From 164876eaf1b586505566c6f32bb873a958a12331 Mon Sep 17 00:00:00 2001 From: Amaury Pouly Date: Fri, 6 Sep 2013 18:19:09 +0200 Subject: imx233: fix i2c issues The i2c core has some bugs: it locks up when the slave doesn't NAK and prevent the dma channel from being resetted. Specifically handle this situation by setting CLR_GOT_A_NAK (workaround) and then reset dma and i2c block. Change-Id: I0e09d38d4301a0ad42dfad785cc934b43f2c4485 --- firmware/target/arm/imx233/i2c-imx233.c | 33 +++++++++++++++++++++++++++------ 1 file changed, 27 insertions(+), 6 deletions(-) (limited to 'firmware') diff --git a/firmware/target/arm/imx233/i2c-imx233.c b/firmware/target/arm/imx233/i2c-imx233.c index ee5ac1ccf6..f99cd97282 100644 --- a/firmware/target/arm/imx233/i2c-imx233.c +++ b/firmware/target/arm/imx233/i2c-imx233.c @@ -80,12 +80,18 @@ void INT_I2C_DMA(void) semaphore_release(&i2c_sema); } -void imx233_i2c_init(void) +void INT_I2C_ERROR(void) +{ + /* reset dma channel on error */ + if(imx233_dma_is_channel_error_irq(APB_I2C)) + imx233_dma_reset_channel(APB_I2C); + /* clear irq flags */ + imx233_dma_clear_channel_interrupt(APB_I2C); + semaphore_release(&i2c_sema); +} + +static void imx233_i2c_reset(void) { - BF_SET(I2C_CTRL0, SFTRST); - /* setup pins (must be done when shutdown) */ - imx233_pinctrl_setup_vpin(VPIN_I2C_SCL, "i2c scl", PINCTRL_DRIVE_4mA, true); - imx233_pinctrl_setup_vpin(VPIN_I2C_SDA, "i2c sda", PINCTRL_DRIVE_4mA, true); /* clear softreset */ imx233_reset_block(&HW_I2C_CTRL0); /* Errata (imx233): @@ -103,7 +109,15 @@ void imx233_i2c_init(void) HW_I2C_TIMING0 = 0x000F0007; /* tHIGH=0.6us, read at 0.3us */ HW_I2C_TIMING1 = 0x001F000F; /* tLOW=1.3us, write at 0.6us */ HW_I2C_TIMING2 = 0x0015000D; - +} + +void imx233_i2c_init(void) +{ + BF_SET(I2C_CTRL0, SFTRST); + /* setup pins (must be done when shutdown) */ + imx233_pinctrl_setup_vpin(VPIN_I2C_SCL, "i2c scl", PINCTRL_DRIVE_4mA, true); + imx233_pinctrl_setup_vpin(VPIN_I2C_SDA, "i2c sda", PINCTRL_DRIVE_4mA, true); + imx233_i2c_reset(); mutex_init(&i2c_mutex); semaphore_init(&i2c_sema, 1, 0); } @@ -183,6 +197,7 @@ enum imx233_i2c_error_t imx233_i2c_end(unsigned timeout) BF_CLR(I2C_CTRL1, ALL_IRQ); imx233_dma_reset_channel(APB_I2C); imx233_icoll_enable_interrupt(INT_SRC_I2C_DMA, true); + imx233_icoll_enable_interrupt(INT_SRC_I2C_ERROR, true); imx233_dma_enable_channel_interrupt(APB_I2C, true); imx233_dma_start_command(APB_I2C, &i2c_stage[0].dma); @@ -195,7 +210,13 @@ enum imx233_i2c_error_t imx233_i2c_end(unsigned timeout) else if(BF_RD(I2C_CTRL1, MASTER_LOSS_IRQ)) ret = I2C_MASTER_LOSS; else if(BF_RD(I2C_CTRL1, NO_SLAVE_ACK_IRQ)) + { + /* the core doesn't like this error, this is a workaround to prevent lock up */ + BF_SET(I2C_CTRL1, CLR_GOT_A_NAK); + imx233_dma_reset_channel(APB_I2C); + imx233_i2c_reset(); ret= I2C_NO_SLAVE_ACK; + } else if(BF_RD(I2C_CTRL1, EARLY_TERM_IRQ)) ret = I2C_SLAVE_NAK; else -- cgit v1.2.3