summaryrefslogtreecommitdiffstats
path: root/include
diff options
context:
space:
mode:
authorFabrice Gasnier <fabrice.gasnier@st.com>2018-05-16 09:35:57 +0200
committerLee Jones <lee.jones@linaro.org>2018-05-16 10:10:38 +0200
commit0c6609805b638debcb7d9d44556546b043ded2e9 (patch)
tree7cac5757b00b73ca2ff3c22a6a21e75109e1856b /include
parentLinux 4.17-rc1 (diff)
downloadlinux-0c6609805b638debcb7d9d44556546b043ded2e9.tar.xz
linux-0c6609805b638debcb7d9d44556546b043ded2e9.zip
mfd: stm32-timers: Add support for DMAs
STM32 Timers can support up to 7 DMA requests: - 4 channels, update, compare and trigger. Optionally request part, or all DMAs from stm32-timers MFD core. Also add routine to implement burst reads using DMA from timer registers. This is exported. So, it can be used by child drivers, PWM capture for instance (but not limited to). Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com> Reviewed-by: Benjamin Gaignard <benjamin.gaignard@linaro.org> Signed-off-by: Lee Jones <lee.jones@linaro.org>
Diffstat (limited to 'include')
-rw-r--r--include/linux/mfd/stm32-timers.h46
1 files changed, 46 insertions, 0 deletions
diff --git a/include/linux/mfd/stm32-timers.h b/include/linux/mfd/stm32-timers.h
index 2aadab6f34a1..9596d5c58859 100644
--- a/include/linux/mfd/stm32-timers.h
+++ b/include/linux/mfd/stm32-timers.h
@@ -8,6 +8,8 @@
#define _LINUX_STM32_GPTIMER_H_
#include <linux/clk.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
#include <linux/regmap.h>
#define TIM_CR1 0x00 /* Control Register 1 */
@@ -27,6 +29,8 @@
#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_DCR 0x48 /* DMA control register */
+#define TIM_DMAR 0x4C /* DMA register for transfer */
#define TIM_CR1_CEN BIT(0) /* Counter Enable */
#define TIM_CR1_DIR BIT(4) /* Counter Direction */
@@ -36,6 +40,13 @@
#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_DIER_UDE BIT(8) /* Update DMA request Enable */
+#define TIM_DIER_CC1DE BIT(9) /* CC1 DMA request Enable */
+#define TIM_DIER_CC2DE BIT(10) /* CC2 DMA request Enable */
+#define TIM_DIER_CC3DE BIT(11) /* CC3 DMA request Enable */
+#define TIM_DIER_CC4DE BIT(12) /* CC4 DMA request Enable */
+#define TIM_DIER_COMDE BIT(13) /* COM DMA request Enable */
+#define TIM_DIER_TDE BIT(14) /* Trigger DMA request Enable */
#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 */
@@ -56,6 +67,8 @@
#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 TIM_DCR_DBA GENMASK(4, 0) /* DMA base addr */
+#define TIM_DCR_DBL GENMASK(12, 8) /* DMA burst len */
#define MAX_TIM_PSC 0xFFFF
#define TIM_CR2_MMS_SHIFT 4
@@ -65,9 +78,42 @@
#define TIM_BDTR_BKF_SHIFT 16
#define TIM_BDTR_BK2F_SHIFT 20
+enum stm32_timers_dmas {
+ STM32_TIMERS_DMA_CH1,
+ STM32_TIMERS_DMA_CH2,
+ STM32_TIMERS_DMA_CH3,
+ STM32_TIMERS_DMA_CH4,
+ STM32_TIMERS_DMA_UP,
+ STM32_TIMERS_DMA_TRIG,
+ STM32_TIMERS_DMA_COM,
+ STM32_TIMERS_MAX_DMAS,
+};
+
+/**
+ * struct stm32_timers_dma - STM32 timer DMA handling.
+ * @completion: end of DMA transfer completion
+ * @phys_base: control registers physical base address
+ * @lock: protect DMA access
+ * @chan: DMA channel in use
+ * @chans: DMA channels available for this timer instance
+ */
+struct stm32_timers_dma {
+ struct completion completion;
+ phys_addr_t phys_base;
+ struct mutex lock;
+ struct dma_chan *chan;
+ struct dma_chan *chans[STM32_TIMERS_MAX_DMAS];
+};
+
struct stm32_timers {
struct clk *clk;
struct regmap *regmap;
u32 max_arr;
+ struct stm32_timers_dma dma; /* Only to be used by the parent */
};
+
+int stm32_timers_dma_burst_read(struct device *dev, u32 *buf,
+ enum stm32_timers_dmas id, u32 reg,
+ unsigned int num_reg, unsigned int bursts,
+ unsigned long tmo_ms);
#endif