diff options
| -rw-r--r-- | arch/arm/mach-at91/at91rm9200.c | 2 | ||||
| -rw-r--r-- | arch/arm/mach-at91/at91rm9200_devices.c | 2 | ||||
| -rw-r--r-- | arch/arm/mach-at91/at91sam9260.c | 3 | ||||
| -rw-r--r-- | arch/arm/mach-at91/at91sam9260_devices.c | 8 | ||||
| -rw-r--r-- | arch/arm/mach-at91/at91sam9261.c | 3 | ||||
| -rw-r--r-- | arch/arm/mach-at91/at91sam9261_devices.c | 8 | ||||
| -rw-r--r-- | arch/arm/mach-at91/at91sam9263.c | 2 | ||||
| -rw-r--r-- | arch/arm/mach-at91/at91sam9263_devices.c | 2 | ||||
| -rw-r--r-- | arch/arm/mach-at91/at91sam9g45.c | 4 | ||||
| -rw-r--r-- | arch/arm/mach-at91/at91sam9g45_devices.c | 4 | ||||
| -rw-r--r-- | arch/arm/mach-at91/at91sam9rl.c | 4 | ||||
| -rw-r--r-- | arch/arm/mach-at91/at91sam9rl_devices.c | 2 | ||||
| -rw-r--r-- | drivers/i2c/busses/Kconfig | 17 | ||||
| -rw-r--r-- | drivers/i2c/busses/Makefile | 1 | ||||
| -rw-r--r-- | drivers/i2c/busses/i2c-at91.c | 505 |
15 files changed, 545 insertions, 22 deletions
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 <n.voss@weinmann.de> + * + * Evolved from original work by: + * Copyright (C) 2004 Rick Bronson + * Converted to 2.6 by Andrew Victor <andrew@sanpeople.com> + * + * Borrowed heavily from original work by: + * Copyright (C) 2000 Philip Edelbrock <phil@stimpy.netroedge.com> + * + * 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 <linux/clk.h> +#include <linux/completion.h> +#include <linux/err.h> +#include <linux/i2c.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/slab.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_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 <n.voss@weinmann.de>"); +MODULE_DESCRIPTION("I2C (TWI) driver for Atmel AT91"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:at91_i2c"); |