i2c: designware: Add support for 16bit register access
The STM SPEAr platform can only access the i2c controller register via 16bit read/write functions. This patch adds support to automatically detect this 16bit access mode. Signed-off-by: Stefan Roese <sr@denx.de> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
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@ -164,9 +164,15 @@ static char *abort_sources[] = {
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u32 dw_readl(struct dw_i2c_dev *dev, int offset)
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{
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u32 value = readl(dev->base + offset);
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u32 value;
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if (dev->swab)
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if (dev->accessor_flags & ACCESS_16BIT)
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value = readw(dev->base + offset) |
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(readw(dev->base + offset + 2) << 16);
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else
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value = readl(dev->base + offset);
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if (dev->accessor_flags & ACCESS_SWAP)
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return swab32(value);
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else
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return value;
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@ -174,10 +180,15 @@ u32 dw_readl(struct dw_i2c_dev *dev, int offset)
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void dw_writel(struct dw_i2c_dev *dev, u32 b, int offset)
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{
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if (dev->swab)
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if (dev->accessor_flags & ACCESS_SWAP)
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b = swab32(b);
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writel(b, dev->base + offset);
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if (dev->accessor_flags & ACCESS_16BIT) {
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writew((u16)b, dev->base + offset);
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writew((u16)(b >> 16), dev->base + offset + 2);
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} else {
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writel(b, dev->base + offset);
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}
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}
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static u32
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@ -251,14 +262,14 @@ int i2c_dw_init(struct dw_i2c_dev *dev)
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input_clock_khz = dev->get_clk_rate_khz(dev);
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/* Configure register endianess access */
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reg = dw_readl(dev, DW_IC_COMP_TYPE);
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if (reg == ___constant_swab32(DW_IC_COMP_TYPE_VALUE)) {
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dev->swab = 1;
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reg = DW_IC_COMP_TYPE_VALUE;
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}
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if (reg != DW_IC_COMP_TYPE_VALUE) {
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/* Configure register endianess access */
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dev->accessor_flags |= ACCESS_SWAP;
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} else if (reg == (DW_IC_COMP_TYPE_VALUE & 0x0000ffff)) {
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/* Configure register access mode 16bit */
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dev->accessor_flags |= ACCESS_16BIT;
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} else if (reg != DW_IC_COMP_TYPE_VALUE) {
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dev_err(dev->dev, "Unknown Synopsys component type: "
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"0x%08x\n", reg);
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return -ENODEV;
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@ -82,7 +82,7 @@ struct dw_i2c_dev {
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unsigned int status;
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u32 abort_source;
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int irq;
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int swab;
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u32 accessor_flags;
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struct i2c_adapter adapter;
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u32 functionality;
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u32 master_cfg;
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@ -90,6 +90,9 @@ struct dw_i2c_dev {
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unsigned int rx_fifo_depth;
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};
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#define ACCESS_SWAP 0x00000001
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#define ACCESS_16BIT 0x00000002
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extern u32 dw_readl(struct dw_i2c_dev *dev, int offset);
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extern void dw_writel(struct dw_i2c_dev *dev, u32 b, int offset);
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extern int i2c_dw_init(struct dw_i2c_dev *dev);
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