From af2a5f09fb6d317a0ec4b5026cd50f0b49a60419 Mon Sep 17 00:00:00 2001 From: Nikolaus Voss Date: Tue, 8 Nov 2011 12:09:30 +0100 Subject: Replace clk_lookup.con_id with clk_lookup.dev_id entries for twi clk The old driver used con_id clock entries. Convert to use dev_id for clock lookup via standard method. Signed-off-by: Nikolaus Voss Tested-by: Ludovic Desroches Reviewed-by: Nicolas Ferre Signed-off-by: Wolfram Sang --- arch/arm/mach-at91/at91rm9200.c | 1 + arch/arm/mach-at91/at91sam9260.c | 1 + arch/arm/mach-at91/at91sam9261.c | 1 + arch/arm/mach-at91/at91sam9263.c | 1 + arch/arm/mach-at91/at91sam9g45.c | 2 ++ arch/arm/mach-at91/at91sam9rl.c | 2 ++ arch/arm/mach-at91/at91sam9x5.c | 3 +++ 7 files changed, 11 insertions(+) (limited to 'arch/arm/mach-at91') diff --git a/arch/arm/mach-at91/at91rm9200.c b/arch/arm/mach-at91/at91rm9200.c index 6f50c6722276..f2112f9c1800 100644 --- a/arch/arm/mach-at91/at91rm9200.c +++ b/arch/arm/mach-at91/at91rm9200.c @@ -187,6 +187,7 @@ 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), CLKDEV_CON_ID("pioA", &pioA_clk), diff --git a/arch/arm/mach-at91/at91sam9260.c b/arch/arm/mach-at91/at91sam9260.c index 30c7f26a4668..57c79eed5fd0 100644 --- a/arch/arm/mach-at91/at91sam9260.c +++ b/arch/arm/mach-at91/at91sam9260.c @@ -211,6 +211,7 @@ static struct clk_lookup periph_clocks_lookups[] = { CLKDEV_CON_DEV_ID("t1_clk", "atmel_tcb.1", &tc4_clk), CLKDEV_CON_DEV_ID("t2_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), diff --git a/arch/arm/mach-at91/at91sam9261.c b/arch/arm/mach-at91/at91sam9261.c index f40762c5fede..71ca1e06a16f 100644 --- a/arch/arm/mach-at91/at91sam9261.c +++ b/arch/arm/mach-at91/at91sam9261.c @@ -178,6 +178,7 @@ 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), CLKDEV_CON_ID("pioA", &pioA_clk), CLKDEV_CON_ID("pioB", &pioB_clk), CLKDEV_CON_ID("pioC", &pioC_clk), diff --git a/arch/arm/mach-at91/at91sam9263.c b/arch/arm/mach-at91/at91sam9263.c index 84b38105231e..2a08305b6571 100644 --- a/arch/arm/mach-at91/at91sam9263.c +++ b/arch/arm/mach-at91/at91sam9263.c @@ -193,6 +193,7 @@ 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), CLKDEV_CON_ID("pioA", &pioA_clk), diff --git a/arch/arm/mach-at91/at91sam9g45.c b/arch/arm/mach-at91/at91sam9g45.c index ef6cedd52e3c..ddf3d3707c54 100644 --- a/arch/arm/mach-at91/at91sam9g45.c +++ b/arch/arm/mach-at91/at91sam9g45.c @@ -237,6 +237,8 @@ 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), diff --git a/arch/arm/mach-at91/at91sam9rl.c b/arch/arm/mach-at91/at91sam9rl.c index 72ce50a50de5..bf79c1fd5939 100644 --- a/arch/arm/mach-at91/at91sam9rl.c +++ b/arch/arm/mach-at91/at91sam9rl.c @@ -186,6 +186,8 @@ 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), CLKDEV_CON_ID("pioA", &pioA_clk), CLKDEV_CON_ID("pioB", &pioB_clk), CLKDEV_CON_ID("pioC", &pioC_clk), diff --git a/arch/arm/mach-at91/at91sam9x5.c b/arch/arm/mach-at91/at91sam9x5.c index 477cf9d06672..4bad4a288c87 100644 --- a/arch/arm/mach-at91/at91sam9x5.c +++ b/arch/arm/mach-at91/at91sam9x5.c @@ -231,6 +231,9 @@ static struct clk_lookup periph_clocks_lookups[] = { CLKDEV_CON_DEV_ID("t0_clk", "f800c000.timer", &tcb0_clk), CLKDEV_CON_DEV_ID("dma_clk", "ffffec00.dma-controller", &dma0_clk), CLKDEV_CON_DEV_ID("dma_clk", "ffffee00.dma-controller", &dma1_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(NULL, "at91_i2c.2", &twi2_clk), CLKDEV_CON_ID("pioA", &pioAB_clk), CLKDEV_CON_ID("pioB", &pioAB_clk), CLKDEV_CON_ID("pioC", &pioCD_clk), -- cgit v1.2.3 From a879e9c34b93ee43f5caa7f94eb17e7af4f6ef50 Mon Sep 17 00:00:00 2001 From: Nikolaus Voss Date: Tue, 8 Nov 2011 11:49:24 +0100 Subject: i2c: at91: remove old polling driver It will get replaced by a superior one. Safe to remove since this one depends on BROKEN anyhow. Signed-off-by: Nikolaus Voss Tested-by: Ludovic Desroches Reviewed-by: Nicolas Ferre [wsa: added commit message] Signed-off-by: Wolfram Sang --- arch/arm/mach-at91/include/mach/at91_twi.h | 68 ------- drivers/i2c/busses/Makefile | 1 - drivers/i2c/busses/i2c-at91.c | 315 ----------------------------- 3 files changed, 384 deletions(-) delete mode 100644 arch/arm/mach-at91/include/mach/at91_twi.h delete mode 100644 drivers/i2c/busses/i2c-at91.c (limited to 'arch/arm/mach-at91') diff --git a/arch/arm/mach-at91/include/mach/at91_twi.h b/arch/arm/mach-at91/include/mach/at91_twi.h deleted file mode 100644 index bb2880f6ba37..000000000000 --- a/arch/arm/mach-at91/include/mach/at91_twi.h +++ /dev/null @@ -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 - diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index ce3c2be7fb40..4f46873282b8 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -28,7 +28,6 @@ obj-$(CONFIG_I2C_HYDRA) += i2c-hydra.o obj-$(CONFIG_I2C_POWERMAC) += i2c-powermac.o # Embedded system I2C/SMBus host controller drivers -obj-$(CONFIG_I2C_AT91) += i2c-at91.o obj-$(CONFIG_I2C_AU1550) += i2c-au1550.o obj-$(CONFIG_I2C_BLACKFIN_TWI) += i2c-bfin-twi.o obj-$(CONFIG_I2C_CPM) += i2c-cpm.o diff --git a/drivers/i2c/busses/i2c-at91.c b/drivers/i2c/busses/i2c-at91.c deleted file mode 100644 index e24484beef07..000000000000 --- a/drivers/i2c/busses/i2c-at91.c +++ /dev/null @@ -1,315 +0,0 @@ -/* - i2c Support for Atmel's AT91 Two-Wire Interface (TWI) - - Copyright (C) 2004 Rick Bronson - Converted to 2.6 by Andrew Victor - - Borrowed heavily from original work by: - Copyright (C) 2000 Philip Edelbrock - - 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. -*/ - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#include -#include -#include - -#define TWI_CLOCK 100000 /* Hz. max 400 Kbits/sec */ - - -static struct clk *twi_clk; -static void __iomem *twi_base; - -#define at91_twi_read(reg) __raw_readl(twi_base + (reg)) -#define at91_twi_write(reg, val) __raw_writel((val), twi_base + (reg)) - - -/* - * Initialize the TWI hardware registers. - */ -static void __devinit at91_twi_hwinit(void) -{ - unsigned long cdiv, ckdiv; - - at91_twi_write(AT91_TWI_IDR, 0xffffffff); /* Disable all interrupts */ - at91_twi_write(AT91_TWI_CR, AT91_TWI_SWRST); /* Reset peripheral */ - at91_twi_write(AT91_TWI_CR, AT91_TWI_MSEN); /* Set Master mode */ - - /* Calcuate clock dividers */ - cdiv = (clk_get_rate(twi_clk) / (2 * TWI_CLOCK)) - 3; - cdiv = cdiv + 1; /* round up */ - ckdiv = 0; - while (cdiv > 255) { - ckdiv++; - cdiv = cdiv >> 1; - } - - if (cpu_is_at91rm9200()) { /* AT91RM9200 Errata #22 */ - if (ckdiv > 5) { - printk(KERN_ERR "AT91 I2C: Invalid TWI_CLOCK value!\n"); - ckdiv = 5; - } - } - - at91_twi_write(AT91_TWI_CWGR, (ckdiv << 16) | (cdiv << 8) | cdiv); -} - -/* - * Poll the i2c status register until the specified bit is set. - * Returns 0 if timed out (100 msec). - */ -static short at91_poll_status(unsigned long bit) -{ - int loop_cntr = 10000; - - do { - udelay(10); - } while (!(at91_twi_read(AT91_TWI_SR) & bit) && (--loop_cntr > 0)); - - return (loop_cntr > 0); -} - -static int xfer_read(struct i2c_adapter *adap, unsigned char *buf, int length) -{ - /* Send Start */ - at91_twi_write(AT91_TWI_CR, AT91_TWI_START); - - /* Read data */ - while (length--) { - if (!length) /* need to send Stop before reading last byte */ - at91_twi_write(AT91_TWI_CR, AT91_TWI_STOP); - if (!at91_poll_status(AT91_TWI_RXRDY)) { - dev_dbg(&adap->dev, "RXRDY timeout\n"); - return -ETIMEDOUT; - } - *buf++ = (at91_twi_read(AT91_TWI_RHR) & 0xff); - } - - return 0; -} - -static int xfer_write(struct i2c_adapter *adap, unsigned char *buf, int length) -{ - /* Load first byte into transmitter */ - at91_twi_write(AT91_TWI_THR, *buf++); - - /* Send Start */ - at91_twi_write(AT91_TWI_CR, AT91_TWI_START); - - do { - if (!at91_poll_status(AT91_TWI_TXRDY)) { - dev_dbg(&adap->dev, "TXRDY timeout\n"); - return -ETIMEDOUT; - } - - length--; /* byte was transmitted */ - - if (length > 0) /* more data to send? */ - at91_twi_write(AT91_TWI_THR, *buf++); - } while (length); - - /* Send Stop */ - at91_twi_write(AT91_TWI_CR, AT91_TWI_STOP); - - return 0; -} - -/* - * Generic i2c master transfer entrypoint. - * - * Note: We do not use Atmel's feature of storing the "internal device address". - * Instead the "internal device address" has to be written using a separate - * i2c message. - * http://lists.arm.linux.org.uk/pipermail/linux-arm-kernel/2004-September/024411.html - */ -static int at91_xfer(struct i2c_adapter *adap, struct i2c_msg *pmsg, int num) -{ - int i, ret; - - dev_dbg(&adap->dev, "at91_xfer: processing %d messages:\n", num); - - for (i = 0; i < num; i++) { - dev_dbg(&adap->dev, " #%d: %sing %d byte%s %s 0x%02x\n", i, - pmsg->flags & I2C_M_RD ? "read" : "writ", - pmsg->len, pmsg->len > 1 ? "s" : "", - pmsg->flags & I2C_M_RD ? "from" : "to", pmsg->addr); - - at91_twi_write(AT91_TWI_MMR, (pmsg->addr << 16) - | ((pmsg->flags & I2C_M_RD) ? AT91_TWI_MREAD : 0)); - - if (pmsg->len && pmsg->buf) { /* sanity check */ - if (pmsg->flags & I2C_M_RD) - ret = xfer_read(adap, pmsg->buf, pmsg->len); - else - ret = xfer_write(adap, pmsg->buf, pmsg->len); - - if (ret) - return ret; - - /* Wait until transfer is finished */ - if (!at91_poll_status(AT91_TWI_TXCOMP)) { - dev_dbg(&adap->dev, "TXCOMP timeout\n"); - return -ETIMEDOUT; - } - } - dev_dbg(&adap->dev, "transfer complete\n"); - pmsg++; /* next message */ - } - return i; -} - -/* - * Return list of supported functionality. - */ -static u32 at91_func(struct i2c_adapter *adapter) -{ - return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; -} - -static struct i2c_algorithm at91_algorithm = { - .master_xfer = at91_xfer, - .functionality = at91_func, -}; - -/* - * Main initialization routine. - */ -static int __devinit at91_i2c_probe(struct platform_device *pdev) -{ - struct i2c_adapter *adapter; - struct resource *res; - int rc; - - res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - if (!res) - return -ENXIO; - - if (!request_mem_region(res->start, resource_size(res), "at91_i2c")) - return -EBUSY; - - twi_base = ioremap(res->start, resource_size(res)); - if (!twi_base) { - rc = -ENOMEM; - goto fail0; - } - - twi_clk = clk_get(NULL, "twi_clk"); - if (IS_ERR(twi_clk)) { - dev_err(&pdev->dev, "no clock defined\n"); - rc = -ENODEV; - goto fail1; - } - - adapter = kzalloc(sizeof(struct i2c_adapter), GFP_KERNEL); - if (adapter == NULL) { - dev_err(&pdev->dev, "can't allocate inteface!\n"); - rc = -ENOMEM; - goto fail2; - } - snprintf(adapter->name, sizeof(adapter->name), "AT91"); - adapter->algo = &at91_algorithm; - adapter->class = I2C_CLASS_HWMON; - adapter->dev.parent = &pdev->dev; - /* adapter->id == 0 ... only one TWI controller for now */ - - platform_set_drvdata(pdev, adapter); - - clk_enable(twi_clk); /* enable peripheral clock */ - at91_twi_hwinit(); /* initialize TWI controller */ - - rc = i2c_add_numbered_adapter(adapter); - if (rc) { - dev_err(&pdev->dev, "Adapter %s registration failed\n", - adapter->name); - goto fail3; - } - - dev_info(&pdev->dev, "AT91 i2c bus driver.\n"); - return 0; - -fail3: - platform_set_drvdata(pdev, NULL); - kfree(adapter); - clk_disable(twi_clk); -fail2: - clk_put(twi_clk); -fail1: - iounmap(twi_base); -fail0: - release_mem_region(res->start, resource_size(res)); - - return rc; -} - -static int __devexit at91_i2c_remove(struct platform_device *pdev) -{ - struct i2c_adapter *adapter = platform_get_drvdata(pdev); - struct resource *res; - int rc; - - rc = i2c_del_adapter(adapter); - platform_set_drvdata(pdev, NULL); - - res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - iounmap(twi_base); - release_mem_region(res->start, resource_size(res)); - - clk_disable(twi_clk); /* disable peripheral clock */ - clk_put(twi_clk); - - return rc; -} - -#ifdef CONFIG_PM - -/* NOTE: could save a few mA by keeping clock off outside of at91_xfer... */ - -static int at91_i2c_suspend(struct device *dev) -{ - clk_disable(twi_clk); - return 0; -} - -static int at91_i2c_resume(struct device *dev) -{ - return clk_enable(twi_clk); -} - -static SIMPLE_DEV_PM_OPS(at91_i2c_pm, at91_i2c_suspend, at91_i2c_resume); -#define AT91_I2C_PM (&at91_i2c_pm) - -#else -#define AT91_I2C_PM NULL -#endif - -static struct platform_driver at91_i2c_driver = { - .probe = at91_i2c_probe, - .remove = __devexit_p(at91_i2c_remove), - .driver = { - .name = "at91_i2c", - .owner = THIS_MODULE, - .pm = AT91_I2C_PM, - }, -}; - -module_platform_driver(at91_i2c_driver); - -MODULE_AUTHOR("Rick Bronson"); -MODULE_DESCRIPTION("I2C (TWI) driver for Atmel AT91"); -MODULE_LICENSE("GPL"); -MODULE_ALIAS("platform:at91_i2c"); -- cgit v1.2.3 From fac368a040484293006bb488e67972aafcf88ec7 Mon Sep 17 00:00:00 2001 From: Nikolaus Voss Date: Tue, 8 Nov 2011 11:49:46 +0100 Subject: i2c: at91: add new driver This driver has the following properties compared to the old driver: 1. Support for multiple interfaces. 2. Interrupt driven I/O as opposed to polling/busy waiting. 3. Support for _one_ repeated start (Sr) condition, which is enough for most real-world applications including all SMBus transfer types. (The hardware does not support issuing arbitrary Sr conditions on the bus.) testing: SoC: at91sam9g45 - BQ20Z80 battery SMBus client. - on a 2.6.38 kernel with several i2c clients (temp-sensor, audio-codec, touchscreen-controller, w1-bridge, io-expanders) Signed-off-by: Nikolaus Voss Reviewed-by: Felipe Balbi Tested-by: Hubert Feurstein Tested-by: Ludovic Desroches Reviewed-by: Nicolas Ferre [wsa: squashed with the following patches from Ludovic to have some flaws fixed: i2c: at91: use managed resources i2c: at91: add warning about transmission issues for some devices i2c: at91: use an id table for SoC dependent parameters ] Signed-off-by: Ludovic Desroches Signed-off-by: Wolfram Sang --- arch/arm/mach-at91/at91rm9200.c | 2 +- arch/arm/mach-at91/at91rm9200_devices.c | 2 +- arch/arm/mach-at91/at91sam9260.c | 3 +- arch/arm/mach-at91/at91sam9260_devices.c | 8 +- arch/arm/mach-at91/at91sam9261.c | 3 +- arch/arm/mach-at91/at91sam9261_devices.c | 8 +- arch/arm/mach-at91/at91sam9263.c | 2 +- arch/arm/mach-at91/at91sam9263_devices.c | 2 +- arch/arm/mach-at91/at91sam9g45.c | 4 +- arch/arm/mach-at91/at91sam9g45_devices.c | 4 +- arch/arm/mach-at91/at91sam9rl.c | 4 +- arch/arm/mach-at91/at91sam9rl_devices.c | 2 +- drivers/i2c/busses/Kconfig | 17 +- drivers/i2c/busses/Makefile | 1 + drivers/i2c/busses/i2c-at91.c | 505 +++++++++++++++++++++++++++++++ 15 files changed, 545 insertions(+), 22 deletions(-) create mode 100644 drivers/i2c/busses/i2c-at91.c (limited to 'arch/arm/mach-at91') diff --git a/arch/arm/mach-at91/at91rm9200.c b/arch/arm/mach-at91/at91rm9200.c index f2112f9c1800..b4f0565aff63 100644 --- a/arch/arm/mach-at91/at91rm9200.c +++ b/arch/arm/mach-at91/at91rm9200.c @@ -187,7 +187,7 @@ 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), + CLKDEV_CON_DEV_ID(NULL, "i2c-at91rm9200", &twi_clk), /* fake hclk clock */ CLKDEV_CON_DEV_ID("hclk", "at91_ohci", &ohci_clk), CLKDEV_CON_ID("pioA", &pioA_clk), diff --git a/arch/arm/mach-at91/at91rm9200_devices.c b/arch/arm/mach-at91/at91rm9200_devices.c index 01fb7325fecc..0b972f2e57eb 100644 --- a/arch/arm/mach-at91/at91rm9200_devices.c +++ b/arch/arm/mach-at91/at91rm9200_devices.c @@ -495,7 +495,7 @@ static struct resource twi_resources[] = { }; static struct platform_device at91rm9200_twi_device = { - .name = "at91_i2c", + .name = "i2c-at91rm9200", .id = -1, .resource = twi_resources, .num_resources = ARRAY_SIZE(twi_resources), diff --git a/arch/arm/mach-at91/at91sam9260.c b/arch/arm/mach-at91/at91sam9260.c index 57c79eed5fd0..5bd19a442365 100644 --- a/arch/arm/mach-at91/at91sam9260.c +++ b/arch/arm/mach-at91/at91sam9260.c @@ -211,7 +211,8 @@ static struct clk_lookup periph_clocks_lookups[] = { CLKDEV_CON_DEV_ID("t1_clk", "atmel_tcb.1", &tc4_clk), CLKDEV_CON_DEV_ID("t2_clk", "atmel_tcb.1", &tc5_clk), CLKDEV_CON_DEV_ID("pclk", "ssc.0", &ssc_clk), - CLKDEV_CON_DEV_ID(NULL, "at91_i2c", &twi_clk), + CLKDEV_CON_DEV_ID(NULL, "i2c-at91sam9260", &twi_clk), + CLKDEV_CON_DEV_ID(NULL, "i2c-at91sam9g20", &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), diff --git a/arch/arm/mach-at91/at91sam9260_devices.c b/arch/arm/mach-at91/at91sam9260_devices.c index bce572a530ef..95fc23aab432 100644 --- a/arch/arm/mach-at91/at91sam9260_devices.c +++ b/arch/arm/mach-at91/at91sam9260_devices.c @@ -503,7 +503,6 @@ static struct resource twi_resources[] = { }; static struct platform_device at91sam9260_twi_device = { - .name = "at91_i2c", .id = -1, .resource = twi_resources, .num_resources = ARRAY_SIZE(twi_resources), @@ -511,6 +510,13 @@ static struct platform_device at91sam9260_twi_device = { void __init at91_add_device_i2c(struct i2c_board_info *devices, int nr_devices) { + /* IP version is not the same on 9260 and g20 */ + if (cpu_is_at91sam9g20()) { + at91sam9260_twi_device.name = "i2c-at91sam9g20"; + } else { + at91sam9260_twi_device.name = "i2c-at91sam9260"; + } + /* pins used for TWI interface */ at91_set_A_periph(AT91_PIN_PA23, 0); /* TWD */ at91_set_multi_drive(AT91_PIN_PA23, 1); diff --git a/arch/arm/mach-at91/at91sam9261.c b/arch/arm/mach-at91/at91sam9261.c index 71ca1e06a16f..8d999eb1a137 100644 --- a/arch/arm/mach-at91/at91sam9261.c +++ b/arch/arm/mach-at91/at91sam9261.c @@ -178,7 +178,8 @@ 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), + CLKDEV_CON_DEV_ID(NULL, "i2c-at91sam9261", &twi_clk), + CLKDEV_CON_DEV_ID(NULL, "i2c-at91sam9g10", &twi_clk), CLKDEV_CON_ID("pioA", &pioA_clk), CLKDEV_CON_ID("pioB", &pioB_clk), CLKDEV_CON_ID("pioC", &pioC_clk), diff --git a/arch/arm/mach-at91/at91sam9261_devices.c b/arch/arm/mach-at91/at91sam9261_devices.c index bc2590d712d0..29188ef7422b 100644 --- a/arch/arm/mach-at91/at91sam9261_devices.c +++ b/arch/arm/mach-at91/at91sam9261_devices.c @@ -317,7 +317,6 @@ static struct resource twi_resources[] = { }; static struct platform_device at91sam9261_twi_device = { - .name = "at91_i2c", .id = -1, .resource = twi_resources, .num_resources = ARRAY_SIZE(twi_resources), @@ -325,6 +324,13 @@ static struct platform_device at91sam9261_twi_device = { void __init at91_add_device_i2c(struct i2c_board_info *devices, int nr_devices) { + /* IP version is not the same on 9261 and g10 */ + if (cpu_is_at91sam9g10()) { + at91sam9261_twi_device.name = "i2c-at91sam9g10"; + } else { + at91sam9261_twi_device.name = "i2c-at91sam9261"; + } + /* pins used for TWI interface */ at91_set_A_periph(AT91_PIN_PA7, 0); /* TWD */ at91_set_multi_drive(AT91_PIN_PA7, 1); diff --git a/arch/arm/mach-at91/at91sam9263.c b/arch/arm/mach-at91/at91sam9263.c index 2a08305b6571..e6b595658e75 100644 --- a/arch/arm/mach-at91/at91sam9263.c +++ b/arch/arm/mach-at91/at91sam9263.c @@ -193,7 +193,7 @@ 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), + CLKDEV_CON_DEV_ID(NULL, "i2c-at91sam9260", &twi_clk), /* fake hclk clock */ CLKDEV_CON_DEV_ID("hclk", "at91_ohci", &ohci_clk), CLKDEV_CON_ID("pioA", &pioA_clk), diff --git a/arch/arm/mach-at91/at91sam9263_devices.c b/arch/arm/mach-at91/at91sam9263_devices.c index 9b6ca734f1a9..3f5288ea64b9 100644 --- a/arch/arm/mach-at91/at91sam9263_devices.c +++ b/arch/arm/mach-at91/at91sam9263_devices.c @@ -574,7 +574,7 @@ static struct resource twi_resources[] = { }; static struct platform_device at91sam9263_twi_device = { - .name = "at91_i2c", + .name = "i2c-at91sam9260", .id = -1, .resource = twi_resources, .num_resources = ARRAY_SIZE(twi_resources), diff --git a/arch/arm/mach-at91/at91sam9g45.c b/arch/arm/mach-at91/at91sam9g45.c index ddf3d3707c54..858f032e5102 100644 --- a/arch/arm/mach-at91/at91sam9g45.c +++ b/arch/arm/mach-at91/at91sam9g45.c @@ -237,8 +237,8 @@ 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(NULL, "i2c-at91sam9g10.0", &twi0_clk), + CLKDEV_CON_DEV_ID(NULL, "i2c-at91sam9g10.1", &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), diff --git a/arch/arm/mach-at91/at91sam9g45_devices.c b/arch/arm/mach-at91/at91sam9g45_devices.c index 1b47319ca00b..ac1b0f8c3b31 100644 --- a/arch/arm/mach-at91/at91sam9g45_devices.c +++ b/arch/arm/mach-at91/at91sam9g45_devices.c @@ -653,7 +653,7 @@ static struct resource twi0_resources[] = { }; static struct platform_device at91sam9g45_twi0_device = { - .name = "at91_i2c", + .name = "i2c-at91sam9g10", .id = 0, .resource = twi0_resources, .num_resources = ARRAY_SIZE(twi0_resources), @@ -673,7 +673,7 @@ static struct resource twi1_resources[] = { }; static struct platform_device at91sam9g45_twi1_device = { - .name = "at91_i2c", + .name = "i2c-at91sam9g10", .id = 1, .resource = twi1_resources, .num_resources = ARRAY_SIZE(twi1_resources), diff --git a/arch/arm/mach-at91/at91sam9rl.c b/arch/arm/mach-at91/at91sam9rl.c index bf79c1fd5939..72e908412222 100644 --- a/arch/arm/mach-at91/at91sam9rl.c +++ b/arch/arm/mach-at91/at91sam9rl.c @@ -186,8 +186,8 @@ 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), + CLKDEV_CON_DEV_ID(NULL, "i2c-at91sam9g20.0", &twi0_clk), + CLKDEV_CON_DEV_ID(NULL, "i2c-at91sam9g20.1", &twi1_clk), CLKDEV_CON_ID("pioA", &pioA_clk), CLKDEV_CON_ID("pioB", &pioB_clk), CLKDEV_CON_ID("pioC", &pioC_clk), diff --git a/arch/arm/mach-at91/at91sam9rl_devices.c b/arch/arm/mach-at91/at91sam9rl_devices.c index b3d365dadef5..0794954953e5 100644 --- a/arch/arm/mach-at91/at91sam9rl_devices.c +++ b/arch/arm/mach-at91/at91sam9rl_devices.c @@ -346,7 +346,7 @@ static struct resource twi_resources[] = { }; static struct platform_device at91sam9rl_twi_device = { - .name = "at91_i2c", + .name = "i2c-at91sam9g20", .id = -1, .resource = twi_resources, .num_resources = ARRAY_SIZE(twi_resources), diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index b4aaa1bd6728..da77c37caf1e 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -290,18 +290,21 @@ comment "I2C system bus drivers (mostly embedded / system-on-chip)" config I2C_AT91 tristate "Atmel AT91 I2C Two-Wire interface (TWI)" - depends on ARCH_AT91 && EXPERIMENTAL && BROKEN + depends on ARCH_AT91 && EXPERIMENTAL help This supports the use of the I2C interface on Atmel AT91 processors. - This driver is BROKEN because the controller which it uses - will easily trigger RX overrun and TX underrun errors. Using - low I2C clock rates may partially work around those issues - on some systems. Another serious problem is that there is no - documented way to issue repeated START conditions, as needed + A serious problem is that there is no documented way to issue + repeated START conditions for more than two messages, as needed to support combined I2C messages. Use the i2c-gpio driver - unless your system can cope with those limitations. + unless your system can cope with this limitation. + + Caution! at91rm9200, at91sam9261, at91sam9260, at91sam9263 devices + don't have clock stretching in transmission mode. For that reason, + you can encounter underrun issues causing premature stop sendings if + the latency to fill the transmission register is too long. If you + are facing this situation, use the i2c-gpio driver. config I2C_AU1550 tristate "Au1550/Au1200/Au1300 SMBus interface" diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 4f46873282b8..ce3c2be7fb40 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -28,6 +28,7 @@ obj-$(CONFIG_I2C_HYDRA) += i2c-hydra.o obj-$(CONFIG_I2C_POWERMAC) += i2c-powermac.o # Embedded system I2C/SMBus host controller drivers +obj-$(CONFIG_I2C_AT91) += i2c-at91.o obj-$(CONFIG_I2C_AU1550) += i2c-au1550.o obj-$(CONFIG_I2C_BLACKFIN_TWI) += i2c-bfin-twi.o obj-$(CONFIG_I2C_CPM) += i2c-cpm.o diff --git a/drivers/i2c/busses/i2c-at91.c b/drivers/i2c/busses/i2c-at91.c new file mode 100644 index 000000000000..78bcad031d6a --- /dev/null +++ b/drivers/i2c/busses/i2c-at91.c @@ -0,0 +1,505 @@ +/* + * i2c Support for Atmel's AT91 Two-Wire Interface (TWI) + * + * Copyright (C) 2011 Weinmann Medical GmbH + * Author: Nikolaus Voss + * + * Evolved from original work by: + * Copyright (C) 2004 Rick Bronson + * Converted to 2.6 by Andrew Victor + * + * Borrowed heavily from original work by: + * Copyright (C) 2000 Philip Edelbrock + * + * 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. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#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_pdata { + unsigned clk_max_div; + unsigned clk_offset; + bool has_unre_flag; +}; + +struct at91_twi_dev { + struct device *dev; + void __iomem *base; + struct completion cmd_complete; + struct clk *clk; + u8 *buf; + size_t buf_len; + struct i2c_msg *msg; + int irq; + unsigned transfer_status; + struct i2c_adapter adapter; + unsigned twi_cwgr_reg; + struct at91_twi_pdata *pdata; +}; + +static unsigned at91_twi_read(struct at91_twi_dev *dev, unsigned reg) +{ + return readl_relaxed(dev->base + reg); +} + +static void at91_twi_write(struct at91_twi_dev *dev, unsigned reg, unsigned val) +{ + writel_relaxed(val, dev->base + reg); +} + +static void at91_disable_twi_interrupts(struct at91_twi_dev *dev) +{ + at91_twi_write(dev, AT91_TWI_IDR, + AT91_TWI_TXCOMP | AT91_TWI_RXRDY | AT91_TWI_TXRDY); +} + +static void at91_init_twi_bus(struct at91_twi_dev *dev) +{ + at91_disable_twi_interrupts(dev); + at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_SWRST); + at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_MSEN); + at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_SVDIS); + at91_twi_write(dev, AT91_TWI_CWGR, dev->twi_cwgr_reg); +} + +/* + * Calculate symmetric clock as stated in datasheet: + * twi_clk = F_MAIN / (2 * (cdiv * (1 << ckdiv) + offset)) + */ +static void __devinit at91_calc_twi_clock(struct at91_twi_dev *dev, int twi_clk) +{ + int ckdiv, cdiv, div; + struct at91_twi_pdata *pdata = dev->pdata; + int offset = pdata->clk_offset; + int max_ckdiv = pdata->clk_max_div; + + div = max(0, (int)DIV_ROUND_UP(clk_get_rate(dev->clk), + 2 * twi_clk) - offset); + ckdiv = fls(div >> 8); + cdiv = div >> ckdiv; + + if (ckdiv > max_ckdiv) { + dev_warn(dev->dev, "%d exceeds ckdiv max value which is %d.\n", + ckdiv, max_ckdiv); + ckdiv = max_ckdiv; + cdiv = 255; + } + + dev->twi_cwgr_reg = (ckdiv << 16) | (cdiv << 8) | cdiv; + dev_dbg(dev->dev, "cdiv %d ckdiv %d\n", cdiv, ckdiv); +} + +static void at91_twi_write_next_byte(struct at91_twi_dev *dev) +{ + if (dev->buf_len <= 0) + return; + + at91_twi_write(dev, AT91_TWI_THR, *dev->buf); + + /* send stop when last byte has been written */ + if (--dev->buf_len == 0) + at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_STOP); + + dev_dbg(dev->dev, "wrote 0x%x, to go %d\n", *dev->buf, dev->buf_len); + + ++dev->buf; +} + +static void at91_twi_read_next_byte(struct at91_twi_dev *dev) +{ + if (dev->buf_len <= 0) + return; + + *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) + 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); + + ++dev->buf; +} + +static irqreturn_t atmel_twi_interrupt(int irq, void *dev_id) +{ + struct at91_twi_dev *dev = dev_id; + const unsigned status = at91_twi_read(dev, AT91_TWI_SR); + const unsigned irqstatus = status & at91_twi_read(dev, AT91_TWI_IMR); + + if (!irqstatus) + return IRQ_NONE; + else if (irqstatus & AT91_TWI_RXRDY) + at91_twi_read_next_byte(dev); + else if (irqstatus & AT91_TWI_TXRDY) + at91_twi_write_next_byte(dev); + + /* catch error flags */ + dev->transfer_status |= status; + + if (irqstatus & AT91_TWI_TXCOMP) { + at91_disable_twi_interrupts(dev); + complete(&dev->cmd_complete); + } + + return IRQ_HANDLED; +} + +static int at91_do_twi_transfer(struct at91_twi_dev *dev) +{ + int ret; + bool has_unre_flag = dev->pdata->has_unre_flag; + + 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); + dev->transfer_status = 0; + if (dev->msg->flags & I2C_M_RD) { + unsigned start_flags = AT91_TWI_START; + + if (at91_twi_read(dev, AT91_TWI_SR) & AT91_TWI_RXRDY) { + dev_err(dev->dev, "RXRDY still set!"); + at91_twi_read(dev, AT91_TWI_RHR); + } + + /* 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 { + at91_twi_write_next_byte(dev); + at91_twi_write(dev, AT91_TWI_IER, + AT91_TWI_TXCOMP | AT91_TWI_TXRDY); + } + + ret = wait_for_completion_interruptible_timeout(&dev->cmd_complete, + dev->adapter.timeout); + if (ret == 0) { + dev_err(dev->dev, "controller timed out\n"); + at91_init_twi_bus(dev); + return -ETIMEDOUT; + } + if (dev->transfer_status & AT91_TWI_NACK) { + dev_dbg(dev->dev, "received nack\n"); + return -EREMOTEIO; + } + if (dev->transfer_status & AT91_TWI_OVRE) { + dev_err(dev->dev, "overrun while reading\n"); + return -EIO; + } + if (has_unre_flag && dev->transfer_status & AT91_TWI_UNRE) { + dev_err(dev->dev, "underrun while writing\n"); + return -EIO; + } + dev_dbg(dev->dev, "transfer complete\n"); + + return 0; +} + +static int at91_twi_xfer(struct i2c_adapter *adap, struct i2c_msg *msg, int num) +{ + struct at91_twi_dev *dev = i2c_get_adapdata(adap); + int ret; + unsigned int_addr_flag = 0; + struct i2c_msg *m_start = msg; + + dev_dbg(&adap->dev, "at91_xfer: processing %d messages:\n", num); + + /* + * The hardware can handle at most two messages concatenated by a + * repeated start via it's internal address feature. + */ + if (num > 2) { + dev_err(dev->dev, + "cannot handle more than two concatenated messages.\n"); + return 0; + } else if (num == 2) { + int internal_address = 0; + int i; + + if (msg->flags & I2C_M_RD) { + dev_err(dev->dev, "first transfer must be write.\n"); + return -EINVAL; + } + if (msg->len > 3) { + dev_err(dev->dev, "first message size must be <= 3.\n"); + return -EINVAL; + } + + /* 1st msg is put into the internal address, start with 2nd */ + m_start = &msg[1]; + for (i = 0; i < msg->len; ++i) { + const unsigned addr = msg->buf[msg->len - 1 - i]; + + internal_address |= addr << (8 * i); + int_addr_flag += AT91_TWI_IADRSZ_1; + } + at91_twi_write(dev, AT91_TWI_IADR, internal_address); + } + + at91_twi_write(dev, AT91_TWI_MMR, (m_start->addr << 16) | int_addr_flag + | ((m_start->flags & I2C_M_RD) ? AT91_TWI_MREAD : 0)); + + dev->buf_len = m_start->len; + dev->buf = m_start->buf; + dev->msg = m_start; + + ret = at91_do_twi_transfer(dev); + + return (ret < 0) ? ret : num; +} + +static u32 at91_twi_func(struct i2c_adapter *adapter) +{ + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL + | I2C_FUNC_SMBUS_READ_BLOCK_DATA; +} + +static struct i2c_algorithm at91_twi_algorithm = { + .master_xfer = at91_twi_xfer, + .functionality = at91_twi_func, +}; + +static struct at91_twi_pdata at91rm9200_config = { + .clk_max_div = 5, + .clk_offset = 3, + .has_unre_flag = true, +}; + +static struct at91_twi_pdata at91sam9261_config = { + .clk_max_div = 5, + .clk_offset = 4, + .has_unre_flag = false, +}; + +static struct at91_twi_pdata at91sam9260_config = { + .clk_max_div = 7, + .clk_offset = 4, + .has_unre_flag = false, +}; + +static struct at91_twi_pdata at91sam9g20_config = { + .clk_max_div = 7, + .clk_offset = 4, + .has_unre_flag = false, +}; + +static struct at91_twi_pdata at91sam9g10_config = { + .clk_max_div = 7, + .clk_offset = 4, + .has_unre_flag = false, +}; + +static const struct platform_device_id at91_twi_devtypes[] = { + { + .name = "i2c-at91rm9200", + .driver_data = (unsigned long) &at91rm9200_config, + }, { + .name = "i2c-at91sam9261", + .driver_data = (unsigned long) &at91sam9261_config, + }, { + .name = "i2c-at91sam9260", + .driver_data = (unsigned long) &at91sam9260_config, + }, { + .name = "i2c-at91sam9g20", + .driver_data = (unsigned long) &at91sam9g20_config, + }, { + .name = "i2c-at91sam9g10", + .driver_data = (unsigned long) &at91sam9g10_config, + }, { + /* sentinel */ + } +}; + +static int __devinit at91_twi_probe(struct platform_device *pdev) +{ + struct at91_twi_dev *dev; + struct resource *mem; + int rc; + + dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL); + if (!dev) + return -ENOMEM; + init_completion(&dev->cmd_complete); + dev->dev = &pdev->dev; + + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!mem) + return -ENODEV; + + dev->pdata = at91_twi_get_driver_data(pdev); + if (!dev->pdata) + return -ENODEV; + + dev->base = devm_request_and_ioremap(&pdev->dev, mem); + if (!dev->base) + return -EBUSY; + + dev->irq = platform_get_irq(pdev, 0); + if (dev->irq < 0) + return dev->irq; + + rc = devm_request_irq(&pdev->dev, dev->irq, atmel_twi_interrupt, 0, + dev_name(dev->dev), dev); + if (rc) { + dev_err(dev->dev, "Cannot get irq %d: %d\n", dev->irq, rc); + return rc; + } + + platform_set_drvdata(pdev, dev); + + dev->clk = devm_clk_get(dev->dev, NULL); + if (IS_ERR(dev->clk)) { + dev_err(dev->dev, "no clock defined\n"); + return -ENODEV; + } + clk_prepare_enable(dev->clk); + + at91_calc_twi_clock(dev, TWI_CLK_HZ); + at91_init_twi_bus(dev); + + snprintf(dev->adapter.name, sizeof(dev->adapter.name), "AT91"); + i2c_set_adapdata(&dev->adapter, dev); + dev->adapter.owner = THIS_MODULE; + dev->adapter.class = I2C_CLASS_HWMON; + dev->adapter.algo = &at91_twi_algorithm; + dev->adapter.dev.parent = dev->dev; + dev->adapter.nr = pdev->id; + dev->adapter.timeout = AT91_I2C_TIMEOUT; + + rc = i2c_add_numbered_adapter(&dev->adapter); + if (rc) { + dev_err(dev->dev, "Adapter %s registration failed\n", + dev->adapter.name); + clk_disable_unprepare(dev->clk); + return rc; + } + + dev_info(dev->dev, "AT91 i2c bus driver.\n"); + return 0; +} + +static int __devexit at91_twi_remove(struct platform_device *pdev) +{ + struct at91_twi_dev *dev = platform_get_drvdata(pdev); + int rc; + + rc = i2c_del_adapter(&dev->adapter); + clk_disable_unprepare(dev->clk); + + return rc; +} + +#ifdef CONFIG_PM + +static int at91_twi_runtime_suspend(struct device *dev) +{ + struct at91_twi_dev *twi_dev = dev_get_drvdata(dev); + + clk_disable(twi_dev->clk); + + return 0; +} + +static int at91_twi_runtime_resume(struct device *dev) +{ + struct at91_twi_dev *twi_dev = dev_get_drvdata(dev); + + return clk_enable(twi_dev->clk); +} + +static const struct dev_pm_ops at91_twi_pm = { + .runtime_suspend = at91_twi_runtime_suspend, + .runtime_resume = at91_twi_runtime_resume, +}; + +#define at91_twi_pm_ops (&at91_twi_pm) +#else +#define at91_twi_pm_ops NULL +#endif + +static struct platform_driver at91_twi_driver = { + .probe = at91_twi_probe, + .remove = __devexit_p(at91_twi_remove), + .id_table = at91_twi_devtypes, + .driver = { + .name = "at91_i2c", + .owner = THIS_MODULE, + .pm = at91_twi_pm_ops, + }, +}; + +static int __init at91_twi_init(void) +{ + return platform_driver_register(&at91_twi_driver); +} + +static void __exit at91_twi_exit(void) +{ + platform_driver_unregister(&at91_twi_driver); +} + +subsys_initcall(at91_twi_init); +module_exit(at91_twi_exit); + +MODULE_AUTHOR("Nikolaus Voss "); +MODULE_DESCRIPTION("I2C (TWI) driver for Atmel AT91"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:at91_i2c"); -- cgit v1.2.3 From 774c8018d2566207c92f47b6421dad7d88bbfd49 Mon Sep 17 00:00:00 2001 From: Nikolaus Voss Date: Tue, 8 Nov 2011 12:11:03 +0100 Subject: arm: at91: G45 TWI: remove open drain setting for twi function gpios The G45 datasheets explicitly states that setting the open drain property on peripheral function gpios is not allowed. (How about other A91 chips?) Signed-off-by: Nikolaus Voss Tested-by: Ludovic Desroches Reviewed-by: Nicolas Ferre Signed-off-by: Wolfram Sang --- arch/arm/mach-at91/at91sam9g45_devices.c | 6 ------ 1 file changed, 6 deletions(-) (limited to 'arch/arm/mach-at91') diff --git a/arch/arm/mach-at91/at91sam9g45_devices.c b/arch/arm/mach-at91/at91sam9g45_devices.c index ac1b0f8c3b31..0fcd8718770f 100644 --- a/arch/arm/mach-at91/at91sam9g45_devices.c +++ b/arch/arm/mach-at91/at91sam9g45_devices.c @@ -686,18 +686,12 @@ 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); } -- cgit v1.2.3 From 94e734655fbe294c50d304547cae033e87ec229e Mon Sep 17 00:00:00 2001 From: Ludovic Desroches Date: Wed, 12 Sep 2012 08:42:13 +0200 Subject: ARM: at91: do not configure at91sam9g10 twi pio as open-drain As indicated in the datasheet, TWD and TWCK must not be programmed as open-drain. Signed-off-by: Ludovic Desroches Acked-by: Nikolaus Voss Acked-by: Nicolas Ferre Signed-off-by: Wolfram Sang --- arch/arm/mach-at91/at91sam9261_devices.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'arch/arm/mach-at91') diff --git a/arch/arm/mach-at91/at91sam9261_devices.c b/arch/arm/mach-at91/at91sam9261_devices.c index 29188ef7422b..50d317940f5a 100644 --- a/arch/arm/mach-at91/at91sam9261_devices.c +++ b/arch/arm/mach-at91/at91sam9261_devices.c @@ -327,16 +327,16 @@ void __init at91_add_device_i2c(struct i2c_board_info *devices, int nr_devices) /* IP version is not the same on 9261 and g10 */ if (cpu_is_at91sam9g10()) { at91sam9261_twi_device.name = "i2c-at91sam9g10"; + /* I2C PIO must not be configured as open-drain on this chip */ } else { at91sam9261_twi_device.name = "i2c-at91sam9261"; + at91_set_multi_drive(AT91_PIN_PA7, 1); + at91_set_multi_drive(AT91_PIN_PA8, 1); } /* pins used for TWI interface */ at91_set_A_periph(AT91_PIN_PA7, 0); /* TWD */ - at91_set_multi_drive(AT91_PIN_PA7, 1); - at91_set_A_periph(AT91_PIN_PA8, 0); /* TWCK */ - at91_set_multi_drive(AT91_PIN_PA8, 1); i2c_register_board_info(0, devices, nr_devices); platform_device_register(&at91sam9261_twi_device); -- cgit v1.2.3 From f7d19b9065569268dd13307213c40d168fb0be82 Mon Sep 17 00:00:00 2001 From: Ludovic Desroches Date: Wed, 12 Sep 2012 08:42:15 +0200 Subject: ARM: at91: add clocks for I2C DT entries Signed-off-by: Ludovic Desroches Acked-by: Nikolaus Voss Acked-by: Nicolas Ferre Signed-off-by: Wolfram Sang --- arch/arm/mach-at91/at91sam9260.c | 1 + arch/arm/mach-at91/at91sam9263.c | 1 + arch/arm/mach-at91/at91sam9g45.c | 2 ++ arch/arm/mach-at91/at91sam9n12.c | 2 ++ arch/arm/mach-at91/at91sam9x5.c | 6 +++--- 5 files changed, 9 insertions(+), 3 deletions(-) (limited to 'arch/arm/mach-at91') diff --git a/arch/arm/mach-at91/at91sam9260.c b/arch/arm/mach-at91/at91sam9260.c index 5bd19a442365..ad29f93f20ca 100644 --- a/arch/arm/mach-at91/at91sam9260.c +++ b/arch/arm/mach-at91/at91sam9260.c @@ -221,6 +221,7 @@ static struct clk_lookup periph_clocks_lookups[] = { CLKDEV_CON_DEV_ID("usart", "fffd0000.serial", &usart3_clk), CLKDEV_CON_DEV_ID("usart", "fffd4000.serial", &usart4_clk), CLKDEV_CON_DEV_ID("usart", "fffd8000.serial", &usart5_clk), + CLKDEV_CON_DEV_ID(NULL, "fffac000.i2c", &twi_clk), /* more tc lookup table for DT entries */ CLKDEV_CON_DEV_ID("t0_clk", "fffa0000.timer", &tc0_clk), CLKDEV_CON_DEV_ID("t1_clk", "fffa0000.timer", &tc1_clk), diff --git a/arch/arm/mach-at91/at91sam9263.c b/arch/arm/mach-at91/at91sam9263.c index e6b595658e75..200d5a7baac2 100644 --- a/arch/arm/mach-at91/at91sam9263.c +++ b/arch/arm/mach-at91/at91sam9263.c @@ -211,6 +211,7 @@ static struct clk_lookup periph_clocks_lookups[] = { CLKDEV_CON_DEV_ID("hclk", "a00000.ohci", &ohci_clk), CLKDEV_CON_DEV_ID("spi_clk", "fffa4000.spi", &spi0_clk), CLKDEV_CON_DEV_ID("spi_clk", "fffa8000.spi", &spi1_clk), + CLKDEV_CON_DEV_ID(NULL, "fff88000.i2c", &twi_clk), }; static struct clk_lookup usart_clocks_lookups[] = { diff --git a/arch/arm/mach-at91/at91sam9g45.c b/arch/arm/mach-at91/at91sam9g45.c index 858f032e5102..84af1b506d92 100644 --- a/arch/arm/mach-at91/at91sam9g45.c +++ b/arch/arm/mach-at91/at91sam9g45.c @@ -256,6 +256,8 @@ static struct clk_lookup periph_clocks_lookups[] = { CLKDEV_CON_DEV_ID("t0_clk", "fffd4000.timer", &tcb0_clk), CLKDEV_CON_DEV_ID("hclk", "700000.ohci", &uhphs_clk), CLKDEV_CON_DEV_ID("ehci_clk", "800000.ehci", &uhphs_clk), + CLKDEV_CON_DEV_ID(NULL, "fff84000.i2c", &twi0_clk), + CLKDEV_CON_DEV_ID(NULL, "fff88000.i2c", &twi1_clk), /* fake hclk clock */ CLKDEV_CON_DEV_ID("hclk", "at91_ohci", &uhphs_clk), CLKDEV_CON_ID("pioA", &pioA_clk), diff --git a/arch/arm/mach-at91/at91sam9n12.c b/arch/arm/mach-at91/at91sam9n12.c index 08494664ab78..732d3d3f4ec5 100644 --- a/arch/arm/mach-at91/at91sam9n12.c +++ b/arch/arm/mach-at91/at91sam9n12.c @@ -169,6 +169,8 @@ static struct clk_lookup periph_clocks_lookups[] = { CLKDEV_CON_DEV_ID("t0_clk", "f8008000.timer", &tcb_clk), CLKDEV_CON_DEV_ID("t0_clk", "f800c000.timer", &tcb_clk), CLKDEV_CON_DEV_ID("dma_clk", "ffffec00.dma-controller", &dma_clk), + CLKDEV_CON_DEV_ID(NULL, "f8010000.i2c", &twi0_clk), + CLKDEV_CON_DEV_ID(NULL, "f8014000.i2c", &twi1_clk), CLKDEV_CON_ID("pioA", &pioAB_clk), CLKDEV_CON_ID("pioB", &pioAB_clk), CLKDEV_CON_ID("pioC", &pioCD_clk), diff --git a/arch/arm/mach-at91/at91sam9x5.c b/arch/arm/mach-at91/at91sam9x5.c index 4bad4a288c87..e5035380dcbc 100644 --- a/arch/arm/mach-at91/at91sam9x5.c +++ b/arch/arm/mach-at91/at91sam9x5.c @@ -231,9 +231,9 @@ static struct clk_lookup periph_clocks_lookups[] = { CLKDEV_CON_DEV_ID("t0_clk", "f800c000.timer", &tcb0_clk), CLKDEV_CON_DEV_ID("dma_clk", "ffffec00.dma-controller", &dma0_clk), CLKDEV_CON_DEV_ID("dma_clk", "ffffee00.dma-controller", &dma1_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(NULL, "at91_i2c.2", &twi2_clk), + CLKDEV_CON_DEV_ID(NULL, "f8010000.i2c", &twi0_clk), + CLKDEV_CON_DEV_ID(NULL, "f8014000.i2c", &twi1_clk), + CLKDEV_CON_DEV_ID(NULL, "f8018000.i2c", &twi2_clk), CLKDEV_CON_ID("pioA", &pioAB_clk), CLKDEV_CON_ID("pioB", &pioAB_clk), CLKDEV_CON_ID("pioC", &pioCD_clk), -- cgit v1.2.3