[v4,07/18] dmaengine: dma-jz4780: Add support for the JZ4770 SoC

[Paul Cercueil <paul@crapouillou.net>]

The JZ4770 SoC has two DMA cores, each one featuring six DMA channels.
The major change is that each channel's clock can be enabled or disabled
through register writes.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Tested-by: Mathieu Malaterre <malat@debian.org>
---
 drivers/dma/dma-jz4780.c | 61 ++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 54 insertions(+), 7 deletions(-)

 v2: - Move transfer_ord_max variable to the new jz4780_dma_soc_data
       structure
     - The documentation update is now in patch 01/17

 v3: The Kconfig update was dropped thanks to patch 06/18

 v4: Pass jz4780_dma_soc_data structure pointer directly as devicetree
     match data; Add a 'flags' field in that structure and macros for
     it, to replace checking vs. the SoC version.

diff --git a/drivers/dma/dma-jz4780.c b/drivers/dma/dma-jz4780.c
index 7683de9fb9ee..184d1a2bf9ba 100644
--- a/drivers/dma/dma-jz4780.c
+++ b/drivers/dma/dma-jz4780.c
@@ -29,6 +29,9 @@
 #define JZ_DMA_REG_DIRQP	0x04
 #define JZ_DMA_REG_DDR		0x08
 #define JZ_DMA_REG_DDRS		0x0c
+#define JZ_DMA_REG_DCKE		0x10
+#define JZ_DMA_REG_DCKES	0x14
+#define JZ_DMA_REG_DCKEC	0x18
 #define JZ_DMA_REG_DMACP	0x1c
 #define JZ_DMA_REG_DSIRQP	0x20
 #define JZ_DMA_REG_DSIRQM	0x24
@@ -87,6 +90,11 @@
 
 #define JZ4780_DMA_CTRL_OFFSET	0x1000
 
+/* macros for use with jz4780_dma_soc_data.flags */
+#define JZ_SOC_DATA_ALLOW_LEGACY_DT	BIT(0)
+#define JZ_SOC_DATA_PROGRAMMABLE_DMA	BIT(1)
+#define JZ_SOC_DATA_PER_CHAN_PM		BIT(2)
+
 /**
  * struct jz4780_dma_hwdesc - descriptor structure read by the DMA controller.
  * @dcm: value for the DCM (channel command) register
@@ -133,6 +141,8 @@ struct jz4780_dma_chan {
 
 struct jz4780_dma_soc_data {
 	unsigned int nb_channels;
+	unsigned int transfer_ord_max;
+	unsigned long flags;
 };
 
 struct jz4780_dma_dev {
@@ -195,6 +205,20 @@ static inline void jz4780_dma_ctrl_writel(struct jz4780_dma_dev *jzdma,
 	writel(val, jzdma->ctrl_base + reg);
 }
 
+static inline void jz4780_dma_chan_enable(struct jz4780_dma_dev *jzdma,
+	unsigned int chn)
+{
+	if (jzdma->soc_data->flags & JZ_SOC_DATA_PER_CHAN_PM)
+		jz4780_dma_ctrl_writel(jzdma, JZ_DMA_REG_DCKES, BIT(chn));
+}
+
+static inline void jz4780_dma_chan_disable(struct jz4780_dma_dev *jzdma,
+	unsigned int chn)
+{
+	if (jzdma->soc_data->flags & JZ_SOC_DATA_PER_CHAN_PM)
+		jz4780_dma_ctrl_writel(jzdma, JZ_DMA_REG_DCKEC, BIT(chn));
+}
+
 static struct jz4780_dma_desc *jz4780_dma_desc_alloc(
 	struct jz4780_dma_chan *jzchan, unsigned int count,
 	enum dma_transaction_type type)
@@ -229,8 +253,10 @@ static void jz4780_dma_desc_free(struct virt_dma_desc *vdesc)
 	kfree(desc);
 }
 
-static uint32_t jz4780_dma_transfer_size(unsigned long val, uint32_t *shift)
+static uint32_t jz4780_dma_transfer_size(struct jz4780_dma_chan *jzchan,
+	unsigned long val, uint32_t *shift)
 {
+	struct jz4780_dma_dev *jzdma = jz4780_dma_chan_parent(jzchan);
 	int ord = ffs(val) - 1;
 
 	/*
@@ -242,8 +268,8 @@ static uint32_t jz4780_dma_transfer_size(unsigned long val, uint32_t *shift)
 	 */
 	if (ord == 3)
 		ord = 2;
-	else if (ord > 7)
-		ord = 7;
+	else if (ord > jzdma->soc_data->transfer_ord_max)
+		ord = jzdma->soc_data->transfer_ord_max;
 
 	*shift = ord;
 
@@ -295,7 +321,7 @@ static int jz4780_dma_setup_hwdesc(struct jz4780_dma_chan *jzchan,
 	 * divisible by the transfer size, and we must not use more than the
 	 * maximum burst specified by the user.
 	 */
-	tsz = jz4780_dma_transfer_size(addr | len | (width * maxburst),
+	tsz = jz4780_dma_transfer_size(jzchan, addr | len | (width * maxburst),
 				       &jzchan->transfer_shift);
 
 	switch (width) {
@@ -424,7 +450,7 @@ static struct dma_async_tx_descriptor *jz4780_dma_prep_dma_memcpy(
 	if (!desc)
 		return NULL;
 
-	tsz = jz4780_dma_transfer_size(dest | src | len,
+	tsz = jz4780_dma_transfer_size(jzchan, dest | src | len,
 				       &jzchan->transfer_shift);
 
 	jzchan->transfer_type = JZ_DMA_DRT_AUTO;
@@ -485,6 +511,9 @@ static void jz4780_dma_begin(struct jz4780_dma_chan *jzchan)
 			(jzchan->curr_hwdesc + 1) % jzchan->desc->count;
 	}
 
+	/* Enable the channel's clock. */
+	jz4780_dma_chan_enable(jzdma, jzchan->id);
+
 	/* Use 4-word descriptors. */
 	jz4780_dma_chn_writel(jzdma, jzchan->id, JZ_DMA_REG_DCS, 0);
 
@@ -532,6 +561,8 @@ static int jz4780_dma_terminate_all(struct dma_chan *chan)
 		jzchan->desc = NULL;
 	}
 
+	jz4780_dma_chan_disable(jzdma, jzchan->id);
+
 	vchan_get_all_descriptors(&jzchan->vchan, &head);
 
 	spin_unlock_irqrestore(&jzchan->vchan.lock, flags);
@@ -543,8 +574,10 @@ static int jz4780_dma_terminate_all(struct dma_chan *chan)
 static void jz4780_dma_synchronize(struct dma_chan *chan)
 {
 	struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
+	struct jz4780_dma_dev *jzdma = jz4780_dma_chan_parent(jzchan);
 
 	vchan_synchronize(&jzchan->vchan);
+	jz4780_dma_chan_disable(jzdma, jzchan->id);
 }
 
 static int jz4780_dma_config(struct dma_chan *chan,
@@ -812,13 +845,16 @@ static int jz4780_dma_probe(struct platform_device *pdev)
 		jzdma->ctrl_base = devm_ioremap_resource(dev, res);
 		if (IS_ERR(jzdma->ctrl_base))
 			return PTR_ERR(jzdma->ctrl_base);
-	} else {
+	} else if (soc_data->flags & JZ_SOC_DATA_ALLOW_LEGACY_DT) {
 		/*
 		 * On JZ4780, if the second memory resource was not supplied,
 		 * assume we're using an old devicetree, and calculate the
 		 * offset to the control registers.
 		 */
 		jzdma->ctrl_base = jzdma->chn_base + JZ4780_DMA_CTRL_OFFSET;
+	} else {
+		dev_err(dev, "failed to get I/O memory\n");
+		return -EINVAL;
 	}
 
 	ret = platform_get_irq(pdev, 0);
@@ -879,7 +915,9 @@ static int jz4780_dma_probe(struct platform_device *pdev)
 	 */
 	jz4780_dma_ctrl_writel(jzdma, JZ_DMA_REG_DMAC,
 			  JZ_DMA_DMAC_DMAE | JZ_DMA_DMAC_FMSC);
-	jz4780_dma_ctrl_writel(jzdma, JZ_DMA_REG_DMACP, 0);
+
+	if (soc_data->flags & JZ_SOC_DATA_PROGRAMMABLE_DMA)
+		jz4780_dma_ctrl_writel(jzdma, JZ_DMA_REG_DMACP, 0);
 
 	INIT_LIST_HEAD(&dd->channels);
 
@@ -935,11 +973,20 @@ static int jz4780_dma_remove(struct platform_device *pdev)
 	return 0;
 }
 
+static const struct jz4780_dma_soc_data jz4770_dma_soc_data = {
+	.nb_channels = 6,
+	.transfer_ord_max = 6,
+	.flags = JZ_SOC_DATA_PER_CHAN_PM,
+};
+
 static const struct jz4780_dma_soc_data jz4780_dma_soc_data = {
 	.nb_channels = 32,
+	.transfer_ord_max = 7,
+	.flags = JZ_SOC_DATA_ALLOW_LEGACY_DT | JZ_SOC_DATA_PROGRAMMABLE_DMA,
 };
 
 static const struct of_device_id jz4780_dma_dt_match[] = {
+	{ .compatible = "ingenic,jz4770-dma", .data = &jz4770_dma_soc_data },
 	{ .compatible = "ingenic,jz4780-dma", .data = &jz4780_dma_soc_data },
 	{},
 };