From b299167652fe58f1ebadb3e3ac84a5a0b74e534e Mon Sep 17 00:00:00 2001 From: Max Filippov Date: Wed, 7 Oct 2015 02:45:11 +0300 Subject: [PATCH] i2c: ocores: support big-endian register layout This allows using OpenCores I2C controller attached to its host in native-endian mode with bi-endian CPUs. Example of such system is Xtensa XTFPGA platform. Acked-by: Peter Korsgaard Signed-off-by: Max Filippov Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-ocores.c | 31 +++++++++++++++++++++++++++---- include/linux/i2c-ocores.h | 1 + 2 files changed, 28 insertions(+), 4 deletions(-) diff --git a/drivers/i2c/busses/i2c-ocores.c b/drivers/i2c/busses/i2c-ocores.c index abf5db7..11b7b87 100644 --- a/drivers/i2c/busses/i2c-ocores.c +++ b/drivers/i2c/busses/i2c-ocores.c @@ -92,6 +92,16 @@ static void oc_setreg_32(struct ocores_i2c *i2c, int reg, u8 value) iowrite32(value, i2c->base + (reg << i2c->reg_shift)); } +static void oc_setreg_16be(struct ocores_i2c *i2c, int reg, u8 value) +{ + iowrite16be(value, i2c->base + (reg << i2c->reg_shift)); +} + +static void oc_setreg_32be(struct ocores_i2c *i2c, int reg, u8 value) +{ + iowrite32be(value, i2c->base + (reg << i2c->reg_shift)); +} + static inline u8 oc_getreg_8(struct ocores_i2c *i2c, int reg) { return ioread8(i2c->base + (reg << i2c->reg_shift)); @@ -107,6 +117,16 @@ static inline u8 oc_getreg_32(struct ocores_i2c *i2c, int reg) return ioread32(i2c->base + (reg << i2c->reg_shift)); } +static inline u8 oc_getreg_16be(struct ocores_i2c *i2c, int reg) +{ + return ioread16be(i2c->base + (reg << i2c->reg_shift)); +} + +static inline u8 oc_getreg_32be(struct ocores_i2c *i2c, int reg) +{ + return ioread32be(i2c->base + (reg << i2c->reg_shift)); +} + static inline void oc_setreg(struct ocores_i2c *i2c, int reg, u8 value) { i2c->setreg(i2c, reg, value); @@ -428,6 +448,9 @@ static int ocores_i2c_probe(struct platform_device *pdev) i2c->reg_io_width = 1; /* Set to default value */ if (!i2c->setreg || !i2c->getreg) { + bool be = pdata ? pdata->big_endian : + of_device_is_big_endian(pdev->dev.of_node); + switch (i2c->reg_io_width) { case 1: i2c->setreg = oc_setreg_8; @@ -435,13 +458,13 @@ static int ocores_i2c_probe(struct platform_device *pdev) break; case 2: - i2c->setreg = oc_setreg_16; - i2c->getreg = oc_getreg_16; + i2c->setreg = be ? oc_setreg_16be : oc_setreg_16; + i2c->getreg = be ? oc_getreg_16be : oc_getreg_16; break; case 4: - i2c->setreg = oc_setreg_32; - i2c->getreg = oc_getreg_32; + i2c->setreg = be ? oc_setreg_32be : oc_setreg_32; + i2c->getreg = be ? oc_getreg_32be : oc_getreg_32; break; default: diff --git a/include/linux/i2c-ocores.h b/include/linux/i2c-ocores.h index 1c06b5c..01edd96 100644 --- a/include/linux/i2c-ocores.h +++ b/include/linux/i2c-ocores.h @@ -15,6 +15,7 @@ struct ocores_i2c_platform_data { u32 reg_shift; /* register offset shift value */ u32 reg_io_width; /* register io read/write width */ u32 clock_khz; /* input clock in kHz */ + bool big_endian; /* registers are big endian */ u8 num_devices; /* number of devices in the devices list */ struct i2c_board_info const *devices; /* devices connected to the bus */ }; -- 2.7.4