Re: [PATCH 3/6] i2c: qup: Add bam dma capabilities
From: Sricharan R
Date: Thu Mar 26 2015 - 02:08:23 EST
Hi Ivan,
On 03/25/2015 06:40 PM, Ivan T. Ivanov wrote:
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.
Ok, will remove it
#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?
Ok. Will add milliseconds.
struct qup_i2c_config {
int tag_ver;
int max_freq;
};
+struct tag {
Please use consistent naming convention.
ok.
+ 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.
ok, will group it.
+
struct completionxfer;
};
+struct i2c_bam_xfer {
Unused.
Right. Will remove the whole thing. Thanks.
+ 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.
+};
+
Infact should be removed.
+static void bam_i2c_callback(void *data)
+{
Please use consistent naming, here and bellow.
ok, will change.
+ 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?
hmm, ok will split couple of small ones.
-static const struct i2c_algorithm qup_i2c_algo = {
+static struct i2c_algorithm qup_i2c_algo = {
Why?
oops. Should not have been changed. Will fix.
.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.
yes. Will fix it.
+ 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"
ok. will change it.
+ if (!qup->dma_rx)
+ return -EPROBE_DEFER;
Don't mask other errors, here and bellow. DMA support should be optional.
Ok, will fix here.
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?
Right. Will add the check.
DMA mapping code omitted from review. I don't understand it well enough, sorry.
Ok, thanks for reviewing the rest.
Regards,
Sricharan
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