This patch implements interrupt sharing and SDA hold time configuration in the designware i2c driver. Both functions are enabled through platform data or device tree. Tested with Linux-3.8rc4 (Synopsys ARC port, see https://github.com/foss-for-synopsys-dwc-arc-processors/linux/commits/arc-3.8-baseline). Signed-off-by: Christian Ruppert <christian.ruppert@xxxxxxxxxx> Signed-off-by: Pierrick Hascoet <pierrick.hascoet@xxxxxxxxxx> --- .../devicetree/bindings/i2c/i2c-designware.txt | 18 ++++++++++ drivers/i2c/busses/i2c-designware-core.c | 6 +++ drivers/i2c/busses/i2c-designware-core.h | 2 + drivers/i2c/busses/i2c-designware-platdrv.c | 34 +++++++++++++++++++- include/linux/i2c/i2c-designware.h | 13 +++++++ 5 files changed, 72 insertions(+), 1 deletions(-) create mode 100644 include/linux/i2c/i2c-designware.h diff --git a/Documentation/devicetree/bindings/i2c/i2c-designware.txt b/Documentation/devicetree/bindings/i2c/i2c-designware.txt index e42a2ee..474386b 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-designware.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-designware.txt @@ -10,6 +10,12 @@ Recommended properties : - clock-frequency : desired I2C bus clock frequency in Hz. +Optional properties : + - interrupts-shared : If this property is present, the interrupt line is + considered shared with other devices. + - sda-hold-time : If this property is present, the register SDA_HOLD will + be initialised with its value. + Example : i2c@f0000 { @@ -20,3 +26,15 @@ Example : interrupts = <11>; clock-frequency = <400000>; }; + + i2c@1120000 { + #address-cells = <1>; + #size-cells = <0>; + compatible = "snps,designware-i2c"; + reg = <0x1120000 0x1000>; + interrupt-parent = <&ictl>; + interrupts = <12 1>; + interrupts-shared; + clock-frequency = <400000>; + sda-hold-time = <0x64>; + }; diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c index cbba7db..36ba0b5 100644 --- a/drivers/i2c/busses/i2c-designware-core.c +++ b/drivers/i2c/busses/i2c-designware-core.c @@ -34,6 +34,7 @@ #include <linux/io.h> #include <linux/pm_runtime.h> #include <linux/delay.h> +#include <linux/i2c/i2c-designware.h> #include "i2c-designware-core.h" /* @@ -66,6 +67,7 @@ #define DW_IC_STATUS 0x70 #define DW_IC_TXFLR 0x74 #define DW_IC_RXFLR 0x78 +#define DW_IC_SDA_HOLD 0x7c #define DW_IC_TX_ABRT_SOURCE 0x80 #define DW_IC_COMP_PARAM_1 0xf4 #define DW_IC_COMP_TYPE 0xfc @@ -309,6 +311,10 @@ int i2c_dw_init(struct dw_i2c_dev *dev) dw_writel(dev, lcnt, DW_IC_FS_SCL_LCNT); dev_dbg(dev->dev, "Fast-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt); + /* Configure SDA Hold Time if required */ + if (dev->pdat_flags & I2C_DW_PDAT_FLAGS_SET_HOLDTIME) + dw_writel(dev, dev->sda_hold_time, DW_IC_SDA_HOLD); + /* Configure Tx/Rx FIFO threshold levels */ dw_writel(dev, dev->tx_fifo_depth - 1, DW_IC_TX_TL); dw_writel(dev, 0, DW_IC_RX_TL); diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h index 9c1840e..ef20477 100644 --- a/drivers/i2c/busses/i2c-designware-core.h +++ b/drivers/i2c/busses/i2c-designware-core.h @@ -88,6 +88,8 @@ struct dw_i2c_dev { u32 master_cfg; unsigned int tx_fifo_depth; unsigned int rx_fifo_depth; + u32 sda_hold_time; + unsigned int pdat_flags; }; #define ACCESS_SWAP 0x00000001 diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c index 343357a..2ad2da3 100644 --- a/drivers/i2c/busses/i2c-designware-platdrv.c +++ b/drivers/i2c/busses/i2c-designware-platdrv.c @@ -34,11 +34,13 @@ #include <linux/sched.h> #include <linux/err.h> #include <linux/interrupt.h> +#include <linux/of.h> #include <linux/of_i2c.h> #include <linux/platform_device.h> #include <linux/pm.h> #include <linux/io.h> #include <linux/slab.h> +#include <linux/i2c/i2c-designware.h> #include "i2c-designware-core.h" static struct i2c_algorithm i2c_dw_algo = { @@ -56,6 +58,28 @@ static int dw_i2c_probe(struct platform_device *pdev) struct i2c_adapter *adap; struct resource *mem, *ioarea; int irq, r; + unsigned long irqf; + struct i2c_designware_platform_data *pdat = pdev->dev.platform_data; + + if ((!pdat) && pdev->dev.of_node) { + struct device_node *node = pdev->dev.of_node; + + pdat = kmalloc(sizeof(struct i2c_designware_platform_data), + GFP_KERNEL); + if (!pdat) + return -ENOMEM; + + pdat->flags = 0; + + if (of_get_property(node, "interrupts-shared", NULL)) + pdat->flags |= I2C_DW_PDAT_FLAGS_SHARE_IRQ; + + if (!of_property_read_u32(node, "sda-hold-time", + &pdat->sda_hold_time)) + pdat->flags |= I2C_DW_PDAT_FLAGS_SET_HOLDTIME; + + pdev->dev.platform_data = pdat; + } /* NOTE: driver uses the static register mapping */ mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); @@ -120,12 +144,20 @@ static int dw_i2c_probe(struct platform_device *pdev) dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1; dev->rx_fifo_depth = ((param1 >> 8) & 0xff) + 1; } + dev->sda_hold_time = pdat->sda_hold_time; + dev->pdat_flags = pdat->flags; + r = i2c_dw_init(dev); if (r) goto err_iounmap; i2c_dw_disable_int(dev); - r = request_irq(dev->irq, i2c_dw_isr, IRQF_DISABLED, pdev->name, dev); + + irqf = IRQF_DISABLED; + if (dev->pdat_flags & I2C_DW_PDAT_FLAGS_SHARE_IRQ) + irqf |= IRQF_SHARED; + + r = request_irq(dev->irq, i2c_dw_isr, irqf, pdev->name, dev); if (r) { dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq); goto err_iounmap; diff --git a/include/linux/i2c/i2c-designware.h b/include/linux/i2c/i2c-designware.h new file mode 100644 index 0000000..ea8192a --- /dev/null +++ b/include/linux/i2c/i2c-designware.h @@ -0,0 +1,13 @@ +#ifndef __I2C_DESIGNWARE_H__ +#define __I2C_DESIGNWARE_H__ + +#include <linux/platform_device.h> + +struct i2c_designware_platform_data { + unsigned int flags; +#define I2C_DW_PDAT_FLAGS_SHARE_IRQ (1L<<0) +#define I2C_DW_PDAT_FLAGS_SET_HOLDTIME (1L<<1) + u32 sda_hold_time; +}; + +#endif /* __I2C_DESIGNWARE_H__ */ -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
