[PATCH 4/6] i2c: exynos5: Add support for ExynosAutoV9 SoC

Sam Protsenko
2021-12-01T19:05:29Z

From: Jaewon Kim <jaewon02.kim@samsung.com>

ExynosAutoV9 functioning logic mostly follows I2C_TYPE_EXYNOS7, but
timing calculation and configuration procedure is changed: e.g. only
timing_s3 has to be set now.

Another change of HSI2C controller in ExynosAutoV9 SoC is that it's now
a part of USIv2 IP-core. No changes is needed for I2C driver though, as
all USI related configuration is done in USI driver.

Signed-off-by: Jaewon Kim <jaewon02.kim@samsung.com>
Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
---
drivers/i2c/busses/i2c-exynos5.c | 62 +++++++++++++++++++++++++++-----
1 file changed, 53 insertions(+), 9 deletions(-)

diff --git a/drivers/i2c/busses/i2c-exynos5.c b/drivers/i2c/busses/i2c-exynos5.c
index c2e4bab11366..5198e71e8dab 100644
--- a/drivers/i2c/busses/i2c-exynos5.c
+++ b/drivers/i2c/busses/i2c-exynos5.c
@@ -169,6 +169,7 @@
enum i2c_type_exynos {
I2C_TYPE_EXYNOS5,
I2C_TYPE_EXYNOS7,
+ I2C_TYPE_EXYNOSAUTOV9,
};

struct exynos5_i2c {
@@ -230,6 +231,11 @@ static const struct exynos_hsi2c_variant exynos7_hsi2c_data = {
.hw = I2C_TYPE_EXYNOS7,
};

+static const struct exynos_hsi2c_variant exynosautov9_hsi2c_data = {
+ .fifo_depth = 64,
+ .hw = I2C_TYPE_EXYNOSAUTOV9,
+};
+
static const struct of_device_id exynos5_i2c_match[] = {
{
.compatible = "samsung,exynos5-hsi2c",
@@ -243,6 +249,9 @@ static const struct of_device_id exynos5_i2c_match[] = {
}, {
.compatible = "samsung,exynos7-hsi2c",
.data = &exynos7_hsi2c_data
+ }, {
+ .compatible = "samsung,exynosautov9-hsi2c",
+ .data = &exynosautov9_hsi2c_data
}, {},
};
MODULE_DEVICE_TABLE(of, exynos5_i2c_match);
@@ -281,6 +290,31 @@ static int exynos5_i2c_set_timing(struct exynos5_i2c *i2c, bool hs_timings)
i2c->op_clock;
int div, clk_cycle, temp;

+ /*
+ * In case of HSI2C controllers in ExynosAutoV9:
+ *
+ * FSCL = IPCLK / ((CLK_DIV + 1) * 16)
+ * T_SCL_LOW = IPCLK * (CLK_DIV + 1) * (N + M)
+ * [N : number of 0's in the TSCL_H_HS]
+ * [M : number of 0's in the TSCL_L_HS]
+ * T_SCL_HIGH = IPCLK * (CLK_DIV + 1) * (N + M)
+ * [N : number of 1's in the TSCL_H_HS]
+ * [M : number of 1's in the TSCL_L_HS]
+ *
+ * Result of (N + M) is always 8.
+ * In general case, we don't need to control timing_s1 and timing_s2.
+ */
+ if (i2c->variant->hw == I2C_TYPE_EXYNOSAUTOV9) {
+ div = ((clkin / (16 * i2c->op_clock)) - 1);
+ i2c_timing_s3 = div << 16;
+ if (hs_timings)
+ writel(i2c_timing_s3, i2c->regs + HSI2C_TIMING_HS3);
+ else
+ writel(i2c_timing_s3, i2c->regs + HSI2C_TIMING_FS3);
+
+ return 0;
+ }
+
/*
* In case of HSI2C controller in Exynos5 series
* FPCLK / FI2C =
@@ -422,7 +456,10 @@ static irqreturn_t exynos5_i2c_irq(int irqno, void *dev_id)
writel(int_status, i2c->regs + HSI2C_INT_STATUS);

/* handle interrupt related to the transfer status */
- if (i2c->variant->hw == I2C_TYPE_EXYNOS7) {
+ switch (i2c->variant->hw) {
+ case I2C_TYPE_EXYNOSAUTOV9:
+ fallthrough;
+ case I2C_TYPE_EXYNOS7:
if (int_status & HSI2C_INT_TRANS_DONE) {
i2c->trans_done = 1;
i2c->state = 0;
@@ -443,7 +480,12 @@ static irqreturn_t exynos5_i2c_irq(int irqno, void *dev_id)
i2c->state = -ETIMEDOUT;
goto stop;
}
- } else if (int_status & HSI2C_INT_I2C) {
+
+ break;
+ case I2C_TYPE_EXYNOS5:
+ if (!(int_status & HSI2C_INT_I2C))
+ break;
+
trans_status = readl(i2c->regs + HSI2C_TRANS_STATUS);
if (trans_status & HSI2C_NO_DEV_ACK) {
dev_dbg(i2c->dev, "No ACK from device\n");
@@ -465,6 +507,8 @@ static irqreturn_t exynos5_i2c_irq(int irqno, void *dev_id)
i2c->trans_done = 1;
i2c->state = 0;
}
+
+ break;
}

if ((i2c->msg->flags & I2C_M_RD) && (int_status &
@@ -569,13 +613,13 @@ static void exynos5_i2c_bus_check(struct exynos5_i2c *i2c)
{
unsigned long timeout;

- if (i2c->variant->hw != I2C_TYPE_EXYNOS7)
+ if (i2c->variant->hw == I2C_TYPE_EXYNOS5)
return;

/*
- * HSI2C_MASTER_ST_LOSE state in EXYNOS7 variant before transaction
- * indicates that bus is stuck (SDA is low). In such case bus recovery
- * can be performed.
+ * HSI2C_MASTER_ST_LOSE state (in Exynos7 and ExynosAutoV9 variants)
+ * before transaction indicates that bus is stuck (SDA is low).
+ * In such case bus recovery can be performed.
*/
timeout = jiffies + msecs_to_jiffies(100);
for (;;) {
@@ -611,10 +655,10 @@ static void exynos5_i2c_message_start(struct exynos5_i2c *i2c, int stop)
unsigned long flags;
unsigned short trig_lvl;

- if (i2c->variant->hw == I2C_TYPE_EXYNOS7)
- int_en |= HSI2C_INT_I2C_TRANS;
- else
+ if (i2c->variant->hw == I2C_TYPE_EXYNOS5)
int_en |= HSI2C_INT_I2C;
+ else
+ int_en |= HSI2C_INT_I2C_TRANS;

i2c_ctl = readl(i2c->regs + HSI2C_CTL);
i2c_ctl &= ~(HSI2C_TXCHON | HSI2C_RXCHON);
--
2.30.2