Re: [PATCH 2/7] add MFD for stm32 timer IP

[Lee Jones]

On Tue, 22 Nov 2016, Benjamin Gaignard wrote:

> This hardware block could at used at same time for PWM generation
> and IIO timer for other IPs like DAC, ADC or other timers.
> PWM and IIO timer configuration are mixed in the same registers
> so we need a MFD to be able to share those registers.
> 
> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@xxxxxx>
> ---
>  drivers/mfd/Kconfig                 |  10 ++
>  drivers/mfd/Makefile                |   2 +
>  drivers/mfd/stm32-mfd-timer.c       | 236 ++++++++++++++++++++++++++++++++++++
>  include/linux/mfd/stm32-mfd-timer.h |  78 ++++++++++++
>  4 files changed, 326 insertions(+)
>  create mode 100644 drivers/mfd/stm32-mfd-timer.c
>  create mode 100644 include/linux/mfd/stm32-mfd-timer.h

This driver is going to need a re-write.

However, it's difficult to provide suggestions, since I've been left
off of the Cc: list for all the other patches.

Please re-send the set with all of the Maintainers Cc'ed on all of
the patches.

> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index c6df644..63aee36 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -1607,6 +1607,15 @@ config MFD_STW481X
>  	  in various ST Microelectronics and ST-Ericsson embedded
>  	  Nomadik series.
>  
> +config MFD_STM32_TIMER
> +	tristate "Support for STM32 multifunctions timer"
> +	select MFD_CORE
> +	select REGMAP
> +	depends on ARCH_STM32
> +	depends on OF
> +	help
> +	  Select multifunction driver (pwm, IIO trigger) for stm32 timers
> +
>  menu "Multimedia Capabilities Port drivers"
>  	depends on ARCH_SA1100
>  
> @@ -1644,4 +1653,5 @@ config MFD_VEXPRESS_SYSREG
>  	  on the ARM Ltd. Versatile Express board.
>  
>  endmenu
> +
>  endif
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index 9834e66..b348c3e 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -211,3 +211,5 @@ obj-$(CONFIG_INTEL_SOC_PMIC)	+= intel-soc-pmic.o
>  obj-$(CONFIG_MFD_MT6397)	+= mt6397-core.o
>  
>  obj-$(CONFIG_MFD_ALTERA_A10SR)	+= altera-a10sr.o
> +
> +obj-$(CONFIG_MFD_STM32_TIMER) 	+= stm32-mfd-timer.o
> diff --git a/drivers/mfd/stm32-mfd-timer.c b/drivers/mfd/stm32-mfd-timer.c
> new file mode 100644
> index 0000000..67e7db3
> --- /dev/null
> +++ b/drivers/mfd/stm32-mfd-timer.c
> @@ -0,0 +1,236 @@
> +/*
> + * stm32-timer.c
> + *
> + * Copyright (C) STMicroelectronics 2016
> + * Author: Benjamin Gaignard <benjamin.gaignard@xxxxxx> for STMicroelectronics.
> + * License terms:  GNU General Public License (GPL), version 2
> + */
> +
> +#include <linux/device.h>
> +#include <linux/init.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +
> +#include <linux/mfd/stm32-mfd-timer.h>
> +
> +static const struct stm32_mfd_timer_cfg mfd_cells_cfg[] = {
> +	{
> +		.pwm_name = "pwm1",
> +		.pwm_compatible = "st,stm32-pwm1",
> +		.trigger_name = "iiotimer1",
> +		.trigger_compatible = "st,stm32-iio-timer1",
> +	},
> +	{
> +		.pwm_name = "pwm2",
> +		.pwm_compatible = "st,stm32-pwm2",
> +		.trigger_name = "iiotimer2",
> +		.trigger_compatible = "st,stm32-iio-timer2",
> +	},
> +	{
> +		.pwm_name = "pwm3",
> +		.pwm_compatible = "st,stm32-pwm3",
> +		.trigger_name = "iiotimer3",
> +		.trigger_compatible = "st,stm32-iio-timer3",
> +	},
> +	{
> +		.pwm_name = "pwm4",
> +		.pwm_compatible = "st,stm32-pwm4",
> +		.trigger_name = "iiotimer4",
> +		.trigger_compatible = "st,stm32-iio-timer4",
> +	},
> +	{
> +		.pwm_name = "pwm5",
> +		.pwm_compatible = "st,stm32-pwm5",
> +		.trigger_name = "iiotimer5",
> +		.trigger_compatible = "st,stm32-iio-timer5",
> +	},
> +	{
> +		.trigger_name = "iiotimer6",
> +		.trigger_compatible = "st,stm32-iio-timer6",
> +	},
> +	{
> +		.trigger_name = "iiotimer7",
> +		.trigger_compatible = "st,stm32-iio-timer7",
> +	},
> +	{
> +		.pwm_name = "pwm8",
> +		.pwm_compatible = "st,stm32-pwm8",
> +		.trigger_name = "iiotimer8",
> +		.trigger_compatible = "st,stm32-iio-timer8",
> +	},
> +	{
> +		.pwm_name = "pwm9",
> +		.pwm_compatible = "st,stm32-pwm9",
> +		.trigger_name = "iiotimer9",
> +		.trigger_compatible = "st,stm32-iio-timer9",
> +	},
> +	{
> +		.pwm_name = "pwm10",
> +		.pwm_compatible = "st,stm32-pwm10",
> +	},
> +	{
> +		.pwm_name = "pwm11",
> +		.pwm_compatible = "st,stm32-pwm11",
> +	},
> +	{
> +		.pwm_name = "pwm12",
> +		.pwm_compatible = "st,stm32-pwm12",
> +		.trigger_name = "iiotimer12",
> +		.trigger_compatible = "st,stm32-iio-timer12",
> +	},
> +	{
> +		.pwm_name = "pwm13",
> +		.pwm_compatible = "st,stm32-pwm13",
> +	},
> +	{
> +		.pwm_name = "pwm14",
> +		.pwm_compatible = "st,stm32-pwm14",
> +	},
> +};
> +
> +static const struct of_device_id stm32_timer_of_match[] = {
> +	{
> +		.compatible = "st,stm32-mfd-timer1",
> +		.data = &mfd_cells_cfg[0],
> +	},
> +	{
> +		.compatible = "st,stm32-mfd-timer2",
> +		.data = &mfd_cells_cfg[1],
> +	},
> +	{
> +		.compatible = "st,stm32-mfd-timer3",
> +		.data = &mfd_cells_cfg[2],
> +	},
> +	{
> +		.compatible = "st,stm32-mfd-timer4",
> +		.data = &mfd_cells_cfg[3],
> +	},
> +	{
> +		.compatible = "st,stm32-mfd-timer5",
> +		.data = &mfd_cells_cfg[4],
> +	},
> +	{
> +		.compatible = "st,stm32-mfd-timer6",
> +		.data = &mfd_cells_cfg[5],
> +	},
> +	{
> +		.compatible = "st,stm32-mfd-timer7",
> +		.data = &mfd_cells_cfg[6],
> +	},
> +	{
> +		.compatible = "st,stm32-mfd-timer8",
> +		.data = &mfd_cells_cfg[7],
> +	},
> +	{
> +		.compatible = "st,stm32-mfd-timer9",
> +		.data = &mfd_cells_cfg[8],
> +	},
> +	{
> +		.compatible = "st,stm32-mfd-timer10",
> +		.data = &mfd_cells_cfg[9],
> +	},
> +	{
> +		.compatible = "st,stm32-mfd-timer11",
> +		.data = &mfd_cells_cfg[10],
> +	},
> +	{
> +		.compatible = "st,stm32-mfd-timer12",
> +		.data = &mfd_cells_cfg[11],
> +	},
> +	{
> +		.compatible = "st,stm32-mfd-timer13",
> +		.data = &mfd_cells_cfg[12],
> +	},
> +	{
> +		.compatible = "st,stm32-mfd-timer14",
> +		.data = &mfd_cells_cfg[13],
> +	},
> +};
> +
> +static const struct regmap_config stm32_timer_regmap_cfg = {
> +	.reg_bits = 32,
> +	.val_bits = 32,
> +	.reg_stride = sizeof(u32),
> +	.max_register = 0x400,
> +	.fast_io = true,
> +};
> +
> +static int stm32_mfd_timer_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct device_node *np = dev->of_node;
> +	struct stm32_mfd_timer_dev *mfd;
> +	struct resource *res;
> +	int ret, nb_cells = 0;
> +	struct mfd_cell *cell = NULL;
> +	void __iomem *mmio;
> +
> +	mfd = devm_kzalloc(dev, sizeof(*mfd), GFP_KERNEL);
> +	if (!mfd)
> +		return -ENOMEM;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (!res)
> +		return -ENOMEM;
> +
> +	mmio = devm_ioremap_resource(dev, res);
> +	if (IS_ERR(mmio))
> +		return PTR_ERR(mmio);
> +
> +	mfd->regmap = devm_regmap_init_mmio_clk(dev, "mfd_timer_clk", mmio,
> +						&stm32_timer_regmap_cfg);
> +	if (IS_ERR(mfd->regmap))
> +		return PTR_ERR(mfd->regmap);
> +
> +	mfd->clk = devm_clk_get(dev, NULL);
> +	if (IS_ERR(mfd->clk))
> +		return PTR_ERR(mfd->clk);
> +
> +	mfd->irq = platform_get_irq(pdev, 0);
> +	if (mfd->irq < 0)
> +		return -EINVAL;
> +
> +	/* populate data structure depending on compatibility */
> +	if (!of_match_node(stm32_timer_of_match, np)->data)
> +		return -EINVAL;
> +
> +	mfd->cfg =
> +	(struct stm32_mfd_timer_cfg *)of_match_node(stm32_timer_of_match, np)->data;
> +
> +	if (mfd->cfg->pwm_name && mfd->cfg->pwm_compatible) {
> +		cell = &mfd->cells[nb_cells++];
> +		cell->name = mfd->cfg->pwm_name;
> +		cell->of_compatible = mfd->cfg->pwm_compatible;
> +		cell->platform_data = mfd;
> +		cell->pdata_size = sizeof(*mfd);
> +	}
> +
> +	if (mfd->cfg->trigger_name && mfd->cfg->trigger_compatible) {
> +		cell = &mfd->cells[nb_cells++];
> +		cell->name = mfd->cfg->trigger_name;
> +		cell->of_compatible = mfd->cfg->trigger_compatible;
> +		cell->platform_data = mfd;
> +		cell->pdata_size = sizeof(*mfd);
> +	}
> +
> +	ret = devm_mfd_add_devices(&pdev->dev, pdev->id, mfd->cells,
> +				   nb_cells, NULL, 0, NULL);
> +	if (ret)
> +		return ret;
> +
> +	platform_set_drvdata(pdev, mfd);
> +
> +	return 0;
> +}
> +
> +static struct platform_driver stm32_mfd_timer_driver = {
> +	.probe		= stm32_mfd_timer_probe,
> +	.driver	= {
> +		.name	= "stm32-mfd-timer",
> +		.of_match_table = stm32_timer_of_match,
> +	},
> +};
> +module_platform_driver(stm32_mfd_timer_driver);
> +
> +MODULE_DESCRIPTION("STMicroelectronics STM32 Timer MFD");
> +MODULE_LICENSE("GPL");
> diff --git a/include/linux/mfd/stm32-mfd-timer.h b/include/linux/mfd/stm32-mfd-timer.h
> new file mode 100644
> index 0000000..4a79c22
> --- /dev/null
> +++ b/include/linux/mfd/stm32-mfd-timer.h
> @@ -0,0 +1,78 @@
> +/*
> + * stm32-mfd-timer.h
> + *
> + * Copyright (C) STMicroelectronics 2016
> + * Author: Benjamin Gaignard <benjamin.gaignard@xxxxxx> for STMicroelectronics.
> + * License terms:  GNU General Public License (GPL), version 2
> + */
> +
> +#ifndef _LINUX_MFD_STM32_TIMER_H_
> +#define _LINUX_MFD_STM32_TIMER_H_
> +
> +#include <linux/clk.h>
> +#include <linux/mfd/core.h>
> +#include <linux/regmap.h>
> +#include <linux/reset.h>
> +
> +#define TIM_CR1		0x00	/* Control Register 1      */
> +#define TIM_CR2		0x04	/* Control Register 2      */
> +#define TIM_SMCR	0x08	/* Slave mode control reg  */
> +#define TIM_DIER	0x0C	/* DMA/interrupt register  */
> +#define TIM_SR		0x10	/* Status register	   */
> +#define TIM_EGR		0x14	/* Event Generation Reg    */
> +#define TIM_CCMR1	0x18	/* Capt/Comp 1 Mode Reg    */
> +#define TIM_CCMR2	0x1C	/* Capt/Comp 2 Mode Reg    */
> +#define TIM_CCER	0x20	/* Capt/Comp Enable Reg    */
> +#define TIM_PSC		0x28	/* Prescaler               */
> +#define TIM_ARR		0x2c	/* Auto-Reload Register    */
> +#define TIM_CCR1	0x34	/* Capt/Comp Register 1    */
> +#define TIM_CCR2	0x38	/* Capt/Comp Register 2    */
> +#define TIM_CCR3	0x3C	/* Capt/Comp Register 3    */
> +#define TIM_CCR4	0x40	/* Capt/Comp Register 4    */
> +#define TIM_BDTR	0x44	/* Break and Dead-Time Reg */
> +
> +#define TIM_CR1_CEN	BIT(0)	/* Counter Enable	   */
> +#define TIM_CR1_ARPE	BIT(7)	/* Auto-reload Preload Ena */
> +#define TIM_CR2_MMS	(BIT(4) | BIT(5) | BIT(6)) /* Master mode selection */
> +#define TIM_SMCR_SMS	(BIT(0) | BIT(1) | BIT(2)) /* Slave mode selection */
> +#define TIM_SMCR_TS	(BIT(4) | BIT(5) | BIT(6)) /* Trigger selection */
> +#define TIM_DIER_UIE	BIT(0)	/* Update interrupt	   */
> +#define TIM_SR_UIF	BIT(0)	/* Update interrupt flag   */
> +#define TIM_EGR_UG	BIT(0)	/* Update Generation       */
> +#define TIM_CCMR_PE	BIT(3)	/* Channel Preload Enable  */
> +#define TIM_CCMR_M1	(BIT(6) | BIT(5))  /* Channel PWM Mode 1 */
> +#define TIM_CCER_CC1E	BIT(0)	/* Capt/Comp 1  out Ena    */
> +#define TIM_CCER_CC1P	BIT(1)	/* Capt/Comp 1  Polarity   */
> +#define TIM_CCER_CC1NE	BIT(2)	/* Capt/Comp 1N out Ena    */
> +#define TIM_CCER_CC1NP	BIT(3)	/* Capt/Comp 1N Polarity   */
> +#define TIM_CCER_CCXE	(BIT(0) | BIT(4) | BIT(8) | BIT(12))
> +#define TIM_BDTR_BKE	BIT(12) /* Break input enable	   */
> +#define TIM_BDTR_BKP	BIT(13) /* Break input polarity	   */
> +#define TIM_BDTR_AOE	BIT(14)	/* Automatic Output Enable */
> +#define TIM_BDTR_MOE	BIT(15)	/* Main Output Enable      */
> +
> +#define STM32_TIMER_CELLS	2
> +#define MAX_TIM_PSC		0xFFFF
> +
> +struct stm32_mfd_timer_cfg {
> +	const char *pwm_name;
> +	const char *pwm_compatible;
> +	const char *trigger_name;
> +	const char *trigger_compatible;
> +};
> +
> +struct stm32_mfd_timer_dev {
> +	/* Device data */
> +	struct device *dev;
> +	struct clk *clk;
> +	int irq;
> +
> +	/* Registers mapping */
> +	struct regmap *regmap;
> +
> +	/* Private data */
> +	struct mfd_cell cells[STM32_TIMER_CELLS];
> +	struct stm32_mfd_timer_cfg *cfg;
> +};
> +
> +#endif

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org â Open source software for ARM SoCs
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