>>>>> "Andreas" == Andreas Larsson <andr...@gaisler.com> writes:
Andreas> The registers in the GRLIB port of the controller are 32-bit
Andreas> and in big endian byte order. The PRELOW and PREHIGH registers
Andreas> are merged into one register. The subsequent registers have
Andreas> their offset decreased accordingly. Hence the register access
Andreas> needs to be handled in a non-standard manner using custom
Andreas> getreg and
Andreas> setreg functions.
Andreas> Signed-off-by: Andreas Larsson <andr...@gaisler.com>
Andreas> ---
Andreas> drivers/i2c/busses/i2c-ocores.c | 57
+++++++++++++++++++++++++++++++++++++-
Andreas> 1 files changed, 55 insertions(+), 2 deletions(-)
Andreas> diff --git a/drivers/i2c/busses/i2c-ocores.c
b/drivers/i2c/busses/i2c-ocores.c
Andreas> index 1eb8a65..e3df62f 100644
Andreas> --- a/drivers/i2c/busses/i2c-ocores.c
Andreas> +++ b/drivers/i2c/busses/i2c-ocores.c
Andreas> @@ -4,6 +4,9 @@
Andreas> *
Andreas> * Peter Korsgaard <jac...@sunsite.dk>
Andreas> *
Andreas> + * Support for the GRLIB port of the controller by
Andreas> + * Andreas Larsson <andr...@gaisler.com>
Andreas> + *
Andreas> * This file is licensed under the terms of the GNU General Public
License
Andreas> * version 2. This program is licensed "as is" without any warranty
of any
Andreas> * kind, whether express or implied.
Andreas> @@ -38,6 +41,8 @@ struct ocores_i2c {
Andreas> int nmsgs;
Andreas> int state; /* see STATE_ */
Andreas> int clock_khz;
Andreas> + void (*setreg)(struct ocores_i2c *i2c, int reg, u8 value);
Andreas> + u8 (*getreg)(struct ocores_i2c *i2c, int reg);
Andreas> };
Andreas> /* registers */
Andreas> @@ -73,7 +78,9 @@ struct ocores_i2c {
Andreas> static inline void oc_setreg(struct ocores_i2c *i2c, int reg, u8
value)
Andreas> {
Andreas> - if (i2c->reg_io_width == 4)
Andreas> + if (i2c->setreg)
Andreas> + i2c->setreg(i2c, reg, value);
Andreas> + else if (i2c->reg_io_width == 4)
Andreas> iowrite32(value, i2c->base + (reg << i2c->reg_shift));
Andreas> else if (i2c->reg_io_width == 2)
Andreas> iowrite16(value, i2c->base + (reg << i2c->reg_shift));
Andreas> @@ -83,7 +90,9 @@ static inline void oc_setreg(struct ocores_i2c
*i2c, int reg, u8 value)
Andreas> static inline u8 oc_getreg(struct ocores_i2c *i2c, int reg)
Andreas> {
Andreas> - if (i2c->reg_io_width == 4)
Andreas> + if (i2c->getreg)
Andreas> + return i2c->getreg(i2c, reg);
Andreas> + else if (i2c->reg_io_width == 4)
Andreas> return ioread32(i2c->base + (reg << i2c->reg_shift));
Andreas> else if (i2c->reg_io_width == 2)
Andreas> return ioread16(i2c->base + (reg << i2c->reg_shift));
Andreas> @@ -91,6 +100,40 @@ static inline u8 oc_getreg(struct ocores_i2c
*i2c, int reg)
Andreas> return ioread8(i2c->base + (reg << i2c->reg_shift));
Andreas> }
Andreas> +/* Read and write functions for the GRLIB port of the controller.
Registers are
Andreas> + * 32-bit big endian and the PRELOW and PREHIGH registers are merged
into one
Andreas> + * register. The subsequent registers has their offset decreased
accordingly. */
Andreas> +static u8 oc_getreg_grlib(struct ocores_i2c *i2c, int reg)
Andreas> +{
Andreas> + u32 rd;
Andreas> + int rreg = reg;
Andreas> + if (reg != OCI2C_PRELOW)
Andreas> + rreg--;
Andreas> + rd = ioread32be(i2c->base + (rreg << i2c->reg_shift));
Andreas> + if (reg == OCI2C_PREHIGH)
Andreas> + return (u8)rd >> 8;
Andreas> + else
Andreas> + return (u8)rd;
Andreas> +}
Andreas> +
Andreas> +static void oc_setreg_grlib(struct ocores_i2c *i2c, int reg, u8
value)
Andreas> +{
Andreas> + u32 curr, wr;
Andreas> + int rreg = reg;
Andreas> + if (reg != OCI2C_PRELOW)
Andreas> + rreg--;
Andreas> + if (reg == OCI2C_PRELOW || reg == OCI2C_PREHIGH) {
Andreas> + curr = ioread32be(i2c->base + (rreg << i2c->reg_shift));
Andreas> + if (reg == OCI2C_PRELOW)
Andreas> + wr = (curr & 0xff00) | value;
Andreas> + else
Andreas> + wr = (((u32)value) << 8) | (curr & 0xff);
Andreas> + } else {
Andreas> + wr = value;
Andreas> + }
Andreas> + iowrite32be(wr, i2c->base + (rreg << i2c->reg_shift));
Are all platforms using i2c-ocores guaranteed to provide ioread32be /
iowrite32be or should we stick an #ifdef CONFIG_SPARC around it?
--
Bye, Peter Korsgaard
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