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path: root/drivers/i2c/busses/i2c-s3c2410.c
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Diffstat (limited to 'drivers/i2c/busses/i2c-s3c2410.c')
-rw-r--r--drivers/i2c/busses/i2c-s3c2410.c103
1 files changed, 87 insertions, 16 deletions
diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
index 424794271703..2ee6cc96ad61 100644
--- a/drivers/i2c/busses/i2c-s3c2410.c
+++ b/drivers/i2c/busses/i2c-s3c2410.c
@@ -49,14 +49,23 @@
#define S3C2410_IICADD 0x08
#define S3C2410_IICDS 0x0C
#define S3C2440_IICLC 0x10
+#define S3C2440_CLK_BYPASS 0x14
+#define S3C2440_IICINT 0x20
+#define S3C2440_IICNCLK_DIV2 0x28
#define S3C2410_IICCON_ACKEN (1 << 7)
#define S3C2410_IICCON_TXDIV_16 (0 << 6)
#define S3C2410_IICCON_TXDIV_512 (1 << 6)
#define S3C2410_IICCON_IRQEN (1 << 5)
#define S3C2410_IICCON_IRQPEND (1 << 4)
+#define S3C2410_IICCON_BUS_RELEASE (1 << 4)
+#define S3C2410_IICCON_IRQEN (1 << 5)
#define S3C2410_IICCON_SCALE(x) ((x) & 0xf)
#define S3C2410_IICCON_SCALEMASK (0xf)
+#define S3C2410_IICCON_BUSHOLD_IRQEN (1 << 8)
+#define S3C2410_IICCON_ACKEN (1 << 7)
+#define S3C2410_IICCON_TXDIV_16 (0 << 6)
+#define S3C2410_IICCON_TXDIV_512 (1 << 6)
#define S3C2410_IICSTAT_MASTER_RX (2 << 6)
#define S3C2410_IICSTAT_MASTER_TX (3 << 6)
@@ -80,11 +89,14 @@
#define S3C2410_IICLC_FILTER_ON (1 << 2)
+#define S3C2440_IICINT_BUSHOLD_CLEAR (1 << 8)
+
/* Treat S3C2410 as baseline hardware, anything else is supported via quirks */
#define QUIRK_S3C2440 (1 << 0)
#define QUIRK_HDMIPHY (1 << 1)
#define QUIRK_NO_GPIO (1 << 2)
#define QUIRK_POLL (1 << 3)
+#define QUIRK_FIMC_I2C (1 << 4)
/* Max time to wait for bus to become idle after a xfer (in us) */
#define S3C2410_IDLE_TIMEOUT 5000
@@ -158,6 +170,8 @@ static const struct of_device_id s3c24xx_i2c_match[] = {
.data = (void *)(QUIRK_S3C2440 | QUIRK_NO_GPIO) },
{ .compatible = "samsung,exynos5-sata-phy-i2c",
.data = (void *)(QUIRK_S3C2440 | QUIRK_POLL | QUIRK_NO_GPIO) },
+ { .compatible = "samsung,exynos5430-fimc-i2c",
+ .data = (void *)(QUIRK_S3C2440 | QUIRK_FIMC_I2C) },
{},
};
MODULE_DEVICE_TABLE(of, s3c24xx_i2c_match);
@@ -213,6 +227,8 @@ static inline void s3c24xx_i2c_enable_ack(struct s3c24xx_i2c *i2c)
unsigned long tmp;
tmp = readl(i2c->regs + S3C2410_IICCON);
+ if (i2c->quirks & QUIRK_FIMC_I2C)
+ tmp &= ~S3C2410_IICCON_BUS_RELEASE;
writel(tmp | S3C2410_IICCON_ACKEN, i2c->regs + S3C2410_IICCON);
}
@@ -222,16 +238,30 @@ static inline void s3c24xx_i2c_disable_irq(struct s3c24xx_i2c *i2c)
{
unsigned long tmp;
- tmp = readl(i2c->regs + S3C2410_IICCON);
- writel(tmp & ~S3C2410_IICCON_IRQEN, i2c->regs + S3C2410_IICCON);
+ if (i2c->quirks & QUIRK_FIMC_I2C) {
+ /* disable bus hold interrupt */
+ tmp = readl(i2c->regs + S3C2410_IICCON);
+ tmp &= ~S3C2410_IICCON_BUSHOLD_IRQEN;
+ writel(tmp, i2c->regs + S3C2410_IICCON);
+ } else {
+ tmp = readl(i2c->regs + S3C2410_IICCON);
+ writel(tmp & ~S3C2410_IICCON_IRQEN, i2c->regs + S3C2410_IICCON);
+ }
}
static inline void s3c24xx_i2c_enable_irq(struct s3c24xx_i2c *i2c)
{
unsigned long tmp;
- tmp = readl(i2c->regs + S3C2410_IICCON);
- writel(tmp | S3C2410_IICCON_IRQEN, i2c->regs + S3C2410_IICCON);
+ if (i2c->quirks & QUIRK_FIMC_I2C) {
+ /* enable bus hold interrupt */
+ tmp = readl(i2c->regs + S3C2410_IICCON);
+ tmp |= S3C2410_IICCON_BUSHOLD_IRQEN;
+ writel(tmp, i2c->regs + S3C2410_IICCON);
+ } else {
+ tmp = readl(i2c->regs + S3C2410_IICCON);
+ writel(tmp | S3C2410_IICCON_IRQEN, i2c->regs + S3C2410_IICCON);
+ }
}
static bool is_ack(struct s3c24xx_i2c *i2c)
@@ -561,9 +591,21 @@ static int i2c_s3c_irq_nextbyte(struct s3c24xx_i2c *i2c, unsigned long iicstat)
/* acknowlegde the IRQ and get back on with the work */
out_ack:
- tmp = readl(i2c->regs + S3C2410_IICCON);
- tmp &= ~S3C2410_IICCON_IRQPEND;
- writel(tmp, i2c->regs + S3C2410_IICCON);
+ if (i2c->quirks & QUIRK_FIMC_I2C) {
+ /* clear bus hold status flag */
+ tmp = readl(i2c->regs + S3C2440_IICINT);
+ tmp |= S3C2440_IICINT_BUSHOLD_CLEAR;
+ writel(tmp, i2c->regs + S3C2440_IICINT);
+
+ /* release the i2c bus */
+ tmp = readl(i2c->regs + S3C2410_IICCON);
+ tmp |= S3C2410_IICCON_IRQPEND;
+ writel(tmp, i2c->regs + S3C2410_IICCON);
+ } else {
+ tmp = readl(i2c->regs + S3C2410_IICCON);
+ tmp &= ~S3C2410_IICCON_IRQPEND;
+ writel(tmp, i2c->regs + S3C2410_IICCON);
+ }
out:
return ret;
}
@@ -589,9 +631,22 @@ static irqreturn_t s3c24xx_i2c_irq(int irqno, void *dev_id)
if (i2c->state == STATE_IDLE) {
dev_dbg(i2c->dev, "IRQ: error i2c->state == IDLE\n");
- tmp = readl(i2c->regs + S3C2410_IICCON);
- tmp &= ~S3C2410_IICCON_IRQPEND;
- writel(tmp, i2c->regs + S3C2410_IICCON);
+ if (i2c->quirks & QUIRK_FIMC_I2C) {
+ /* clear bus hold status flag */
+ tmp = readl(i2c->regs + S3C2440_IICINT);
+ tmp |= S3C2440_IICINT_BUSHOLD_CLEAR;
+ writel(tmp, i2c->regs + S3C2440_IICINT);
+
+ /* release the i2c bus */
+ tmp = readl(i2c->regs + S3C2410_IICCON);
+ tmp |= S3C2410_IICCON_IRQPEND;
+ writel(tmp, i2c->regs + S3C2410_IICCON);
+ } else {
+ tmp = readl(i2c->regs + S3C2410_IICCON);
+ tmp &= ~S3C2410_IICCON_IRQPEND;
+ writel(tmp, i2c->regs + S3C2410_IICCON);
+ }
+
goto out;
}
@@ -828,24 +883,34 @@ static const struct i2c_algorithm s3c24xx_i2c_algorithm = {
* return the divisor settings for a given frequency
*/
-static int s3c24xx_i2c_calcdivisor(unsigned long clkin, unsigned int wanted,
+static int s3c24xx_i2c_calcdivisor(struct s3c24xx_i2c *i2c,
+ unsigned long clkin, unsigned int wanted,
unsigned int *div1, unsigned int *divs)
{
unsigned int calc_divs = clkin / wanted;
unsigned int calc_div1;
+ unsigned int clk_prescaler;
+
+ if (i2c->quirks & QUIRK_FIMC_I2C) {
+ /* Input NCLK is used directly in i2c */
+ writel(0, i2c->regs + S3C2440_IICNCLK_DIV2);
+ writeb(1, i2c->regs + S3C2440_CLK_BYPASS);
+ clk_prescaler = 32;
+ } else
+ clk_prescaler = 16;
if (calc_divs > (16*16))
calc_div1 = 512;
else
- calc_div1 = 16;
+ calc_div1 = clk_prescaler;
calc_divs += calc_div1-1;
calc_divs /= calc_div1;
if (calc_divs == 0)
calc_divs = 1;
- if (calc_divs > 17)
- calc_divs = 17;
+ if (calc_divs > (clk_prescaler + 1))
+ calc_divs = clk_prescaler + 1;
*divs = calc_divs;
*div1 = calc_div1;
@@ -863,12 +928,17 @@ static int s3c24xx_i2c_calcdivisor(unsigned long clkin, unsigned int wanted,
static int s3c24xx_i2c_clockrate(struct s3c24xx_i2c *i2c, unsigned int *got)
{
struct s3c2410_platform_i2c *pdata = i2c->pdata;
- unsigned long clkin = clk_get_rate(i2c->clk);
+ unsigned long clkin;
unsigned int divs, div1;
unsigned long target_frequency;
u32 iiccon;
int freq;
+ if (i2c->quirks & QUIRK_FIMC_I2C)
+ clkin = 24000000;/* NCLK is fixed 24Mhz */
+ else
+ clkin = clk_get_rate(i2c->clk);
+
i2c->clkrate = clkin;
clkin /= 1000; /* clkin now in KHz */
@@ -878,7 +948,8 @@ static int s3c24xx_i2c_clockrate(struct s3c24xx_i2c *i2c, unsigned int *got)
target_frequency /= 1000; /* Target frequency now in KHz */
- freq = s3c24xx_i2c_calcdivisor(clkin, target_frequency, &div1, &divs);
+ freq = s3c24xx_i2c_calcdivisor(i2c, clkin, target_frequency, &div1,
+ &divs);
if (freq > target_frequency) {
dev_err(i2c->dev,
generated by cgit v1.2.3 (git 2.39.1) at 2024-09-21 04:28:10 +0000