[PATCH v9 2/8] MFD: add STM32 Timers driver

Benjamin Gaignard
2017-01-20T09:18:00Z

This hardware block could at used at same time for PWM generation
and IIO timers.
PWM and IIO timer configuration are mixed in the same registers
so we need a multi fonction driver to be able to share those registers.

version 7:
- rebase on v4.10-rc2

version 6:
- rename files to stm32-timers
- rename functions to stm32_timers_xxx

version 5:
- fix Lee comments about detect function
- add missing dependency on REGMAP_MMIO

version 4:
- add a function to detect Auto Reload Register (ARR) size
- rename the structure shared with other drivers

version 2:
- rename driver "stm32-gptimer" to be align with SoC documentation
- only keep one compatible
- use of_platform_populate() instead of devm_mfd_add_devices()

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@st.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
---
drivers/mfd/Kconfig | 11 ++++++
drivers/mfd/Makefile | 2 +
drivers/mfd/stm32-timers.c | 80 ++++++++++++++++++++++++++++++++++++++++
include/linux/mfd/stm32-timers.h | 71 +++++++++++++++++++++++++++++++++++
4 files changed, 164 insertions(+)
create mode 100644 drivers/mfd/stm32-timers.c
create mode 100644 include/linux/mfd/stm32-timers.h

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 4ce3b6f..d0c14b8 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -1621,6 +1621,17 @@ config MFD_STW481X
in various ST Microelectronics and ST-Ericsson embedded
Nomadik series.

+config MFD_STM32_TIMERS
+ tristate "Support for STM32 Timers"
+ depends on (ARCH_STM32 && OF) || COMPILE_TEST
+ select MFD_CORE
+ select REGMAP
+ select REGMAP_MMIO
+ help
+ Select this option to enable STM32 timers driver used
+ for PWM and IIO Timer. This driver allow to share the
+ registers between the others drivers.
+
menu "Multimedia Capabilities Port drivers"
depends on ARCH_SA1100

diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index dda4d4f..876ca86 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -212,3 +212,5 @@ obj-$(CONFIG_MFD_MT6397) += mt6397-core.o

obj-$(CONFIG_MFD_ALTERA_A10SR) += altera-a10sr.o
obj-$(CONFIG_MFD_SUN4I_GPADC) += sun4i-gpadc.o
+
+obj-$(CONFIG_MFD_STM32_TIMERS) += stm32-timers.o
diff --git a/drivers/mfd/stm32-timers.c b/drivers/mfd/stm32-timers.c
new file mode 100644
index 0000000..41bd901
--- /dev/null
+++ b/drivers/mfd/stm32-timers.c
@@ -0,0 +1,80 @@
+/*
+ * Copyright (C) STMicroelectronics 2016
+ *
+ * Author: Benjamin Gaignard <benjamin.gaignard@st.com>
+ *
+ * License terms: GNU General Public License (GPL), version 2
+ */
+
+#include <linux/mfd/stm32-timers.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/reset.h>
+
+static const struct regmap_config stm32_timers_regmap_cfg = {
+ .reg_bits = 32,
+ .val_bits = 32,
+ .reg_stride = sizeof(u32),
+ .max_register = 0x400,
+};
+
+static void stm32_timers_get_arr_size(struct stm32_timers *ddata)
+{
+ /*
+ * Only the available bits will be written so when readback
+ * we get the maximum value of auto reload register
+ */
+ regmap_write(ddata->regmap, TIM_ARR, ~0L);
+ regmap_read(ddata->regmap, TIM_ARR, &ddata->max_arr);
+ regmap_write(ddata->regmap, TIM_ARR, 0x0);
+}
+
+static int stm32_timers_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct stm32_timers *ddata;
+ struct resource *res;
+ void __iomem *mmio;
+
+ ddata = devm_kzalloc(dev, sizeof(*ddata), GFP_KERNEL);
+ if (!ddata)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ mmio = devm_ioremap_resource(dev, res);
+ if (IS_ERR(mmio))
+ return PTR_ERR(mmio);
+
+ ddata->regmap = devm_regmap_init_mmio_clk(dev, "int", mmio,
+ &stm32_timers_regmap_cfg);
+ if (IS_ERR(ddata->regmap))
+ return PTR_ERR(ddata->regmap);
+
+ ddata->clk = devm_clk_get(dev, NULL);
+ if (IS_ERR(ddata->clk))
+ return PTR_ERR(ddata->clk);
+
+ stm32_timers_get_arr_size(ddata);
+
+ platform_set_drvdata(pdev, ddata);
+
+ return of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);
+}
+
+static const struct of_device_id stm32_timers_of_match[] = {
+ { .compatible = "st,stm32-timers", },
+ { /* end node */ },
+};
+MODULE_DEVICE_TABLE(of, stm32_timers_of_match);
+
+static struct platform_driver stm32_timers_driver = {
+ .probe = stm32_timers_probe,
+ .driver = {
+ .name = "stm32-timers",
+ .of_match_table = stm32_timers_of_match,
+ },
+};
+module_platform_driver(stm32_timers_driver);
+
+MODULE_DESCRIPTION("STMicroelectronics STM32 Timers");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/mfd/stm32-timers.h b/include/linux/mfd/stm32-timers.h
new file mode 100644
index 0000000..d030004
--- /dev/null
+++ b/include/linux/mfd/stm32-timers.h
@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) STMicroelectronics 2016
+ *
+ * Author: Benjamin Gaignard <benjamin.gaignard@st.com>
+ *
+ * License terms: GNU General Public License (GPL), version 2
+ */
+
+#ifndef _LINUX_STM32_GPTIMER_H_
+#define _LINUX_STM32_GPTIMER_H_
+
+#include <linux/clk.h>
+#include <linux/regmap.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_CC2E BIT(4) /* Capt/Comp 2 out Ena */
+#define TIM_CCER_CC3E BIT(8) /* Capt/Comp 3 out Ena */
+#define TIM_CCER_CC4E BIT(12) /* Capt/Comp 4 out Ena */
+#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 TIM_BDTR_BKF (BIT(16) | BIT(17) | BIT(18) | BIT(19))
+#define TIM_BDTR_BK2F (BIT(20) | BIT(21) | BIT(22) | BIT(23))
+#define TIM_BDTR_BK2E BIT(24) /* Break 2 input enable */
+#define TIM_BDTR_BK2P BIT(25) /* Break 2 input polarity */
+
+#define MAX_TIM_PSC 0xFFFF
+#define TIM_CR2_MMS_SHIFT 4
+#define TIM_SMCR_TS_SHIFT 4
+#define TIM_BDTR_BKF_MASK 0xF
+#define TIM_BDTR_BKF_SHIFT 16
+#define TIM_BDTR_BK2F_SHIFT 20
+
+struct stm32_timers {
+ struct clk *clk;
+ struct regmap *regmap;
+ u32 max_arr;
+};
+#endif
--
1.9.1