Sigma Designs chips use a variant of this controller with the following
differences:
- The BUSY bit in the STATUS register is inverted
- Bit 8 of the CONFIG register must be set
- The controller can generate interrupts
This patch adds support for the first two of these. It also calculates
and sets the correct clock divisor if a clk is provided. The bus
frequency is optionally speficied in the device tree node.
Signed-off-by: Mans Rullgard
---
drivers/i2c/busses/Kconfig | 6 ++--
drivers/i2c/busses/i2c-xlr.c | 81 +---
2 files changed, 80 insertions(+), 7 deletions(-)
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index f764e3a..fdedf59 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -944,11 +944,11 @@ config I2C_XILINX
will be called xilinx_i2c.
config I2C_XLR
- tristate "XLR I2C support"
- depends on CPU_XLR
+ tristate "Netlogic XLR and Sigma Designs I2C support"
+ depends on CPU_XLR || ARCH_TANGOX
help
This driver enables support for the on-chip I2C interface of
- the Netlogic XLR/XLS MIPS processors.
+ the Netlogic XLR/XLS MIPS processors and Sigma Designs SOCs.
This driver can also be built as a module. If so, the module
will be called i2c-xlr.
diff --git a/drivers/i2c/busses/i2c-xlr.c b/drivers/i2c/busses/i2c-xlr.c
index 8b36bcf..10fb916 100644
--- a/drivers/i2c/busses/i2c-xlr.c
+++ b/drivers/i2c/busses/i2c-xlr.c
@@ -17,6 +17,8 @@
#include
#include
#include
+#include
+#include
/* XLR I2C REGISTERS */
#define XLR_I2C_CFG0x00
@@ -63,11 +65,23 @@ static inline u32 xlr_i2c_rdreg(u32 __iomem *base, unsigned
int reg)
return __raw_readl(base + reg);
}
+struct xlr_i2c_config {
+ u32 status_busy;/* value of STATUS[0] when busy */
+ u32 cfg_extra; /* extra CFG bits to set */
+};
+
struct xlr_i2c_private {
struct i2c_adapter adap;
u32 __iomem *iobase;
+ const struct xlr_i2c_config *cfg;
+ struct clk *clk;
};
+static int xlr_i2c_busy(struct xlr_i2c_private *priv, u32 status)
+{
+ return (status & XLR_I2C_BUS_BUSY) == priv->cfg->status_busy;
+}
+
static int xlr_i2c_tx(struct xlr_i2c_private *priv, u16 len,
u8 *buf, u16 addr)
{
@@ -80,7 +94,8 @@ static int xlr_i2c_tx(struct xlr_i2c_private *priv, u16 len,
offset = buf[0];
xlr_i2c_wreg(priv->iobase, XLR_I2C_ADDR, offset);
xlr_i2c_wreg(priv->iobase, XLR_I2C_DEVADDR, addr);
- xlr_i2c_wreg(priv->iobase, XLR_I2C_CFG, XLR_I2C_CFG_ADDR);
+ xlr_i2c_wreg(priv->iobase, XLR_I2C_CFG,
+ XLR_I2C_CFG_ADDR | priv->cfg->cfg_extra);
xlr_i2c_wreg(priv->iobase, XLR_I2C_BYTECNT, len - 1);
timeout = msecs_to_jiffies(XLR_I2C_TIMEOUT);
@@ -121,7 +136,7 @@ retry:
if (i2c_status & XLR_I2C_ACK_ERR)
return -EIO;
- if ((i2c_status & XLR_I2C_BUS_BUSY) == 0 && pos >= len)
+ if (!xlr_i2c_busy(priv, i2c_status) && pos >= len)
return 0;
}
dev_err(&adap->dev, "I2C transmit timeout\n");
@@ -136,7 +151,8 @@ static int xlr_i2c_rx(struct xlr_i2c_private *priv, u16
len, u8 *buf, u16 addr)
int nbytes, timedout;
u8 byte;
- xlr_i2c_wreg(priv->iobase, XLR_I2C_CFG, XLR_I2C_CFG_NOADDR);
+ xlr_i2c_wreg(priv->iobase, XLR_I2C_CFG,
+ XLR_I2C_CFG_NOADDR | priv->cfg->cfg_extra);
xlr_i2c_wreg(priv->iobase, XLR_I2C_BYTECNT, len);
xlr_i2c_wreg(priv->iobase, XLR_I2C_DEVADDR, addr);
@@ -174,7 +190,7 @@ retry:
if (i2c_status & XLR_I2C_ACK_ERR)
return -EIO;
- if ((i2c_status & XLR_I2C_BUS_BUSY) == 0)
+ if (!xlr_i2c_busy(priv, i2c_status))
return 0;
}
@@ -190,6 +206,10 @@ static int xlr_i2c_xfer(struct i2c_adapter *adap,
int ret = 0;
struct xlr_i2c_private *priv = i2c_get_adapdata(adap);
+ ret = clk_enable(priv->clk);
+ if (ret)
+ return ret;
+
for (i = 0; ret == 0 && i < num; i++) {
msg = &msgs[i];
if (msg->flags & I2C_M_RD)
@@ -200,6 +220,8 @@ static int xlr_i2c_xfer(struct i2c_adapter *adap,
msg->addr);
}
+ clk_disable(priv->clk);
+
return (ret != 0) ? ret : num;
}
@@ -214,22 +236,70 @@ static struct i2c_algorithm xlr_i2c_algo = {
.functionality = xlr_func,
};
+static const struct xlr_i2c_config xlr_i2c_config_default = {
+ .status_busy= XLR_I2C_BUS_BUSY,
+ .cfg_extra = 0,
+};
+
+static const struct xlr_i2c_config xlr_i2c_config_tangox = {
+ .status_busy= 0,
+ .cfg_extra = 1 << 8,
+};
+
+static const struct of_device_id xlr_i2c_dt_ids[] = {
+ {
+
