From 6eb89ef029fe22aee518a9dc75b9ee5d6ef9b3fe Mon Sep 17 00:00:00 2001 From: Gao Pan Date: Fri, 2 Dec 2016 11:38:16 +0800 Subject: [PATCH] i2c: fsl-lpi2c: read lpi2c fifo size in probe() The lpi2c fifo size is a read only parameter resides Parameter Register. It's better to read lpi2c tx/rx fifo size in probe() other than just define a macro for it. Signed-off-by: Gao Pan Reviewed-by: Vladimir Zapolskiy Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-imx-lpi2c.c | 24 +++++++++++++++--------- 1 file changed, 15 insertions(+), 9 deletions(-) diff --git a/drivers/i2c/busses/i2c-imx-lpi2c.c b/drivers/i2c/busses/i2c-imx-lpi2c.c index 9794ff6feefb..c62b7cd475f8 100644 --- a/drivers/i2c/busses/i2c-imx-lpi2c.c +++ b/drivers/i2c/busses/i2c-imx-lpi2c.c @@ -83,9 +83,6 @@ #define I2C_CLK_RATIO 2 #define CHUNK_DATA 256 -#define LPI2C_RX_FIFOSIZE 4 -#define LPI2C_TX_FIFOSIZE 4 - #define LPI2C_DEFAULT_RATE 100000 #define STARDARD_MAX_BITRATE 400000 #define FAST_MAX_BITRATE 1000000 @@ -118,6 +115,8 @@ struct lpi2c_imx_struct { unsigned int delivered; unsigned int block_data; unsigned int bitrate; + unsigned int txfifosize; + unsigned int rxfifosize; enum lpi2c_imx_mode mode; }; @@ -346,7 +345,7 @@ static int lpi2c_imx_txfifo_empty(struct lpi2c_imx_struct *lpi2c_imx) static void lpi2c_imx_set_tx_watermark(struct lpi2c_imx_struct *lpi2c_imx) { - writel(LPI2C_TX_FIFOSIZE >> 1, lpi2c_imx->base + LPI2C_MFCR); + writel(lpi2c_imx->txfifosize >> 1, lpi2c_imx->base + LPI2C_MFCR); } static void lpi2c_imx_set_rx_watermark(struct lpi2c_imx_struct *lpi2c_imx) @@ -355,8 +354,8 @@ static void lpi2c_imx_set_rx_watermark(struct lpi2c_imx_struct *lpi2c_imx) remaining = lpi2c_imx->msglen - lpi2c_imx->delivered; - if (remaining > (LPI2C_RX_FIFOSIZE >> 1)) - temp = LPI2C_RX_FIFOSIZE >> 1; + if (remaining > (lpi2c_imx->rxfifosize >> 1)) + temp = lpi2c_imx->rxfifosize >> 1; else temp = 0; @@ -369,7 +368,7 @@ static void lpi2c_imx_write_txfifo(struct lpi2c_imx_struct *lpi2c_imx) txcnt = readl(lpi2c_imx->base + LPI2C_MFSR) & 0xff; - while (txcnt < LPI2C_TX_FIFOSIZE) { + while (txcnt < lpi2c_imx->txfifosize) { if (lpi2c_imx->delivered == lpi2c_imx->msglen) break; @@ -554,6 +553,7 @@ static int lpi2c_imx_probe(struct platform_device *pdev) { struct lpi2c_imx_struct *lpi2c_imx; struct resource *res; + unsigned int temp; int irq, ret; lpi2c_imx = devm_kzalloc(&pdev->dev, sizeof(*lpi2c_imx), GFP_KERNEL); @@ -599,12 +599,18 @@ static int lpi2c_imx_probe(struct platform_device *pdev) i2c_set_adapdata(&lpi2c_imx->adapter, lpi2c_imx); platform_set_drvdata(pdev, lpi2c_imx); - ret = clk_prepare(lpi2c_imx->clk); + ret = clk_prepare_enable(lpi2c_imx->clk); if (ret) { - dev_err(&pdev->dev, "clk prepare failed %d\n", ret); + dev_err(&pdev->dev, "clk enable failed %d\n", ret); return ret; } + temp = readl(lpi2c_imx->base + LPI2C_PARAM); + lpi2c_imx->txfifosize = 1 << (temp & 0x0f); + lpi2c_imx->rxfifosize = 1 << ((temp >> 8) & 0x0f); + + clk_disable(lpi2c_imx->clk); + ret = i2c_add_adapter(&lpi2c_imx->adapter); if (ret) goto clk_unprepare; -- 2.20.1