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>
---
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);
--
2.3.2
--
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