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 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.gaign...@st.com>
---
 drivers/mfd/Kconfig               | 11 ++++++
 drivers/mfd/Makefile              |  2 +
 drivers/mfd/stm32-gptimer.c       | 80 +++++++++++++++++++++++++++++++++++++++
 include/linux/mfd/stm32-gptimer.h | 64 +++++++++++++++++++++++++++++++
 4 files changed, 157 insertions(+)
 create mode 100644 drivers/mfd/stm32-gptimer.c
 create mode 100644 include/linux/mfd/stm32-gptimer.h

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index c6df644..b797312 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -1607,6 +1607,17 @@ config MFD_STW481X
          in various ST Microelectronics and ST-Ericsson embedded
          Nomadik series.
 
+config MFD_STM32_GP_TIMER
+       tristate "Support for STM32 General Purpose Timer"
+       depends on (ARCH_STM32 && OF) || COMPILE_TEST
+       select MFD_CORE
+       select REGMAP
+       select REGMAP_MMIO
+       help
+         Select this option to enable STM32 general purpose timer
+         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 9834e66..86353b9 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_GP_TIMER)       += stm32-gptimer.o
diff --git a/drivers/mfd/stm32-gptimer.c b/drivers/mfd/stm32-gptimer.c
new file mode 100644
index 0000000..0642f1a
--- /dev/null
+++ b/drivers/mfd/stm32-gptimer.c
@@ -0,0 +1,80 @@
+/*
+ * Copyright (C) STMicroelectronics 2016
+ *
+ * Author: Benjamin Gaignard <benjamin.gaign...@st.com>
+ *
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+
+#include <linux/mfd/stm32-gptimer.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/reset.h>
+
+static const struct regmap_config stm32_gptimer_regmap_cfg = {
+       .reg_bits = 32,
+       .val_bits = 32,
+       .reg_stride = sizeof(u32),
+       .max_register = 0x400,
+};
+
+static void stm32_gptimer_get_arr_size(struct stm32_gptimer *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_gptimer_probe(struct platform_device *pdev)
+{
+       struct device *dev = &pdev->dev;
+       struct stm32_gptimer *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, "clk_int", mmio,
+                                                 &stm32_gptimer_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_gptimer_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_gptimer_of_match[] = {
+       { .compatible = "st,stm32-gptimer", },
+       { /* sentinelle */ },
+};
+MODULE_DEVICE_TABLE(of, stm32_gptimer_of_match);
+
+static struct platform_driver stm32_gptimer_driver = {
+       .probe = stm32_gptimer_probe,
+       .driver = {
+               .name = "stm32-gptimer",
+               .of_match_table = stm32_gptimer_of_match,
+       },
+};
+module_platform_driver(stm32_gptimer_driver);
+
+MODULE_DESCRIPTION("STMicroelectronics STM32 General Purpose Timer");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/mfd/stm32-gptimer.h 
b/include/linux/mfd/stm32-gptimer.h
new file mode 100644
index 0000000..567a15e
--- /dev/null
+++ b/include/linux/mfd/stm32-gptimer.h
@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) STMicroelectronics 2016
+ *
+ * Author: Benjamin Gaignard <benjamin.gaign...@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 MAX_TIM_PSC            0xFFFF
+#define TIM_CR2_MMS_SHIFT      4
+#define TIM_SMCR_TS_SHIFT      4
+
+struct stm32_gptimer {
+       struct clk *clk;
+       struct regmap *regmap;
+       u32 max_arr;
+};
+#endif
-- 
1.9.1

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