The registers are 32-bit and in big endian byte order. The PRELOW and PREHIGH
registers are merged into one register. The subsequent registers have their
offset decreased accordingly.
Signed-off-by: Andreas Larsson <andreas@xxxxxxxxxxx>
---
drivers/i2c/busses/i2c-ocores.c | 47 +++++++++++++++++++++++++++++++++++++++
1 files changed, 47 insertions(+), 0 deletions(-)
diff --git a/drivers/i2c/busses/i2c-ocores.c b/drivers/i2c/busses/i2c-ocores.c
index de93b2d..1895e8c 100644
--- a/drivers/i2c/busses/i2c-ocores.c
+++ b/drivers/i2c/busses/i2c-ocores.c
@@ -4,6 +4,9 @@
*
* Peter Korsgaard <jacmet@xxxxxxxxxx>
*
+ * Modified by Andreas Larsson <andreas@xxxxxxxxxxx> to support the GRLIB port
+ * of the controller.
+ *
* This file is licensed under the terms of the GNU General Public License
* version 2. This program is licensed "as is" without any warranty of any
* kind, whether express or implied.
@@ -99,6 +102,40 @@ static inline u8 oc_getreg(struct ocores_i2c *i2c, int reg)
return ioread8(i2c->base + (reg << i2c->reg_shift));
}
+/* Read and write functions for the GRLIB port of the controller. Registers are
+ * 32-bit big endian and the PRELOW and PREHIGH registers are merged into one
+ * register. The subsequent registers has their offset decreased accordingly. */
+static u8 oc_getreg_grlib(struct ocores_i2c *i2c, int reg)
+{
+ u32 rd;
+ int rreg = reg;
+ if (reg != OCI2C_PRELOW)
+ rreg--;
+ rd = ioread32be(i2c->base + (rreg << i2c->reg_shift));
+ if (reg == OCI2C_PREHIGH)
+ return (u8)rd >> 8;
+ else
+ return (u8)rd;
+}
+
+static void oc_setreg_grlib(struct ocores_i2c *i2c, int reg, u8 value)
+{
+ u32 curr, wr;
+ int rreg = reg;
+ if (reg != OCI2C_PRELOW)
+ rreg--;
+ if (reg == OCI2C_PRELOW || reg == OCI2C_PREHIGH) {
+ curr = ioread32be(i2c->base + (rreg << i2c->reg_shift));
+ if (reg == OCI2C_PRELOW)
+ wr = (curr & 0xff00) | value;
+ else
+ wr = (((u32)value) << 8) | (curr & 0xff);
+ } else {
+ wr = value;
+ }
+ iowrite32be(wr, i2c->base + (rreg << i2c->reg_shift));
+}
+
static void ocores_process(struct ocores_i2c *i2c)
{
struct i2c_msg *msg = i2c->msg;
@@ -241,6 +278,7 @@ static int ocores_i2c_of_probe(struct platform_device *pdev,
{
struct device_node *np = pdev->dev.of_node;
u32 val;
+ const char *name;
if (of_property_read_u32(np, "reg-shift", &i2c->reg_shift)) {
/* no 'reg-shift', check for deprecated 'regstep' */
@@ -265,6 +303,15 @@ static int ocores_i2c_of_probe(struct platform_device *pdev,
of_property_read_u32(pdev->dev.of_node, "reg-io-width",
&i2c->reg_io_width);
+
+ name = of_get_property(pdev->dev.of_node, "name", NULL);
+ if (name && (!strcmp(name, "GAISLER_I2CMST") ||
+ !strcmp(name, "01_028"))) {
+ dev_dbg(&pdev->dev, "GRLIB variant of i2c-ocores\n");
+ i2c->setreg = oc_setreg_grlib;
+ i2c->getreg = oc_getreg_grlib;
+ }
+
return 0;
}
#else
--
1.7.0.4
--
To unsubscribe from this list: send the line "unsubscribe linux-i2c" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
