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path: root/drivers/i2c/busses/i2c-img-scb.c
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Diffstat (limited to 'drivers/i2c/busses/i2c-img-scb.c')
-rw-r--r--drivers/i2c/busses/i2c-img-scb.c73
1 files changed, 43 insertions, 30 deletions
diff --git a/drivers/i2c/busses/i2c-img-scb.c b/drivers/i2c/busses/i2c-img-scb.c
index 00ffd6613..3795fe130 100644
--- a/drivers/i2c/busses/i2c-img-scb.c
+++ b/drivers/i2c/busses/i2c-img-scb.c
@@ -278,8 +278,6 @@
#define ISR_COMPLETE(err) (ISR_COMPLETE_M | (ISR_STATUS_M & (err)))
#define ISR_FATAL(err) (ISR_COMPLETE(err) | ISR_FATAL_M)
-#define REL_SOC_IP_SCB_2_2_1 0x00020201
-
enum img_i2c_mode {
MODE_INACTIVE,
MODE_RAW,
@@ -536,6 +534,7 @@ static void img_i2c_read_fifo(struct img_i2c *i2c)
u32 fifo_status;
u8 data;
+ img_i2c_wr_rd_fence(i2c);
fifo_status = img_i2c_readl(i2c, SCB_FIFO_STATUS_REG);
if (fifo_status & FIFO_READ_EMPTY)
break;
@@ -544,7 +543,6 @@ static void img_i2c_read_fifo(struct img_i2c *i2c)
*i2c->msg.buf = data;
img_i2c_writel(i2c, SCB_READ_FIFO_REG, 0xff);
- img_i2c_wr_rd_fence(i2c);
i2c->msg.len--;
i2c->msg.buf++;
}
@@ -556,12 +554,12 @@ static void img_i2c_write_fifo(struct img_i2c *i2c)
while (i2c->msg.len) {
u32 fifo_status;
+ img_i2c_wr_rd_fence(i2c);
fifo_status = img_i2c_readl(i2c, SCB_FIFO_STATUS_REG);
if (fifo_status & FIFO_WRITE_FULL)
break;
img_i2c_writel(i2c, SCB_WRITE_DATA_REG, *i2c->msg.buf);
- img_i2c_wr_rd_fence(i2c);
i2c->msg.len--;
i2c->msg.buf++;
}
@@ -859,7 +857,7 @@ static unsigned int img_i2c_auto(struct img_i2c *i2c,
}
/* Enable transaction halt on start bit */
- if (!i2c->last_msg && i2c->line_status & LINESTAT_START_BIT_DET) {
+ if (!i2c->last_msg && line_status & LINESTAT_START_BIT_DET) {
img_i2c_transaction_halt(i2c, true);
/* we're no longer interested in the slave event */
i2c->int_enable &= ~INT_SLAVE_EVENT;
@@ -1062,6 +1060,15 @@ static int img_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
i2c->last_msg = (i == num - 1);
reinit_completion(&i2c->msg_complete);
+ /*
+ * Clear line status and all interrupts before starting a
+ * transfer, as we may have unserviced interrupts from
+ * previous transfers that might be handled in the context
+ * of the new transfer.
+ */
+ img_i2c_writel(i2c, SCB_INT_CLEAR_REG, ~0);
+ img_i2c_writel(i2c, SCB_CLEAR_REG, ~0);
+
if (atomic)
img_i2c_atomic_start(i2c);
else if (msg->flags & I2C_M_RD)
@@ -1120,13 +1127,8 @@ static int img_i2c_init(struct img_i2c *i2c)
return -EINVAL;
}
- if (rev == REL_SOC_IP_SCB_2_2_1) {
- i2c->need_wr_rd_fence = true;
- dev_info(i2c->adap.dev.parent, "fence quirk enabled");
- }
-
- bitrate_khz = i2c->bitrate / 1000;
- clk_khz = clk_get_rate(i2c->scb_clk) / 1000;
+ /* Fencing enabled by default. */
+ i2c->need_wr_rd_fence = true;
/* Determine what mode we're in from the bitrate */
timing = timings[0];
@@ -1136,6 +1138,17 @@ static int img_i2c_init(struct img_i2c *i2c)
break;
}
}
+ if (i2c->bitrate > timings[ARRAY_SIZE(timings) - 1].max_bitrate) {
+ dev_warn(i2c->adap.dev.parent,
+ "requested bitrate (%u) is higher than the max bitrate supported (%u)\n",
+ i2c->bitrate,
+ timings[ARRAY_SIZE(timings) - 1].max_bitrate);
+ timing = timings[ARRAY_SIZE(timings) - 1];
+ i2c->bitrate = timing.max_bitrate;
+ }
+
+ bitrate_khz = i2c->bitrate / 1000;
+ clk_khz = clk_get_rate(i2c->scb_clk) / 1000;
/* Find the prescale that would give us that inc (approx delay = 0) */
prescale = SCB_OPT_INC * clk_khz / (256 * 16 * bitrate_khz);
@@ -1182,32 +1195,32 @@ static int img_i2c_init(struct img_i2c *i2c)
((bitrate_khz * clk_period) / 2))
int_bitrate++;
- /* Setup TCKH value */
- tckh = timing.tckh / clk_period;
- if (timing.tckh % clk_period)
- tckh++;
+ /*
+ * Setup clock duty cycle, start with 50% and adjust TCKH and TCKL
+ * values from there if they don't meet minimum timing requirements
+ */
+ tckh = int_bitrate / 2;
+ tckl = int_bitrate - tckh;
- if (tckh > 0)
- data = tckh - 1;
- else
- data = 0;
+ /* Adjust TCKH and TCKL values */
+ data = DIV_ROUND_UP(timing.tckl, clk_period);
- img_i2c_writel(i2c, SCB_TIME_TCKH_REG, data);
+ if (tckl < data) {
+ tckl = data;
+ tckh = int_bitrate - tckl;
+ }
- /* Setup TCKL value */
- tckl = int_bitrate - tckh;
+ if (tckh > 0)
+ --tckh;
if (tckl > 0)
- data = tckl - 1;
- else
- data = 0;
+ --tckl;
- img_i2c_writel(i2c, SCB_TIME_TCKL_REG, data);
+ img_i2c_writel(i2c, SCB_TIME_TCKH_REG, tckh);
+ img_i2c_writel(i2c, SCB_TIME_TCKL_REG, tckl);
/* Setup TSDH value */
- tsdh = timing.tsdh / clk_period;
- if (timing.tsdh % clk_period)
- tsdh++;
+ tsdh = DIV_ROUND_UP(timing.tsdh, clk_period);
if (tsdh > 1)
data = tsdh - 1;