + 0x16)
+#define NPCM7XX_FAN_REG_TCPCFG(base, n) (NPCM7XX_FAN_REG_BASE(base, n) + 0x18)
+#define NPCM7XX_FAN_REG_TINASEL(base, n) (NPCM7XX_FAN_REG_BASE(base, n) + 0x1A)
+#define NPCM7XX_FAN_REG_TINBSEL(base, n) (NPCM7XX_FAN_REG_BASE(base, n) + 0x1C)
+
+#define NPCM7XX_FAN_TCKC_CLKX_NONE 0
+#define NPCM7XX_FAN_TCKC_CLK1_APB BIT(0)
+#define NPCM7XX_FAN_TCKC_CLK2_APB BIT(3)
+
+#define NPCM7XX_FAN_TMCTRL_TBEN BIT(6)
+#define NPCM7XX_FAN_TMCTRL_TAEN BIT(5)
+#define NPCM7XX_FAN_TMCTRL_TBEDG BIT(4)
+#define NPCM7XX_FAN_TMCTRL_TAEDG BIT(3)
+#define NPCM7XX_FAN_TMCTRL_MODE_5 BIT(2)
+
+#define NPCM7XX_FAN_TICLR_CLEAR_ALL GENMASK(5, 0)
+#define NPCM7XX_FAN_TICLR_TFCLR BIT(5)
+#define NPCM7XX_FAN_TICLR_TECLR BIT(4)
+#define NPCM7XX_FAN_TICLR_TDCLR BIT(3)
+#define NPCM7XX_FAN_TICLR_TCCLR BIT(2)
+#define NPCM7XX_FAN_TICLR_TBCLR BIT(1)
+#define NPCM7XX_FAN_TICLR_TACLR BIT(0)
+
+#define NPCM7XX_FAN_TIEN_ENABLE_ALL GENMASK(5, 0)
+#define NPCM7XX_FAN_TIEN_TFIEN BIT(5)
+#define NPCM7XX_FAN_TIEN_TEIEN BIT(4)
+#define NPCM7XX_FAN_TIEN_TDIEN BIT(3)
+#define NPCM7XX_FAN_TIEN_TCIEN BIT(2)
+#define NPCM7XX_FAN_TIEN_TBIEN BIT(1)
+#define NPCM7XX_FAN_TIEN_TAIEN BIT(0)
+
+#define NPCM7XX_FAN_TICTRL_TFPND BIT(5)
+#define NPCM7XX_FAN_TICTRL_TEPND BIT(4)
+#define NPCM7XX_FAN_TICTRL_TDPND BIT(3)
+#define NPCM7XX_FAN_TICTRL_TCPND BIT(2)
+#define NPCM7XX_FAN_TICTRL_TBPND BIT(1)
+#define NPCM7XX_FAN_TICTRL_TAPND BIT(0)
+
+#define NPCM7XX_FAN_TCPCFG_HIBEN BIT(7)
+#define NPCM7XX_FAN_TCPCFG_EQBEN BIT(6)
+#define NPCM7XX_FAN_TCPCFG_LOBEN BIT(5)
+#define NPCM7XX_FAN_TCPCFG_CPBSEL BIT(4)
+#define NPCM7XX_FAN_TCPCFG_HIAEN BIT(3)
+#define NPCM7XX_FAN_TCPCFG_EQAEN BIT(2)
+#define NPCM7XX_FAN_TCPCFG_LOAEN BIT(1)
+#define NPCM7XX_FAN_TCPCFG_CPASEL BIT(0)
+
+/* FAN General Definition */
+/* Define the maximum FAN channel number */
+#define NPCM7XX_FAN_MAX_MODULE 8
+#define NPCM7XX_FAN_MAX_CHN_NUM_IN_A_MODULE 2
+#define NPCM7XX_FAN_MAX_CHN_NUM 16
+
+/*
+ * Get Fan Tach Timeout (base on clock 214843.75Hz, 1 cnt = 4.654us)
+ * Timeout 94ms ~= 0x5000
+ * (The minimum FAN speed could to support ~640RPM/pulse 1,
+ * 320RPM/pulse 2, ...-- 10.6Hz)
+ */
+#define NPCM7XX_FAN_TIMEOUT 0x5000
+#define NPCM7XX_FAN_TCNT 0xFFFF
+#define NPCM7XX_FAN_TCPA (NPCM7XX_FAN_TCNT - NPCM7XX_FAN_TIMEOUT)
+#define NPCM7XX_FAN_TCPB (NPCM7XX_FAN_TCNT - NPCM7XX_FAN_TIMEOUT)
+
+#define NPCM7XX_FAN_POLL_TIMER_200MS 200
+#define NPCM7XX_FAN_DEFAULT_PULSE_PER_REVOLUTION 2
+#define NPCM7XX_FAN_TINASEL_FANIN_DEFAULT 0
+#define NPCM7XX_FAN_CLK_PRESCALE 255
+
+#define NPCM7XX_FAN_CMPA 0
+#define NPCM7XX_FAN_CMPB 1
+
+/* Obtain the fan number */
+#define NPCM7XX_FAN_INPUT(fan, cmp) (((fan) << 1) + (cmp))
+
+/* fan sample status */
+#define FAN_DISABLE 0xFF
+#define FAN_INIT 0x00
+#define FAN_PREPARE_TO_GET_FIRST_CAPTURE 0x01
+#define FAN_ENOUGH_SAMPLE 0x02
+
+struct npcm7xx_fan_dev {
+ u8 fan_st_flg;
+ u8 fan_pls_per_rev;
+ u16 fan_cnt;
+ u32 fan_cnt_tmp;
+};
+
+struct npcm7xx_cooling_device {
+ char name[THERMAL_NAME_LENGTH];
+ struct npcm7xx_pwm_fan_data *data;
+ struct thermal_cooling_device *tcdev;
+ int pwm_port;
+ u8 *cooling_levels;
+ u8 max_state;
+ u8 cur_state;
+};
+
+struct npcm7xx_pwm_fan_data {
+ void __iomem *pwm_base;
+ void __iomem *fan_base;
+ unsigned long pwm_clk_freq;
+ unsigned long fan_clk_freq;
+ struct clk *pwm_clk;
+ struct clk *fan_clk;
+ struct mutex pwm_lock[NPCM7XX_PWM_MAX_MODULES];
+ spinlock_t fan_lock[NPCM7XX_FAN_MAX_MODULE];
+ int fan_irq[NPCM7XX_FAN_MAX_MODULE];
+ bool pwm_present[NPCM7XX_PWM_MAX_CHN_NUM];
+ bool fan_present[NPCM7XX_FAN_MAX_CHN_NUM];
+ u32 input_clk_freq;
+ struct timer_list fan_timer;
+ struct npcm7xx_fan_dev fan_dev[NPCM7XX_FAN_MAX_CHN_NUM];
+ struct npcm7xx_cooling_device *cdev[NPCM7XX_PWM_MAX_CHN_NUM];
+ u8 fan_select;
+};
+
+static int npcm7xx_pwm_config_set(struct npcm7xx_pwm_fan_data *data,
+ int channel, u16 val)
+{
+ u32 pwm_ch = (channel % NPCM7XX_PWM_MAX_CHN_NUM_IN_A_MODULE);
+ u32 module = (channel / NPCM7XX_PWM_MAX_CHN_NUM_IN_A_MODULE);
+ u32 tmp_buf, ctrl_en_bit, env_bit;
+
+ /*
+ * Config PWM Comparator register for setting duty cycle
+ */
+ mutex_lock(&data->pwm_lock[module]);
+
+ /* write new CMR value */
+ iowrite32(val, NPCM7XX_PWM_REG_CMRx(data->pwm_base, module, pwm_ch));
+ tmp_buf = ioread32(NPCM7XX_PWM_REG_CR(data->pwm_base, module));
+
+ switch (pwm_ch) {
+ case 0:
+ ctrl_en_bit = NPCM7XX_PWM_CTRL_CH0_EN_BIT;
+ env_bit = NPCM7XX_PWM_CTRL_CH0_INV_BIT;
+ break;
+ case 1:
+ ctrl_en_bit = NPCM7XX_PWM_CTRL_CH1_EN_BIT;
+ env_bit = NPCM7XX_PWM_CTRL_CH1_INV_BIT;
+ break;
+ case 2:
+ ctrl_en_bit = NPCM7XX_PWM_CTRL_CH2_EN_BIT;
+ env_bit = NPCM7XX_PWM_CTRL_CH2_INV_BIT;
+ break;
+ case 3:
+ ctrl_en_bit = NPCM7XX_PWM_CTRL_CH3_EN_BIT;
+ env_bit = NPCM7XX_PWM_CTRL_CH3_INV_BIT;
+ break;
+ default:
+ return -ENODEV;
+ }
+
+ if (val == 0) {
+ /* Disable PWM */
+ tmp_buf &= ~ctrl_en_bit;
+ tmp_buf |= env_bit;
+ } else {
+ /* Enable PWM */
+ tmp_buf |= ctrl_en_bit;
+ tmp_buf &= ~env_bit;
+ }
+
+ iowrite32(tmp_buf, NPCM7XX_PWM_REG_CR(data->pwm_base, module));
+ mutex_unlock(&data->pwm_lock[module]);
+
+ return 0;
+}
+
+static inline void npcm7xx_fan_start_capture(struct npcm7xx_pwm_fan_data *data,
+ u8 fan, u8 cmp)
+{
+ u8 fan_id;
+ u8 reg_mode;
+ u8 reg_int;
+ unsigned long flags;
+
+ fan_id = NPCM7XX_FAN_INPUT(fan, cmp);
+
+ /* to check whether any fan tach is enable */
+ if (data->fan_dev[fan_id].fan_st_flg != FAN_DISABLE) {
+ /* reset status */
+ spin_lock_irqsave(&data->fan_lock[fan], flags);
+
+ data->fan_dev[fan_id].fan_st_flg = FAN_INIT;
+ reg_int = ioread8(NPCM7XX_FAN_REG_TIEN(data->fan_base, fan));
+
+ /*
+ * the interrupt enable bits do not need to be cleared before
+ * it sets, the interrupt enable bits are cleared only on reset.
+ * the clock unit control register is behaving in the same
+ * manner that the interrupt enable register behave.
+ */
+ if (cmp == NPCM7XX_FAN_CMPA) {
+ /* enable interrupt */
+ iowrite8(reg_int | (NPCM7XX_FAN_TIEN_TAIEN |
+ NPCM7XX_FAN_TIEN_TEIEN),
+ NPCM7XX_FAN_REG_TIEN(data->fan_base, fan));
+
+ reg_mode = NPCM7XX_FAN_TCKC_CLK1_APB
+ | ioread8(NPCM7XX_FAN_REG_TCKC(data->fan_base,
+ fan));
+
+ /* start to Capture */
+ iowrite8(reg_mode, NPCM7XX_FAN_REG_TCKC(data->fan_base,
+ fan));
+ } else {
+ /* enable interrupt */
+ iowrite8(reg_int | (NPCM7XX_FAN_TIEN_TBIEN |
+ NPCM7XX_FAN_TIEN_TFIEN),
+ NPCM7XX_FAN_REG_TIEN(data->fan_base, fan));
+
+ reg_mode =
+ NPCM7XX_FAN_TCKC_CLK2_APB
+ | ioread8(NPCM7XX_FAN_REG_TCKC(data->fan_base,
+ fan));
+
+ /* start to Capture */
+ iowrite8(reg_mode,
+ NPCM7XX_FAN_REG_TCKC(data->fan_base, fan));
+ }
+
+ spin_unlock_irqrestore(&data->fan_lock[fan], flags);
+ }
+}
+
+/*
+ * Enable a background timer to poll fan tach value, (200ms * 4)
+ * to polling all fan
+ */
+static void npcm7xx_fan_polling(struct timer_list *t)
+{
+ struct npcm7xx_pwm_fan_data *data;
+ unsigned long flags;
+ int i;
+
+ data = from_timer(data, t, fan_timer);
+
+ /*
+ * Polling two module per one round,
+ * FAN01 & FAN89 / FAN23 & FAN1011 / FAN45 & FAN1213 / FAN67 & FAN1415
+ */
+ for (i = data->fan_select; i < NPCM7XX_FAN_MAX_MODULE;
+ i = i + 4) {
+ /* clear the flag and reset the counter (TCNT) */
+ spin_lock_irqsave(&data->fan_lock[i], flags);
+ iowrite8(NPCM7XX_FAN_TICLR_CLEAR_ALL,
+ NPCM7XX_FAN_REG_TICLR(data->fan_base, i));
+ spin_unlock_irqrestore(&data->fan_lock[i], flags);
+
+ if (data->fan_present[i * 2]) {
+ spin_lock_irqsave(&data->fan_lock[i], flags);
+ iowrite16(NPCM7XX_FAN_TCNT,
+ NPCM7XX_FAN_REG_TCNT1(data->fan_base, i));
+ spin_unlock_irqrestore(&data->fan_lock[i], flags);
+ npcm7xx_fan_start_capture(data, i, NPCM7XX_FAN_CMPA);
+ }
+ if (data->fan_present[(i * 2) + 1]) {
+ spin_lock_irqsave(&data->fan_lock[i], flags);
+ iowrite16(NPCM7XX_FAN_TCNT,
+ NPCM7XX_FAN_REG_TCNT2(data->fan_base, i));
+ spin_unlock_irqrestore(&data->fan_lock[i], flags);
+ npcm7xx_fan_start_capture(data, i, NPCM7XX_FAN_CMPB);
+ }
+ }
+
+ data->fan_select++;
+ data->fan_select &= 0x3;
+
+ /* reset the timer interval */
+ data->fan_timer.expires = jiffies +
+ msecs_to_jiffies(NPCM7XX_FAN_POLL_TIMER_200MS);
+ add_timer(&data->fan_timer);
+}
+
+static inline void npcm7xx_fan_compute(struct npcm7xx_pwm_fan_data *data,
+ u8 fan, u8 cmp, u8 fan_id, u8 flag_int,
+ u8 flag_mode, u8 flag_clear)
+{
+ u8 reg_int;
+ u8 reg_mode;
+ u16 fan_cap;
+
+ if (cmp == NPCM7XX_FAN_CMPA)
+ fan_cap = ioread16(NPCM7XX_FAN_REG_TCRA(data->fan_base, fan));
+ else
+ fan_cap = ioread16(NPCM7XX_FAN_REG_TCRB(data->fan_base, fan));
+
+ /* clear capature flag, H/W will auto reset the NPCM7XX_FAN_TCNTx */
+ iowrite8(flag_clear, NPCM7XX_FAN_REG_TICLR(data->fan_base, fan));
+
+ if (data->fan_dev[fan_id].fan_st_flg == FAN_INIT) {
+ /* First capture, drop it */
+ data->fan_dev[fan_id].fan_st_flg =
+ FAN_PREPARE_TO_GET_FIRST_CAPTURE;
+
+ /* reset counter */
+ data->fan_dev[fan_id].fan_cnt_tmp = 0;
+ } else if (data->fan_dev[fan_id].fan_st_flg < FAN_ENOUGH_SAMPLE) {
+ /*
+ * collect the enough sample,
+ * (ex: 2 pulse fan need to get 2 sample)
+ */
+ data->fan_dev[fan_id].fan_cnt_tmp +=
+ (NPCM7XX_FAN_TCNT - fan_cap);
+
+ data->fan_dev[fan_id].fan_st_flg++;
+ } else {
+ /* get enough sample or fan disable */
+ if (data->fan_dev[fan_id].fan_st_flg == FAN_ENOUGH_SAMPLE) {
+ data->fan_dev[fan_id].fan_cnt_tmp +=
+ (NPCM7XX_FAN_TCNT - fan_cap);
+
+ /* compute finial average cnt per pulse */
+ data->fan_dev[fan_id].fan_cnt =
+ data->fan_dev[fan_id].fan_cnt_tmp /
+ FAN_ENOUGH_SAMPLE;
+
+ data->fan_dev[fan_id].fan_st_flg = FAN_INIT;
+ }
+
+ reg_int = ioread8(NPCM7XX_FAN_REG_TIEN(data->fan_base, fan));
+
+ /* disable interrupt */
+ iowrite8((reg_int & ~flag_int),
+ NPCM7XX_FAN_REG_TIEN(data->fan_base, fan));
+ reg_mode = ioread8(NPCM7XX_FAN_REG_TCKC(data->fan_base, fan));
+
+ /* stop capturing */
+ iowrite8((reg_mode & ~flag_mode),
+ NPCM7XX_FAN_REG_TCKC(data->fan_base, fan));
+ }
+}
+
+static inline void npcm7xx_check_cmp(struct npcm7xx_pwm_fan_data *data,
+ u8 fan, u8 cmp, u8 flag)
+{
+ u8 reg_int;
+ u8 reg_mode;
+ u8 flag_timeout;
+ u8 flag_cap;
+ u8 flag_clear;
+ u8 flag_int;
+ u8 flag_mode;
+ u8 fan_id;
+
+ fan_id = NPCM7XX_FAN_INPUT(fan, cmp);
+
+ if (cmp == NPCM7XX_FAN_CMPA) {
+ flag_cap = NPCM7XX_FAN_TICTRL_TAPND;
+ flag_timeout = NPCM7XX_FAN_TICTRL_TEPND;
+ flag_int = NPCM7XX_FAN_TIEN_TAIEN | NPCM7XX_FAN_TIEN_TEIEN;
+ flag_mode = NPCM7XX_FAN_TCKC_CLK1_APB;
+ flag_clear = NPCM7XX_FAN_TICLR_TACLR | NPCM7XX_FAN_TICLR_TECLR;
+ } else {
+ flag_cap = NPCM7XX_FAN_TICTRL_TBPND;
+ flag_timeout = NPCM7XX_FAN_TICTRL_TFPND;
+ flag_int = NPCM7XX_FAN_TIEN_TBIEN | NPCM7XX_FAN_TIEN_TFIEN;
+ flag_mode = NPCM7XX_FAN_TCKC_CLK2_APB;
+ flag_clear = NPCM7XX_FAN_TICLR_TBCLR | NPCM7XX_FAN_TICLR_TFCLR;
+ }
+
+ if (flag & flag_timeout) {
+ reg_int = ioread8(NPCM7XX_FAN_REG_TIEN(data->fan_base, fan));
+
+ /* disable interrupt */
+ iowrite8((reg_int & ~flag_int),
+ NPCM7XX_FAN_REG_TIEN(data->fan_base, fan));
+
+ /* clear interrupt flag */
+ iowrite8(flag_clear,
+ NPCM7XX_FAN_REG_TICLR(data->fan_base, fan));
+
+ reg_mode = ioread8(NPCM7XX_FAN_REG_TCKC(data->fan_base, fan));
+
+ /* stop capturing */
+ iowrite8((reg_mode & ~flag_mode),
+ NPCM7XX_FAN_REG_TCKC(data->fan_base, fan));
+
+ /*
+ * If timeout occurs (NPCM7XX_FAN_TIMEOUT), the fan doesn't
+ * connect or speed is lower than 10.6Hz (320RPM/pulse2).
+ * In these situation, the RPM output should be zero.
+ */
+ data->fan_dev[fan_id].fan_cnt = 0;
+ } else {
+ /* input capture is occurred */
+ if (flag & flag_cap)
+ npcm7xx_fan_compute(data, fan, cmp, fan_id, flag_int,
+ flag_mode, flag_clear);
+ }
+}
+
+static irqreturn_t npcm7xx_fan_isr(int irq, void *dev_id)
+{
+ struct npcm7xx_pwm_fan_data *data = dev_id;
+ unsigned long flags;
+ int module;
+ u8 flag;
+
+ module = irq - data->fan_irq[0];
+ spin_lock_irqsave(&data->fan_lock[module], flags);
+
+ flag = ioread8(NPCM7XX_FAN_REG_TICTRL(data->fan_base, module));
+ if (flag > 0) {
+ npcm7xx_check_cmp(data, module, NPCM7XX_FAN_CMPA, flag);
+ npcm7xx_check_cmp(data, module, NPCM7XX_FAN_CMPB, flag);
+ spin_unlock_irqrestore(&data->fan_lock[module], flags);
+ return IRQ_HANDLED;
+ }
+
+ spin_unlock_irqrestore(&data->fan_lock[module], flags);
+
+ return IRQ_NONE;
+}
+
+static int npcm7xx_read_pwm(struct device *dev, u32 attr, int channel,
+ long *val)
+{
+ struct npcm7xx_pwm_fan_data *data = dev_get_drvdata(dev);
+ u32 pmw_ch = (channel % NPCM7XX_PWM_MAX_CHN_NUM_IN_A_MODULE);
+ u32 module = (channel / NPCM7XX_PWM_MAX_CHN_NUM_IN_A_MODULE);
+
+ switch (attr) {
+ case hwmon_pwm_input:
+ *val = ioread32
+ (NPCM7XX_PWM_REG_CMRx(data->pwm_base, module, pmw_ch));
+ return 0;
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static int npcm7xx_write_pwm(struct device *dev, u32 attr, int channel,
+ long val)
+{
+ struct npcm7xx_pwm_fan_data *data = dev_get_drvdata(dev);
+ int err;
+
+ switch (attr) {
+ case hwmon_pwm_input:
+ if (val < 0 || val > NPCM7XX_PWM_COMPARATOR_MAX)
+ return -EINVAL;
+ err = npcm7xx_pwm_config_set(data, channel, (u16)val);
+ break;
+ default:
+ err = -EOPNOTSUPP;
+ break;
+ }
+
+ return err;
+}
+
+static umode_t npcm7xx_pwm_is_visible(const void *_data, u32 attr, int channel)
+{
+ const struct npcm7xx_pwm_fan_data *data = _data;
+
+ if (!data->pwm_present[channel])
+ return 0;
+
+ switch (attr) {
+ case hwmon_pwm_input:
+ return 0644;
+ default:
+ return 0;
+ }
+}
+
+static int npcm7xx_read_fan(struct device *dev, u32 attr, int channel,
+ long *val)
+{
+ struct npcm7xx_pwm_fan_data *data = dev_get_drvdata(dev);
+
+ switch (attr) {
+ case hwmon_fan_input:
+ *val = 0;
+ if (data->fan_dev[channel].fan_cnt <= 0)
+ return data->fan_dev[channel].fan_cnt;
+
+ /* Convert the raw reading to RPM */
+ if (data->fan_dev[channel].fan_cnt > 0 &&
+ data->fan_dev[channel].fan_pls_per_rev > 0)
+ *val = ((data->input_clk_freq * 60) /
+ (data->fan_dev[channel].fan_cnt *
+ data->fan_dev[channel].fan_pls_per_rev));
+ return 0;
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static umode_t npcm7xx_fan_is_visible(const void *_data, u32 attr, int channel)
+{
+ const struct npcm7xx_pwm_fan_data *data = _data;
+
+ if (!data->fan_present[channel])
+ return 0;
+
+ switch (attr) {
+ case hwmon_fan_input:
+ return 0444;
+ default:
+ return 0;
+ }
+}
+
+static int npcm7xx_read(struct device *dev, enum hwmon_sensor_types type,
+ u32 attr, int channel, long *val)
+{
+ switch (type) {
+ case hwmon_pwm:
+ return npcm7xx_read_pwm(dev, attr, channel, val);
+ case hwmon_fan:
+ return npcm7xx_read_fan(dev, attr, channel, val);
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static int npcm7xx_write(struct device *dev, enum hwmon_sensor_types type,
+ u32 attr, int channel, long val)
+{
+ switch (type) {
+ case hwmon_pwm:
+ return npcm7xx_write_pwm(dev, attr, channel, val);
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static umode_t npcm7xx_is_visible(const void *data,
+ enum hwmon_sensor_types type,
+ u32 attr, int channel)
+{
+ switch (type) {
+ case hwmon_pwm:
+ return npcm7xx_pwm_is_visible(data, attr, channel);
+ case hwmon_fan:
+ return npcm7xx_fan_is_visible(data, attr, channel);
+ default:
+ return 0;
+ }
+}
+
+static const u32 npcm7xx_pwm_config[] = {
+ HWMON_PWM_INPUT,
+ HWMON_PWM_INPUT,
+ HWMON_PWM_INPUT,
+ HWMON_PWM_INPUT,
+ HWMON_PWM_INPUT,
+ HWMON_PWM_INPUT,
+ HWMON_PWM_INPUT,
+ HWMON_PWM_INPUT,
+ 0
+};
+
+static const struct hwmon_channel_info npcm7xx_pwm = {
+ .type = hwmon_pwm,
+ .config = npcm7xx_pwm_config,
+};
+
+static const u32 npcm7xx_fan_config[] = {
+ HWMON_F_INPUT,
+ HWMON_F_INPUT,
+ HWMON_F_INPUT,
+ HWMON_F_INPUT,
+ HWMON_F_INPUT,
+ HWMON_F_INPUT,
+ HWMON_F_INPUT,
+ HWMON_F_INPUT,
+ HWMON_F_INPUT,
+ HWMON_F_INPUT,
+ HWMON_F_INPUT,
+ HWMON_F_INPUT,
+ HWMON_F_INPUT,
+ HWMON_F_INPUT,
+ HWMON_F_INPUT,
+ HWMON_F_INPUT,
+ 0
+};
+
+static const struct hwmon_channel_info npcm7xx_fan = {
+ .type = hwmon_fan,
+ .config = npcm7xx_fan_config,
+};
+
+static const struct hwmon_channel_info *npcm7xx_info[] = {
+ &npcm7xx_pwm,
+ &npcm7xx_fan,
+ NULL
+};
+
+static const struct hwmon_ops npcm7xx_hwmon_ops = {
+ .is_visible = npcm7xx_is_visible,
+ .read = npcm7xx_read,
+ .write = npcm7xx_write,
+};
+
+static const struct hwmon_chip_info npcm7xx_chip_info = {
+ .ops = &npcm7xx_hwmon_ops,
+ .info = npcm7xx_info,
+};
+
+static u32 npcm7xx_pwm_init(struct npcm7xx_pwm_fan_data *data)
+{
+ int m, ch;
+ u32 prescale_val, output_freq;
+
+ data->pwm_clk_freq = clk_get_rate(data->pwm_clk);
+
+ /* Adjust NPCM7xx PWMs output frequency to ~25Khz */
+ output_freq = data->pwm_clk_freq / PWN_CNT_DEFAULT;
+ prescale_val = DIV_ROUND_CLOSEST(output_freq, PWM_OUTPUT_FREQ_25KHZ);
+
+ /* If prescale_val = 0, then the prescale output clock is stopped */
+ if (prescale_val < MIN_PRESCALE1)
+ prescale_val = MIN_PRESCALE1;
+ /*
+ * prescale_val need to decrement in one because in the PWM Prescale
+ * register the Prescale value increment by one
+ */
+ prescale_val--;
+
+ /* Setting PWM Prescale Register value register to both modules */
+ prescale_val |= (prescale_val << NPCM7XX_PWM_PRESCALE_SHIFT_CH01);
+
+ for (m = 0; m < NPCM7XX_PWM_MAX_MODULES ; m++) {
+ iowrite32(prescale_val, NPCM7XX_PWM_REG_PR(data->pwm_base, m));
+ iowrite32(NPCM7XX_PWM_PRESCALE2_DEFAULT,
+ NPCM7XX_PWM_REG_CSR(data->pwm_base, m));
+ iowrite32(NPCM7XX_PWM_CTRL_MODE_DEFAULT,
+ NPCM7XX_PWM_REG_CR(data->pwm_base, m));
+
+ for (ch = 0; ch < NPCM7XX_PWM_MAX_CHN_NUM_IN_A_MODULE; ch++) {
+ iowrite32(NPCM7XX_PWM_COUNTER_DEFAULT_NUM,
+ NPCM7XX_PWM_REG_CNRx(data->pwm_base, m, ch));
+ }
+ }
+
+ return output_freq / ((prescale_val & 0xf) + 1);
+}
+
+static void npcm7xx_fan_init(struct npcm7xx_pwm_fan_data *data)
+{
+ int md;
+ int ch;
+ int i;
+ u32 apb_clk_freq;
+
+ for (md = 0; md < NPCM7XX_FAN_MAX_MODULE; md++) {
+ /* stop FAN0~7 clock */
+ iowrite8(NPCM7XX_FAN_TCKC_CLKX_NONE,
+ NPCM7XX_FAN_REG_TCKC(data->fan_base, md));
+
+ /* disable all interrupt */
+ iowrite8(0x00, NPCM7XX_FAN_REG_TIEN(data->fan_base, md));
+
+ /* clear all interrupt */
+ iowrite8(NPCM7XX_FAN_TICLR_CLEAR_ALL,
+ NPCM7XX_FAN_REG_TICLR(data->fan_base, md));
+
+ /* set FAN0~7 clock prescaler */
+ iowrite8(NPCM7XX_FAN_CLK_PRESCALE,
+ NPCM7XX_FAN_REG_TPRSC(data->fan_base, md));
+
+ /* set FAN0~7 mode (high-to-low transition) */
+ iowrite8((NPCM7XX_FAN_TMCTRL_MODE_5 | NPCM7XX_FAN_TMCTRL_TBEN |
+ NPCM7XX_FAN_TMCTRL_TAEN),
+ NPCM7XX_FAN_REG_TMCTRL(data->fan_base, md));
+
+ /* set FAN0~7 Initial Count/Cap */
+ iowrite16(NPCM7XX_FAN_TCNT,
+ NPCM7XX_FAN_REG_TCNT1(data->fan_base, md));
+ iowrite16(NPCM7XX_FAN_TCNT,
+ NPCM7XX_FAN_REG_TCNT2(data->fan_base, md));
+
+ /* set FAN0~7 compare (equal to count) */
+ iowrite8((NPCM7XX_FAN_TCPCFG_EQAEN | NPCM7XX_FAN_TCPCFG_EQBEN),
+ NPCM7XX_FAN_REG_TCPCFG(data->fan_base, md));
+
+ /* set FAN0~7 compare value */
+ iowrite16(NPCM7XX_FAN_TCPA,
+ NPCM7XX_FAN_REG_TCPA(data->fan_base, md));
+ iowrite16(NPCM7XX_FAN_TCPB,
+ NPCM7XX_FAN_REG_TCPB(data->fan_base, md));
+
+ /* set FAN0~7 fan input FANIN 0~15 */
+ iowrite8(NPCM7XX_FAN_TINASEL_FANIN_DEFAULT,
+ NPCM7XX_FAN_REG_TINASEL(data->fan_base, md));
+ iowrite8(NPCM7XX_FAN_TINASEL_FANIN_DEFAULT,
+ NPCM7XX_FAN_REG_TINBSEL(data->fan_base, md));
+
+ for (i = 0; i < NPCM7XX_FAN_MAX_CHN_NUM_IN_A_MODULE; i++) {
+ ch = md * NPCM7XX_FAN_MAX_CHN_NUM_IN_A_MODULE + i;
+ data->fan_dev[ch].fan_st_flg = FAN_DISABLE;
+ data->fan_dev[ch].fan_pls_per_rev =
+ NPCM7XX_FAN_DEFAULT_PULSE_PER_REVOLUTION;
+ data->fan_dev[ch].fan_cnt = 0;
+ }
+ }
+
+ apb_clk_freq = clk_get_rate(data->fan_clk);
+
+ /* Fan tach input clock = APB clock / prescalar, default is 255. */
+ data->input_clk_freq = apb_clk_freq / (NPCM7XX_FAN_CLK_PRESCALE + 1);
+}
+
+static int
+npcm7xx_pwm_cz_get_max_state(struct thermal_cooling_device *tcdev,
+ unsigned long *state)
+{
+ struct npcm7xx_cooling_device *cdev = tcdev->devdata;
+
+ *state = cdev->max_state;
+
+ return 0;
+}
+
+static int
+npcm7xx_pwm_cz_get_cur_state(struct thermal_cooling_device *tcdev,
+ unsigned long *state)
+{
+ struct npcm7xx_cooling_device *cdev = tcdev->devdata;
+
+ *state = cdev->cur_state;
+
+ return 0;
+}
+
+static int
+npcm7xx_pwm_cz_set_cur_state(struct thermal_cooling_device *tcdev,
+ unsigned long state)
+{
+ struct npcm7xx_cooling_device *cdev = tcdev->devdata;
+ int ret;
+
+ if (state > cdev->max_state)
+ return -EINVAL;
+
+ cdev->cur_state = state;
+ ret = npcm7xx_pwm_config_set(cdev->data, cdev->pwm_port,
+ cdev->cooling_levels[cdev->cur_state]);
+
+ return ret;
+}
+
+static const struct thermal_cooling_device_ops npcm7xx_pwm_cool_ops = {
+ .get_max_state = npcm7xx_pwm_cz_get_max_state,
+ .get_cur_state = npcm7xx_pwm_cz_get_cur_state,
+ .set_cur_state = npcm7xx_pwm_cz_set_cur_state,
+};
+
+static int npcm7xx_create_pwm_cooling(struct device *dev,
+ struct device_node *child,
+ struct npcm7xx_pwm_fan_data *data,
+ u32 pwm_port, u8 num_levels)
+{
+ int ret;
+ struct npcm7xx_cooling_device *cdev;
+
+ cdev = devm_kzalloc(dev, sizeof(*cdev), GFP_KERNEL);
+ if (!cdev)
+ return -ENOMEM;
+
+ cdev->cooling_levels = devm_kzalloc(dev, num_levels, GFP_KERNEL);
+ if (!cdev->cooling_levels)
+ return -ENOMEM;
+
+ cdev->max_state = num_levels - 1;
+ ret = of_property_read_u8_array(child, "cooling-levels",
+ cdev->cooling_levels,
+ num_levels);
+ if (ret) {
+ dev_err(dev, "Property 'cooling-levels' cannot be read.\n");
+ return ret;
+ }
+ snprintf(cdev->name, THERMAL_NAME_LENGTH, "%s%d", child->name,
+ pwm_port);
+
+ cdev->tcdev = thermal_of_cooling_device_register(child,
+ cdev->name,
+ cdev,
+ &npcm7xx_pwm_cool_ops);
+ if (IS_ERR(cdev->tcdev))
+ return PTR_ERR(cdev->tcdev);
+
+ cdev->data = data;
+ cdev->pwm_port = pwm_port;
+
+ data->cdev[pwm_port] = cdev;
+
+ return 0;
+}
+
+static int npcm7xx_en_pwm_fan(struct device *dev,
+ struct device_node *child,
+ struct npcm7xx_pwm_fan_data *data)
+{
+ u8 *fan_ch;
+ u8 pwm_port;
+ int ret, fan_cnt;
+ u8 index, ch;
+
+ ret = of_property_read_u8(child, "pwm-ch", &pwm_port);
+ if (ret)
+ return ret;
+
+ data->pwm_present[pwm_port] = true;
+ ret = npcm7xx_pwm_config_set(data, pwm_port,
+ NPCM7XX_PWM_COMPARATOR_DEFAULT_NUM);
+
+ ret = of_property_count_u8_elems(child, "cooling-levels");
+ if (ret > 0) {
+ ret = npcm7xx_create_pwm_cooling(dev, child, data, pwm_port,
+ ret);
+ if (ret)
+ return ret;
+ }
+
+ fan_cnt = of_property_count_u8_elems(child, "fan-ch");
+ if (fan_cnt < 1)
+ return -EINVAL;
+
+ fan_ch = devm_kzalloc(dev, sizeof(*fan_ch) * fan_cnt, GFP_KERNEL);
+ if (!fan_ch)
+ return -ENOMEM;
+
+ ret = of_property_read_u8_array(child, "fan-ch", fan_ch, fan_cnt);
+ if (ret)
+ return ret;
+
+ for (ch = 0; ch < fan_cnt; ch++) {
+ index = fan_ch[ch];
+ data->fan_present[index] = true;
+ data->fan_dev[index].fan_st_flg = FAN_INIT;
+ }
+
+ return 0;
+}
+
+static int npcm7xx_pwm_fan_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *np, *child;
+ struct npcm7xx_pwm_fan_data *data;
+ struct resource *res;
+ struct device *hwmon;
+ char name[20];
+ int ret, cnt;
+ u32 output_freq;
+ u32 i;
+
+ np = dev->of_node;
+
+ data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "pwm_base");
+ if (!res) {
+ dev_err(dev, "PWM of_address_to_resource fail\n");
+ return -ENODEV;
+ }
+
+ data->pwm_base = devm_ioremap_resource(dev, res);
+ dev_dbg(dev, "pwm base resource is %pR\n", res);
+ if (IS_ERR(data->pwm_base)) {
+ dev_err(dev, "pwm probe failed: can't read pwm base address\n");
+ return PTR_ERR(data->pwm_base);
+ }
+
+ data->pwm_clk = devm_clk_get(dev, "clk_apb3");
+ if (IS_ERR(data->pwm_clk)) {
+ dev_err(dev, "pwm probe failed: can't read clk.\n");
+ return PTR_ERR(data->pwm_clk);
+ }
+
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "fan_base");
+ if (!res) {
+ dev_err(dev, "fan of_address_to_resource fail\n");
+ return -ENODEV;
+ }
+
+ data->fan_base = devm_ioremap_resource(dev, res);
+ dev_dbg(dev, "fan base resource is %pR\n", res);
+ if (IS_ERR(data->fan_base)) {
+ dev_err(dev, "fan probe failed: can't read fan base address.\n");
+ return PTR_ERR(data->fan_base);
+ }
+
+ data->fan_clk = devm_clk_get(dev, "clk_apb4");
+ if (IS_ERR(data->fan_clk)) {
+ dev_err(dev, "FAN probe failed: can't read clk.\n");
+ return PTR_ERR(data->fan_clk);
+ }
+
+ output_freq = npcm7xx_pwm_init(data);
+ npcm7xx_fan_init(data);
+
+ for (cnt = 0; cnt < NPCM7XX_PWM_MAX_MODULES ; cnt++)
+ mutex_init(&data->pwm_lock[cnt]);
+
+ for (i = 0; i < NPCM7XX_FAN_MAX_MODULE; i++) {
+ spin_lock_init(&data->fan_lock[i]);
+
+ data->fan_irq[i] = platform_get_irq(pdev, i);
+ if (data->fan_irq[i] < 0) {
+ dev_err(dev, "%s - failed to map irq %d\n",
+ __func__, i);
+ ret = data->fan_irq[i];
+ return ret;
+ }
+
+ sprintf(name, "NPCM7XX-FAN-MD%d", i);
+ ret = devm_request_irq(dev, data->fan_irq[i], npcm7xx_fan_isr,
+ 0, name, (void *)data);
+ if (ret) {
+ dev_err(dev, "NPCM7XX: register irq FAN%d failed\n", i);
+ return ret;
+ }
+ }
+
+ for_each_child_of_node(np, child) {
+ ret = npcm7xx_en_pwm_fan(dev, child, data);
+ if (ret) {
+ dev_err(dev, "npcm7xx_en_pwm_fan failed ret %d\n", ret);
+ of_node_put(child);
+ return ret;
+ }
+ }
+
+ hwmon = devm_hwmon_device_register_with_info(dev, "npcm7xx_pwm_fan",
+ data, &npcm7xx_chip_info,
+ NULL);
+ if (IS_ERR(hwmon)) {
+ dev_err(dev, "PWM Driver failed - devm_hwmon_device_register_with_groups failed\n");
+ return PTR_ERR(hwmon);
+ }
+
+ for (i = 0; i < NPCM7XX_FAN_MAX_CHN_NUM; i++) {
+ if (data->fan_present[i]) {
+ /* fan timer initialization */
+ data->fan_timer.expires = jiffies +
+ msecs_to_jiffies(NPCM7XX_FAN_POLL_TIMER_200MS);
+ timer_setup(&data->fan_timer,
+ npcm7xx_fan_polling, 0);
+ add_timer(&data->fan_timer);
+ break;
+ }
+ }
+
+ pr_info("NPCM7XX PWM-FAN Driver probed, output Freq %dHz[PWM], input Freq %dHz[FAN]\n",
+ output_freq, data->input_clk_freq);
+
+ return 0;
+}
+
+static const struct of_device_id of_pwm_fan_match_table[] = {
+ { .compatible = "nuvoton,npcm750-pwm-fan", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, of_pwm_fan_match_table);
+
+static struct platform_driver npcm7xx_pwm_fan_driver = {
+ .probe = npcm7xx_pwm_fan_probe,
+ .driver = {
+ .name = "npcm7xx_pwm_fan",
+ .of_match_table = of_pwm_fan_match_table,
+ },
+};
+
+module_platform_driver(npcm7xx_pwm_fan_driver);
+
+MODULE_DESCRIPTION("Nuvoton NPCM7XX PWM and Fan Tacho driver");
+MODULE_AUTHOR("Tomer Maimon <[email protected]>");
+MODULE_LICENSE("GPL v2");
--
2.14.1


2018-06-24 12:48:41

by Tomer Maimon

[permalink] [raw]
Subject: [PATCH v4 1/2] dt-binding: hwmon: Add NPCM7xx PWM and Fan controller documentation

Added device tree binding documentation for Nuvoton BMC
NPCM7xx Pulse Width Modulation (PWM) and Fan tach controller.
The PWM controller can support upto 8 PWM output ports.
The Fan tach controller can support upto 16 tachometer inputs.

Signed-off-by: Tomer Maimon <[email protected]>
---
.../devicetree/bindings/hwmon/npcm750-pwm-fan.txt | 84 ++++++++++++++++++++++
1 file changed, 84 insertions(+)
create mode 100644 Documentation/devicetree/bindings/hwmon/npcm750-pwm-fan.txt

diff --git a/Documentation/devicetree/bindings/hwmon/npcm750-pwm-fan.txt b/Documentation/devicetree/bindings/hwmon/npcm750-pwm-fan.txt
new file mode 100644
index 000000000000..a9eacda34f92
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/npcm750-pwm-fan.txt
@@ -0,0 +1,84 @@
+Nuvoton NPCM7xx PWM and Fan Tacho controller device driver
+
+The NPCM7xx has two identical Pulse-width modulation (PWM) controller modules,
+Each PWM module has four PWM controller outputs, Totally 8 PWM controller outputs.
+
+The NPCM7xx has eight identical Fan tachometer controller modules,
+Each Fan module has two Fan controller inputs, Totally 16 Fan controller inputs.
+
+Required properties for pwm-fan node:
+- compatible : "nuvoton,npcm750-pwm-fan" for Poleg NPCM7XX.
+- reg : specifies physical base address and size of the registers.
+- reg-names : must contain:
+ * "pwm-base" for the PWM registers.
+ * "fan-base" for the Fan registers.
+- clocks : phandle of reference clocks.
+- clock-names : must contain
+ * "clk_apb3" for clock of PWM controller.
+ * "clk_apb4" for clock of Fan controller.
+- interrupts : contain the Fan interrupts with flags for falling edge.
+- pinctrl-names : a pinctrl state named "default" must be defined.
+- pinctrl-0 : phandle referencing pin configuration of the PWM and Fan
+ controller ports.
+
+pwm subnode format:
+===================
+Under pwm subnode can be upto 8 child nodes, each child node representing a PWM channel.
+Each pwm subnode must have one PWM channel and atleast one Fan tach channel.
+
+For PWM channel can be configured cooling-levels to create cooling device.
+Cooling device could be bound to a thermal zone for the thermal control.
+
+Required properties for each child node:
+- pwm-ch : specify the PWM output channel.
+ integer value in the range 0 through 7, that represent
+ the PWM channel number that used.
+
+- fan-ch : specify the Fan input channel.
+ integer value in the range 0 through 15, that represent
+ the Fan channel number that used.
+
+ At least one Fan tach input channel is required
+
+Optional property for each child node:
+- cooling-levels: PWM duty cycle values in a range from 0 to 255
+ which correspond to thermal cooling states.
+
+Examples:
+
+pwm_fan:pwm_fan_controller@103000 {
+ compatible = "nuvoton,npcm750-pwm-fan";
+ reg = <0x103000 0x2000>,
+ <0x180000 0x8000>;
+ reg-names = "pwm_base", "fan_base";
+ clocks = <&clk NPCM7XX_CLK_APB3>,
+ <&clk NPCM7XX_CLK_APB4>;
+ clock-names = "clk_apb3","clk_apb4";
+ interrupts = <GIC_SPI 96 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SPI 97 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SPI 98 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SPI 99 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SPI 100 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SPI 101 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SPI 102 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SPI 103 IRQ_TYPE_LEVEL_HIGH>;
+ pinctrl-names = "default";
+ pinctrl-0 = <&pwm0_pins &pwm1_pins &pwm2_pins
+ &fanin0_pins &fanin1_pins &fanin2_pins
+ &fanin3_pins &fanin4_pins>;
+
+ pwm@0 {
+ pwm-ch = /bits/ 8 <0x00>;
+ fan-ch = /bits/ 8 <0x00 0x01>;
+ cooling-levels = <127 255>;
+ };
+ pwm@1 {
+ pwm-ch = /bits/ 8 <0x01>;
+ fan-ch = /bits/ 8 <0x02 0x03>;
+ };
+ pwm@2 {
+ pwm-ch = /bits/ 8 <0x02>;
+ fan-ch = /bits/ 8 <0x04>;
+ };
+
+};
\ No newline at end of file
--
2.14.1


2018-06-25 12:46:17

by Dan Carpenter

[permalink] [raw]
Subject: Re: [PATCH v4 2/2] hwmon: npcm750: add NPCM7xx PWM and Fan driver

Hi Tomer,

I love your patch! Perhaps something to improve:

[auto build test WARNING on hwmon/hwmon-next]
[also build test WARNING on v4.18-rc2 next-20180622]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url: https://github.com/0day-ci/linux/commits/Tomer-Maimon/dt-binding-hwmon-Add-NPCM7xx-PWM-and-Fan-controller-documentation/20180624-205017
base: https://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging.git hwmon-next

New smatch warnings:
drivers/hwmon/npcm750-pwm-fan.c:261 npcm7xx_pwm_config_set() warn: inconsistent returns 'mutex:&data->pwm_lock[module]'.
Locked on: line 245
Unlocked on: line 261

Old smatch warnings:
drivers/hwmon/npcm750-pwm-fan.c:836 npcm7xx_pwm_cz_set_cur_state() warn: potential spectre issue 'cdev->cooling_levels'

# https://github.com/0day-ci/linux/commit/5ef6a0a11de5f3f0711993a20b13820cc0884c7e
git remote add linux-review https://github.com/0day-ci/linux
git remote update linux-review
git checkout 5ef6a0a11de5f3f0711993a20b13820cc0884c7e
vim +261 drivers/hwmon/npcm750-pwm-fan.c

5ef6a0a1 Tomer Maimon 2018-06-24 210
5ef6a0a1 Tomer Maimon 2018-06-24 211 static int npcm7xx_pwm_config_set(struct npcm7xx_pwm_fan_data *data,
5ef6a0a1 Tomer Maimon 2018-06-24 212 int channel, u16 val)
5ef6a0a1 Tomer Maimon 2018-06-24 213 {
5ef6a0a1 Tomer Maimon 2018-06-24 214 u32 pwm_ch = (channel % NPCM7XX_PWM_MAX_CHN_NUM_IN_A_MODULE);
5ef6a0a1 Tomer Maimon 2018-06-24 215 u32 module = (channel / NPCM7XX_PWM_MAX_CHN_NUM_IN_A_MODULE);
5ef6a0a1 Tomer Maimon 2018-06-24 216 u32 tmp_buf, ctrl_en_bit, env_bit;
5ef6a0a1 Tomer Maimon 2018-06-24 217
5ef6a0a1 Tomer Maimon 2018-06-24 218 /*
5ef6a0a1 Tomer Maimon 2018-06-24 219 * Config PWM Comparator register for setting duty cycle
5ef6a0a1 Tomer Maimon 2018-06-24 220 */
5ef6a0a1 Tomer Maimon 2018-06-24 221 mutex_lock(&data->pwm_lock[module]);
5ef6a0a1 Tomer Maimon 2018-06-24 222
5ef6a0a1 Tomer Maimon 2018-06-24 223 /* write new CMR value */
5ef6a0a1 Tomer Maimon 2018-06-24 224 iowrite32(val, NPCM7XX_PWM_REG_CMRx(data->pwm_base, module, pwm_ch));
5ef6a0a1 Tomer Maimon 2018-06-24 225 tmp_buf = ioread32(NPCM7XX_PWM_REG_CR(data->pwm_base, module));
5ef6a0a1 Tomer Maimon 2018-06-24 226
5ef6a0a1 Tomer Maimon 2018-06-24 227 switch (pwm_ch) {
5ef6a0a1 Tomer Maimon 2018-06-24 228 case 0:
5ef6a0a1 Tomer Maimon 2018-06-24 229 ctrl_en_bit = NPCM7XX_PWM_CTRL_CH0_EN_BIT;
5ef6a0a1 Tomer Maimon 2018-06-24 230 env_bit = NPCM7XX_PWM_CTRL_CH0_INV_BIT;
5ef6a0a1 Tomer Maimon 2018-06-24 231 break;
5ef6a0a1 Tomer Maimon 2018-06-24 232 case 1:
5ef6a0a1 Tomer Maimon 2018-06-24 233 ctrl_en_bit = NPCM7XX_PWM_CTRL_CH1_EN_BIT;
5ef6a0a1 Tomer Maimon 2018-06-24 234 env_bit = NPCM7XX_PWM_CTRL_CH1_INV_BIT;
5ef6a0a1 Tomer Maimon 2018-06-24 235 break;
5ef6a0a1 Tomer Maimon 2018-06-24 236 case 2:
5ef6a0a1 Tomer Maimon 2018-06-24 237 ctrl_en_bit = NPCM7XX_PWM_CTRL_CH2_EN_BIT;
5ef6a0a1 Tomer Maimon 2018-06-24 238 env_bit = NPCM7XX_PWM_CTRL_CH2_INV_BIT;
5ef6a0a1 Tomer Maimon 2018-06-24 239 break;
5ef6a0a1 Tomer Maimon 2018-06-24 240 case 3:
5ef6a0a1 Tomer Maimon 2018-06-24 241 ctrl_en_bit = NPCM7XX_PWM_CTRL_CH3_EN_BIT;
5ef6a0a1 Tomer Maimon 2018-06-24 242 env_bit = NPCM7XX_PWM_CTRL_CH3_INV_BIT;
5ef6a0a1 Tomer Maimon 2018-06-24 243 break;
5ef6a0a1 Tomer Maimon 2018-06-24 244 default:
5ef6a0a1 Tomer Maimon 2018-06-24 245 return -ENODEV;
^^^^^^^^^^^^^^
5ef6a0a1 Tomer Maimon 2018-06-24 246 }
5ef6a0a1 Tomer Maimon 2018-06-24 247
5ef6a0a1 Tomer Maimon 2018-06-24 248 if (val == 0) {
5ef6a0a1 Tomer Maimon 2018-06-24 249 /* Disable PWM */
5ef6a0a1 Tomer Maimon 2018-06-24 250 tmp_buf &= ~ctrl_en_bit;
5ef6a0a1 Tomer Maimon 2018-06-24 251 tmp_buf |= env_bit;
5ef6a0a1 Tomer Maimon 2018-06-24 252 } else {
5ef6a0a1 Tomer Maimon 2018-06-24 253 /* Enable PWM */
5ef6a0a1 Tomer Maimon 2018-06-24 254 tmp_buf |= ctrl_en_bit;
5ef6a0a1 Tomer Maimon 2018-06-24 255 tmp_buf &= ~env_bit;
5ef6a0a1 Tomer Maimon 2018-06-24 256 }
5ef6a0a1 Tomer Maimon 2018-06-24 257
5ef6a0a1 Tomer Maimon 2018-06-24 258 iowrite32(tmp_buf, NPCM7XX_PWM_REG_CR(data->pwm_base, module));
5ef6a0a1 Tomer Maimon 2018-06-24 259 mutex_unlock(&data->pwm_lock[module]);
5ef6a0a1 Tomer Maimon 2018-06-24 260
5ef6a0a1 Tomer Maimon 2018-06-24 @261 return 0;
5ef6a0a1 Tomer Maimon 2018-06-24 262 }
5ef6a0a1 Tomer Maimon 2018-06-24 263

---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation

2018-06-25 17:15:26

by Rob Herring (Arm)

[permalink] [raw]
Subject: Re: [PATCH v4 1/2] dt-binding: hwmon: Add NPCM7xx PWM and Fan controller documentation

On Sun, Jun 24, 2018 at 03:41:54PM +0300, Tomer Maimon wrote:
> Added device tree binding documentation for Nuvoton BMC
> NPCM7xx Pulse Width Modulation (PWM) and Fan tach controller.
> The PWM controller can support upto 8 PWM output ports.
> The Fan tach controller can support upto 16 tachometer inputs.
>
> Signed-off-by: Tomer Maimon <[email protected]>
> ---
> .../devicetree/bindings/hwmon/npcm750-pwm-fan.txt | 84 ++++++++++++++++++++++
> 1 file changed, 84 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/hwmon/npcm750-pwm-fan.txt
>
> diff --git a/Documentation/devicetree/bindings/hwmon/npcm750-pwm-fan.txt b/Documentation/devicetree/bindings/hwmon/npcm750-pwm-fan.txt
> new file mode 100644
> index 000000000000..a9eacda34f92
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/hwmon/npcm750-pwm-fan.txt
> @@ -0,0 +1,84 @@
> +Nuvoton NPCM7xx PWM and Fan Tacho controller device driver

Bindings are for h/w, not drivers.

> +
> +The NPCM7xx has two identical Pulse-width modulation (PWM) controller modules,
> +Each PWM module has four PWM controller outputs, Totally 8 PWM controller outputs.
> +
> +The NPCM7xx has eight identical Fan tachometer controller modules,
> +Each Fan module has two Fan controller inputs, Totally 16 Fan controller inputs.

Have you looked at other fan ctrlr bindings?f This looks like similar
h/w to ASpeed. Really, I'd like to see a common doc that describes the
structure and common properties.

> +
> +Required properties for pwm-fan node:
> +- compatible : "nuvoton,npcm750-pwm-fan" for Poleg NPCM7XX.
> +- reg : specifies physical base address and size of the registers.
> +- reg-names : must contain:
> + * "pwm-base" for the PWM registers.
> + * "fan-base" for the Fan registers.

'-base' is redundant. And your example doesn't match.

> +- clocks : phandle of reference clocks.
> +- clock-names : must contain
> + * "clk_apb3" for clock of PWM controller.
> + * "clk_apb4" for clock of Fan controller.
> +- interrupts : contain the Fan interrupts with flags for falling edge.
> +- pinctrl-names : a pinctrl state named "default" must be defined.
> +- pinctrl-0 : phandle referencing pin configuration of the PWM and Fan
> + controller ports.
> +
> +pwm subnode format:
> +===================
> +Under pwm subnode can be upto 8 child nodes, each child node representing a PWM channel.
> +Each pwm subnode must have one PWM channel and atleast one Fan tach channel.
> +
> +For PWM channel can be configured cooling-levels to create cooling device.
> +Cooling device could be bound to a thermal zone for the thermal control.
> +
> +Required properties for each child node:
> +- pwm-ch : specify the PWM output channel.
> + integer value in the range 0 through 7, that represent
> + the PWM channel number that used.
> +
> +- fan-ch : specify the Fan input channel.
> + integer value in the range 0 through 15, that represent
> + the Fan channel number that used.

This is really the tach channel.


> +
> + At least one Fan tach input channel is required
> +
> +Optional property for each child node:
> +- cooling-levels: PWM duty cycle values in a range from 0 to 255
> + which correspond to thermal cooling states.
> +
> +Examples:
> +
> +pwm_fan:pwm_fan_controller@103000 {

fan-controller@...

> + compatible = "nuvoton,npcm750-pwm-fan";
> + reg = <0x103000 0x2000>,
> + <0x180000 0x8000>;
> + reg-names = "pwm_base", "fan_base";
> + clocks = <&clk NPCM7XX_CLK_APB3>,
> + <&clk NPCM7XX_CLK_APB4>;
> + clock-names = "clk_apb3","clk_apb4";
> + interrupts = <GIC_SPI 96 IRQ_TYPE_LEVEL_HIGH>,
> + <GIC_SPI 97 IRQ_TYPE_LEVEL_HIGH>,
> + <GIC_SPI 98 IRQ_TYPE_LEVEL_HIGH>,
> + <GIC_SPI 99 IRQ_TYPE_LEVEL_HIGH>,
> + <GIC_SPI 100 IRQ_TYPE_LEVEL_HIGH>,
> + <GIC_SPI 101 IRQ_TYPE_LEVEL_HIGH>,
> + <GIC_SPI 102 IRQ_TYPE_LEVEL_HIGH>,
> + <GIC_SPI 103 IRQ_TYPE_LEVEL_HIGH>;
> + pinctrl-names = "default";
> + pinctrl-0 = <&pwm0_pins &pwm1_pins &pwm2_pins
> + &fanin0_pins &fanin1_pins &fanin2_pins
> + &fanin3_pins &fanin4_pins>;
> +
> + pwm@0 {

The sub-nodes should be "fan" nodes.

A unit-address without reg property is not valid.

> + pwm-ch = /bits/ 8 <0x00>;

Use 'reg' like ASpeed binding.

> + fan-ch = /bits/ 8 <0x00 0x01>;
> + cooling-levels = <127 255>;
> + };
> + pwm@1 {
> + pwm-ch = /bits/ 8 <0x01>;
> + fan-ch = /bits/ 8 <0x02 0x03>;
> + };
> + pwm@2 {
> + pwm-ch = /bits/ 8 <0x02>;
> + fan-ch = /bits/ 8 <0x04>;
> + };
> +
> +};
> \ No newline at end of file

^^^

> --
> 2.14.1
>
> --
> To unsubscribe from this list: send the line "unsubscribe devicetree" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html

2018-06-26 15:05:43

by Rob Herring (Arm)

[permalink] [raw]
Subject: Re: [PATCH v4 1/2] dt-binding: hwmon: Add NPCM7xx PWM and Fan controller documentation

On Mon, Jun 25, 2018 at 4:20 PM Tomer Maimon <[email protected]> wrote:
>
> Hi Rob,
>
>
> On 25 June 2018 at 20:14, Rob Herring <[email protected]> wrote:
>>
>> On Sun, Jun 24, 2018 at 03:41:54PM +0300, Tomer Maimon wrote:
>> > Added device tree binding documentation for Nuvoton BMC
>> > NPCM7xx Pulse Width Modulation (PWM) and Fan tach controller.
>> > The PWM controller can support upto 8 PWM output ports.
>> > The Fan tach controller can support upto 16 tachometer inputs.
>> >
>> > Signed-off-by: Tomer Maimon <[email protected]>
>> > ---
>> > .../devicetree/bindings/hwmon/npcm750-pwm-fan.txt | 84 ++++++++++++++++++++++
>> > 1 file changed, 84 insertions(+)
>> > create mode 100644 Documentation/devicetree/bindings/hwmon/npcm750-pwm-fan.txt
>> >
>> > diff --git a/Documentation/devicetree/bindings/hwmon/npcm750-pwm-fan.txt b/Documentation/devicetree/bindings/hwmon/npcm750-pwm-fan.txt
>> > new file mode 100644
>> > index 000000000000..a9eacda34f92
>> > --- /dev/null
>> > +++ b/Documentation/devicetree/bindings/hwmon/npcm750-pwm-fan.txt
>> > @@ -0,0 +1,84 @@
>> > +Nuvoton NPCM7xx PWM and Fan Tacho controller device driver
>>
>> Bindings are for h/w, not drivers.
>>
>> > +
>> > +The NPCM7xx has two identical Pulse-width modulation (PWM) controller modules,
>> > +Each PWM module has four PWM controller outputs, Totally 8 PWM controller outputs.
>> > +
>> > +The NPCM7xx has eight identical Fan tachometer controller modules,
>> > +Each Fan module has two Fan controller inputs, Totally 16 Fan controller inputs.
>>
>> Have you looked at other fan ctrlr bindings?f This looks like similar
>> h/w to ASpeed. Really, I'd like to see a common doc that describes the
>
>
> We do not have the same H/W as Aspeed, I believe in the near future we will need to add
> more DT properties that will used only in the NPCM7xx module.

I didn't say it was the same. Both are multi-channel PWMs with tach
inputs. Presumably, they can attach to the same types of fans as there
are only a limited number of types of fans and none of them are
specific to any fan controller.

>> structure and common properties.
>
>
> what do you mean by common structure and common properties?

When we have multiple bindings for the same class of device/hw, we
define all the common parts in a common binding doc. This often
doesn't happen at first, so we end up with a variety of bindings until
we see some commonality.

In this case, for structure, having sub-nodes for fans. As fans are
not specific to the controllers, their node should not be defined by
the controller binding. It's also how you describe the fan type,
number of fans, the PWM connections, the tach connections, etc.

Rob