diff options
Diffstat (limited to 'patches.at91/0173-i2c-at91-add-new-driver.patch')
| -rw-r--r-- | patches.at91/0173-i2c-at91-add-new-driver.patch | 776 |
1 files changed, 776 insertions, 0 deletions
diff --git a/patches.at91/0173-i2c-at91-add-new-driver.patch b/patches.at91/0173-i2c-at91-add-new-driver.patch new file mode 100644 index 00000000000000..ab9fcc693ee246 --- /dev/null +++ b/patches.at91/0173-i2c-at91-add-new-driver.patch @@ -0,0 +1,776 @@ +From 3fbefb2c85df4c467c48f9963119f26c62d7a31b Mon Sep 17 00:00:00 2001 +From: Nikolaus Voss <n.voss@weinmann.de> +Date: Tue, 8 Nov 2011 11:49:46 +0100 +Subject: i2c: at91: add new driver + +commit fac368a040484293006bb488e67972aafcf88ec7 upstream. + +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 <n.voss@weinmann.de> +Reviewed-by: Felipe Balbi <balbi@ti.com> +Tested-by: Hubert Feurstein <h.feurstein@gmail.com> +Tested-by: Ludovic Desroches <ludovic.desroches@atmel.com> +Reviewed-by: Nicolas Ferre <nicolas.ferre@atmel.com> + +[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 <ludovic.desroches@atmel.com> +Signed-off-by: Wolfram Sang <w.sang@pengutronix.de> +--- + 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 + +--- a/arch/arm/mach-at91/at91rm9200.c ++++ b/arch/arm/mach-at91/at91rm9200.c +@@ -187,7 +187,7 @@ static struct clk_lookup periph_clocks_l + 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), +--- a/arch/arm/mach-at91/at91rm9200_devices.c ++++ b/arch/arm/mach-at91/at91rm9200_devices.c +@@ -511,7 +511,7 @@ 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), +--- a/arch/arm/mach-at91/at91sam9260.c ++++ b/arch/arm/mach-at91/at91sam9260.c +@@ -203,7 +203,8 @@ static struct clk_lookup periph_clocks_l + 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), +--- a/arch/arm/mach-at91/at91sam9260_devices.c ++++ b/arch/arm/mach-at91/at91sam9260_devices.c +@@ -418,7 +418,6 @@ 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), +@@ -426,6 +425,13 @@ static struct platform_device at91sam926 + + 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); +--- a/arch/arm/mach-at91/at91sam9261.c ++++ b/arch/arm/mach-at91/at91sam9261.c +@@ -178,7 +178,8 @@ static struct clk_lookup periph_clocks_l + 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), +--- a/arch/arm/mach-at91/at91sam9261_devices.c ++++ b/arch/arm/mach-at91/at91sam9261_devices.c +@@ -319,7 +319,6 @@ 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), +@@ -327,6 +326,13 @@ static struct platform_device at91sam926 + + 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); +--- a/arch/arm/mach-at91/at91sam9263.c ++++ b/arch/arm/mach-at91/at91sam9263.c +@@ -193,7 +193,7 @@ static struct clk_lookup periph_clocks_l + 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), +--- a/arch/arm/mach-at91/at91sam9263_devices.c ++++ b/arch/arm/mach-at91/at91sam9263_devices.c +@@ -601,7 +601,7 @@ 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), +--- a/arch/arm/mach-at91/at91sam9g45.c ++++ b/arch/arm/mach-at91/at91sam9g45.c +@@ -222,8 +222,8 @@ static struct clk_lookup periph_clocks_l + 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), +--- a/arch/arm/mach-at91/at91sam9g45_devices.c ++++ b/arch/arm/mach-at91/at91sam9g45_devices.c +@@ -651,7 +651,7 @@ 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), +@@ -671,7 +671,7 @@ 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), +--- a/arch/arm/mach-at91/at91sam9rl.c ++++ b/arch/arm/mach-at91/at91sam9rl.c +@@ -186,8 +186,8 @@ static struct clk_lookup periph_clocks_l + 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), +--- a/arch/arm/mach-at91/at91sam9rl_devices.c ++++ b/arch/arm/mach-at91/at91sam9rl_devices.c +@@ -348,7 +348,7 @@ 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), +--- a/drivers/i2c/busses/Kconfig ++++ b/drivers/i2c/busses/Kconfig +@@ -287,18 +287,21 @@ comment "I2C system bus drivers (mostly + + 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" +--- 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 +--- /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"); |