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 <[email protected]> --- 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 <[email protected]> * + * Modified by Andreas Larsson <[email protected]> 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 [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
