diff options
| -rw-r--r-- | Documentation/devicetree/bindings/i2c/i2c-stu300.txt | 15 | ||||
| -rw-r--r-- | drivers/i2c/busses/Kconfig | 13 | ||||
| -rw-r--r-- | drivers/i2c/busses/Makefile | 1 | ||||
| -rw-r--r-- | drivers/i2c/busses/i2c-stu300.c | 1008 |
4 files changed, 0 insertions, 1037 deletions
diff --git a/Documentation/devicetree/bindings/i2c/i2c-stu300.txt b/Documentation/devicetree/bindings/i2c/i2c-stu300.txt deleted file mode 100644 index bd81a482634f..000000000000 --- a/Documentation/devicetree/bindings/i2c/i2c-stu300.txt +++ /dev/null @@ -1,15 +0,0 @@ -ST Microelectronics DDC I2C - -Required properties : -- compatible : Must be "st,ddci2c" -- reg: physical base address of the controller and length of memory mapped - region. -- interrupts: interrupt number to the cpu. -- #address-cells = <1>; -- #size-cells = <0>; - -Optional properties: -- Child nodes conforming to i2c bus binding - -Examples : - diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index ce2efb56df54..4fe74259d44c 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -1032,19 +1032,6 @@ config I2C_STM32F7 This driver can also be built as module. If so, the module will be called i2c-stm32f7. -config I2C_STU300 - tristate "ST Microelectronics DDC I2C interface" - depends on MACH_U300 || COMPILE_TEST - default y if MACH_U300 - help - If you say yes to this option, support will be included for the - I2C interface from ST Microelectronics simply called "DDC I2C" - supporting both I2C and DDC, used in e.g. the U300 series - mobile platforms. - - This driver can also be built as a module. If so, the module - will be called i2c-stu300. - config I2C_SUN6I_P2WI tristate "Allwinner sun6i internal P2WI controller" depends on RESET_CONTROLLER diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 1c30bba977ef..572d5fcc6016 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -103,7 +103,6 @@ obj-$(CONFIG_I2C_ST) += i2c-st.o obj-$(CONFIG_I2C_STM32F4) += i2c-stm32f4.o i2c-stm32f7-drv-objs := i2c-stm32f7.o i2c-stm32.o obj-$(CONFIG_I2C_STM32F7) += i2c-stm32f7-drv.o -obj-$(CONFIG_I2C_STU300) += i2c-stu300.o obj-$(CONFIG_I2C_SUN6I_P2WI) += i2c-sun6i-p2wi.o obj-$(CONFIG_I2C_SYNQUACER) += i2c-synquacer.o obj-$(CONFIG_I2C_TEGRA) += i2c-tegra.o diff --git a/drivers/i2c/busses/i2c-stu300.c b/drivers/i2c/busses/i2c-stu300.c deleted file mode 100644 index 64d739baf480..000000000000 --- a/drivers/i2c/busses/i2c-stu300.c +++ /dev/null @@ -1,1008 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-only -/* - * Copyright (C) 2007-2012 ST-Ericsson AB - * ST DDC I2C master mode driver, used in e.g. U300 series platforms. - * Author: Linus Walleij <linus.walleij@stericsson.com> - * Author: Jonas Aaberg <jonas.aberg@stericsson.com> - */ -#include <linux/init.h> -#include <linux/module.h> -#include <linux/platform_device.h> -#include <linux/delay.h> -#include <linux/i2c.h> -#include <linux/spinlock.h> -#include <linux/completion.h> -#include <linux/err.h> -#include <linux/interrupt.h> -#include <linux/clk.h> -#include <linux/io.h> -#include <linux/slab.h> - -/* the name of this kernel module */ -#define NAME "stu300" - -/* CR (Control Register) 8bit (R/W) */ -#define I2C_CR (0x00000000) -#define I2C_CR_RESET_VALUE (0x00) -#define I2C_CR_RESET_UMASK (0x00) -#define I2C_CR_DDC1_ENABLE (0x80) -#define I2C_CR_TRANS_ENABLE (0x40) -#define I2C_CR_PERIPHERAL_ENABLE (0x20) -#define I2C_CR_DDC2B_ENABLE (0x10) -#define I2C_CR_START_ENABLE (0x08) -#define I2C_CR_ACK_ENABLE (0x04) -#define I2C_CR_STOP_ENABLE (0x02) -#define I2C_CR_INTERRUPT_ENABLE (0x01) -/* SR1 (Status Register 1) 8bit (R/-) */ -#define I2C_SR1 (0x00000004) -#define I2C_SR1_RESET_VALUE (0x00) -#define I2C_SR1_RESET_UMASK (0x00) -#define I2C_SR1_EVF_IND (0x80) -#define I2C_SR1_ADD10_IND (0x40) -#define I2C_SR1_TRA_IND (0x20) -#define I2C_SR1_BUSY_IND (0x10) -#define I2C_SR1_BTF_IND (0x08) -#define I2C_SR1_ADSL_IND (0x04) -#define I2C_SR1_MSL_IND (0x02) -#define I2C_SR1_SB_IND (0x01) -/* SR2 (Status Register 2) 8bit (R/-) */ -#define I2C_SR2 (0x00000008) -#define I2C_SR2_RESET_VALUE (0x00) -#define I2C_SR2_RESET_UMASK (0x40) -#define I2C_SR2_MASK (0xBF) -#define I2C_SR2_SCLFAL_IND (0x80) -#define I2C_SR2_ENDAD_IND (0x20) -#define I2C_SR2_AF_IND (0x10) -#define I2C_SR2_STOPF_IND (0x08) -#define I2C_SR2_ARLO_IND (0x04) -#define I2C_SR2_BERR_IND (0x02) -#define I2C_SR2_DDC2BF_IND (0x01) -/* CCR (Clock Control Register) 8bit (R/W) */ -#define I2C_CCR (0x0000000C) -#define I2C_CCR_RESET_VALUE (0x00) -#define I2C_CCR_RESET_UMASK (0x00) -#define I2C_CCR_MASK (0xFF) -#define I2C_CCR_FMSM (0x80) -#define I2C_CCR_CC_MASK (0x7F) -/* OAR1 (Own Address Register 1) 8bit (R/W) */ -#define I2C_OAR1 (0x00000010) -#define I2C_OAR1_RESET_VALUE (0x00) -#define I2C_OAR1_RESET_UMASK (0x00) -#define I2C_OAR1_ADD_MASK (0xFF) -/* OAR2 (Own Address Register 2) 8bit (R/W) */ -#define I2C_OAR2 (0x00000014) -#define I2C_OAR2_RESET_VALUE (0x40) -#define I2C_OAR2_RESET_UMASK (0x19) -#define I2C_OAR2_MASK (0xE6) -#define I2C_OAR2_FR_25_10MHZ (0x00) -#define I2C_OAR2_FR_10_1667MHZ (0x20) -#define I2C_OAR2_FR_1667_2667MHZ (0x40) -#define I2C_OAR2_FR_2667_40MHZ (0x60) -#define I2C_OAR2_FR_40_5333MHZ (0x80) -#define I2C_OAR2_FR_5333_66MHZ (0xA0) -#define I2C_OAR2_FR_66_80MHZ (0xC0) -#define I2C_OAR2_FR_80_100MHZ (0xE0) -#define I2C_OAR2_FR_MASK (0xE0) -#define I2C_OAR2_ADD_MASK (0x06) -/* DR (Data Register) 8bit (R/W) */ -#define I2C_DR (0x00000018) -#define I2C_DR_RESET_VALUE (0x00) -#define I2C_DR_RESET_UMASK (0xFF) -#define I2C_DR_D_MASK (0xFF) -/* ECCR (Extended Clock Control Register) 8bit (R/W) */ -#define I2C_ECCR (0x0000001C) -#define I2C_ECCR_RESET_VALUE (0x00) -#define I2C_ECCR_RESET_UMASK (0xE0) -#define I2C_ECCR_MASK (0x1F) -#define I2C_ECCR_CC_MASK (0x1F) - -/* - * These events are more or less responses to commands - * sent into the hardware, presumably reflecting the state - * of an internal state machine. - */ -enum stu300_event { - STU300_EVENT_NONE = 0, - STU300_EVENT_1, - STU300_EVENT_2, - STU300_EVENT_3, - STU300_EVENT_4, - STU300_EVENT_5, - STU300_EVENT_6, - STU300_EVENT_7, - STU300_EVENT_8, - STU300_EVENT_9 -}; - -enum stu300_error { - STU300_ERROR_NONE = 0, - STU300_ERROR_ACKNOWLEDGE_FAILURE, - STU300_ERROR_BUS_ERROR, - STU300_ERROR_ARBITRATION_LOST, - STU300_ERROR_UNKNOWN -}; - -/* timeout waiting for the controller to respond */ -#define STU300_TIMEOUT (msecs_to_jiffies(1000)) - -/* - * The number of address send athemps tried before giving up. - * If the first one fails it seems like 5 to 8 attempts are required. - */ -#define NUM_ADDR_RESEND_ATTEMPTS 12 - -/* I2C clock speed, in Hz 0-400kHz*/ -static unsigned int scl_frequency = I2C_MAX_STANDARD_MODE_FREQ; -module_param(scl_frequency, uint, 0644); - -/** - * struct stu300_dev - the stu300 driver state holder - * @pdev: parent platform device - * @adapter: corresponding I2C adapter - * @clk: hardware block clock - * @irq: assigned interrupt line - * @cmd_issue_lock: this locks the following cmd_ variables - * @cmd_complete: acknowledge completion for an I2C command - * @cmd_event: expected event coming in as a response to a command - * @cmd_err: error code as response to a command - * @speed: current bus speed in Hz - * @msg_index: index of current message - * @msg_len: length of current message - */ - -struct stu300_dev { - struct platform_device *pdev; - struct i2c_adapter adapter; - void __iomem *virtbase; - struct clk *clk; - int irq; - spinlock_t cmd_issue_lock; - struct completion cmd_complete; - enum stu300_event cmd_event; - enum stu300_error cmd_err; - unsigned int speed; - int msg_index; - int msg_len; -}; - -/* Local forward function declarations */ -static int stu300_init_hw(struct stu300_dev *dev); - -/* - * The block needs writes in both MSW and LSW in order - * for all data lines to reach their destination. - */ -static inline void stu300_wr8(u32 value, void __iomem *address) -{ - writel((value << 16) | value, address); -} - -/* - * This merely masks off the duplicates which appear - * in bytes 1-3. You _MUST_ use 32-bit bus access on this - * device, else it will not work. - */ -static inline u32 stu300_r8(void __iomem *address) -{ - return readl(address) & 0x000000FFU; -} - -static void stu300_irq_enable(struct stu300_dev *dev) -{ - u32 val; - val = stu300_r8(dev->virtbase + I2C_CR); - val |= I2C_CR_INTERRUPT_ENABLE; - /* Twice paranoia (possible HW glitch) */ - stu300_wr8(val, dev->virtbase + I2C_CR); - stu300_wr8(val, dev->virtbase + I2C_CR); -} - -static void stu300_irq_disable(struct stu300_dev *dev) -{ - u32 val; - val = stu300_r8(dev->virtbase + I2C_CR); - val &= ~I2C_CR_INTERRUPT_ENABLE; - /* Twice paranoia (possible HW glitch) */ - stu300_wr8(val, dev->virtbase + I2C_CR); - stu300_wr8(val, dev->virtbase + I2C_CR); -} - - -/* - * Tells whether a certain event or events occurred in - * response to a command. The events represent states in - * the internal state machine of the hardware. The events - * are not very well described in the hardware - * documentation and can only be treated as abstract state - * machine states. - * - * @ret 0 = event has not occurred or unknown error, any - * other value means the correct event occurred or an error. - */ - -static int stu300_event_occurred(struct stu300_dev *dev, - enum stu300_event mr_event) { - u32 status1; - u32 status2; - - /* What event happened? */ - status1 = stu300_r8(dev->virtbase + I2C_SR1); - - if (!(status1 & I2C_SR1_EVF_IND)) - /* No event at all */ - return 0; - - status2 = stu300_r8(dev->virtbase + I2C_SR2); - - /* Block any multiple interrupts */ - stu300_irq_disable(dev); - - /* Check for errors first */ - if (status2 & I2C_SR2_AF_IND) { - dev->cmd_err = STU300_ERROR_ACKNOWLEDGE_FAILURE; - return 1; - } else if (status2 & I2C_SR2_BERR_IND) { - dev->cmd_err = STU300_ERROR_BUS_ERROR; - return 1; - } else if (status2 & I2C_SR2_ARLO_IND) { - dev->cmd_err = STU300_ERROR_ARBITRATION_LOST; - return 1; - } - - switch (mr_event) { - case STU300_EVENT_1: - if (status1 & I2C_SR1_ADSL_IND) - return 1; - break; - case STU300_EVENT_2: - case STU300_EVENT_3: - case STU300_EVENT_7: - case STU300_EVENT_8: - if (status1 & I2C_SR1_BTF_IND) { - return 1; - } - break; - case STU300_EVENT_4: - if (status2 & I2C_SR2_STOPF_IND) - return 1; - break; - case STU300_EVENT_5: - if (status1 & I2C_SR1_SB_IND) - /* Clear start bit */ - return 1; - break; - case STU300_EVENT_6: - if (status2 & I2C_SR2_ENDAD_IND) { - /* First check for any errors */ - return 1; - } - break; - case STU300_EVENT_9: - if (status1 & I2C_SR1_ADD10_IND) - return 1; - break; - default: - break; - } - /* If we get here, we're on thin ice. - * Here we are in a status where we have - * gotten a response that does not match - * what we requested. - */ - dev->cmd_err = STU300_ERROR_UNKNOWN; - dev_err(&dev->pdev->dev, - "Unhandled interrupt! %d sr1: 0x%x sr2: 0x%x\n", - mr_event, status1, status2); - return 0; -} - -static irqreturn_t stu300_irh(int irq, void *data) -{ - struct stu300_dev *dev = data; - int res; - - /* Just make sure that the block is clocked */ - clk_enable(dev->clk); - - /* See if this was what we were waiting for */ - spin_lock(&dev->cmd_issue_lock); - - res = stu300_event_occurred(dev, dev->cmd_event); - if (res || dev->cmd_err != STU300_ERROR_NONE) - complete(&dev->cmd_complete); - - spin_unlock(&dev->cmd_issue_lock); - - clk_disable(dev->clk); - - return IRQ_HANDLED; -} - -/* - * Sends a command and then waits for the bits masked by *flagmask* - * to go high or low by IRQ awaiting. - */ -static int stu300_start_and_await_event(struct stu300_dev *dev, - u8 cr_value, - enum stu300_event mr_event) -{ - int ret; - - /* Lock command issue, fill in an event we wait for */ - spin_lock_irq(&dev->cmd_issue_lock); - init_completion(&dev->cmd_complete); - dev->cmd_err = STU300_ERROR_NONE; - dev->cmd_event = mr_event; - spin_unlock_irq(&dev->cmd_issue_lock); - - /* Turn on interrupt, send command and wait. */ - cr_value |= I2C_CR_INTERRUPT_ENABLE; - stu300_wr8(cr_value, dev->virtbase + I2C_CR); - ret = wait_for_completion_interruptible_timeout(&dev->cmd_complete, - STU300_TIMEOUT); - if (ret < 0) { - dev_err(&dev->pdev->dev, - "wait_for_completion_interruptible_timeout() " - "returned %d waiting for event %04x\n", ret, mr_event); - return ret; - } - - if (ret == 0) { - dev_err(&dev->pdev->dev, "controller timed out " - "waiting for event %d, reinit hardware\n", mr_event); - (void) stu300_init_hw(dev); - return -ETIMEDOUT; - } - - if (dev->cmd_err != STU300_ERROR_NONE) { - dev_err(&dev->pdev->dev, "controller (start) " - "error %d waiting for event %d, reinit hardware\n", - dev->cmd_err, mr_event); - (void) stu300_init_hw(dev); - return -EIO; - } - - return 0; -} - -/* - * This waits for a flag to be set, if it is not set on entry, an interrupt is - * configured to wait for the flag using a completion. - */ -static int stu300_await_event(struct stu300_dev *dev, - enum stu300_event mr_event) -{ - int ret; - - /* Is it already here? */ - spin_lock_irq(&dev->cmd_issue_lock); - dev->cmd_err = STU300_ERROR_NONE; - dev->cmd_event = mr_event; - - init_completion(&dev->cmd_complete); - - /* Turn on the I2C interrupt for current operation */ - stu300_irq_enable(dev); - - /* Unlock the command block and wait for the event to occur */ - spin_unlock_irq(&dev->cmd_issue_lock); - - ret = wait_for_completion_interruptible_timeout(&dev->cmd_complete, - STU300_TIMEOUT); - if (ret < 0) { - dev_err(&dev->pdev->dev, - "wait_for_completion_interruptible_timeout()" - "returned %d waiting for event %04x\n", ret, mr_event); - return ret; - } - - if (ret == 0) { - if (mr_event != STU300_EVENT_6) { - dev_err(&dev->pdev->dev, "controller " - "timed out waiting for event %d, reinit " - "hardware\n", mr_event); - (void) stu300_init_hw(dev); - } - return -ETIMEDOUT; - } - - if (dev->cmd_err != STU300_ERROR_NONE) { - if (mr_event != STU300_EVENT_6) { - dev_err(&dev->pdev->dev, "controller " - "error (await_event) %d waiting for event %d, " - "reinit hardware\n", dev->cmd_err, mr_event); - (void) stu300_init_hw(dev); - } - return -EIO; - } - - return 0; -} - -/* - * Waits for the busy bit to go low by repeated polling. - */ -#define BUSY_RELEASE_ATTEMPTS 10 -static int stu300_wait_while_busy(struct stu300_dev *dev) -{ - unsigned long timeout; - int i; - - for (i = 0; i < BUSY_RELEASE_ATTEMPTS; i++) { - timeout = jiffies + STU300_TIMEOUT; - - while (!time_after(jiffies, timeout)) { - /* Is not busy? */ - if ((stu300_r8(dev->virtbase + I2C_SR1) & - I2C_SR1_BUSY_IND) == 0) - return 0; - msleep(1); - } - - dev_err(&dev->pdev->dev, "transaction timed out " - "waiting for device to be free (not busy). " - "Attempt: %d\n", i+1); - - dev_err(&dev->pdev->dev, "base address = " - "0x%p, reinit hardware\n", dev->virtbase); - - (void) stu300_init_hw(dev); - } - - dev_err(&dev->pdev->dev, "giving up after %d attempts " - "to reset the bus.\n", BUSY_RELEASE_ATTEMPTS); - - return -ETIMEDOUT; -} - -struct stu300_clkset { - unsigned long rate; - u32 setting; -}; - -static const struct stu300_clkset stu300_clktable[] = { - { 0, 0xFFU }, - { 2500000, I2C_OAR2_FR_25_10MHZ }, - { 10000000, I2C_OAR2_FR_10_1667MHZ }, - { 16670000, I2C_OAR2_FR_1667_2667MHZ }, - { 26670000, I2C_OAR2_FR_2667_40MHZ }, - { 40000000, I2C_OAR2_FR_40_5333MHZ }, - { 53330000, I2C_OAR2_FR_5333_66MHZ }, - { 66000000, I2C_OAR2_FR_66_80MHZ }, - { 80000000, I2C_OAR2_FR_80_100MHZ }, - { 100000000, 0xFFU }, -}; - - -static int stu300_set_clk(struct stu300_dev *dev, unsigned long clkrate) -{ - - u32 val; - int i = 0; - - /* Locate the appropriate clock setting */ - while (i < ARRAY_SIZE(stu300_clktable) - 1 && - stu300_clktable[i].rate < clkrate) - i++; - - if (stu300_clktable[i].setting == 0xFFU) { - dev_err(&dev->pdev->dev, "too %s clock rate requested " - "(%lu Hz).\n", i ? "high" : "low", clkrate); - return -EINVAL; - } - - stu300_wr8(stu300_clktable[i].setting, - dev->virtbase + I2C_OAR2); - - dev_dbg(&dev->pdev->dev, "Clock rate %lu Hz, I2C bus speed %d Hz " - "virtbase %p\n", clkrate, dev->speed, dev->virtbase); - - if (dev->speed > I2C_MAX_STANDARD_MODE_FREQ) - /* Fast Mode I2C */ - val = ((clkrate/dev->speed) - 9)/3 + 1; - else - /* Standard Mode I2C */ - val = ((clkrate/dev->speed) - 7)/2 + 1; - - /* According to spec the divider must be > 2 */ - if (val < 0x002) { - dev_err(&dev->pdev->dev, "too low clock rate (%lu Hz).\n", - clkrate); - return -EINVAL; - } - - /* We have 12 bits clock divider only! */ - if (val & 0xFFFFF000U) { - dev_err(&dev->pdev->dev, "too high clock rate (%lu Hz).\n", - clkrate); - return -EINVAL; - } - - if (dev->speed > I2C_MAX_STANDARD_MODE_FREQ) { - /* CC6..CC0 */ - stu300_wr8((val & I2C_CCR_CC_MASK) | I2C_CCR_FMSM, - dev->virtbase + I2C_CCR); - dev_dbg(&dev->pdev->dev, "set clock divider to 0x%08x, " - "Fast Mode I2C\n", val); - } else { - /* CC6..CC0 */ - stu300_wr8((val & I2C_CCR_CC_MASK), - dev->virtbase + I2C_CCR); - dev_dbg(&dev->pdev->dev, "set clock divider to " - "0x%08x, Standard Mode I2C\n", val); - } - - /* CC11..CC7 */ - stu300_wr8(((val >> 7) & 0x1F), - dev->virtbase + I2C_ECCR); - - return 0; -} - - -static int stu300_init_hw(struct stu300_dev *dev) -{ - u32 dummy; - unsigned long clkrate; - int ret; - - /* Disable controller */ - stu300_wr8(0x00, dev->virtbase + I2C_CR); - /* - * Set own address to some default value (0x00). - * We do not support slave mode anyway. - */ - stu300_wr8(0x00, dev->virtbase + I2C_OAR1); - /* - * The I2C controller only operates properly in 26 MHz but we - * program this driver as if we didn't know. This will also set the two - * high bits of the own address to zero as well. - * There is no known hardware issue with running in 13 MHz - * However, speeds over 200 kHz are not used. - */ - clkrate = clk_get_rate(dev->clk); - ret = stu300_set_clk(dev, clkrate); - - if (ret) - return ret; - /* - * Enable block, do it TWICE (hardware glitch) - * Setting bit 7 can enable DDC mode. (Not used currently.) - */ - stu300_wr8(I2C_CR_PERIPHERAL_ENABLE, - dev->virtbase + I2C_CR); - stu300_wr8(I2C_CR_PERIPHERAL_ENABLE, - dev->virtbase + I2C_CR); - /* Make a dummy read of the status register SR1 & SR2 */ - dummy = stu300_r8(dev->virtbase + I2C_SR2); - dummy = stu300_r8(dev->virtbase + I2C_SR1); - - return 0; -} - - - -/* Send slave address. */ -static int stu300_send_address(struct stu300_dev *dev, - struct i2c_msg *msg, int resend) -{ - u32 val; - int ret; - - if (msg->flags & I2C_M_TEN) { - /* This is probably how 10 bit addresses look */ - val = (0xf0 | (((u32) msg->addr & 0x300) >> 7)) & - I2C_DR_D_MASK; - if (msg->flags & I2C_M_RD) - /* This is the direction bit */ - val |= 0x01; - } else { - val = i2c_8bit_addr_from_msg(msg); - } - - if (resend) { - if (msg->flags & I2C_M_RD) - dev_dbg(&dev->pdev->dev, "read resend\n"); - else - dev_dbg(&dev->pdev->dev, "write resend\n"); - } - - stu300_wr8(val, dev->virtbase + I2C_DR); - - /* For 10bit addressing, await 10bit request (EVENT 9) */ - if (msg->flags & I2C_M_TEN) { - ret = stu300_await_event(dev, STU300_EVENT_9); - /* - * The slave device wants a 10bit address, send the rest - * of the bits (the LSBits) - */ - val = msg->addr & I2C_DR_D_MASK; - /* This clears "event 9" */ - stu300_wr8(val, dev->virtbase + I2C_DR); - if (ret != 0) - return ret; - } - /* FIXME: Why no else here? two events for 10bit? - * Await event 6 (normal) or event 9 (10bit) - */ - - if (resend) - dev_dbg(&dev->pdev->dev, "await event 6\n"); - ret = stu300_await_event(dev, STU300_EVENT_6); - - /* - * Clear any pending EVENT 6 no matter what happened during - * await_event. - */ - val = stu300_r8(dev->virtbase + I2C_CR); - val |= I2C_CR_PERIPHERAL_ENABLE; - stu300_wr8(val, dev->virtbase + I2C_CR); - - return ret; -} - -static int stu300_xfer_msg(struct i2c_adapter *adap, - struct i2c_msg *msg, int stop) -{ - u32 cr; - u32 val; - u32 i; - int ret; - int attempts = 0; - struct stu300_dev *dev = i2c_get_adapdata(adap); - - clk_enable(dev->clk); - - /* Remove this if (0) to trace each and every message. */ - if (0) { - dev_dbg(&dev->pdev->dev, "I2C message to: 0x%04x, len: %d, " - "flags: 0x%04x, stop: %d\n", - msg->addr, msg->len, msg->flags, stop); - } - - /* - * For some reason, sending the address sometimes fails when running - * on the 13 MHz clock. No interrupt arrives. This is a work around, - * which tries to restart and send the address up to 10 times before - * really giving up. Usually 5 to 8 attempts are enough. - */ - do { - if (attempts) - dev_dbg(&dev->pdev->dev, "wait while busy\n"); - /* Check that the bus is free, or wait until some timeout */ - ret = stu300_wait_while_busy(dev); - if (ret != 0) - goto exit_disable; - - if (attempts) - dev_dbg(&dev->pdev->dev, "re-int hw\n"); - /* - * According to ST, there is no problem if the clock is - * changed between 13 and 26 MHz during a transfer. - */ - ret = stu300_init_hw(dev); - if (ret) - goto exit_disable; - - /* Send a start condition */ - cr = I2C_CR_PERIPHERAL_ENABLE; - /* Setting the START bit puts the block in master mode */ - if (!(msg->flags & I2C_M_NOSTART)) - cr |= I2C_CR_START_ENABLE; - if ((msg->flags & I2C_M_RD) && (msg->len > 1)) - /* On read more than 1 byte, we need ack. */ - cr |= I2C_CR_ACK_ENABLE; - /* Check that it gets through */ - if (!(msg->flags & I2C_M_NOSTART)) { - if (attempts) - dev_dbg(&dev->pdev->dev, "send start event\n"); - ret = stu300_start_and_await_event(dev, cr, - STU300_EVENT_5); - } - - if (attempts) - dev_dbg(&dev->pdev->dev, "send address\n"); - - if (ret == 0) - /* Send address */ - ret = stu300_send_address(dev, msg, attempts != 0); - - if (ret != 0) { - attempts++; - dev_dbg(&dev->pdev->dev, "failed sending address, " - "retrying. Attempt: %d msg_index: %d/%d\n", - attempts, dev->msg_index, dev->msg_len); - } - - } while (ret != 0 && attempts < NUM_ADDR_RESEND_ATTEMPTS); - - if (attempts < NUM_ADDR_RESEND_ATTEMPTS && attempts > 0) { - dev_dbg(&dev->pdev->dev, "managed to get address " - "through after %d attempts\n", attempts); - } else if (attempts == NUM_ADDR_RESEND_ATTEMPTS) { - dev_dbg(&dev->pdev->dev, "I give up, tried %d times " - "to resend address.\n", - NUM_ADDR_RESEND_ATTEMPTS); - goto exit_disable; - } - - - if (msg->flags & I2C_M_RD) { - /* READ: we read the actual bytes one at a time */ - for (i = 0; i < msg->len; i++) { - if (i == msg->len-1) { - /* - * Disable ACK and set STOP condition before - * reading last byte - */ - val = I2C_CR_PERIPHERAL_ENABLE; - - if (stop) - val |= I2C_CR_STOP_ENABLE; - - stu300_wr8(val, - dev->virtbase + I2C_CR); - } - /* Wait for this byte... */ - ret = stu300_await_event(dev, STU300_EVENT_7); - if (ret != 0) - goto exit_disable; - /* This clears event 7 */ - msg->buf[i] = (u8) stu300_r8(dev->virtbase + I2C_DR); - } - } else { - /* WRITE: we send the actual bytes one at a time */ - for (i = 0; i < msg->len; i++) { - /* Write the byte */ - stu300_wr8(msg->buf[i], - dev->virtbase + I2C_DR); - /* Check status */ - ret = stu300_await_event(dev, STU300_EVENT_8); - /* Next write to DR will clear event 8 */ - if (ret != 0) { - dev_err(&dev->pdev->dev, "error awaiting " - "event 8 (%d)\n", ret); - goto exit_disable; - } - } - /* Check NAK */ - if (!(msg->flags & I2C_M_IGNORE_NAK)) { - if (stu300_r8(dev->virtbase + I2C_SR2) & - I2C_SR2_AF_IND) { - dev_err(&dev->pdev->dev, "I2C payload " - "send returned NAK!\n"); - ret = -EIO; - goto exit_disable; - } - } - if (stop) { - /* Send stop condition */ - val = I2C_CR_PERIPHERAL_ENABLE; - val |= I2C_CR_STOP_ENABLE; - stu300_wr8(val, dev->virtbase + I2C_CR); - } - } - - /* Check that the bus is free, or wait until some timeout occurs */ - ret = stu300_wait_while_busy(dev); - if (ret != 0) { - dev_err(&dev->pdev->dev, "timeout waiting for transfer " - "to commence.\n"); - goto exit_disable; - } - - /* Dummy read status registers */ - val = stu300_r8(dev->virtbase + I2C_SR2); - val = stu300_r8(dev->virtbase + I2C_SR1); - ret = 0; - - exit_disable: - /* Disable controller */ - stu300_wr8(0x00, dev->virtbase + I2C_CR); - clk_disable(dev->clk); - return ret; -} - -static int stu300_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, - int num) -{ - int ret = -1; - int i; - - struct stu300_dev *dev = i2c_get_adapdata(adap); - dev->msg_len = num; - - for (i = 0; i < num; i++) { - /* - * Another driver appears to send stop for each message, - * here we only do that for the last message. Possibly some - * peripherals require this behaviour, then their drivers - * have to send single messages in order to get "stop" for - * each message. - */ - dev->msg_index = i; - - ret = stu300_xfer_msg(adap, &msgs[i], (i == (num - 1))); - - if (ret != 0) { - num = ret; - break; - } - } - - return num; -} - -static int stu300_xfer_todo(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) -{ - /* TODO: implement polling for this case if need be. */ - WARN(1, "%s: atomic transfers not implemented\n", dev_name(&adap->dev)); - return -EOPNOTSUPP; -} - -static u32 stu300_func(struct i2c_adapter *adap) -{ - /* This is the simplest thing you can think of... */ - return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR; -} - -static const struct i2c_algorithm stu300_algo = { - .master_xfer = stu300_xfer, - .master_xfer_atomic = stu300_xfer_todo, - .functionality = stu300_func, -}; - -static const struct i2c_adapter_quirks stu300_quirks = { - .flags = I2C_AQ_NO_ZERO_LEN, -}; - -static int stu300_probe(struct platform_device *pdev) -{ - struct stu300_dev *dev; - struct i2c_adapter *adap; - int bus_nr; - int ret = 0; - - dev = devm_kzalloc(&pdev->dev, sizeof(struct stu300_dev), GFP_KERNEL); - if (!dev) - return -ENOMEM; - - bus_nr = pdev->id; - dev->clk = devm_clk_get(&pdev->dev, NULL); - if (IS_ERR(dev->clk)) { - dev_err(&pdev->dev, "could not retrieve i2c bus clock\n"); - return PTR_ERR(dev->clk); - } - - dev->pdev = pdev; - dev->virtbase = devm_platform_ioremap_resource(pdev, 0); - dev_dbg(&pdev->dev, "initialize bus device I2C%d on virtual " - "base %p\n", bus_nr, dev->virtbase); - if (IS_ERR(dev->virtbase)) - return PTR_ERR(dev->virtbase); - - dev->irq = platform_get_irq(pdev, 0); - ret = devm_request_irq(&pdev->dev, dev->irq, stu300_irh, 0, NAME, dev); - if (ret < 0) - return ret; - - dev->speed = scl_frequency; - - clk_prepare_enable(dev->clk); - ret = stu300_init_hw(dev); - clk_disable(dev->clk); - if (ret != 0) { - dev_err(&dev->pdev->dev, "error initializing hardware.\n"); - return -EIO; - } - - /* IRQ event handling initialization */ - spin_lock_init(&dev->cmd_issue_lock); - dev->cmd_event = STU300_EVENT_NONE; - dev->cmd_err = STU300_ERROR_NONE; - - adap = &dev->adapter; - adap->owner = THIS_MODULE; - /* DDC class but actually often used for more generic I2C */ - adap->class = I2C_CLASS_DEPRECATED; - strlcpy(adap->name, "ST Microelectronics DDC I2C adapter", - sizeof(adap->name)); - adap->nr = bus_nr; - adap->algo = &stu300_algo; - adap->dev.parent = &pdev->dev; - adap->dev.of_node = pdev->dev.of_node; - adap->quirks = &stu300_quirks; - - i2c_set_adapdata(adap, dev); - - /* i2c device drivers may be active on return from add_adapter() */ - ret = i2c_add_numbered_adapter(adap); - if (ret) - return ret; - - platform_set_drvdata(pdev, dev); - dev_info(&pdev->dev, "ST DDC I2C @ %p, irq %d\n", - dev->virtbase, dev->irq); - - return 0; -} - -#ifdef CONFIG_PM_SLEEP -static int stu300_suspend(struct device *device) -{ - struct stu300_dev *dev = dev_get_drvdata(device); - - /* Turn off everything */ - stu300_wr8(0x00, dev->virtbase + I2C_CR); - return 0; -} - -static int stu300_resume(struct device *device) -{ - int ret = 0; - struct stu300_dev *dev = dev_get_drvdata(device); - - clk_enable(dev->clk); - ret = stu300_init_hw(dev); - clk_disable(dev->clk); - - if (ret != 0) - dev_err(device, "error re-initializing hardware.\n"); - return ret; -} - -static SIMPLE_DEV_PM_OPS(stu300_pm, stu300_suspend, stu300_resume); -#define STU300_I2C_PM (&stu300_pm) -#else -#define STU300_I2C_PM NULL -#endif - -static int stu300_remove(struct platform_device *pdev) -{ - struct stu300_dev *dev = platform_get_drvdata(pdev); - - i2c_del_adapter(&dev->adapter); - /* Turn off everything */ - stu300_wr8(0x00, dev->virtbase + I2C_CR); - return 0; -} - -static const struct of_device_id stu300_dt_match[] = { - { .compatible = "st,ddci2c" }, - {}, -}; -MODULE_DEVICE_TABLE(of, stu300_dt_match); - -static struct platform_driver stu300_i2c_driver = { - .driver = { - .name = NAME, - .pm = STU300_I2C_PM, - .of_match_table = stu300_dt_match, - }, - .probe = stu300_probe, - .remove = stu300_remove, - -}; - -static int __init stu300_init(void) -{ - return platform_driver_register(&stu300_i2c_driver); -} - -static void __exit stu300_exit(void) -{ - platform_driver_unregister(&stu300_i2c_driver); -} - -/* - * The systems using this bus often have very basic devices such - * as regulators on the I2C bus, so this needs to be loaded early. - * Therefore it is registered in the subsys_initcall(). - */ -subsys_initcall(stu300_init); -module_exit(stu300_exit); - -MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>"); -MODULE_DESCRIPTION("ST Micro DDC I2C adapter (" NAME ")"); -MODULE_LICENSE("GPL"); -MODULE_ALIAS("platform:" NAME); |