1 files changed, 52 insertions, 82 deletions

diff --git a/drivers/i2c/busses/i2c-meson.c b/drivers/i2c/busses/i2c-meson.c
index 73b97c71a484..88d15b92ec35 100644
--- a/drivers/i2c/busses/i2c-meson.c
+++ b/drivers/i2c/busses/i2c-meson.c
@@ -35,10 +35,11 @@
 #define REG_CTRL_STATUS		BIT(2)
 #define REG_CTRL_ERROR		BIT(3)
 #define REG_CTRL_CLKDIV_SHIFT	12
-#define REG_CTRL_CLKDIV_MASK	((BIT(10) - 1) << REG_CTRL_CLKDIV_SHIFT)
+#define REG_CTRL_CLKDIV_MASK	GENMASK(21, 12)
+#define REG_CTRL_CLKDIVEXT_SHIFT 28
+#define REG_CTRL_CLKDIVEXT_MASK	GENMASK(29, 28)
 
 #define I2C_TIMEOUT_MS		500
-#define DEFAULT_FREQ		100000
 
 enum {
 	TOKEN_END = 0,
@@ -54,7 +55,6 @@ enum {
 	STATE_IDLE,
 	STATE_READ,
 	STATE_WRITE,
-	STATE_STOP,
 };
 
 /**
@@ -73,7 +73,6 @@ enum {
  * @error:	Flag set when an error is received
  * @lock:	To avoid race conditions between irq handler and xfer code
  * @done:	Completion used to wait for transfer termination
- * @frequency:	Operating frequency of I2C bus clock
  * @tokens:	Sequence of tokens to be written to the device
  * @num_tokens:	Number of tokens
  */
@@ -82,7 +81,6 @@ struct meson_i2c {
 	struct device		*dev;
 	void __iomem		*regs;
 	struct clk		*clk;
-	int			irq;
 
 	struct i2c_msg		*msg;
 	int			state;
@@ -93,7 +91,6 @@ struct meson_i2c {
 
 	spinlock_t		lock;
 	struct completion	done;
-	unsigned int		frequency;
 	u32			tokens[2];
 	int			num_tokens;
 };
@@ -126,23 +123,27 @@ static void meson_i2c_add_token(struct meson_i2c *i2c, int token)
 	i2c->num_tokens++;
 }
 
-static void meson_i2c_write_tokens(struct meson_i2c *i2c)
-{
-	writel(i2c->tokens[0], i2c->regs + REG_TOK_LIST0);
-	writel(i2c->tokens[1], i2c->regs + REG_TOK_LIST1);
-}
-
-static void meson_i2c_set_clk_div(struct meson_i2c *i2c)
+static void meson_i2c_set_clk_div(struct meson_i2c *i2c, unsigned int freq)
 {
 	unsigned long clk_rate = clk_get_rate(i2c->clk);
 	unsigned int div;
 
-	div = DIV_ROUND_UP(clk_rate, i2c->frequency * 4);
+	div = DIV_ROUND_UP(clk_rate, freq * 4);
+
+	/* clock divider has 12 bits */
+	if (div >= (1 << 12)) {
+		dev_err(i2c->dev, "requested bus frequency too low\n");
+		div = (1 << 12) - 1;
+	}
+
 	meson_i2c_set_mask(i2c, REG_CTRL, REG_CTRL_CLKDIV_MASK,
-			   div << REG_CTRL_CLKDIV_SHIFT);
+			   (div & GENMASK(9, 0)) << REG_CTRL_CLKDIV_SHIFT);
+
+	meson_i2c_set_mask(i2c, REG_CTRL, REG_CTRL_CLKDIVEXT_MASK,
+			   (div >> 10) << REG_CTRL_CLKDIVEXT_SHIFT);
 
 	dev_dbg(i2c->dev, "%s: clk %lu, freq %u, div %u\n", __func__,
-		clk_rate, i2c->frequency, div);
+		clk_rate, freq, div);
 }
 
 static void meson_i2c_get_data(struct meson_i2c *i2c, char *buf, int len)
@@ -156,10 +157,10 @@ static void meson_i2c_get_data(struct meson_i2c *i2c, char *buf, int len)
 	dev_dbg(i2c->dev, "%s: data %08x %08x len %d\n", __func__,
 		rdata0, rdata1, len);
 
-	for (i = 0; i < min_t(int, 4, len); i++)
+	for (i = 0; i < min(4, len); i++)
 		*buf++ = (rdata0 >> i * 8) & 0xff;
 
-	for (i = 4; i < min_t(int, 8, len); i++)
+	for (i = 4; i < min(8, len); i++)
 		*buf++ = (rdata1 >> (i - 4) * 8) & 0xff;
 }
 
@@ -168,10 +169,10 @@ static void meson_i2c_put_data(struct meson_i2c *i2c, char *buf, int len)
 	u32 wdata0 = 0, wdata1 = 0;
 	int i;
 
-	for (i = 0; i < min_t(int, 4, len); i++)
+	for (i = 0; i < min(4, len); i++)
 		wdata0 |= *buf++ << (i * 8);
 
-	for (i = 4; i < min_t(int, 8, len); i++)
+	for (i = 4; i < min(8, len); i++)
 		wdata1 |= *buf++ << ((i - 4) * 8);
 
 	writel(wdata0, i2c->regs + REG_TOK_WDATA0);
@@ -186,7 +187,7 @@ static void meson_i2c_prepare_xfer(struct meson_i2c *i2c)
 	bool write = !(i2c->msg->flags & I2C_M_RD);
 	int i;
 
-	i2c->count = min_t(int, i2c->msg->len - i2c->pos, 8);
+	i2c->count = min(i2c->msg->len - i2c->pos, 8);
 
 	for (i = 0; i < i2c->count - 1; i++)
 		meson_i2c_add_token(i2c, TOKEN_DATA);
@@ -200,19 +201,12 @@ static void meson_i2c_prepare_xfer(struct meson_i2c *i2c)
 
 	if (write)
 		meson_i2c_put_data(i2c, i2c->msg->buf + i2c->pos, i2c->count);
-}
-
-static void meson_i2c_stop(struct meson_i2c *i2c)
-{
-	dev_dbg(i2c->dev, "%s: last %d\n", __func__, i2c->last);
 
-	if (i2c->last) {
-		i2c->state = STATE_STOP;
+	if (i2c->last && i2c->pos + i2c->count >= i2c->msg->len)
 		meson_i2c_add_token(i2c, TOKEN_STOP);
-	} else {
-		i2c->state = STATE_IDLE;
-		complete(&i2c->done);
-	}
+
+	writel(i2c->tokens[0], i2c->regs + REG_TOK_LIST0);
+	writel(i2c->tokens[1], i2c->regs + REG_TOK_LIST1);
 }
 
 static irqreturn_t meson_i2c_irq(int irqno, void *dev_id)
@@ -223,12 +217,18 @@ static irqreturn_t meson_i2c_irq(int irqno, void *dev_id)
 	spin_lock(&i2c->lock);
 
 	meson_i2c_reset_tokens(i2c);
+	meson_i2c_set_mask(i2c, REG_CTRL, REG_CTRL_START, 0);
 	ctrl = readl(i2c->regs + REG_CTRL);
 
 	dev_dbg(i2c->dev, "irq: state %d, pos %d, count %d, ctrl %08x\n",
 		i2c->state, i2c->pos, i2c->count, ctrl);
 
-	if (ctrl & REG_CTRL_ERROR && i2c->state != STATE_IDLE) {
+	if (i2c->state == STATE_IDLE) {
+		spin_unlock(&i2c->lock);
+		return IRQ_NONE;
+	}
+
+	if (ctrl & REG_CTRL_ERROR) {
 		/*
 		 * The bit is set when the IGNORE_NAK bit is cleared
 		 * and the device didn't respond. In this case, the
@@ -242,48 +242,21 @@ static irqreturn_t meson_i2c_irq(int irqno, void *dev_id)
 		goto out;
 	}
 
-	switch (i2c->state) {
-	case STATE_READ:
-		if (i2c->count > 0) {
-			meson_i2c_get_data(i2c, i2c->msg->buf + i2c->pos,
-					   i2c->count);
-			i2c->pos += i2c->count;
-		}
-
-		if (i2c->pos >= i2c->msg->len) {
-			meson_i2c_stop(i2c);
-			break;
-		}
-
-		meson_i2c_prepare_xfer(i2c);
-		break;
-	case STATE_WRITE:
-		i2c->pos += i2c->count;
+	if (i2c->state == STATE_READ && i2c->count)
+		meson_i2c_get_data(i2c, i2c->msg->buf + i2c->pos, i2c->count);
 
-		if (i2c->pos >= i2c->msg->len) {
-			meson_i2c_stop(i2c);
-			break;
-		}
+	i2c->pos += i2c->count;
 
-		meson_i2c_prepare_xfer(i2c);
-		break;
-	case STATE_STOP:
+	if (i2c->pos >= i2c->msg->len) {
 		i2c->state = STATE_IDLE;
 		complete(&i2c->done);
-		break;
-	case STATE_IDLE:
-		break;
+		goto out;
 	}
 
+	/* Restart the processing */
+	meson_i2c_prepare_xfer(i2c);
+	meson_i2c_set_mask(i2c, REG_CTRL, REG_CTRL_START, REG_CTRL_START);
 out:
-	if (i2c->state != STATE_IDLE) {
-		/* Restart the processing */
-		meson_i2c_write_tokens(i2c);
-		meson_i2c_set_mask(i2c, REG_CTRL, REG_CTRL_START, 0);
-		meson_i2c_set_mask(i2c, REG_CTRL, REG_CTRL_START,
-				   REG_CTRL_START);
-	}
-
 	spin_unlock(&i2c->lock);
 
 	return IRQ_HANDLED;
@@ -323,7 +296,6 @@ static int meson_i2c_xfer_msg(struct meson_i2c *i2c, struct i2c_msg *msg,
 
 	i2c->state = (msg->flags & I2C_M_RD) ? STATE_READ : STATE_WRITE;
 	meson_i2c_prepare_xfer(i2c);
-	meson_i2c_write_tokens(i2c);
 	reinit_completion(&i2c->done);
 
 	/* Start the transfer */
@@ -359,21 +331,19 @@ static int meson_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
 			  int num)
 {
 	struct meson_i2c *i2c = adap->algo_data;
-	int i, ret = 0, count = 0;
+	int i, ret = 0;
 
 	clk_enable(i2c->clk);
-	meson_i2c_set_clk_div(i2c);
 
 	for (i = 0; i < num; i++) {
 		ret = meson_i2c_xfer_msg(i2c, msgs + i, i == num - 1);
 		if (ret)
 			break;
-		count++;
 	}
 
 	clk_disable(i2c->clk);
 
-	return ret ? ret : count;
+	return ret ?: i;
 }
 
 static u32 meson_i2c_func(struct i2c_adapter *adap)
@@ -391,15 +361,14 @@ static int meson_i2c_probe(struct platform_device *pdev)
 	struct device_node *np = pdev->dev.of_node;
 	struct meson_i2c *i2c;
 	struct resource *mem;
-	int ret = 0;
+	struct i2c_timings timings;
+	int irq, ret = 0;
 
 	i2c = devm_kzalloc(&pdev->dev, sizeof(struct meson_i2c), GFP_KERNEL);
 	if (!i2c)
 		return -ENOMEM;
 
-	if (of_property_read_u32(pdev->dev.of_node, "clock-frequency",
-				 &i2c->frequency))
-		i2c->frequency = DEFAULT_FREQ;
+	i2c_parse_fw_timings(&pdev->dev, &timings, true);
 
 	i2c->dev = &pdev->dev;
 	platform_set_drvdata(pdev, i2c);
@@ -418,14 +387,13 @@ static int meson_i2c_probe(struct platform_device *pdev)
 	if (IS_ERR(i2c->regs))
 		return PTR_ERR(i2c->regs);
 
-	i2c->irq = platform_get_irq(pdev, 0);
-	if (i2c->irq < 0) {
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
 		dev_err(&pdev->dev, "can't find IRQ\n");
-		return i2c->irq;
+		return irq;
 	}
 
-	ret = devm_request_irq(&pdev->dev, i2c->irq, meson_i2c_irq,
-			       0, dev_name(&pdev->dev), i2c);
+	ret = devm_request_irq(&pdev->dev, irq, meson_i2c_irq, 0, NULL, i2c);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "can't request IRQ\n");
 		return ret;
@@ -457,6 +425,8 @@ static int meson_i2c_probe(struct platform_device *pdev)
 		return ret;
 	}
 
+	meson_i2c_set_clk_div(i2c, timings.bus_freq_hz);
+
 	return 0;
 }