diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-xlp9xx.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-xlp9xx.c | 44 |
1 files changed, 40 insertions, 4 deletions
diff --git a/drivers/i2c/busses/i2c-xlp9xx.c b/drivers/i2c/busses/i2c-xlp9xx.c index 6b106e94bc09..b970bf8f38e5 100644 --- a/drivers/i2c/busses/i2c-xlp9xx.c +++ b/drivers/i2c/busses/i2c-xlp9xx.c @@ -7,6 +7,7 @@ */ #include <linux/acpi.h> +#include <linux/clk.h> #include <linux/completion.h> #include <linux/i2c.h> #include <linux/init.h> @@ -81,9 +82,12 @@ struct xlp9xx_i2c_dev { struct completion msg_complete; int irq; bool msg_read; + bool len_recv; + bool client_pec; u32 __iomem *base; u32 msg_buf_remaining; u32 msg_len; + u32 ip_clk_hz; u32 clk_hz; u32 msg_err; u8 *msg_buf; @@ -141,10 +145,25 @@ static void xlp9xx_i2c_fill_tx_fifo(struct xlp9xx_i2c_dev *priv) static void xlp9xx_i2c_drain_rx_fifo(struct xlp9xx_i2c_dev *priv) { u32 len, i; - u8 *buf = priv->msg_buf; + u8 rlen, *buf = priv->msg_buf; len = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_FIFOWCNT) & XLP9XX_I2C_FIFO_WCNT_MASK; + if (!len) + return; + if (priv->len_recv) { + /* read length byte */ + rlen = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_MRXFIFO); + *buf++ = rlen; + len--; + if (priv->client_pec) + ++rlen; + /* update remaining bytes and message length */ + priv->msg_buf_remaining = rlen; + priv->msg_len = rlen + 1; + priv->len_recv = false; + } + len = min(priv->msg_buf_remaining, len); for (i = 0; i < len; i++, buf++) *buf = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_MRXFIFO); @@ -213,7 +232,7 @@ static int xlp9xx_i2c_init(struct xlp9xx_i2c_dev *priv) * The controller uses 5 * SCL clock internally. * So prescale value should be divided by 5. */ - prescale = DIV_ROUND_UP(XLP9XX_I2C_IP_CLK_FREQ, priv->clk_hz); + prescale = DIV_ROUND_UP(priv->ip_clk_hz, priv->clk_hz); prescale = ((prescale - 8) / 5) - 1; xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_CTRL, XLP9XX_I2C_CTRL_RST); xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_CTRL, XLP9XX_I2C_CTRL_EN | @@ -228,7 +247,7 @@ static int xlp9xx_i2c_xfer_msg(struct xlp9xx_i2c_dev *priv, struct i2c_msg *msg, int last_msg) { unsigned long timeleft; - u32 intr_mask, cmd, val; + u32 intr_mask, cmd, val, len; priv->msg_buf = msg->buf; priv->msg_buf_remaining = priv->msg_len = msg->len; @@ -261,9 +280,13 @@ static int xlp9xx_i2c_xfer_msg(struct xlp9xx_i2c_dev *priv, struct i2c_msg *msg, else val &= ~XLP9XX_I2C_CTRL_ADDMODE; + priv->len_recv = msg->flags & I2C_M_RECV_LEN; + len = priv->len_recv ? XLP9XX_I2C_FIFO_SIZE : msg->len; + priv->client_pec = msg->flags & I2C_CLIENT_PEC; + /* set data length to be transferred */ val = (val & ~XLP9XX_I2C_CTRL_MCTLEN_MASK) | - (msg->len << XLP9XX_I2C_CTRL_MCTLEN_SHIFT); + (len << XLP9XX_I2C_CTRL_MCTLEN_SHIFT); xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_CTRL, val); /* fill fifo during tx */ @@ -310,6 +333,9 @@ static int xlp9xx_i2c_xfer_msg(struct xlp9xx_i2c_dev *priv, struct i2c_msg *msg, return -ETIMEDOUT; } + /* update msg->len with actual received length */ + if (msg->flags & I2C_M_RECV_LEN) + msg->len = priv->msg_len; return 0; } @@ -342,9 +368,19 @@ static const struct i2c_algorithm xlp9xx_i2c_algo = { static int xlp9xx_i2c_get_frequency(struct platform_device *pdev, struct xlp9xx_i2c_dev *priv) { + struct clk *clk; u32 freq; int err; + clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(clk)) { + priv->ip_clk_hz = XLP9XX_I2C_IP_CLK_FREQ; + dev_dbg(&pdev->dev, "using default input frequency %u\n", + priv->ip_clk_hz); + } else { + priv->ip_clk_hz = clk_get_rate(clk); + } + err = device_property_read_u32(&pdev->dev, "clock-frequency", &freq); if (err) { freq = XLP9XX_I2C_DEFAULT_FREQ; |