[PATCH / RFC] Resubmitting : Basic OMAP2430 High speed I2C & Speed handling

[PATCH / RFC] Resubmitting : Basic OMAP2430 High speed I2C & Speed handling

[Syed Mohammed, Khasim]

Resubmitting after incorporating review comments

This patch moves I2C speed parameter (from module) to platform data.
Also added basic High Speed support based on I2C bus speed. 

This patch is tested for high speed I2C (with TWL4030 Keypad) and works as
expected.

Signed-off-by: Syed Mohammed Khasim  <x0khasim@ti.com>

Files:
 drivers/i2c/busses/i2c-omap.c
 arch/arm/mach-omap2/clock.h
 arch/arm/mach-omap2/devices.c
 arch/arm/plat-omap/devices.c 
 arch/arm/mach-omap2/board-2430sdp.c

=============================================================================
--- linux-omap/arch/arm/mach-omap2/board-2430sdp.c	2007-03-02 17:12:25.000000000 -0600
+++ lin_for_hsi2c/arch/arm/mach-omap2/board-2430sdp.c	2007-04-23 18:54:23.000000000 -0500
@@ -192,6 +192,78 @@ static struct omap_board_config_kernel s
 	{OMAP_TAG_UART, &sdp2430_uart_config},
 };
 
+#if	defined(CONFIG_I2C_OMAP) || defined(CONFIG_I2C_OMAP_MODULE)
+
+#define OMAP2_I2C_BASE1		0x48070000
+#define OMAP2_I2C_BASE2		0x48072000
+#define OMAP2_I2C_INT1		56
+#define OMAP2_I2C_INT2		57
+
+static u32 omap2_i2c1_clkrate	= 400;
+static u32 omap2_i2c2_clkrate	= 2600;
+
+static struct resource i2c_resources1[] = {
+	{
+		.start	= OMAP2_I2C_BASE1,
+		.end	= OMAP2_I2C_BASE1 + 0x3f,
+		.flags	= IORESOURCE_MEM,
+	},
+	{
+		.start	= OMAP2_I2C_INT1,
+		.flags	= IORESOURCE_IRQ,
+	},
+};
+
+static struct resource i2c_resources2[] = {
+	{
+		.start	= OMAP2_I2C_BASE2,
+		.end	= OMAP2_I2C_BASE2 + 0x3f,
+		.flags	= IORESOURCE_MEM,
+	},
+	{
+		.start	= OMAP2_I2C_INT2,
+		.flags	= IORESOURCE_IRQ,
+	},
+};
+
+static struct platform_device omap_i2c_device1 = {
+	.name		= "i2c_omap",
+	.id		= 1,
+	.num_resources	= ARRAY_SIZE(i2c_resources1),
+	.resource	= i2c_resources1,
+	.dev		= {
+		.platform_data	= &omap2_i2c1_clkrate,
+	},
+};
+
+static struct platform_device omap_i2c_device2 = {
+	.name		= "i2c_omap",
+	.id		= 2,
+	.num_resources	= ARRAY_SIZE(i2c_resources2),
+	.resource	= i2c_resources2,
+	.dev		= {
+		.platform_data	= &omap2_i2c2_clkrate,
+	},
+};
+
+static void omap_init_i2c(void)
+{
+	(void) platform_device_register(&omap_i2c_device2);
+	(void) platform_device_register(&omap_i2c_device1);
+}
+
+#else
+
+static void omap_init_i2c(void) {}
+
+#endif
+
+static int __init omap2430_i2c_init(void)
+{
+	omap_init_i2c();
+	return 0;
+}
+
 static void __init omap_2430sdp_init(void)
 {
 	platform_add_devices(sdp2430_devices, ARRAY_SIZE(sdp2430_devices));
@@ -205,6 +277,8 @@ static void __init omap_2430sdp_map_io(v
 	omap2_map_common_io();
 }
 
+arch_initcall(omap2430_i2c_init);
+
 MACHINE_START(OMAP_2430SDP, "OMAP2430 sdp2430 board")
 	/* Maintainer: Syed Khasim - Texas Instruments Inc */
 	.phys_io	= 0x48000000,

--- linux-omap/arch/arm/mach-omap2/devices.c	2007-04-02 02:29:57.000000000 -0500
+++ lin_for_hsi2c/arch/arm/mach-omap2/devices.c	2007-04-23 17:16:27.000000000 -0500
@@ -25,11 +25,13 @@
 #include <asm/arch/gpio.h>
 #include <asm/arch/eac.h>
 
+#if	!defined(CONFIG_ARCH_OMAP243X)
 #if	defined(CONFIG_I2C_OMAP) || defined(CONFIG_I2C_OMAP_MODULE)
 
 #define OMAP2_I2C_BASE2		0x48072000
 #define OMAP2_I2C_INT2		57
 
+static u32 omap2_i2c2_clkrate	= 100;
 static struct resource i2c_resources2[] = {
 	{
 		.start		= OMAP2_I2C_BASE2,
@@ -47,6 +49,9 @@ static struct platform_device omap_i2c_d
 	.id             = 2,
 	.num_resources	= ARRAY_SIZE(i2c_resources2),
 	.resource	= i2c_resources2,
+	.dev		= {
+		.platform_data	= &omap2_i2c2_clkrate,
+	},
 };
 
 /* See also arch/arm/plat-omap/devices.c for first I2C on 24xx */
@@ -55,11 +60,10 @@ static void omap_init_i2c(void)
 	/* REVISIT: Second I2C not in use on H4? */
 	if (machine_is_omap_h4())
 		return;
+
+	omap_cfg_reg(J15_24XX_I2C2_SCL);
+	omap_cfg_reg(H19_24XX_I2C2_SDA);
 
-	if (!cpu_is_omap2430()) {
-		omap_cfg_reg(J15_24XX_I2C2_SCL);
-		omap_cfg_reg(H19_24XX_I2C2_SDA);
-	}
 	(void) platform_device_register(&omap_i2c_device2);
 }
 
@@ -68,6 +72,7 @@ static void omap_init_i2c(void)
 static void omap_init_i2c(void) {}
 
 #endif
+#endif
 
 #if defined(CONFIG_OMAP_DSP) || defined(CONFIG_OMAP_DSP_MODULE)
 #define OMAP2_MBOX_BASE		IO_ADDRESS(OMAP24XX_MAILBOX_BASE)
@@ -241,7 +246,9 @@ static int __init omap2_init_devices(voi
 	/* please keep these calls, and their implementations above,
 	 * in alphabetical order so they're easier to sort through.
 	 */
-	omap_init_i2c();
+	if (!cpu_is_omap2430()) {
+		omap_init_i2c();
+	}
 	omap_init_mbox();
 	omap_init_mcspi();
 	omap_init_sti();

--- linux-omap/arch/arm/plat-omap/devices.c	2007-04-04 18:13:49.000000000 -0500
+++ lin_for_hsi2c/arch/arm/plat-omap/devices.c	2007-04-23 18:38:08.000000000 -0500
@@ -89,6 +89,7 @@ static inline void omap_init_dsp(void) {
 #endif	/* CONFIG_OMAP_DSP */
 
 /*-------------------------------------------------------------------------*/
+#if	!defined(CONFIG_ARCH_OMAP243X)
 #if	defined(CONFIG_I2C_OMAP) || defined(CONFIG_I2C_OMAP_MODULE)
 
 #define	OMAP1_I2C_BASE		0xfffb3800
@@ -97,6 +98,8 @@ static inline void omap_init_dsp(void) {
 #define OMAP1_I2C_INT		INT_I2C
 #define OMAP2_I2C_INT1		56
 
+static u32 omap2_i2c1_clkrate	= 100;
+
 static struct resource i2c_resources1[] = {
 	{
 		.start		= 0,
@@ -116,12 +119,15 @@ static struct platform_device omap_i2c_d
 	.id             = 1,
 	.num_resources	= ARRAY_SIZE(i2c_resources1),
 	.resource	= i2c_resources1,
+	.dev		= {
+		.platform_data	= &omap2_i2c1_clkrate,
+	},
 };
 
 /* See also arch/arm/mach-omap2/devices.c for second I2C on 24xx */
 static void omap_init_i2c(void)
 {
-	if (cpu_is_omap24xx()) {
+	if (cpu_is_omap242x()) {
 		i2c_resources1[0].start = OMAP2_I2C_BASE1;
 		i2c_resources1[0].end = OMAP2_I2C_BASE1 + OMAP_I2C_SIZE;
 		i2c_resources1[1].start = OMAP2_I2C_INT1;
@@ -151,7 +157,7 @@ static void omap_init_i2c(void)
 #else
 static inline void omap_init_i2c(void) {}
 #endif
-
+#endif
 /*-------------------------------------------------------------------------*/
 #if	defined(CONFIG_KEYBOARD_OMAP) || defined(CONFIG_KEYBOARD_OMAP_MODULE)
 
@@ -258,6 +264,7 @@ static struct omap_mmc_conf mmc2_conf;
 
 static u64 mmc2_dmamask = 0xffffffff;
 
+
 static struct resource mmc2_resources[] = {
 	{
 		.start		= OMAP_MMC2_BASE,
@@ -512,7 +519,9 @@ static int __init omap_init_devices(void
 	omap_init_uwire();
 	omap_init_wdt();
 	omap_init_rng();
-	omap_init_i2c();
+	if (!cpu_is_omap2430()) {
+		omap_init_i2c();
+	}
 	return 0;
 }
 arch_initcall(omap_init_devices);

--- linux-omap/arch/arm/mach-omap2/clock.h	2007-03-13 13:03:43.000000000 -0600
+++ lin_for_hsi2c/arch/arm/mach-omap2/clock.h	2007-04-10 11:02:37.000000000 -0500
@@ -1761,7 +1761,8 @@ static struct clk i2c2_fck = {
 };
 
 static struct clk i2chs2_fck = {
-	.name		= "i2chs2_fck",
+	.name		= "i2chs_fck",
+	.id		= 2,
 	.parent		= &func_96m_ck,
 	.flags		= CLOCK_IN_OMAP243X,
 	.enable_reg	= (void __iomem *)&CM_FCLKEN2_CORE,
@@ -1790,7 +1791,8 @@ static struct clk i2c1_fck = {
 };
 
 static struct clk i2chs1_fck = {
-	.name		= "i2chs1_fck",
+	.name		= "i2chs_fck",
+	.id		= 1,
 	.parent		= &func_96m_ck,
 	.flags		= CLOCK_IN_OMAP243X,
 	.enable_reg	= (void __iomem *)&CM_FCLKEN2_CORE,

--- linux-omap/drivers/i2c/busses/i2c-omap.c	2007-04-23 19:17:32.000000000 -0500
+++ lin_for_hsi2c/drivers/i2c/busses/i2c-omap.c	2007-04-23 19:33:49.000000000 -0500
@@ -89,6 +89,7 @@
 /* I2C Configuration Register (OMAP_I2C_CON): */
 #define OMAP_I2C_CON_EN		(1 << 15)	/* I2C module enable */
 #define OMAP_I2C_CON_BE		(1 << 14)	/* Big endian mode */
+#define OMAP_I2C_CON_OPMODE	(1 << 12)	/* High Speed support */
 #define OMAP_I2C_CON_STB	(1 << 11)	/* Start byte mode (master) */
 #define OMAP_I2C_CON_MST	(1 << 10)	/* Master/slave mode */
 #define OMAP_I2C_CON_TRX	(1 << 9)	/* TX/RX mode (master only) */
@@ -97,6 +98,10 @@
 #define OMAP_I2C_CON_STP	(1 << 1)	/* Stop cond (master only) */
 #define OMAP_I2C_CON_STT	(1 << 0)	/* Start condition (master) */
 
+/* I2C SCL time value when Master */
+#define OMAP_I2C_SCLL_HSSCLL	8
+#define OMAP_I2C_SCLH_HSSCLH	8
+
 /* I2C System Test Register (OMAP_I2C_SYSTEST): */
 #ifdef DEBUG
 #define OMAP_I2C_SYSTEST_ST_EN		(1 << 15)	/* System test enable */
@@ -115,12 +120,6 @@
 /* I2C System Configuration Register (OMAP_I2C_SYSC): */
 #define OMAP_I2C_SYSC_SRST		(1 << 1)	/* Soft Reset */
 
-/* REVISIT: Use platform_data instead of module parameters */
-/* Fast Mode = 400 kHz, Standard = 100 kHz */
-static int clock = 100; /* Default: 100 kHz */
-module_param(clock, int, 0);
-MODULE_PARM_DESC(clock, "Set I2C clock in kHz: 400=fast mode (default == 100)");
-
 struct omap_i2c_dev {
 	struct device		*dev;
 	void __iomem		*base;		/* virtual */
@@ -129,6 +128,7 @@ struct omap_i2c_dev {
 	struct clk		*fclk;		/* Functional clock */
 	struct completion	cmd_complete;
 	struct resource		*ioarea;
+	u32			speed;		/* Speed of bus in Khz */
 	u16			cmd_err;
 	u8			*buf;
 	size_t			buf_len;
@@ -156,17 +156,28 @@ static int omap_i2c_get_clocks(struct om
 			return -ENODEV;
 		}
 	}
-
-	dev->fclk = clk_get(dev->dev, "i2c_fck");
-	if (IS_ERR(dev->fclk)) {
-		if (dev->iclk != NULL) {
-			clk_put(dev->iclk);
-			dev->iclk = NULL;
+	/* For I2C operations on 2430 we need 96Mhz clock */
+	if (cpu_is_omap2430()) {
+		dev->fclk = clk_get(dev->dev, "i2chs_fck");
+		if (IS_ERR(dev->fclk)) {
+			if (dev->iclk != NULL) {
+				clk_put(dev->iclk);
+				dev->iclk = NULL;
+			}
+			dev->fclk = NULL;
+			return -ENODEV;
+		}
+	} else {
+		dev->fclk = clk_get(dev->dev, "i2c_fck");
+		if (IS_ERR(dev->fclk)) {
+			if (dev->iclk != NULL) {
+				clk_put(dev->iclk);
+				dev->iclk = NULL;
+			}
+			dev->fclk = NULL;
+			return -ENODEV;
 		}
-		dev->fclk = NULL;
-		return -ENODEV;
 	}
-
 	return 0;
 }
 
@@ -196,9 +207,11 @@ static void omap_i2c_disable_clocks(stru
 
 static int omap_i2c_init(struct omap_i2c_dev *dev)
 {
-	u16 psc = 0;
+	u16 psc = 0, scll = 0, sclh = 0;
+	u16 fsscll = 0, fssclh = 0, hsscll = 0, hssclh = 0;
 	unsigned long fclk_rate = 12000000;
 	unsigned long timeout;
+	unsigned long internal_clk = 0;
 
 	if (!dev->rev1) {
 		omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, OMAP_I2C_SYSC_SRST);
@@ -240,19 +253,48 @@ static int omap_i2c_init(struct omap_i2c
 		if (fclk_rate > 12000000)
 			psc = fclk_rate / 12000000;
 	}
+
+	if (cpu_is_omap2430()) {
+
+		/* HSI2C controller internal clk rate should be 19.2 Mhz */
+		internal_clk = 19200;
+		fclk_rate = clk_get_rate(dev->fclk) / 1000;
+
+		/* Compute prescaler divisor */
+		psc = fclk_rate / internal_clk;
+		psc = psc - 1;
+
+		/* If configured for High Speed */
+		if (dev->speed > 400) {
+			/* For first phase of HS mode */
+			fsscll = internal_clk / (400 * 2) - 6;
+			fssclh = internal_clk / (400 * 2) - 6;
+
+			/* For second phase of HS mode */
+			hsscll = fclk_rate / (dev->speed * 2) - 6;
+			hssclh = fclk_rate / (dev->speed * 2) - 6;
+		} else {
+			/* To handle F/S modes */
+			fsscll = internal_clk / (dev->speed * 2) - 6;
+			fssclh = internal_clk / (dev->speed * 2) - 6;
+		}
+		scll = (hsscll << OMAP_I2C_SCLL_HSSCLL) | fsscll;
+		sclh = (hssclh << OMAP_I2C_SCLH_HSSCLH) | fssclh;
+	} else {
+		/* Program desired operating rate */
+		fclk_rate /= (psc + 1) * 1000;
+		if (psc > 2)
+			psc = 2;
+		scll = fclk_rate / (dev->speed * 2) - 7 + psc;
+		sclh = fclk_rate / (dev->speed * 2) - 7 + psc;
+	}
 
 	/* Setup clock prescaler to obtain approx 12MHz I2C module clock: */
 	omap_i2c_write_reg(dev, OMAP_I2C_PSC_REG, psc);
 
-	/* Program desired operating rate */
-	fclk_rate /= (psc + 1) * 1000;
-	if (psc > 2)
-		psc = 2;
-
-	omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG,
-			   fclk_rate / (clock * 2) - 7 + psc);
-	omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG,
-			   fclk_rate / (clock * 2) - 7 + psc);
+	/* SCL low and high time values */
+	omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG, scll);
+	omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG, sclh);
 
 	/* Take the I2C module out of reset: */
 	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
@@ -337,6 +379,11 @@ static int omap_i2c_xfer_msg(struct i2c_
 	dev->cmd_err = 0;
 
 	w = OMAP_I2C_CON_EN | OMAP_I2C_CON_MST | OMAP_I2C_CON_STT;
+
+	/* High speed configuration */
+	if (dev->speed > 400)
+		w |= OMAP_I2C_CON_OPMODE;
+
 	if (msg->flags & I2C_M_TEN)
 		w |= OMAP_I2C_CON_XA;
 	if (!(msg->flags & I2C_M_RD))
@@ -583,6 +630,7 @@ omap_i2c_probe(struct platform_device *p
 	struct i2c_adapter	*adap;
 	struct resource		*mem, *irq, *ioarea;
 	int r;
+	u32 *speed = NULL;
 
 	/* NOTE: driver uses the static register mapping */
 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -603,17 +651,18 @@ omap_i2c_probe(struct platform_device *p
 		return -EBUSY;
 	}
 
-	if (clock > 200)
-		clock = 400;	/* Fast mode */
-	else
-		clock = 100;	/* Standard mode */
-
 	dev = kzalloc(sizeof(struct omap_i2c_dev), GFP_KERNEL);
 	if (!dev) {
 		r = -ENOMEM;
 		goto err_release_region;
 	}
-
+
+	if (pdev->dev.platform_data != NULL)
+		speed = (u32 *) pdev->dev.platform_data;
+	else
+		*speed = 100; /* Defualt speed */
+
+	dev->speed = *speed;
 	dev->dev = &pdev->dev;
 	dev->irq = irq->start;
 	dev->base = (void __iomem *) IO_ADDRESS(mem->start);
@@ -639,7 +688,7 @@ omap_i2c_probe(struct platform_device *p
 	}
 	r = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG) & 0xff;
 	dev_info(dev->dev, "bus %d rev%d.%d at %d kHz\n",
-		 pdev->id, r >> 4, r & 0xf, clock);
+		 pdev->id, r >> 4, r & 0xf, dev->speed);
 
 	adap = &dev->adapter;
 	i2c_set_adapdata(adap, dev);

Re: [PATCH / RFC] Resubmitting : Basic OMAP2430 High speed I2C & Speed handling

[Tony Lindgren]

* Syed Mohammed, Khasim <x0khasim@ti.com> [070424 00:52]:
> Resubmitting after incorporating review comments
> 
> This patch moves I2C speed parameter (from module) to platform data.
> Also added basic High Speed support based on I2C bus speed. 
> 
> This patch is tested for high speed I2C (with TWL4030 Keypad) and works as
> expected.
> 
> Signed-off-by: Syed Mohammed Khasim  <x0khasim@ti.com>
> 
> Files:
>  drivers/i2c/busses/i2c-omap.c
>  arch/arm/mach-omap2/clock.h
>  arch/arm/mach-omap2/devices.c
>  arch/arm/plat-omap/devices.c 
>  arch/arm/mach-omap2/board-2430sdp.c
> 

Pushing today. I've split the driver into a separate patch.

Tony