[PATCH 4/4] i2c: i2c-ocores: support for 16bit and 32bit IO
From: Jayachandran C <hidden>
Date: 2012-07-13 06:39:03
Also in:
linux-i2c
Subsystem:
i2c subsystem, i2c subsystem host drivers, open firmware and flattened device tree bindings, opencores i2c bus driver, the rest · Maintainers:
Andi Shyti, Rob Herring, Krzysztof Kozlowski, Conor Dooley, Peter Korsgaard, Andrew Lunn, Linus Torvalds
Possibly related (same subject, not in this thread)
- 2012-06-05 · [PATCH 4/4] i2c: i2c-ocores: support for 16bit and 32bit IO · Jayachandran C <hidden>
From: Ganesan Ramalingam <ganesanr-dY08KVG/lbpWk0Htik3J/w@public.gmane.org> Some architectures supports only 16-bit or 32-bit read/write access to their IO space. Add a 'reg-io-width' platform and OF parameter which specifies the IO width to support these platforms. reg-io-width can be specified as 1, 2 or 4, and has a default value of 1 if it is unspecified. Signed-off-by: Ganesan Ramalingam <ganesanr-dY08KVG/lbpWk0Htik3J/w@public.gmane.org> Signed-off-by: Jayachandran C <jayachandranc-oSioyQM9ZPnuBjGU1YDckgC/G2K4zDHf@public.gmane.org> --- .../devicetree/bindings/i2c/i2c-ocores.txt | 2 ++ drivers/i2c/busses/i2c-ocores.c | 21 ++++++++++++++++++-- include/linux/i2c-ocores.h | 1 + 3 files changed, 22 insertions(+), 2 deletions(-)
diff --git a/Documentation/devicetree/bindings/i2c/i2c-ocores.txt b/Documentation/devicetree/bindings/i2c/i2c-ocores.txt
index 1c9334b..c15781f 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-ocores.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c-ocores.txt@@ -10,6 +10,7 @@ Required properties: Optional properties: - reg-shift : device register offsets are shifted by this value +- reg-io-width : io register width in bytes (1, 2 or 4) - regstep : deprecated, use reg-shift above Example:
@@ -23,6 +24,7 @@ Example: clock-frequency = <20000000>; reg-shift = <0>; /* 8 bit registers */ + reg-io-width = <1>; /* 8 bit read/write */ dummy@60 { compatible = "dummy";
diff --git a/drivers/i2c/busses/i2c-ocores.c b/drivers/i2c/busses/i2c-ocores.c
index fb8db30..7e710bd 100644
--- a/drivers/i2c/busses/i2c-ocores.c
+++ b/drivers/i2c/busses/i2c-ocores.c@@ -30,6 +30,7 @@ struct ocores_i2c { void __iomem *base; int reg_shift; + int reg_io_width; wait_queue_head_t wait; struct i2c_adapter adap; struct i2c_msg *msg;
@@ -72,12 +73,22 @@ struct ocores_i2c { static inline void oc_setreg(struct ocores_i2c *i2c, int reg, u8 value) { - iowrite8(value, i2c->base + (reg << i2c->reg_shift)); + if (i2c->reg_io_width == 4) + iowrite32(value, i2c->base + (reg << i2c->reg_shift)); + else if (i2c->reg_io_width == 2) + iowrite16(value, i2c->base + (reg << i2c->reg_shift)); + else + iowrite8(value, i2c->base + (reg << i2c->reg_shift)); } static inline u8 oc_getreg(struct ocores_i2c *i2c, int reg) { - return ioread8(i2c->base + (reg << i2c->reg_shift)); + if (i2c->reg_io_width == 4) + return ioread32(i2c->base + (reg << i2c->reg_shift)); + else if (i2c->reg_io_width == 2) + return ioread16(i2c->base + (reg << i2c->reg_shift)); + else + return ioread8(i2c->base + (reg << i2c->reg_shift)); } static void ocores_process(struct ocores_i2c *i2c)
@@ -245,6 +256,8 @@ static int ocores_i2c_of_probe(struct platform_device *pdev, } i2c->clock_khz = val / 1000; + if (!of_property_read_u32(pdev->dev.of_node, "reg-io-width", &val)) + i2c->reg_io_width = val; return 0; } #else
@@ -287,6 +300,7 @@ static int __devinit ocores_i2c_probe(struct platform_device *pdev) pdata = pdev->dev.platform_data; if (pdata) { i2c->reg_shift = pdata->reg_shift; + i2c->reg_io_width = pdata->reg_io_width; i2c->clock_khz = pdata->clock_khz; } else { ret = ocores_i2c_of_probe(pdev, i2c);
@@ -294,6 +308,9 @@ static int __devinit ocores_i2c_probe(struct platform_device *pdev) return ret; } + if (i2c->reg_io_width == 0) + i2c->reg_io_width = 1; /* Set to default value */ + ocores_init(i2c); init_waitqueue_head(&i2c->wait);
diff --git a/include/linux/i2c-ocores.h b/include/linux/i2c-ocores.h
index 75d7767..5fef682 100644
--- a/include/linux/i2c-ocores.h
+++ b/include/linux/i2c-ocores.h@@ -13,6 +13,7 @@ struct ocores_i2c_platform_data { int reg_shift; /* register offset shift value */ + int reg_io_width; /* register io read/write width */ u32 clock_khz; /* input clock in kHz */ u8 num_devices; /* number of devices in the devices list */ struct i2c_board_info const *devices; /* devices connected to the bus */
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1.7.9.5