On 16/12/15 12:49, Kamal Dasu wrote:
> Broadcoms DSL, CM (cable modem)and STB I2C core implementation have
> 8 data in/out registers that can transfer 8 bytes or 32 bytes max.
> Cable and DSL "Peripheral" i2c cores use single byte per data
> register and the STB can use 4 byte per data register transfer.
> Adding support to take care of this difference. Accordingly added
> the compatible string for SoCs using the "Peripheral" I2C block.
>
> Signed-off-by: Kamal Dasu <kdasu.kdev@xxxxxxxxx>
Reviewed-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
Thanks Kamal!
> ---
> drivers/i2c/busses/i2c-brcmstb.c | 80 ++++++++++++++++++++++++++++------------
> 1 file changed, 56 insertions(+), 24 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-brcmstb.c b/drivers/i2c/busses/i2c-brcmstb.c
> index 8e9637e..3711df1 100644
> --- a/drivers/i2c/busses/i2c-brcmstb.c
> +++ b/drivers/i2c/busses/i2c-brcmstb.c
> @@ -25,13 +25,16 @@
> #include <linux/version.h>
>
> #define N_DATA_REGS 8
> -#define N_DATA_BYTES (N_DATA_REGS * 4)
>
> -/* BSC count register field definitions */
> -#define BSC_CNT_REG1_MASK 0x0000003f
> -#define BSC_CNT_REG1_SHIFT 0
> -#define BSC_CNT_REG2_MASK 0x00000fc0
> -#define BSC_CNT_REG2_SHIFT 6
> +/*
> + * PER_I2C/BSC count register mask depends on 1 byte/4 byte data register
> + * size. Cable modem and DSL SoCs with Peripheral i2c cores use 1 byte per
> + * data register whereas STB SoCs use 4 byte per data register transfer,
> + * account for this difference in total count per transaction and mask to
> + * use.
> + */
> +#define BSC_CNT_REG1_MASK(nb) (nb == 1 ? GENMASK(3, 0) : GENMASK(5, 0))
> +#define BSC_CNT_REG1_SHIFT 0
>
> /* BSC CTL register field definitions */
> #define BSC_CTL_REG_DTF_MASK 0x00000003
> @@ -41,7 +44,7 @@
> #define BSC_CTL_REG_INT_EN_SHIFT 6
> #define BSC_CTL_REG_DIV_CLK_MASK 0x00000080
>
> -/* BSC_IIC_ENABLE r/w enable and interrupt field defintions */
> +/* BSC_IIC_ENABLE r/w enable and interrupt field definitions */
> #define BSC_IIC_EN_RESTART_MASK 0x00000040
> #define BSC_IIC_EN_NOSTART_MASK 0x00000020
> #define BSC_IIC_EN_NOSTOP_MASK 0x00000010
> @@ -169,6 +172,7 @@ struct brcmstb_i2c_dev {
> struct completion done;
> bool is_suspended;
> u32 clk_freq_hz;
> + int data_regsz;
> };
>
> /* register accessors for both be and le cpu arch */
> @@ -186,6 +190,16 @@ struct brcmstb_i2c_dev {
> #define bsc_writel(_dev, _val, _reg) \
> __bsc_writel(_val, _dev->base + offsetof(struct bsc_regs, _reg))
>
> +static inline int brcmstb_i2c_get_xfersz(struct brcmstb_i2c_dev *dev)
> +{
> + return (N_DATA_REGS * dev->data_regsz);
> +}
> +
> +static inline int brcmstb_i2c_get_data_regsz(struct brcmstb_i2c_dev *dev)
> +{
> + return dev->data_regsz;
> +}
> +
> static void brcmstb_i2c_enable_disable_irq(struct brcmstb_i2c_dev *dev,
> bool int_en)
> {
> @@ -323,14 +337,16 @@ static int brcmstb_i2c_xfer_bsc_data(struct brcmstb_i2c_dev *dev,
> u8 *buf, unsigned int len,
> struct i2c_msg *pmsg)
> {
> - int cnt, byte, rc;
> + int cnt, byte, i, rc;
> enum bsc_xfer_cmd cmd;
> u32 ctl_reg;
> struct bsc_regs *pi2creg = dev->bsc_regmap;
> int no_ack = pmsg->flags & I2C_M_IGNORE_NAK;
> + int data_regsz = brcmstb_i2c_get_data_regsz(dev);
> + int xfersz = brcmstb_i2c_get_xfersz(dev);
>
> /* see if the transaction needs to check NACK conditions */
> - if (no_ack || len <= N_DATA_BYTES) {
> + if (no_ack || len <= xfersz) {
> cmd = (pmsg->flags & I2C_M_RD) ? CMD_RD_NOACK
> : CMD_WR_NOACK;
> pi2creg->ctlhi_reg |= BSC_CTLHI_REG_IGNORE_ACK_MASK;
> @@ -348,20 +364,22 @@ static int brcmstb_i2c_xfer_bsc_data(struct brcmstb_i2c_dev *dev,
> pi2creg->ctl_reg = ctl_reg | DTF_RD_MASK;
>
> /* set the read/write length */
> - bsc_writel(dev, BSC_CNT_REG1_MASK & (len << BSC_CNT_REG1_SHIFT),
> - cnt_reg);
> + bsc_writel(dev, BSC_CNT_REG1_MASK(data_regsz) &
> + (len << BSC_CNT_REG1_SHIFT), cnt_reg);
>
> /* Write data into data_in register */
> +
> if (cmd == CMD_WR || cmd == CMD_WR_NOACK) {
> - for (cnt = 0; cnt < len; cnt += 4) {
> + for (cnt = 0, i = 0; cnt < len; cnt += data_regsz, i++) {
> u32 word = 0;
>
> - for (byte = 0; byte < 4; byte++) {
> - word >>= 8;
> + for (byte = 0; byte < data_regsz; byte++) {
> + word >>= BITS_PER_BYTE;
> if ((cnt + byte) < len)
> - word |= buf[cnt + byte] << 24;
> + word |= buf[cnt + byte] <<
> + (BITS_PER_BYTE * (data_regsz - 1));
> }
> - bsc_writel(dev, word, data_in[cnt >> 2]);
> + bsc_writel(dev, word, data_in[i]);
> }
> }
>
> @@ -373,14 +391,15 @@ static int brcmstb_i2c_xfer_bsc_data(struct brcmstb_i2c_dev *dev,
> return rc;
> }
>
> + /* Read data from data_out register */
> if (cmd == CMD_RD || cmd == CMD_RD_NOACK) {
> - for (cnt = 0; cnt < len; cnt += 4) {
> - u32 data = bsc_readl(dev, data_out[cnt >> 2]);
> + for (cnt = 0, i = 0; cnt < len; cnt += data_regsz, i++) {
> + u32 data = bsc_readl(dev, data_out[i]);
>
> - for (byte = 0; byte < 4 &&
> + for (byte = 0; byte < data_regsz &&
> (byte + cnt) < len; byte++) {
> buf[cnt + byte] = data & 0xff;
> - data >>= 8;
> + data >>= BITS_PER_BYTE;
> }
> }
> }
> @@ -448,6 +467,7 @@ static int brcmstb_i2c_xfer(struct i2c_adapter *adapter,
> int bytes_to_xfer;
> u8 *tmp_buf;
> int len = 0;
> + int xfersz = brcmstb_i2c_get_xfersz(dev);
>
> if (dev->is_suspended)
> return -EBUSY;
> @@ -482,9 +502,9 @@ static int brcmstb_i2c_xfer(struct i2c_adapter *adapter,
>
> /* Perform data transfer */
> while (len) {
> - bytes_to_xfer = min(len, N_DATA_BYTES);
> + bytes_to_xfer = min(len, xfersz);
>
> - if (len <= N_DATA_BYTES && i == (num - 1))
> + if (len <= xfersz && i == (num - 1))
> brcmstb_set_i2c_start_stop(dev,
> ~(COND_START_STOP));
>
> @@ -542,8 +562,12 @@ static void brcmstb_i2c_set_bus_speed(struct brcmstb_i2c_dev *dev)
>
> static void brcmstb_i2c_set_bsc_reg_defaults(struct brcmstb_i2c_dev *dev)
> {
> - /* 4 byte data register */
> - dev->bsc_regmap->ctlhi_reg = BSC_CTLHI_REG_DATAREG_SIZE_MASK;
> + if (brcmstb_i2c_get_data_regsz(dev) == sizeof(u32))
> + /* set 4 byte data in/out xfers */
> + dev->bsc_regmap->ctlhi_reg = BSC_CTLHI_REG_DATAREG_SIZE_MASK;
> + else
> + dev->bsc_regmap->ctlhi_reg &= ~BSC_CTLHI_REG_DATAREG_SIZE_MASK;
> +
> bsc_writel(dev, dev->bsc_regmap->ctlhi_reg, ctlhi_reg);
> /* set bus speed */
> brcmstb_i2c_set_bus_speed(dev);
> @@ -608,6 +632,13 @@ static int brcmstb_i2c_probe(struct platform_device *pdev)
> dev->clk_freq_hz = bsc_clk[0].hz;
> }
>
> + /* set the data in/out register size for compatible SoCs */
> + if (of_device_is_compatible(dev->device->of_node,
> + "brcmstb,brcmper-i2c"))
> + dev->data_regsz = sizeof(u8);
> + else
> + dev->data_regsz = sizeof(u32);
> +
> brcmstb_i2c_set_bsc_reg_defaults(dev);
>
> /* Add the i2c adapter */
> @@ -674,6 +705,7 @@ static SIMPLE_DEV_PM_OPS(brcmstb_i2c_pm, brcmstb_i2c_suspend,
>
> static const struct of_device_id brcmstb_i2c_of_match[] = {
> {.compatible = "brcm,brcmstb-i2c"},
> + {.compatible = "brcm,brcmper-i2c"},
> {},
> };
> MODULE_DEVICE_TABLE(of, brcmstb_i2c_of_match);
>
--
Florian
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