HSI2C module on Exynos5260 differs from current modules in following ways: 1. HSI2C on Exynos5260 has fifo_depth of 16bytes 2. Module needs to be reset as a part of init sequence. Hence, Following changes are involved. 1. Add a new compatible string and Updates the Documentation dt bindings. 2. Introduce a variant struct to support the changes in H/W 3. Reset the module during init. Thus, bringing the module back to default state irrespective of what firmware did with it. Signed-off-by: Naveen Krishna Chatradhi <ich.naveen@xxxxxxxxxxx> Signed-off-by: Pankaj Dubey <pankaj.dubey@xxxxxxxxxxx> --- This patch is under review at https://lkml.org/lkml/2014/2/6/590 and https://lkml.org/lkml/2014/2/6/151 As per Wolfram's comments, both the patches were squashed here. .../devicetree/bindings/i2c/i2c-exynos5.txt | 11 +++- drivers/i2c/busses/i2c-exynos5.c | 67 ++++++++++++++++---- 2 files changed, 64 insertions(+), 14 deletions(-) diff --git a/Documentation/devicetree/bindings/i2c/i2c-exynos5.txt b/Documentation/devicetree/bindings/i2c/i2c-exynos5.txt index 056732c..d4745e3 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-exynos5.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-exynos5.txt @@ -5,7 +5,14 @@ at various speeds ranging from 100khz to 3.4Mhz. Required properties: - compatible: value should be. - -> "samsung,exynos5-hsi2c", for i2c compatible with exynos5 hsi2c. + -> "samsung,exynos5-hsi2c", (DEPRECATED) + for i2c compatible with HSI2C available + on Exynos5250 and Exynos5420 SoCs. + -> "samsung,exynos5250-hsi2c", for i2c compatible with HSI2C available + on Exynos5250 and Exynos5420 SoCs. + -> "samsung,exynos5260-hsi2c", for i2c compatible with HSI2C available + on Exynos5260 SoCs. + - reg: physical base address of the controller and length of memory mapped region. - interrupts: interrupt number to the cpu. @@ -26,7 +33,7 @@ Optional properties: Example: hsi2c@12ca0000 { - compatible = "samsung,exynos5-hsi2c"; + compatible = "samsung,exynos5250-hsi2c"; reg = <0x12ca0000 0x100>; interrupts = <56>; clock-frequency = <100000>; diff --git a/drivers/i2c/busses/i2c-exynos5.c b/drivers/i2c/busses/i2c-exynos5.c index 00af0a0..043d6d8 100644 --- a/drivers/i2c/busses/i2c-exynos5.c +++ b/drivers/i2c/busses/i2c-exynos5.c @@ -76,12 +76,6 @@ #define HSI2C_RXFIFO_TRIGGER_LEVEL(x) ((x) << 4) #define HSI2C_TXFIFO_TRIGGER_LEVEL(x) ((x) << 16) -/* As per user manual FIFO max depth is 64bytes */ -#define HSI2C_FIFO_MAX 0x40 -/* default trigger levels for Tx and Rx FIFOs */ -#define HSI2C_DEF_TXFIFO_LVL (HSI2C_FIFO_MAX - 0x30) -#define HSI2C_DEF_RXFIFO_LVL (HSI2C_FIFO_MAX - 0x10) - /* I2C_TRAILING_CTL Register bits */ #define HSI2C_TRAILING_COUNT (0xf) @@ -183,14 +177,54 @@ struct exynos5_i2c { * 2. Fast speed upto 1Mbps */ int speed_mode; + + /* Version of HS-I2C Hardware */ + struct exynos_hsi2c_variant *variant; +}; + +/** + * struct exynos_hsi2c_variant - platform specific HSI2C driver data + * @fifo_depth: the fifo depth supported by the HSI2C module + * + * Specifies platform specific configuration of HSI2C module. + * Note: A structure for driver specific platform data is used for future + * expansion of its usage. + */ +struct exynos_hsi2c_variant { + unsigned int fifo_depth; +}; + +static const struct exynos_hsi2c_variant exynos5250_hsi2c_data = { + .fifo_depth = 64, +}; + +static const struct exynos_hsi2c_variant exynos5260_hsi2c_data = { + .fifo_depth = 16, }; static const struct of_device_id exynos5_i2c_match[] = { - { .compatible = "samsung,exynos5-hsi2c" }, - {}, + { + .compatible = "samsung,exynos5-hsi2c", + .data = &exynos5250_hsi2c_data + }, { + .compatible = "samsung,exynos5250-hsi2c", + .data = &exynos5250_hsi2c_data + }, { + .compatible = "samsung,exynos5260-hsi2c", + .data = &exynos5260_hsi2c_data + }, {}, }; MODULE_DEVICE_TABLE(of, exynos5_i2c_match); +static inline struct exynos_hsi2c_variant *exynos5_i2c_get_variant + (struct platform_device *pdev) +{ + const struct of_device_id *match; + + match = of_match_node(exynos5_i2c_match, pdev->dev.of_node); + return (struct exynos_hsi2c_variant *)match->data; +} + static void exynos5_i2c_clr_pend_irq(struct exynos5_i2c *i2c) { writel(readl(i2c->regs + HSI2C_INT_STATUS), @@ -415,7 +449,7 @@ static irqreturn_t exynos5_i2c_irq(int irqno, void *dev_id) fifo_status = readl(i2c->regs + HSI2C_FIFO_STATUS); fifo_level = HSI2C_TX_FIFO_LVL(fifo_status); - len = HSI2C_FIFO_MAX - fifo_level; + len = i2c->variant->fifo_depth - fifo_level; if (len > (i2c->msg->len - i2c->msg_ptr)) len = i2c->msg->len - i2c->msg_ptr; @@ -483,6 +517,7 @@ static void exynos5_i2c_message_start(struct exynos5_i2c *i2c, int stop) u32 i2c_auto_conf = 0; u32 fifo_ctl; unsigned long flags; + unsigned short trig_lvl; i2c_ctl = readl(i2c->regs + HSI2C_CTL); i2c_ctl &= ~(HSI2C_TXCHON | HSI2C_RXCHON); @@ -493,13 +528,19 @@ static void exynos5_i2c_message_start(struct exynos5_i2c *i2c, int stop) i2c_auto_conf = HSI2C_READ_WRITE; - fifo_ctl |= HSI2C_RXFIFO_TRIGGER_LEVEL(HSI2C_DEF_TXFIFO_LVL); + trig_lvl = (i2c->msg->len > i2c->variant->fifo_depth) ? + (i2c->variant->fifo_depth * 3/4) : i2c->msg->len; + fifo_ctl |= HSI2C_RXFIFO_TRIGGER_LEVEL(trig_lvl); + int_en |= (HSI2C_INT_RX_ALMOSTFULL_EN | HSI2C_INT_TRAILING_EN); } else { i2c_ctl |= HSI2C_TXCHON; - fifo_ctl |= HSI2C_TXFIFO_TRIGGER_LEVEL(HSI2C_DEF_RXFIFO_LVL); + trig_lvl = (i2c->msg->len > i2c->variant->fifo_depth) ? + (i2c->variant->fifo_depth * 1/4) : i2c->msg->len; + fifo_ctl |= HSI2C_TXFIFO_TRIGGER_LEVEL(trig_lvl); + int_en |= HSI2C_INT_TX_ALMOSTEMPTY_EN; } @@ -691,7 +732,9 @@ static int exynos5_i2c_probe(struct platform_device *pdev) if (ret) goto err_clk; - exynos5_i2c_init(i2c); + i2c->variant = exynos5_i2c_get_variant(pdev); + + exynos5_i2c_reset(i2c); ret = i2c_add_adapter(&i2c->adap); if (ret < 0) { -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
