Merge branch 'i2c/for-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

Pull i2c updates from Wolfram Sang: "Highlights: - new drivers for Mediatek I2C, APM X-Gene, Broadcom Settop - major updates to at91, davinci - bugfixes to the mux infrastructure when dealing with the new quirk mechanism - more users for the bus recovery feature - further improvements to the slave framework Plus the usual bunch of smaller driver and core improvements and fixes. There is one patch removing old code from an ARM platform. This has been acked by the sh_mobile maintainer Simon Horman" * 'i2c/for-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (48 commits) i2c: busses: i2c-bcm2835: limits cdiv to allowed values i2c: sh_mobile: use proper type for timeout i2c: sh_mobile: use adapter default for timeout i2c: rcar: use proper type for timeout i2c: rcar: use adapter default for timeout i2c: designware: Make sure the device is suspended before disabling runtime PM i2c: tegra: apply size limit quirk i2c: tegra: don't advertise SMBUS_QUICK i2c: octeon: remove unused signal handling i2c: davinci: Optimize SCL generation i2c: mux: pca954x: Use __i2c_transfer because of quirks i2c: mux: Use __i2c_transfer() instead of calling parent's master_xfer() i2c: use parent adapter quirks in mux i2c: bcm2835: clear reserved bits in S-Register ARM: shmobile: r8a7740: remove I2C errata handling i2c: sh_mobile: add errata workaround i2c: at91: fix code checker warnings i2c: busses: xgene-slimpro: fix incorrect __init declation for probe i2c: davinci: Avoid sending to own address i2c: davinci: Refactor i2c_davinci_wait_bus_not_busy() ...
2026-05-01 15:00:59 -07:00 · 2015-06-25 18:42:39 -07:00
parent 9390bd0d14 a294aba164
commit 24867481b8
35 changed files with 2729 additions and 220 deletions
@@ -2,8 +2,8 @@ I2C for Atmel platforms

 Required properties :
 - compatible : Must be "atmel,at91rm9200-i2c", "atmel,at91sam9261-i2c",
-     "atmel,at91sam9260-i2c", "atmel,at91sam9g20-i2c", "atmel,at91sam9g10-i2c"
-     or "atmel,at91sam9x5-i2c"
+     "atmel,at91sam9260-i2c", "atmel,at91sam9g20-i2c", "atmel,at91sam9g10-i2c",
+     "atmel,at91sam9x5-i2c" or "atmel,sama5d2-i2c"
 - reg: physical base address of the controller and length of memory mapped
     region.
 - interrupts: interrupt number to the cpu.
@@ -13,6 +13,10 @@ Required properties :

 Optional properties:
 - clock-frequency: Desired I2C bus frequency in Hz, otherwise defaults to 100000
+- dmas: A list of two dma specifiers, one for each entry in dma-names.
+- dma-names: should contain "tx" and "rx".
+- atmel,fifo-size: maximum number of data the RX and TX FIFOs can store for FIFO
+  capable I2C controllers.
 - Child nodes conforming to i2c bus binding

 Examples :
@@ -32,3 +36,25 @@ i2c0: i2c@fff84000 {
 		pagesize = <128>;
 	}
 }
+
+i2c0: i2c@f8034600 {
+	compatible = "atmel,sama5d2-i2c";
+	reg = <0xf8034600 0x100>;
+	interrupts = <19 IRQ_TYPE_LEVEL_HIGH 7>;
+	dmas = <&dma0
+		(AT91_XDMAC_DT_MEM_IF(0) | AT91_XDMAC_DT_PER_IF(1))
+		AT91_XDMAC_DT_PERID(11)>,
+	       <&dma0
+		(AT91_XDMAC_DT_MEM_IF(0) | AT91_XDMAC_DT_PER_IF(1))
+		AT91_XDMAC_DT_PERID(12)>;
+	dma-names = "tx", "rx";
+	#address-cells = <1>;
+	#size-cells = <0>;
+	clocks = <&flx0>;
+	atmel,fifo-size = <16>;
+
+	wm8731: wm8731@1a {
+		compatible = "wm8731";
+		reg = <0x1a>;
+	};
+};
@@ -0,0 +1,28 @@
+Broadcom stb bsc iic master controller
+
+Required properties:
+
+- compatible: should be "brcm,brcmstb-i2c"
+- clock-frequency: 32-bit decimal value of iic master clock freqency in Hz
+		   valid values are 375000, 390000, 187500, 200000
+		   93750, 97500, 46875 and 50000
+- reg: specifies the base physical address and size of the registers
+
+Optional properties :
+
+- interrupt-parent: specifies the phandle to the parent interrupt controller
+  this one is cascaded from
+- interrupts: specifies the interrupt number, the irq line to be used
+- interrupt-names: Interrupt name string
+
+Example:
+
+bsca: i2c@f0406200 {
+      clock-frequency = <390000>;
+      compatible = "brcm,brcmstb-i2c";
+      interrupt-parent = <&irq0_intc>;
+      reg = <0xf0406200 0x58>;
+      interrupts = <0x18>;
+      interrupt-names = "upg_bsca";
+};
+
@@ -0,0 +1,41 @@
+* Mediatek's I2C controller
+
+The Mediatek's I2C controller is used to interface with I2C devices.
+
+Required properties:
+  - compatible: value should be either of the following.
+      (a) "mediatek,mt6577-i2c", for i2c compatible with mt6577 i2c.
+      (b) "mediatek,mt6589-i2c", for i2c compatible with mt6589 i2c.
+      (c) "mediatek,mt8127-i2c", for i2c compatible with mt8127 i2c.
+      (d) "mediatek,mt8135-i2c", for i2c compatible with mt8135 i2c.
+      (e) "mediatek,mt8173-i2c", for i2c compatible with mt8173 i2c.
+  - reg: physical base address of the controller and dma base, length of memory
+    mapped region.
+  - interrupts: interrupt number to the cpu.
+  - clock-div: the fixed value for frequency divider of clock source in i2c
+    module. Each IC may be different.
+  - clocks: clock name from clock manager
+  - clock-names: Must include "main" and "dma", if enable have-pmic need include
+    "pmic" extra.
+
+Optional properties:
+  - clock-frequency: Frequency in Hz of the bus when transfer, the default value
+    is 100000.
+  - mediatek,have-pmic: platform can control i2c form special pmic side.
+    Only mt6589 and mt8135 support this feature.
+  - mediatek,use-push-pull: IO config use push-pull mode.
+
+Example:
+
+	i2c0: i2c@1100d000 {
+			compatible = "mediatek,mt6577-i2c";
+			reg = <0x1100d000 0x70>,
+			      <0x11000300 0x80>;
+			interrupts = <GIC_SPI 44 IRQ_TYPE_LEVEL_LOW>;
+			clock-frequency = <400000>;
+			mediatek,have-pmic;
+			clock-div = <16>;
+			clocks = <&i2c0_ck>, <&ap_dma_ck>;
+			clock-names = "main", "dma";
+	};
+
@@ -0,0 +1,15 @@
+APM X-Gene SLIMpro Mailbox I2C Driver
+
+An I2C controller accessed over the "SLIMpro" mailbox.
+
+Required properties :
+
+ - compatible : should be "apm,xgene-slimpro-i2c"
+ - mboxes : use the label reference for the mailbox as the first parameter.
+	    The second parameter is the channel number.
+
+Example :
+	i2cslimpro {
+		compatible = "apm,xgene-slimpro-i2c";
+		mboxes = <&mailbox 0>;
+	};
@@ -3,16 +3,16 @@ Linux I2C slave interface description

 by Wolfram Sang <wsa@sang-engineering.com> in 2014-15

-Linux can also be an I2C slave in case I2C controllers have slave support.
-Besides this HW requirement, one also needs a software backend providing the
-actual functionality. An example for this is the slave-eeprom driver, which
-acts as a dual memory driver. While another I2C master on the bus can access it
-like a regular EEPROM, the Linux I2C slave can access the content via sysfs and
-retrieve/provide information as needed. The software backend driver and the I2C
-bus driver communicate via events. Here is a small graph visualizing the data
-flow and the means by which data is transported. The dotted line marks only one
-example. The backend could also use e.g. a character device, be in-kernel
-only, or something completely different:
+Linux can also be an I2C slave if the I2C controller in use has slave
+functionality. For that to work, one needs slave support in the bus driver plus
+a hardware independent software backend providing the actual functionality. An
+example for the latter is the slave-eeprom driver, which acts as a dual memory
+driver. While another I2C master on the bus can access it like a regular
+EEPROM, the Linux I2C slave can access the content via sysfs and handle data as
+needed. The backend driver and the I2C bus driver communicate via events. Here
+is a small graph visualizing the data flow and the means by which data is
+transported. The dotted line marks only one example. The backend could also
+use a character device, be in-kernel only, or something completely different:


              e.g. sysfs        I2C slave events        I/O registers
@@ -43,6 +43,11 @@ behaviour and setup.
 Developer manual
 ================

+First, the events which are used by the bus driver and the backend will be
+described in detail. After that, some implementation hints for extending bus
+drivers and writing backends will be given.
+
+
 I2C slave events
 ----------------

@@ -13,7 +13,6 @@
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */
-#include <linux/delay.h>
 #include <linux/dma-mapping.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
@@ -690,56 +689,6 @@ void __init r8a7740_meram_workaround(void)
 	}
 }

-#define ICCR	0x0004
-#define ICSTART	0x0070
-
-#define i2c_read(reg, offset)		ioread8(reg + offset)
-#define i2c_write(reg, offset, data)	iowrite8(data, reg + offset)
-
-/*
- * r8a7740 chip has lasting errata on I2C I/O pad reset.
- * this is work-around for it.
- */
-static void r8a7740_i2c_workaround(struct platform_device *pdev)
-{
-	struct resource *res;
-	void __iomem *reg;
-
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (unlikely(!res)) {
-		pr_err("r8a7740 i2c workaround fail (cannot find resource)\n");
-		return;
-	}
-
-	reg = ioremap(res->start, resource_size(res));
-	if (unlikely(!reg)) {
-		pr_err("r8a7740 i2c workaround fail (cannot map IO)\n");
-		return;
-	}
-
-	i2c_write(reg, ICCR, i2c_read(reg, ICCR) | 0x80);
-	i2c_read(reg, ICCR); /* dummy read */
-
-	i2c_write(reg, ICSTART, i2c_read(reg, ICSTART) | 0x10);
-	i2c_read(reg, ICSTART); /* dummy read */
-
-	udelay(10);
-
-	i2c_write(reg, ICCR, 0x01);
-	i2c_write(reg, ICSTART, 0x00);
-
-	udelay(10);
-
-	i2c_write(reg, ICCR, 0x10);
-	udelay(10);
-	i2c_write(reg, ICCR, 0x00);
-	udelay(10);
-	i2c_write(reg, ICCR, 0x10);
-	udelay(10);
-
-	iounmap(reg);
-}
-
 void __init r8a7740_add_standard_devices(void)
 {
 	static struct pm_domain_device domain_devices[] __initdata = {
@@ -766,10 +715,6 @@ void __init r8a7740_add_standard_devices(void)
 		{ "A3SP", &usb_dma_device },
 	};

-	/* I2C work-around */
-	r8a7740_i2c_workaround(&i2c0_device);
-	r8a7740_i2c_workaround(&i2c1_device);
-
 	r8a7740_init_pm_domains();

 	/* add devices */
@@ -521,7 +521,7 @@ static int pca_init(struct i2c_adapter *adap)

 		pca_set_con(pca_data, I2C_PCA_CON_ENSIO);
 	}
-	udelay(500); /* 500 us for oscilator to stabilise */
+	udelay(500); /* 500 us for oscillator to stabilise */

 	return 0;
 }
@@ -392,6 +392,16 @@ config I2C_BCM_KONA

 	  If you do not need KONA I2C interface, say N.

+config I2C_BRCMSTB
+	tristate "BRCM Settop I2C controller"
+	depends on ARCH_BRCMSTB || COMPILE_TEST
+	default y
+	help
+	  If you say yes to this option, support will be included for the
+	  I2C interface on the Broadcom Settop SoCs.
+
+	  If you do not need I2C interface, say N.
+
 config I2C_BLACKFIN_TWI
 	tristate "Blackfin TWI I2C support"
 	depends on BLACKFIN
@@ -419,7 +429,7 @@ config I2C_CADENCE

 config I2C_CBUS_GPIO
 	tristate "CBUS I2C driver"
-	depends on GPIOLIB
+	depends on GPIOLIB || COMPILE_TEST
 	help
 	  Support for CBUS access using I2C API. Mostly relevant for Nokia
 	  Internet Tablets (770, N800 and N810).
@@ -525,7 +535,7 @@ config I2C_EXYNOS5

 config I2C_GPIO
 	tristate "GPIO-based bitbanging I2C"
-	depends on GPIOLIB
+	depends on GPIOLIB || COMPILE_TEST
 	select I2C_ALGOBIT
 	help
 	  This is a very simple bitbanging I2C driver utilizing the
@@ -620,6 +630,15 @@ config I2C_MPC
 	  This driver can also be built as a module.  If so, the module
 	  will be called i2c-mpc.

+config I2C_MT65XX
+	tristate "MediaTek I2C adapter"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	help
+	  This selects the MediaTek(R) Integrated Inter Circuit bus driver
+	  for MT65xx and MT81xx.
+	  If you want to use MediaTek(R) I2C interface, say Y or M here.
+	  If unsure, say N.
+
 config I2C_MV64XXX
 	tristate "Marvell mv64xxx I2C Controller"
 	depends on MV64X60 || PLAT_ORION || ARCH_SUNXI
@@ -1110,6 +1129,15 @@ config I2C_CROS_EC_TUNNEL
 	  connected there. This will work whatever the interface used to
 	  talk to the EC (SPI, I2C or LPC).

+config I2C_XGENE_SLIMPRO
+	tristate "APM X-Gene SoC I2C SLIMpro devices support"
+	depends on ARCH_XGENE && MAILBOX
+	help
+	  Enable I2C bus access using the APM X-Gene SoC SLIMpro
+	  co-processor. The I2C device access the I2C bus via the X-Gene
+	  to SLIMpro (On chip coprocessor) mailbox mechanism.
+	  If unsure, say N.
+
 config SCx200_ACB
 	tristate "Geode ACCESS.bus support"
 	depends on X86_32 && PCI
@@ -60,6 +60,7 @@ obj-$(CONFIG_I2C_JZ4780)	+= i2c-jz4780.o
 obj-$(CONFIG_I2C_KEMPLD)	+= i2c-kempld.o
 obj-$(CONFIG_I2C_MESON)		+= i2c-meson.o
 obj-$(CONFIG_I2C_MPC)		+= i2c-mpc.o
+obj-$(CONFIG_I2C_MT65XX)	+= i2c-mt65xx.o
 obj-$(CONFIG_I2C_MV64XXX)	+= i2c-mv64xxx.o
 obj-$(CONFIG_I2C_MXS)		+= i2c-mxs.o
 obj-$(CONFIG_I2C_NOMADIK)	+= i2c-nomadik.o
@@ -105,11 +106,13 @@ obj-$(CONFIG_I2C_VIPERBOARD)	+= i2c-viperboard.o
 # Other I2C/SMBus bus drivers
 obj-$(CONFIG_I2C_ACORN)		+= i2c-acorn.o
 obj-$(CONFIG_I2C_BCM_KONA)	+= i2c-bcm-kona.o
+obj-$(CONFIG_I2C_BRCMSTB)	+= i2c-brcmstb.o
 obj-$(CONFIG_I2C_CROS_EC_TUNNEL)	+= i2c-cros-ec-tunnel.o
 obj-$(CONFIG_I2C_ELEKTOR)	+= i2c-elektor.o
 obj-$(CONFIG_I2C_OPAL)		+= i2c-opal.o
 obj-$(CONFIG_I2C_PCA_ISA)	+= i2c-pca-isa.o
 obj-$(CONFIG_I2C_SIBYTE)	+= i2c-sibyte.o
+obj-$(CONFIG_I2C_XGENE_SLIMPRO) += i2c-xgene-slimpro.o
 obj-$(CONFIG_SCx200_ACB)	+= scx200_acb.o

 ccflags-$(CONFIG_I2C_DEBUG_BUS) := -DDEBUG
@@ -42,6 +42,10 @@
 #define IBML_LOW_SEXT		0x18
 #define TIMER_CLOCK_DIV		0x1c
 #define I2C_BUS_MONITOR		0x20
+#define   BM_SDAC		BIT(3)
+#define   BM_SCLC		BIT(2)
+#define   BM_SDAS		BIT(1)
+#define   BM_SCLS		BIT(0)
 #define SOFT_RESET		0x24
 #define MST_COMMAND		0x28
 #define   CMD_BUSY		(1<<3)
@@ -394,6 +398,9 @@ static int axxia_i2c_xfer_msg(struct axxia_i2c_dev *idev, struct i2c_msg *msg)
 	if (time_left == 0)
 		idev->msg_err = -ETIMEDOUT;

+	if (idev->msg_err == -ETIMEDOUT)
+		i2c_recover_bus(&idev->adapter);
+
 	if (unlikely(idev->msg_err) && idev->msg_err != -ENXIO)
 		axxia_i2c_init(idev);

@@ -437,6 +444,39 @@ axxia_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 	return ret ? : i;
 }

+static int axxia_i2c_get_scl(struct i2c_adapter *adap)
+{
+	struct axxia_i2c_dev *idev = i2c_get_adapdata(adap);
+
+	return !!(readl(idev->base + I2C_BUS_MONITOR) & BM_SCLS);
+}
+
+static void axxia_i2c_set_scl(struct i2c_adapter *adap, int val)
+{
+	struct axxia_i2c_dev *idev = i2c_get_adapdata(adap);
+	u32 tmp;
+
+	/* Preserve SDA Control */
+	tmp = readl(idev->base + I2C_BUS_MONITOR) & BM_SDAC;
+	if (!val)
+		tmp |= BM_SCLC;
+	writel(tmp, idev->base + I2C_BUS_MONITOR);
+}
+
+static int axxia_i2c_get_sda(struct i2c_adapter *adap)
+{
+	struct axxia_i2c_dev *idev = i2c_get_adapdata(adap);
+
+	return !!(readl(idev->base + I2C_BUS_MONITOR) & BM_SDAS);
+}
+
+static struct i2c_bus_recovery_info axxia_i2c_recovery_info = {
+	.recover_bus = i2c_generic_scl_recovery,
+	.get_scl = axxia_i2c_get_scl,
+	.set_scl = axxia_i2c_set_scl,
+	.get_sda = axxia_i2c_get_sda,
+};
+
 static u32 axxia_i2c_func(struct i2c_adapter *adap)
 {
 	u32 caps = (I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR |
@@ -511,6 +551,7 @@ static int axxia_i2c_probe(struct platform_device *pdev)
 	strlcpy(idev->adapter.name, pdev->name, sizeof(idev->adapter.name));
 	idev->adapter.owner = THIS_MODULE;
 	idev->adapter.algo = &axxia_i2c_algo;
+	idev->adapter.bus_recovery_info = &axxia_i2c_recovery_info;
 	idev->adapter.quirks = &axxia_i2c_quirks;
 	idev->adapter.dev.parent = &pdev->dev;
 	idev->adapter.dev.of_node = pdev->dev.of_node;
@@ -91,6 +91,7 @@ struct bcm_iproc_i2c_dev {
 	void __iomem *base;

 	struct i2c_adapter adapter;
+	unsigned int bus_speed;

 	struct completion done;
 	int xfer_is_done;
@@ -309,6 +310,7 @@ static int bcm_iproc_i2c_cfg_speed(struct bcm_iproc_i2c_dev *iproc_i2c)
 		bus_speed = 400000;
 	}

+	iproc_i2c->bus_speed = bus_speed;
 	val = readl(iproc_i2c->base + TIM_CFG_OFFSET);
 	val &= ~(1 << TIM_CFG_MODE_400_SHIFT);
 	val |= (bus_speed == 400000) << TIM_CFG_MODE_400_SHIFT;
@@ -439,6 +441,60 @@ static int bcm_iproc_i2c_remove(struct platform_device *pdev)
 	return 0;
 }

+#ifdef CONFIG_PM_SLEEP
+
+static int bcm_iproc_i2c_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct bcm_iproc_i2c_dev *iproc_i2c = platform_get_drvdata(pdev);
+
+	/* make sure there's no pending interrupt when we go into suspend */
+	writel(0, iproc_i2c->base + IE_OFFSET);
+	readl(iproc_i2c->base + IE_OFFSET);
+	synchronize_irq(iproc_i2c->irq);
+
+	/* now disable the controller */
+	bcm_iproc_i2c_enable_disable(iproc_i2c, false);
+
+	return 0;
+}
+
+static int bcm_iproc_i2c_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct bcm_iproc_i2c_dev *iproc_i2c = platform_get_drvdata(pdev);
+	int ret;
+	u32 val;
+
+	/*
+	 * Power domain could have been shut off completely in system deep
+	 * sleep, so re-initialize the block here
+	 */
+	ret = bcm_iproc_i2c_init(iproc_i2c);
+	if (ret)
+		return ret;
+
+	/* configure to the desired bus speed */
+	val = readl(iproc_i2c->base + TIM_CFG_OFFSET);
+	val &= ~(1 << TIM_CFG_MODE_400_SHIFT);
+	val |= (iproc_i2c->bus_speed == 400000) << TIM_CFG_MODE_400_SHIFT;
+	writel(val, iproc_i2c->base + TIM_CFG_OFFSET);
+
+	bcm_iproc_i2c_enable_disable(iproc_i2c, true);
+
+	return 0;
+}
+
+static const struct dev_pm_ops bcm_iproc_i2c_pm_ops = {
+	.suspend_late = &bcm_iproc_i2c_suspend,
+	.resume_early = &bcm_iproc_i2c_resume
+};
+
+#define BCM_IPROC_I2C_PM_OPS (&bcm_iproc_i2c_pm_ops)
+#else
+#define BCM_IPROC_I2C_PM_OPS NULL
+#endif /* CONFIG_PM_SLEEP */
+
 static const struct of_device_id bcm_iproc_i2c_of_match[] = {
 	{ .compatible = "brcm,iproc-i2c" },
 	{ /* sentinel */ }
@@ -449,6 +505,7 @@ static struct platform_driver bcm_iproc_i2c_driver = {
 	.driver = {
 		.name = "bcm-iproc-i2c",
 		.of_match_table = bcm_iproc_i2c_of_match,
+		.pm = BCM_IPROC_I2C_PM_OPS,
 	},
 	.probe = bcm_iproc_i2c_probe,
 	.remove = bcm_iproc_i2c_remove,
@@ -50,6 +50,11 @@
 #define BCM2835_I2C_S_CLKT	BIT(9)
 #define BCM2835_I2C_S_LEN	BIT(10) /* Fake bit for SW error reporting */

+#define BCM2835_I2C_BITMSK_S	0x03FF
+
+#define BCM2835_I2C_CDIV_MIN	0x0002
+#define BCM2835_I2C_CDIV_MAX	0xFFFE
+
 #define BCM2835_I2C_TIMEOUT (msecs_to_jiffies(1000))

 struct bcm2835_i2c_dev {
@@ -111,6 +116,7 @@ static irqreturn_t bcm2835_i2c_isr(int this_irq, void *data)
 	u32 val, err;

 	val = bcm2835_i2c_readl(i2c_dev, BCM2835_I2C_S);
+	val &= BCM2835_I2C_BITMSK_S;
 	bcm2835_i2c_writel(i2c_dev, BCM2835_I2C_S, val);

 	err = val & (BCM2835_I2C_S_CLKT | BCM2835_I2C_S_ERR);
@@ -258,6 +264,11 @@ static int bcm2835_i2c_probe(struct platform_device *pdev)
 	 */
 	if (divider & 1)
 		divider++;
+	if ((divider < BCM2835_I2C_CDIV_MIN) ||
+	    (divider > BCM2835_I2C_CDIV_MAX)) {
+		dev_err(&pdev->dev, "Invalid clock-frequency\n");
+		return -ENODEV;
+	}
 	bcm2835_i2c_writel(i2c_dev, BCM2835_I2C_DIV, divider);

 	irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
@@ -41,8 +41,8 @@

 #define DAVINCI_I2C_TIMEOUT	(1*HZ)
 #define DAVINCI_I2C_MAX_TRIES	2
-#define I2C_DAVINCI_INTR_ALL    (DAVINCI_I2C_IMR_AAS | \
-				 DAVINCI_I2C_IMR_SCD | \
+#define DAVINCI_I2C_OWN_ADDRESS	0x08
+#define I2C_DAVINCI_INTR_ALL    (DAVINCI_I2C_IMR_SCD | \
 				 DAVINCI_I2C_IMR_ARDY | \
 				 DAVINCI_I2C_IMR_NACK | \
 				 DAVINCI_I2C_IMR_AL)
@@ -204,9 +204,30 @@ static void i2c_davinci_calc_clk_dividers(struct davinci_i2c_dev *dev)
 		psc++;	/* better to run under spec than over */
 	d = (psc >= 2) ? 5 : 7 - psc;

-	clk = ((input_clock / (psc + 1)) / (pdata->bus_freq * 1000)) - (d << 1);
-	clkh = clk >> 1;
-	clkl = clk - clkh;
+	clk = ((input_clock / (psc + 1)) / (pdata->bus_freq * 1000));
+	/* Avoid driving the bus too fast because of rounding errors above */
+	if (input_clock / (psc + 1) / clk > pdata->bus_freq * 1000)
+		clk++;
+	/*
+	 * According to I2C-BUS Spec 2.1, in FAST-MODE LOW period should be at
+	 * least 1.3uS, which is not the case with 50% duty cycle. Driving HIGH
+	 * to LOW ratio as 1 to 2 is more safe.
+	 */
+	if (pdata->bus_freq > 100)
+		clkl = (clk << 1) / 3;
+	else
+		clkl = (clk >> 1);
+	/*
+	 * It's not always possible to have 1 to 2 ratio when d=7, so fall back
+	 * to minimal possible clkh in this case.
+	 */
+	if (clk >= clkl + d) {
+		clkh = clk - clkl - d;
+		clkl -= d;
+	} else {
+		clkh = 0;
+		clkl = clk - (d << 1);
+	}

 	davinci_i2c_write_reg(dev, DAVINCI_I2C_PSC_REG, psc);
 	davinci_i2c_write_reg(dev, DAVINCI_I2C_CLKH_REG, clkh);
@@ -233,7 +254,7 @@ static int i2c_davinci_init(struct davinci_i2c_dev *dev)
 	/* Respond at reserved "SMBus Host" slave address" (and zero);
 	 * we seem to have no option to not respond...
 	 */
-	davinci_i2c_write_reg(dev, DAVINCI_I2C_OAR_REG, 0x08);
+	davinci_i2c_write_reg(dev, DAVINCI_I2C_OAR_REG, DAVINCI_I2C_OWN_ADDRESS);

 	dev_dbg(dev->dev, "PSC  = %d\n",
 		davinci_i2c_read_reg(dev, DAVINCI_I2C_PSC_REG));
@@ -350,29 +371,25 @@ static struct i2c_bus_recovery_info davinci_i2c_scl_recovery_info = {
 /*
 * Waiting for bus not busy
 */
-static int i2c_davinci_wait_bus_not_busy(struct davinci_i2c_dev *dev,
-					 char allow_sleep)
+static int i2c_davinci_wait_bus_not_busy(struct davinci_i2c_dev *dev)
 {
-	unsigned long timeout;
-	static u16 to_cnt;
+	unsigned long timeout = jiffies + dev->adapter.timeout;

-	timeout = jiffies + dev->adapter.timeout;
-	while (davinci_i2c_read_reg(dev, DAVINCI_I2C_STR_REG)
-	       & DAVINCI_I2C_STR_BB) {
-		if (to_cnt <= DAVINCI_I2C_MAX_TRIES) {
-			if (time_after(jiffies, timeout)) {
-				dev_warn(dev->dev,
-				"timeout waiting for bus ready\n");
-				to_cnt++;
-				return -ETIMEDOUT;
-			} else {
-				to_cnt = 0;
-				i2c_recover_bus(&dev->adapter);
-			}
-		}
-		if (allow_sleep)
-			schedule_timeout(1);
-	}
+	do {
+		if (!(davinci_i2c_read_reg(dev, DAVINCI_I2C_STR_REG) & DAVINCI_I2C_STR_BB))
+			return 0;
+		schedule_timeout_uninterruptible(1);
+	} while (time_before_eq(jiffies, timeout));
+
+	dev_warn(dev->dev, "timeout waiting for bus ready\n");
+	i2c_recover_bus(&dev->adapter);
+
+	/*
+	 * if bus is still "busy" here, it's most probably a HW problem like
+	 * short-circuit
+	 */
+	if (davinci_i2c_read_reg(dev, DAVINCI_I2C_STR_REG) & DAVINCI_I2C_STR_BB)
+		return -EIO;

 	return 0;
 }
@@ -390,6 +407,11 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop)
 	u16 w;
 	unsigned long time_left;

+	if (msg->addr == DAVINCI_I2C_OWN_ADDRESS) {
+		dev_warn(dev->dev, "transfer to own address aborted\n");
+		return -EADDRNOTAVAIL;
+	}
+
 	/* Introduce a delay, required for some boards (e.g Davinci EVM) */
 	if (pdata->bus_delay)
 		udelay(pdata->bus_delay);
@@ -505,7 +527,7 @@ i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)

 	dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num);

-	ret = i2c_davinci_wait_bus_not_busy(dev, 1);
+	ret = i2c_davinci_wait_bus_not_busy(dev);
 	if (ret < 0) {
 		dev_warn(dev->dev, "timeout waiting for bus ready\n");
 		return ret;
@@ -281,7 +281,8 @@ static int dw_i2c_remove(struct platform_device *pdev)

 	i2c_dw_disable(dev);

-	pm_runtime_put(&pdev->dev);
+	pm_runtime_dont_use_autosuspend(&pdev->dev);
+	pm_runtime_put_sync(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);

 	if (has_acpi_companion(&pdev->dev))
@@ -298,6 +299,22 @@ static const struct of_device_id dw_i2c_of_match[] = {
 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
 #endif

+#ifdef CONFIG_PM_SLEEP
+static int dw_i2c_prepare(struct device *dev)
+{
+	return pm_runtime_suspended(dev);
+}
+
+static void dw_i2c_complete(struct device *dev)
+{
+	if (dev->power.direct_complete)
+		pm_request_resume(dev);
+}
+#else
+#define dw_i2c_prepare	NULL
+#define dw_i2c_complete	NULL
+#endif
+
 #ifdef CONFIG_PM
 static int dw_i2c_suspend(struct device *dev)
 {
@@ -322,10 +339,18 @@ static int dw_i2c_resume(struct device *dev)

 	return 0;
 }
-#endif

-static UNIVERSAL_DEV_PM_OPS(dw_i2c_dev_pm_ops, dw_i2c_suspend,
-			    dw_i2c_resume, NULL);
+static const struct dev_pm_ops dw_i2c_dev_pm_ops = {
+	.prepare = dw_i2c_prepare,
+	.complete = dw_i2c_complete,
+	SET_SYSTEM_SLEEP_PM_OPS(dw_i2c_suspend, dw_i2c_resume)
+	SET_RUNTIME_PM_OPS(dw_i2c_suspend, dw_i2c_resume, NULL)
+};
+
+#define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops)
+#else
+#define DW_I2C_DEV_PMOPS NULL
+#endif

 /* work with hotplug and coldplug */
 MODULE_ALIAS("platform:i2c_designware");
@@ -337,7 +362,7 @@ static struct platform_driver dw_i2c_driver = {
 		.name	= "i2c_designware",
 		.of_match_table = of_match_ptr(dw_i2c_of_match),
 		.acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
-		.pm	= &dw_i2c_dev_pm_ops,
+		.pm	= DW_I2C_DEV_PMOPS,
 	},
 };

@@ -241,7 +241,7 @@ static struct imx_i2c_hwdata vf610_i2c_hwdata = {

 };

-static struct platform_device_id imx_i2c_devtype[] = {
+static const struct platform_device_id imx_i2c_devtype[] = {
 	{
 		.name = "imx1-i2c",
 		.driver_data = (kernel_ulong_t)&imx1_i2c_hwdata,
@@ -784,7 +784,7 @@ static int mxs_i2c_get_ofdata(struct mxs_i2c_dev *i2c)
 	return 0;
 }

-static struct platform_device_id mxs_i2c_devtype[] = {
+static const struct platform_device_id mxs_i2c_devtype[] = {
 	{
 		.name = "imx23-i2c",
 		.driver_data = MXS_I2C_V1,
@@ -200,7 +200,7 @@ static int octeon_i2c_test_iflg(struct octeon_i2c *i2c)
 */
 static int octeon_i2c_wait(struct octeon_i2c *i2c)
 {
-	int result;
+	long result;

 	octeon_i2c_int_enable(i2c);

@@ -210,10 +210,7 @@ static int octeon_i2c_wait(struct octeon_i2c *i2c)

 	octeon_i2c_int_disable(i2c);

-	if (result < 0) {
-		dev_dbg(i2c->dev, "%s: wait interrupted\n", __func__);
-		return result;
-	} else if (result == 0) {
+	if (result == 0) {
 		dev_dbg(i2c->dev, "%s: timeout\n", __func__);
 		return -ETIMEDOUT;
 	}
--- a/Show More
+++ b/Show More