Re: [PATCH 3/6] i2c: qup: Add bam dma capabilities
From: Ivan T. Ivanov <hidden>
Date: 2015-03-25 13:11:09
Also in:
linux-arm-kernel, linux-arm-msm, linux-i2c, lkml
Hi Sricharan, On Fri, 2015-03-13 at 23:19 +0530, Sricharan R wrote:
#define QUP_I2C_MASTER_GEN 0x408 +#define QUP_I2C_MASTER_CONFIG 0x408
Unused.
#define QUP_READ_LIMIT 256 +#define MX_TX_RX_LEN SZ_64K +#define MX_BLOCKS (MX_TX_RX_LEN / QUP_READ_LIMIT) + +#define TOUT_MAX 300 /* Max timeout for 32k tx/tx */
seconds, muliseconds?
struct qup_i2c_config {
int tag_ver;
int max_freq;
};
+struct tag {Please use consistent naming convention.
quoted hunk ↗ jump to hunk
+ u8 *start; + dma_addr_t addr; +}; + struct qup_i2c_dev { struct device*dev; void __iomem*base;@@ -157,9 +181,35 @@ struct qup_i2c_dev { /* QUP core errors */ u32 qup_err; + /* dma parameters */ + bool is_dma; + struct dma_pool *dpool; + struct tag start_tag; + struct tag scratch_tag; + struct tag footer_tag; + struct dma_chan *dma_tx; + struct dma_chan *dma_rx; + struct scatterlist *sg_tx; + struct scatterlist *sg_rx; + dma_addr_tsg_tx_phys; + dma_addr_tsg_rx_phys;
Maybe these could be organized in structure per direction.
+
struct completionxfer;
};
+struct i2c_bam_xfer {Unused.
+ struct qup_i2c_dev *qup; + u32 start_len; + + u32 rx_nents; + u32 tx_nents; + + struct dma_async_tx_descriptor *tx_desc; + dma_cookie_t tx_cookie; + struct dma_async_tx_descriptor *rx_desc; + dma_cookie_t rx_cookie;
structure per direction.
+}; +
+static void bam_i2c_callback(void *data)
+{Please use consistent naming, here and bellow.
+ struct qup_i2c_dev *qup = data;
+
+ complete(&qup->xfer);
+}
+
+static int get_start_tag(u8 *tag, struct i2c_msg *msg, int first, int last,
+ int blen)
+{
+ u8 addr = (msg->addr << 1) | ((msg->flags & I2C_M_RD) == I2C_M_RD);
+ u8 op;
+ int len = 0;
+
+ /* always issue stop for each read block */
+ if (last) {
+ if (msg->flags & I2C_M_RD)
+ op = QUP_TAG_V2_DATARD_STOP;
+ else
+ op = QUP_TAG_V2_DATAWR_STOP;
+ } else {
+ if (msg->flags & I2C_M_RD)
+ op = QUP_TAG_V2_DATARD;
+ else
+ op = QUP_TAG_V2_DATAWR;
+ }
+
+ if (msg->flags & I2C_M_TEN) {
+ len += 5;
+ tag[0] = QUP_TAG_V2_START;
+ tag[1] = addr;
+ tag[2] = op;
+ tag[3] = blen;
+
+ if (msg->flags & I2C_M_RD && last) {
+ len += 2;
+ tag[4] = QUP_BAM_INPUT_EOT;
+ tag[5] = QUP_BAM_FLUSH_STOP;
+ }
+ } else {
+ if (first) {
+ tag[len++] = QUP_TAG_V2_START;
+ tag[len++] = addr;
+ }
+
+ tag[len++] = op;
+ tag[len++] = blen;
+
+ if (msg->flags & I2C_M_RD & last) {
+ tag[len++] = QUP_BAM_INPUT_EOT;
+ tag[len++] = QUP_BAM_FLUSH_STOP;
+ }
+ }
+
+ return len;
+}Maybe could be split to 2 functions?
-static const struct i2c_algorithm qup_i2c_algo = {
+static struct i2c_algorithm qup_i2c_algo = {Why?
quoted hunk ↗ jump to hunk
.master_xfer= qup_i2c_xfer, .functionality= qup_i2c_func, };@@ -839,6 +1136,7 @@ static int qup_i2c_probe(struct platform_device *pdev) u32 clk_freq = 100000; const struct qup_i2c_config *config; const struct of_device_id *of_id; + int blocks; qup = devm_kzalloc(&pdev->dev, sizeof(*qup), GFP_KERNEL); if (!qup)@@ -875,6 +1173,53 @@ static int qup_i2c_probe(struct platform_device *pdev) return qup->irq; } + if (of_device_is_compatible(pdev->dev.of_node, "qcom,i2c-qup-v2.1.1") || + of_device_is_compatible(pdev->dev.of_node, + "qcom,i2c-qup-v2.2.1")) {
Logic will be simpler if you check just for version 1 of the controller.
+ qup->dma_rx = dma_request_slave_channel(&pdev->dev, "bam-rx"); +
Please use dma_request_slave_channel_reason. As Andy noted, please use just "rx", "tx"
+ if (!qup->dma_rx) + return -EPROBE_DEFER;
Don't mask other errors, here and bellow. DMA support should be optional.
quoted hunk ↗ jump to hunk
dev_err(qup->dev, "Could not get core clock\n");@@ -989,6 +1334,14 @@ static int qup_i2c_remove(struct platform_device *pdev) { struct qup_i2c_dev *qup = platform_get_drvdata(pdev); + dma_pool_free(qup->dpool, qup->start_tag.start, + qup->start_tag.addr); + dma_pool_free(qup->dpool, qup->scratch_tag.start, + qup->scratch_tag.addr); + dma_pool_free(qup->dpool, qup->footer_tag.start, + qup->footer_tag.addr); + dma_pool_destroy(qup->dpool);
Only if is_dma, right? DMA mapping code omitted from review. I don't understand it well enough, sorry. Regards, Ivan -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html