AT91: replace broken TWI driver i2c-at91.c

deleted file mode 100644
index bb2880f..0000000
@@ -1,68 +0,0 @@
-/*
- * arch/arm/mach-at91/include/mach/at91_twi.h
- *
- * Copyright (C) 2005 Ivan Kokshaysky
- * Copyright (C) SAN People
- *
- * Two-wire Interface (TWI) registers.
- * Based on AT91RM9200 datasheet revision E.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- */
-
-#ifndef AT91_TWI_H
-#define AT91_TWI_H
-
-#define	AT91_TWI_CR		0x00		/* Control Register */
-#define		AT91_TWI_START		(1 <<  0)	/* Send a Start Condition */
-#define		AT91_TWI_STOP		(1 <<  1)	/* Send a Stop Condition */
-#define		AT91_TWI_MSEN		(1 <<  2)	/* Master Transfer Enable */
-#define		AT91_TWI_MSDIS		(1 <<  3)	/* Master Transfer Disable */
-#define		AT91_TWI_SVEN		(1 <<  4)	/* Slave Transfer Enable [SAM9260 only] */
-#define		AT91_TWI_SVDIS		(1 <<  5)	/* Slave Transfer Disable [SAM9260 only] */
-#define		AT91_TWI_SWRST		(1 <<  7)	/* Software Reset */
-
-#define	AT91_TWI_MMR		0x04		/* Master Mode Register */
-#define		AT91_TWI_IADRSZ		(3    <<  8)	/* Internal Device Address Size */
-#define			AT91_TWI_IADRSZ_NO		(0 << 8)
-#define			AT91_TWI_IADRSZ_1		(1 << 8)
-#define			AT91_TWI_IADRSZ_2		(2 << 8)
-#define			AT91_TWI_IADRSZ_3		(3 << 8)
-#define		AT91_TWI_MREAD		(1    << 12)	/* Master Read Direction */
-#define		AT91_TWI_DADR		(0x7f << 16)	/* Device Address */
-
-#define	AT91_TWI_SMR		0x08		/* Slave Mode Register [SAM9260 only] */
-#define		AT91_TWI_SADR		(0x7f << 16)	/* Slave Address */
-
-#define	AT91_TWI_IADR		0x0c		/* Internal Address Register */
-
-#define	AT91_TWI_CWGR		0x10		/* Clock Waveform Generator Register */
-#define		AT91_TWI_CLDIV		(0xff <<  0)	/* Clock Low Divisor */
-#define		AT91_TWI_CHDIV		(0xff <<  8)	/* Clock High Divisor */
-#define		AT91_TWI_CKDIV		(7    << 16)	/* Clock Divider */
-
-#define	AT91_TWI_SR		0x20		/* Status Register */
-#define		AT91_TWI_TXCOMP		(1 <<  0)	/* Transmission Complete */
-#define		AT91_TWI_RXRDY		(1 <<  1)	/* Receive Holding Register Ready */
-#define		AT91_TWI_TXRDY		(1 <<  2)	/* Transmit Holding Register Ready */
-#define		AT91_TWI_SVREAD		(1 <<  3)	/* Slave Read [SAM9260 only] */
-#define		AT91_TWI_SVACC		(1 <<  4)	/* Slave Access [SAM9260 only] */
-#define		AT91_TWI_GACC		(1 <<  5)	/* General Call Access [SAM9260 only] */
-#define		AT91_TWI_OVRE		(1 <<  6)	/* Overrun Error [AT91RM9200 only] */
-#define		AT91_TWI_UNRE		(1 <<  7)	/* Underrun Error [AT91RM9200 only] */
-#define		AT91_TWI_NACK		(1 <<  8)	/* Not Acknowledged */
-#define		AT91_TWI_ARBLST		(1 <<  9)	/* Arbitration Lost [SAM9260 only] */
-#define		AT91_TWI_SCLWS		(1 << 10)	/* Clock Wait State [SAM9260 only] */
-#define		AT91_TWI_EOSACC		(1 << 11)	/* End of Slave Address [SAM9260 only] */
-
-#define	AT91_TWI_IER		0x24		/* Interrupt Enable Register */
-#define	AT91_TWI_IDR		0x28		/* Interrupt Disable Register */
-#define	AT91_TWI_IMR		0x2c		/* Interrupt Mask Register */
-#define	AT91_TWI_RHR		0x30		/* Receive Holding Register */
-#define	AT91_TWI_THR		0x34		/* Transmit Holding Register */
-
-#endif
-

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index ecdd54d..e69d5e0 100644
@@ -219,6 +219,7 @@ static struct clk_lookup periph_clocks_lookups[] = {
 	CLKDEV_CON_DEV_ID("t0_clk", "atmel_tcb.0", &tcb_clk),
 	CLKDEV_CON_DEV_ID("pclk", "ssc.0", &ssc0_clk),
 	CLKDEV_CON_DEV_ID("pclk", "ssc.1", &ssc1_clk),
+	CLKDEV_CON_DEV_ID(NULL, "at91_i2c", &twi_clk),
 	/* fake hclk clock */
 	CLKDEV_CON_DEV_ID("hclk", "at91_ohci", &ohci_clk),
 };

index 713d3bd..a52f777 100644
@@ -193,6 +193,7 @@ static struct clk_lookup periph_clocks_lookups[] = {
 	CLKDEV_CON_DEV_ID("pclk", "ssc.0", &ssc0_clk),
 	CLKDEV_CON_DEV_ID("pclk", "ssc.1", &ssc1_clk),
 	CLKDEV_CON_DEV_ID("pclk", "ssc.2", &ssc2_clk),
+	CLKDEV_CON_DEV_ID(NULL, "at91_i2c", &twi_clk),
 	/* fake hclk clock */
 	CLKDEV_CON_DEV_ID("hclk", "at91_ohci", &ohci_clk),
 };

index b84a9f6..6e98738 100644
@@ -199,6 +199,7 @@ static struct clk_lookup periph_clocks_lookups[] = {
 	CLKDEV_CON_DEV_ID("t4_clk", "atmel_tcb.1", &tc4_clk),
 	CLKDEV_CON_DEV_ID("t5_clk", "atmel_tcb.1", &tc5_clk),
 	CLKDEV_CON_DEV_ID("pclk", "ssc.0", &ssc_clk),
+	CLKDEV_CON_DEV_ID(NULL, "at91_i2c", &twi_clk),
 	/* more usart lookup table for DT entries */
 	CLKDEV_CON_DEV_ID("usart", "fffff200.serial", &mck),
 	CLKDEV_CON_DEV_ID("usart", "fffb0000.serial", &usart0_clk),

index 658a518..4946fb5 100644
@@ -176,6 +176,7 @@ static struct clk_lookup periph_clocks_lookups[] = {
 	CLKDEV_CON_DEV_ID("pclk", "ssc.1", &ssc1_clk),
 	CLKDEV_CON_DEV_ID("pclk", "ssc.2", &ssc2_clk),
 	CLKDEV_CON_DEV_ID("hclk", "at91_ohci", &hck0),
+	CLKDEV_CON_DEV_ID(NULL, "at91_i2c", &twi_clk),
 };
 
 static struct clk_lookup usart_clocks_lookups[] = {

index f83fbb0..2c14e43 100644
@@ -189,6 +189,7 @@ static struct clk_lookup periph_clocks_lookups[] = {
 	CLKDEV_CON_DEV_ID("spi_clk", "atmel_spi.0", &spi0_clk),
 	CLKDEV_CON_DEV_ID("spi_clk", "atmel_spi.1", &spi1_clk),
 	CLKDEV_CON_DEV_ID("t0_clk", "atmel_tcb.0", &tcb_clk),
+	CLKDEV_CON_DEV_ID(NULL, "at91_i2c", &twi_clk),
 	/* fake hclk clock */
 	CLKDEV_CON_DEV_ID("hclk", "at91_ohci", &ohci_clk),
 };

index 318b040..357f056 100644
@@ -220,6 +220,8 @@ static struct clk_lookup periph_clocks_lookups[] = {
 	CLKDEV_CON_DEV_ID("spi_clk", "atmel_spi.1", &spi1_clk),
 	CLKDEV_CON_DEV_ID("t0_clk", "atmel_tcb.0", &tcb0_clk),
 	CLKDEV_CON_DEV_ID("t0_clk", "atmel_tcb.1", &tcb0_clk),
+	CLKDEV_CON_DEV_ID(NULL, "at91_i2c.0", &twi0_clk),
+	CLKDEV_CON_DEV_ID(NULL, "at91_i2c.1", &twi1_clk),
 	CLKDEV_CON_DEV_ID("pclk", "ssc.0", &ssc0_clk),
 	CLKDEV_CON_DEV_ID("pclk", "ssc.1", &ssc1_clk),
 	CLKDEV_CON_DEV_ID(NULL, "atmel-trng", &trng_clk),

index a238105..312beb5 100644
@@ -184,6 +184,8 @@ static struct clk_lookup periph_clocks_lookups[] = {
 	CLKDEV_CON_DEV_ID("t2_clk", "atmel_tcb.0", &tc2_clk),
 	CLKDEV_CON_DEV_ID("pclk", "ssc.0", &ssc0_clk),
 	CLKDEV_CON_DEV_ID("pclk", "ssc.1", &ssc1_clk),
+	CLKDEV_CON_DEV_ID(NULL, "at91_i2c.0", &twi0_clk),
+	CLKDEV_CON_DEV_ID(NULL, "at91_i2c.1", &twi1_clk),
 };
 
 static struct clk_lookup usart_clocks_lookups[] = {

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index 09a16d6..8743b14 100644
@@ -684,18 +684,12 @@ void __init at91_add_device_i2c(short i2c_id, struct i2c_board_info *devices, in
 	/* pins used for TWI interface */
 	if (i2c_id == 0) {
 		at91_set_A_periph(AT91_PIN_PA20, 0);		/* TWD */
-		at91_set_multi_drive(AT91_PIN_PA20, 1);
-
 		at91_set_A_periph(AT91_PIN_PA21, 0);		/* TWCK */
-		at91_set_multi_drive(AT91_PIN_PA21, 1);
 
 		platform_device_register(&at91sam9g45_twi0_device);
 	} else {
 		at91_set_A_periph(AT91_PIN_PB10, 0);		/* TWD */
-		at91_set_multi_drive(AT91_PIN_PB10, 1);
-
 		at91_set_A_periph(AT91_PIN_PB11, 0);		/* TWCK */
-		at91_set_multi_drive(AT91_PIN_PB11, 1);
 
 		platform_device_register(&at91sam9g45_twi1_device);
 	}

index 1c9d329..3ef89e9 100644
@@ -32,7 +32,7 @@
 #include "i2c-at91.h"
 
 #define TWI_CLK_HZ		100000			/* max 400 Kbits/s */
-#define AT91_I2C_TIMEOUT	msecs_to_jiffies(10)	/* transfer timeout */
+#define AT91_I2C_TIMEOUT	msecs_to_jiffies(100)	/* transfer timeout */
 
 struct at91_twi_dev {
 	struct device		*dev;

@@ -41,6 +41,7 @@ struct at91_twi_dev {
 	struct clk		*clk;
 	u8			*buf;
 	size_t			buf_len;
+	struct i2c_msg		*msg;
 	int			irq;
 	unsigned		transfer_status;
 	struct i2c_adapter	adapter;

@@ -113,9 +114,18 @@ static void at91_twi_write_next_byte(struct at91_twi_dev *dev)
 static void at91_twi_read_next_byte(struct at91_twi_dev *dev)
 {
 	*dev->buf = at91_twi_read(dev, AT91_TWI_RHR) & 0xff;
+	--dev->buf_len;
+
+	/* handle I2C_SMBUS_BLOCK_DATA */
+	if (unlikely(dev->msg->flags & I2C_M_RECV_LEN)) {
+		dev->msg->flags &= ~I2C_M_RECV_LEN;
+		dev->buf_len += *dev->buf;
+		dev->msg->len = dev->buf_len + 1;
+		dev_dbg(dev->dev, "received block length %d\n", dev->buf_len);
+	}
 
 	/* send stop if second but last byte has been read */
-	if (--dev->buf_len == 1)
+	if (dev->buf_len == 1)
 		at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_STOP);
 
 	dev_dbg(dev->dev, "read 0x%x, to go %d\n", *dev->buf, dev->buf_len);

@@ -144,17 +154,21 @@ static irqreturn_t atmel_twi_interrupt(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
-static int at91_do_twi_transfer(struct at91_twi_dev *dev, bool is_read)
+static int at91_do_twi_transfer(struct at91_twi_dev *dev)
 {
 	int ret;
 
+	dev_dbg(dev->dev, "transfer: %s %d bytes.\n",
+		(dev->msg->flags & I2C_M_RD) ? "read" : "write", dev->buf_len);
+
 	INIT_COMPLETION(dev->cmd_complete);
-	if (is_read) {
-		if (dev->buf_len <= 1)
-			at91_twi_write(dev, AT91_TWI_CR,
-				       AT91_TWI_START | AT91_TWI_STOP);
-		else
-			at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_START);
+	if (dev->msg->flags & I2C_M_RD) {
+		unsigned start_flags = AT91_TWI_START;
+
+		/* if only one byte is to be read, immediately stop transfer */
+		if (dev->buf_len <= 1 && !(dev->msg->flags & I2C_M_RECV_LEN))
+			start_flags |= AT91_TWI_STOP;
+		at91_twi_write(dev, AT91_TWI_CR, start_flags);
 		at91_twi_write(dev, AT91_TWI_IER,
 			       AT91_TWI_TXCOMP | AT91_TWI_RXRDY);
 	} else {

@@ -229,17 +243,17 @@ static int at91_twi_xfer(struct i2c_adapter *adap, struct i2c_msg *msg, int num)
 
 	dev->buf_len = m_start->len;
 	dev->buf = m_start->buf;
+	dev->msg = m_start;
 
-	ret = at91_do_twi_transfer(dev, m_start->flags & I2C_M_RD);
-	if (ret < 0)
-		return ret;
+	ret = at91_do_twi_transfer(dev);
 
-	return num;
+	return (ret < 0) ? ret : num;
 }
 
 static u32 at91_twi_func(struct i2c_adapter *adapter)
 {
-	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL
+		| I2C_FUNC_SMBUS_READ_BLOCK_DATA;
 }
 
 static struct i2c_algorithm at91_twi_algorithm = {

@@ -326,6 +340,7 @@ err_unuse_clocks:
 	iounmap(dev->base);
 err_mem_ioremap:
 	clk_disable(dev->clk);
+	clk_unprepare(dev->clk);
 	clk_put(dev->clk);
 err_free_mem:
 	kfree(dev);

@@ -343,6 +358,7 @@ static int __devexit at91_twi_remove(struct platform_device *pdev)
 
 	rc = i2c_del_adapter(&dev->adapter);
 	clk_disable(dev->clk);
+	clk_unprepare(dev->clk);
 	clk_put(dev->clk);
 	free_irq(dev->irq, dev);
 	iounmap(dev->base);

index 3ef89e9..34deef4 100644
@@ -29,11 +29,40 @@
 
 #include <mach/cpu.h>
 
-#include "i2c-at91.h"
-
 #define TWI_CLK_HZ		100000			/* max 400 Kbits/s */
 #define AT91_I2C_TIMEOUT	msecs_to_jiffies(100)	/* transfer timeout */
 
+/* AT91 TWI register definitions */
+#define	AT91_TWI_CR		0x0000	/* Control Register */
+#define	AT91_TWI_START		0x0001	/* Send a Start Condition */
+#define	AT91_TWI_STOP		0x0002	/* Send a Stop Condition */
+#define	AT91_TWI_MSEN		0x0004	/* Master Transfer Enable */
+#define	AT91_TWI_SVDIS		0x0020	/* Slave Transfer Disable */
+#define	AT91_TWI_SWRST		0x0080	/* Software Reset */
+
+#define	AT91_TWI_MMR		0x0004	/* Master Mode Register */
+#define	AT91_TWI_IADRSZ_1	0x0100	/* Internal Device Address Size */
+#define	AT91_TWI_MREAD		0x1000	/* Master Read Direction */
+
+#define	AT91_TWI_IADR		0x000c	/* Internal Address Register */
+
+#define	AT91_TWI_CWGR		0x0010	/* Clock Waveform Generator Reg */
+
+#define	AT91_TWI_SR		0x0020	/* Status Register */
+#define	AT91_TWI_TXCOMP		0x0001	/* Transmission Complete */
+#define	AT91_TWI_RXRDY		0x0002	/* Receive Holding Register Ready */
+#define	AT91_TWI_TXRDY		0x0004	/* Transmit Holding Register Ready */
+
+#define	AT91_TWI_OVRE		0x0040	/* Overrun Error */
+#define	AT91_TWI_UNRE		0x0080	/* Underrun Error */
+#define	AT91_TWI_NACK		0x0100	/* Not Acknowledged */
+
+#define	AT91_TWI_IER		0x0024	/* Interrupt Enable Register */
+#define	AT91_TWI_IDR		0x0028	/* Interrupt Disable Register */
+#define	AT91_TWI_IMR		0x002c	/* Interrupt Mask Register */
+#define	AT91_TWI_RHR		0x0030	/* Receive Holding Register */
+#define	AT91_TWI_THR		0x0034	/* Transmit Holding Register */
+
 struct at91_twi_dev {
 	struct device		*dev;
 	void __iomem		*base;

80 lines not on this page · raw message

index adad70d..495fd24 100644
@@ -496,9 +496,18 @@ static struct resource twi_resources[] = {
 	},
 };
 
+static const struct platform_device_id twi_id = {
+	/*
+	 * driver_data is "1" for hardware with ckdiv upper limit == 5
+	 * (AT91RM9200 erratum 22), "0" for twi modules without this bug
+	 */
+	.driver_data	= 0,
+};
+
 static struct platform_device at91cap9_twi_device = {
 	.name		= "at91_i2c",
 	.id		= -1,
+	.id_entry	= &twi_id,
 	.resource	= twi_resources,
 	.num_resources	= ARRAY_SIZE(twi_resources),
 };

index 66591fa..8db7383 100644
@@ -493,9 +493,18 @@ static struct resource twi_resources[] = {
 	},
 };
 
+static const struct platform_device_id twi_id = {
+	/*
+	 * driver_data is "1" for hardware with ckdiv upper limit == 5
+	 * (AT91RM9200 erratum 22), "0" for twi modules without this bug
+	 */
+	.driver_data	= 1,
+};
+
 static struct platform_device at91rm9200_twi_device = {
 	.name		= "at91_i2c",
 	.id		= -1,
+	.id_entry	= &twi_id,
 	.resource	= twi_resources,
 	.num_resources	= ARRAY_SIZE(twi_resources),
 };

index 25e3464..1e9a075 100644
@@ -498,9 +498,18 @@ static struct resource twi_resources[] = {
 	},
 };
 
+static const struct platform_device_id twi_id = {
+	/*
+	 * driver_data is "1" for hardware with ckdiv upper limit == 5
+	 * (AT91RM9200 erratum 22), "0" for twi modules without this bug
+	 */
+	.driver_data	= 0,
+};
+
 static struct platform_device at91sam9260_twi_device = {
 	.name		= "at91_i2c",
 	.id		= -1,
+	.id_entry	= &twi_id,
 	.resource	= twi_resources,
 	.num_resources	= ARRAY_SIZE(twi_resources),
 };

index ae78f4d..16f22b7 100644
@@ -315,9 +315,18 @@ static struct resource twi_resources[] = {
 	},
 };
 
+static const struct platform_device_id twi_id = {
+	/*
+	 * driver_data is "1" for hardware with ckdiv upper limit == 5
+	 * (AT91RM9200 erratum 22), "0" for twi modules without this bug
+	 */
+	.driver_data	= 0,
+};
+
 static struct platform_device at91sam9261_twi_device = {
 	.name		= "at91_i2c",
 	.id		= -1,
+	.id_entry	= &twi_id,
 	.resource	= twi_resources,
 	.num_resources	= ARRAY_SIZE(twi_resources),
 };

index ad017eb..346d258 100644
@@ -571,9 +571,18 @@ static struct resource twi_resources[] = {
 	},
 };
 
+static const struct platform_device_id twi_id = {
+	/*
+	 * driver_data is "1" for hardware with ckdiv upper limit == 5
+	 * (AT91RM9200 erratum 22), "0" for twi modules without this bug
+	 */
+	.driver_data	= 0,
+};
+
 static struct platform_device at91sam9263_twi_device = {
 	.name		= "at91_i2c",
 	.id		= -1,
+	.id_entry	= &twi_id,
 	.resource	= twi_resources,
 	.num_resources	= ARRAY_SIZE(twi_resources),
 };

index 8743b14..5916f0e 100644
@@ -650,9 +650,18 @@ static struct resource twi0_resources[] = {
 	},
 };
 
+static const struct platform_device_id twi_id = {
+	/*
+	 * driver_data is "1" for hardware with ckdiv upper limit == 5
+	 * (AT91RM9200 erratum 22), "0" for twi modules without this bug
+	 */
+	.driver_data	= 0,
+};
+
 static struct platform_device at91sam9g45_twi0_device = {
 	.name		= "at91_i2c",
 	.id		= 0,
+	.id_entry	= &twi_id,
 	.resource	= twi0_resources,
 	.num_resources	= ARRAY_SIZE(twi0_resources),
 };

@@ -673,6 +682,7 @@ static struct resource twi1_resources[] = {
 static struct platform_device at91sam9g45_twi1_device = {
 	.name		= "at91_i2c",
 	.id		= 1,
+	.id_entry	= &twi_id,
 	.resource	= twi1_resources,
 	.num_resources	= ARRAY_SIZE(twi1_resources),
 };

index 628eb56..bec28b5 100644
@@ -350,9 +350,18 @@ static struct resource twi_resources[] = {
 	},
 };
 
+static const struct platform_device_id twi_id = {
+	/*
+	 * driver_data is "1" for hardware with ckdiv upper limit == 5
+	 * (AT91RM9200 erratum 22), "0" for twi modules without this bug
+	 */
+	.driver_data	= 0,
+};
+
 static struct platform_device at91sam9rl_twi_device = {
 	.name		= "at91_i2c",
 	.id		= -1,
+	.id_entry	= &twi_id,
 	.resource	= twi_resources,
 	.num_resources	= ARRAY_SIZE(twi_resources),
 };

index 34deef4..4364dd1 100644
@@ -27,8 +27,6 @@
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 
-#include <mach/cpu.h>
-
 #define TWI_CLK_HZ		100000			/* max 400 Kbits/s */
 #define AT91_I2C_TIMEOUT	msecs_to_jiffies(100)	/* transfer timeout */
 

@@ -74,6 +72,7 @@ struct at91_twi_dev {
 	int			irq;
 	unsigned		transfer_status;
 	struct i2c_adapter	adapter;
+	bool			has_ckdiv_limit_bug;
 };
 
 static unsigned at91_twi_read(struct at91_twi_dev *dev, unsigned reg)

@@ -110,7 +109,7 @@ static void __devinit at91_set_twi_clock(struct at91_twi_dev *dev, int twi_clk)
 	int ckdiv = fls(div >> 8);
 	const int cdiv = div >> ckdiv;
 
-	if (cpu_is_at91rm9200() && (ckdiv > 5)) {
+	if (dev->has_ckdiv_limit_bug && (ckdiv > 5)) {
 		dev_warn(dev->dev, "AT91RM9200 erratum 22: using ckdiv = 5.\n");
 		ckdiv = 5;
 	}

@@ -314,6 +313,8 @@ static int __devinit at91_twi_probe(struct platform_device *pdev)
 		goto err_release_region;
 	}
 
+	dev->has_ckdiv_limit_bug = pdev->id_entry->driver_data == 1;
+
 	init_completion(&dev->cmd_complete);
 
 	dev->dev = &pdev->dev;