2021-08-23 13:07:57

by Kewei Xu

[permalink] [raw]
Subject: [PATCH v5 0/7] Introducing an attribute to select the time setting

v5:
1. Replace the previous variable name "default_timing_adjust" with "use-default-timing"
2. Added waiting for dma reset mechanism
3. Remove received patch(dt-bindings: i2c: update bindings for MT8195 SOC)

v4:
1. Remove the repeated assignment of the inter_clk_div parameter
2. Modify the wrong assignment of OFFSET_MULTI_DMA
3. Unify the log print format of the i2c_dump_register() and drop the extra outer parentheses
4. Place the fixes at the very least
5. Add fixed tags 25708278f810 ("i2c: mediatek: Add i2c support for MediaTek MT8183")
6. Add "i2c: mediatek: modify bus speed calculation formula"
7. Fix single line characters exceeding 80 characters
8. Combine two different series of patches.

v3:
1. Fix code errors caused by v2 modification

v2:
1. Add "dt-bindings: i2c: add attribute default-timing-adjust"
2. Split the fix into sepatate patch.

Kewei Xu (7):
i2c: mediatek: fixing the incorrect register offset
i2c: mediatek: Reset the handshake signal between i2c and dma
i2c: mediatek: Dump i2c/dma register when a timeout occurs
dt-bindings: i2c: add attribute use-default-timing
i2c: mediatek: Add OFFSET_EXT_CONF setting back
i2c: mediatek: Isolate speed setting via dts for special devices
i2c: mediatek: modify bus speed calculation formula

.../devicetree/bindings/i2c/i2c-mt65xx.txt | 2 +
drivers/i2c/busses/i2c-mt65xx.c | 207 ++++++++++++++++--
2 files changed, 192 insertions(+), 17 deletions(-)

--
2.18.0


2021-08-23 13:08:00

by Kewei Xu

[permalink] [raw]
Subject: [PATCH 6/7] i2c: mediatek: Isolate speed setting via dts for special devices

In the commit be5ce0e97cc7 ("i2c: mediatek: Add i2c ac-timing adjust
support"), the I2C timing calculation has been revised to support
ac-timing adjustment, however that will break on some I2C components.
As a result we want to introduce a new setting "default-adjust-timing"
so those components can choose to use the old (default) timing algorithm.

Fixes: be5ce0e97cc7 ("i2c: mediatek: Add i2c ac-timing adjust support")
Signed-off-by: Kewei Xu <[email protected]>
---
drivers/i2c/busses/i2c-mt65xx.c | 77 ++++++++++++++++++++++++++++++++++++++---
1 file changed, 73 insertions(+), 4 deletions(-)

diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
index 4da6b43..18b5659 100644
--- a/drivers/i2c/busses/i2c-mt65xx.c
+++ b/drivers/i2c/busses/i2c-mt65xx.c
@@ -66,6 +66,7 @@
#define I2C_DMA_HARD_RST 0x0002
#define I2C_DMA_HANDSHAKE_RST 0x0004

+#define I2C_DEFAULT_CLK_DIV 5
#define MAX_SAMPLE_CNT_DIV 8
#define MAX_STEP_CNT_DIV 64
#define MAX_CLOCK_DIV 256
@@ -250,6 +251,7 @@ struct mtk_i2c {
struct clk *clk_arb; /* Arbitrator clock for i2c */
bool have_pmic; /* can use i2c pins from PMIC */
bool use_push_pull; /* IO config push-pull mode */
+ bool use_default_timing; /* no timing adjust mode */

u16 irq_stat; /* interrupt status */
unsigned int clk_src_div;
@@ -532,7 +534,11 @@ static void mtk_i2c_init_hw(struct mtk_i2c *i2c)
else
ext_conf_val = I2C_FS_START_CON;

- if (i2c->dev_comp->timing_adjust) {
+ if (i2c->use_default_timing) {
+ if (i2c->dev_comp->timing_adjust)
+ mtk_i2c_writew(i2c, I2C_DEFAULT_CLK_DIV - 1,
+ OFFSET_CLOCK_DIV);
+ } else if (i2c->dev_comp->timing_adjust) {
ext_conf_val = i2c->ac_timing.ext;
mtk_i2c_writew(i2c, i2c->ac_timing.inter_clk_div,
OFFSET_CLOCK_DIV);
@@ -615,7 +621,7 @@ static int mtk_i2c_check_ac_timing(struct mtk_i2c *i2c,
unsigned int sample_ns = div_u64(1000000000ULL * (sample_cnt + 1),
clk_src);

- if (!i2c->dev_comp->timing_adjust)
+ if (i2c->use_default_timing || !i2c->dev_comp->timing_adjust)
return 0;

if (i2c->dev_comp->ltiming_adjust)
@@ -775,7 +781,65 @@ static int mtk_i2c_calculate_speed(struct mtk_i2c *i2c, unsigned int clk_src,
return 0;
}

-static int mtk_i2c_set_speed(struct mtk_i2c *i2c, unsigned int parent_clk)
+static int mtk_i2c_set_speed_default_timing(struct mtk_i2c *i2c,
+ unsigned int parent_clk)
+{
+ unsigned int clk_src;
+ unsigned int step_cnt;
+ unsigned int sample_cnt;
+ unsigned int l_step_cnt;
+ unsigned int l_sample_cnt;
+ unsigned int target_speed;
+ int ret;
+
+ if (i2c->dev_comp->timing_adjust)
+ i2c->clk_src_div *= I2C_DEFAULT_CLK_DIV;
+
+ clk_src = parent_clk / i2c->clk_src_div;
+ target_speed = i2c->speed_hz;
+
+ if (target_speed > I2C_MAX_FAST_MODE_PLUS_FREQ) {
+ /* Set master code speed register */
+ ret = mtk_i2c_calculate_speed(i2c, clk_src,
+ I2C_MAX_FAST_MODE_FREQ,
+ &l_step_cnt, &l_sample_cnt);
+ if (ret < 0)
+ return ret;
+
+ i2c->timing_reg = (l_sample_cnt << 8) | l_step_cnt;
+
+ /* Set the high speed mode register */
+ ret = mtk_i2c_calculate_speed(i2c, clk_src, target_speed,
+ &step_cnt, &sample_cnt);
+ if (ret < 0)
+ return ret;
+
+ i2c->high_speed_reg = I2C_TIME_DEFAULT_VALUE |
+ (sample_cnt << 12) | (step_cnt << 8);
+
+ if (i2c->dev_comp->ltiming_adjust)
+ i2c->ltiming_reg = (l_sample_cnt << 6) | l_step_cnt |
+ (sample_cnt << 12) | (step_cnt << 9);
+ } else {
+ ret = mtk_i2c_calculate_speed(i2c, clk_src, target_speed,
+ &step_cnt, &sample_cnt);
+ if (ret < 0)
+ return ret;
+
+ i2c->timing_reg = (sample_cnt << 8) | step_cnt;
+
+ /* Disable the high speed transaction */
+ i2c->high_speed_reg = I2C_TIME_CLR_VALUE;
+
+ if (i2c->dev_comp->ltiming_adjust)
+ i2c->ltiming_reg = (sample_cnt << 6) | step_cnt;
+ }
+
+ return 0;
+}
+
+static int mtk_i2c_set_speed_adjust_timing(struct mtk_i2c *i2c,
+ unsigned int parent_clk)
{
unsigned int clk_src;
unsigned int step_cnt;
@@ -1271,6 +1335,8 @@ static int mtk_i2c_parse_dt(struct device_node *np, struct mtk_i2c *i2c)
i2c->have_pmic = of_property_read_bool(np, "mediatek,have-pmic");
i2c->use_push_pull =
of_property_read_bool(np, "mediatek,use-push-pull");
+ i2c->use_default_timing =
+ of_property_read_bool(np, "mediatek,use-default-timing");

i2c_parse_fw_timings(i2c->dev, &i2c->timing_info, true);

@@ -1357,7 +1423,10 @@ static int mtk_i2c_probe(struct platform_device *pdev)

strlcpy(i2c->adap.name, I2C_DRV_NAME, sizeof(i2c->adap.name));

- ret = mtk_i2c_set_speed(i2c, clk_get_rate(clk));
+ if (i2c->use_default_timing)
+ ret = mtk_i2c_set_speed_default_timing(i2c, clk_get_rate(clk));
+ else
+ ret = mtk_i2c_set_speed_adjust_timing(i2c, clk_get_rate(clk));
if (ret) {
dev_err(&pdev->dev, "Failed to set the speed.\n");
return -EINVAL;
--
1.9.1

2021-08-23 13:08:43

by Kewei Xu

[permalink] [raw]
Subject: [PATCH 1/7] i2c: mediatek: fixing the incorrect register offset

The reason for the modification here is that the previous
offset information is incorrect, OFFSET_DEBUGSTAT = 0xE4 is
the correct value.

Fixes: 25708278f810 ("i2c: mediatek: Add i2c support for MediaTek MT8183")
Signed-off-by: Kewei Xu <[email protected]>
Reviewed-by: Chen-Yu Tsai <[email protected]>
---
drivers/i2c/busses/i2c-mt65xx.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
index 4ca716e..2661ed0 100644
--- a/drivers/i2c/busses/i2c-mt65xx.c
+++ b/drivers/i2c/busses/i2c-mt65xx.c
@@ -193,7 +193,7 @@ enum I2C_REGS_OFFSET {
[OFFSET_CLOCK_DIV] = 0x48,
[OFFSET_SOFTRESET] = 0x50,
[OFFSET_SCL_MIS_COMP_POINT] = 0x90,
- [OFFSET_DEBUGSTAT] = 0xe0,
+ [OFFSET_DEBUGSTAT] = 0xe4,
[OFFSET_DEBUGCTRL] = 0xe8,
[OFFSET_FIFO_STAT] = 0xf4,
[OFFSET_FIFO_THRESH] = 0xf8,
--
1.9.1

2021-08-23 13:09:12

by Kewei Xu

[permalink] [raw]
Subject: [PATCH 3/7] i2c: mediatek: Dump i2c/dma register when a timeout occurs

When a timeout error occurs in i2c transter, it is usually related
to the i2c/dma IP hardware configuration. Therefore, the purpose of
this patch is to dump the key register values of i2c/dma when a
timeout occurs in i2c for debugging.

Signed-off-by: Kewei Xu <[email protected]>
---
drivers/i2c/busses/i2c-mt65xx.c | 56 ++++++++++++++++++++++++++++++++++++++++-
1 file changed, 55 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
index abda525..633bce4 100644
--- a/drivers/i2c/busses/i2c-mt65xx.c
+++ b/drivers/i2c/busses/i2c-mt65xx.c
@@ -129,6 +129,7 @@ enum I2C_REGS_OFFSET {
OFFSET_HS,
OFFSET_SOFTRESET,
OFFSET_DCM_EN,
+ OFFSET_MULTI_DMA,
OFFSET_PATH_DIR,
OFFSET_DEBUGSTAT,
OFFSET_DEBUGCTRL,
@@ -196,6 +197,7 @@ enum I2C_REGS_OFFSET {
[OFFSET_TRANSFER_LEN_AUX] = 0x44,
[OFFSET_CLOCK_DIV] = 0x48,
[OFFSET_SOFTRESET] = 0x50,
+ [OFFSET_MULTI_DMA] = 0x8c,
[OFFSET_SCL_MIS_COMP_POINT] = 0x90,
[OFFSET_DEBUGSTAT] = 0xe4,
[OFFSET_DEBUGCTRL] = 0xe8,
@@ -837,6 +839,57 @@ static int mtk_i2c_set_speed(struct mtk_i2c *i2c, unsigned int parent_clk)
return 0;
}

+static void i2c_dump_register(struct mtk_i2c *i2c)
+{
+ dev_err(i2c->dev, "SLAVE_ADDR: 0x%x, INTR_MASK: 0x%x\n",
+ mtk_i2c_readw(i2c, OFFSET_SLAVE_ADDR),
+ mtk_i2c_readw(i2c, OFFSET_INTR_MASK));
+ dev_err(i2c->dev, "INTR_STAT: 0x%x, CONTROL: 0x%x\n",
+ mtk_i2c_readw(i2c, OFFSET_INTR_STAT),
+ mtk_i2c_readw(i2c, OFFSET_CONTROL));
+ dev_err(i2c->dev, "TRANSFER_LEN: 0x%x, TRANSAC_LEN: 0x%x\n",
+ mtk_i2c_readw(i2c, OFFSET_TRANSFER_LEN),
+ mtk_i2c_readw(i2c, OFFSET_TRANSAC_LEN));
+ dev_err(i2c->dev, "DELAY_LEN: 0x%x, HTIMING: 0x%x\n",
+ mtk_i2c_readw(i2c, OFFSET_DELAY_LEN),
+ mtk_i2c_readw(i2c, OFFSET_TIMING));
+ dev_err(i2c->dev, "START: 0x%x, EXT_CONF: 0x%x\n",
+ mtk_i2c_readw(i2c, OFFSET_START),
+ mtk_i2c_readw(i2c, OFFSET_EXT_CONF));
+ dev_err(i2c->dev, "HS: 0x%x, IO_CONFIG: 0x%x\n",
+ mtk_i2c_readw(i2c, OFFSET_HS),
+ mtk_i2c_readw(i2c, OFFSET_IO_CONFIG));
+ dev_err(i2c->dev, "DCM_EN: 0x%x, TRANSFER_LEN_AUX: 0x%x\n",
+ mtk_i2c_readw(i2c, OFFSET_DCM_EN),
+ mtk_i2c_readw(i2c, OFFSET_TRANSFER_LEN_AUX));
+ dev_err(i2c->dev, "CLOCK_DIV: 0x%x, FIFO_STAT: 0x%x\n",
+ mtk_i2c_readw(i2c, OFFSET_CLOCK_DIV),
+ mtk_i2c_readw(i2c, OFFSET_FIFO_STAT));
+ dev_err(i2c->dev, "DEBUGCTRL : 0x%x, DEBUGSTAT: 0x%x\n",
+ mtk_i2c_readw(i2c, OFFSET_DEBUGCTRL),
+ mtk_i2c_readw(i2c, OFFSET_DEBUGSTAT));
+ if (i2c->dev_comp->regs == mt_i2c_regs_v2) {
+ dev_err(i2c->dev, "LTIMING: 0x%x, MULTI_DMA: 0x%x\n",
+ mtk_i2c_readw(i2c, OFFSET_LTIMING),
+ mtk_i2c_readw(i2c, OFFSET_MULTI_DMA));
+ }
+ dev_err(i2c->dev, "\nDMA_INT_FLAG: 0x%x, DMA_INT_EN: 0x%x\n",
+ readl(i2c->pdmabase + OFFSET_INT_FLAG),
+ readl(i2c->pdmabase + OFFSET_INT_EN));
+ dev_err(i2c->dev, "DMA_EN: 0x%x, DMA_CON: 0x%x\n",
+ readl(i2c->pdmabase + OFFSET_EN),
+ readl(i2c->pdmabase + OFFSET_CON));
+ dev_err(i2c->dev, "DMA_TX_MEM_ADDR: 0x%x, DMA_RX_MEM_ADDR: 0x%x\n",
+ readl(i2c->pdmabase + OFFSET_TX_MEM_ADDR),
+ readl(i2c->pdmabase + OFFSET_RX_MEM_ADDR));
+ dev_err(i2c->dev, "DMA_TX_LEN: 0x%x, DMA_RX_LEN: 0x%x\n",
+ readl(i2c->pdmabase + OFFSET_TX_LEN),
+ readl(i2c->pdmabase + OFFSET_RX_LEN));
+ dev_err(i2c->dev, "DMA_TX_4G_MODE: 0x%x, DMA_RX_4G_MODE: 0x%x",
+ readl(i2c->pdmabase + OFFSET_TX_4G_MODE),
+ readl(i2c->pdmabase + OFFSET_RX_4G_MODE));
+}
+
static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
int num, int left_num)
{
@@ -1065,7 +1118,8 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
}

if (ret == 0) {
- dev_dbg(i2c->dev, "addr: %x, transfer timeout\n", msgs->addr);
+ dev_err(i2c->dev, "addr: %x, transfer timeout\n", msgs->addr);
+ i2c_dump_register(i2c);
mtk_i2c_init_hw(i2c);
return -ETIMEDOUT;
}
--
1.9.1

2021-08-23 13:09:19

by Kewei Xu

[permalink] [raw]
Subject: [PATCH 7/7] i2c: mediatek: modify bus speed calculation formula

When clock-div is 0 or greater than 1, the bus speed
calculated by the old speed calculation formula will be
larger than the target speed. So we update the formula.

Signed-off-by: Kewei Xu <[email protected]>
---
drivers/i2c/busses/i2c-mt65xx.c | 35 +++++++++++++++++++++++++----------
1 file changed, 25 insertions(+), 10 deletions(-)

diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
index 18b5659..0b42acd8 100644
--- a/drivers/i2c/busses/i2c-mt65xx.c
+++ b/drivers/i2c/busses/i2c-mt65xx.c
@@ -69,11 +69,12 @@
#define I2C_DEFAULT_CLK_DIV 5
#define MAX_SAMPLE_CNT_DIV 8
#define MAX_STEP_CNT_DIV 64
-#define MAX_CLOCK_DIV 256
+#define MAX_CLOCK_DIV_8BITS 256
+#define MAX_CLOCK_DIV_5BITS 32
#define MAX_HS_STEP_CNT_DIV 8
-#define I2C_STANDARD_MODE_BUFFER (1000 / 2)
-#define I2C_FAST_MODE_BUFFER (300 / 2)
-#define I2C_FAST_MODE_PLUS_BUFFER (20 / 2)
+#define I2C_STANDARD_MODE_BUFFER (1000 / 3)
+#define I2C_FAST_MODE_BUFFER (300 / 3)
+#define I2C_FAST_MODE_PLUS_BUFFER (20 / 3)

#define I2C_CONTROL_RS (0x1 << 1)
#define I2C_CONTROL_DMA_EN (0x1 << 2)
@@ -725,14 +726,26 @@ static int mtk_i2c_calculate_speed(struct mtk_i2c *i2c, unsigned int clk_src,
unsigned int best_mul;
unsigned int cnt_mul;
int ret = -EINVAL;
+ int clock_div_constraint = 0;

if (target_speed > I2C_MAX_HIGH_SPEED_MODE_FREQ)
target_speed = I2C_MAX_HIGH_SPEED_MODE_FREQ;

+ if (i2c->use_default_timing) {
+ clock_div_constraint = 0;
+ } else if (i2c->dev_comp->ltiming_adjust &&
+ i2c->ac_timing.inter_clk_div > 1) {
+ clock_div_constraint = 1;
+ } else if (i2c->dev_comp->ltiming_adjust &&
+ i2c->ac_timing.inter_clk_div == 0) {
+ clock_div_constraint = -1;
+ }
+
max_step_cnt = mtk_i2c_max_step_cnt(target_speed);
base_step_cnt = max_step_cnt;
/* Find the best combination */
- opt_div = DIV_ROUND_UP(clk_src >> 1, target_speed);
+ opt_div = DIV_ROUND_UP(clk_src >> 1, target_speed) +
+ clock_div_constraint;
best_mul = MAX_SAMPLE_CNT_DIV * max_step_cnt;

/* Search for the best pair (sample_cnt, step_cnt) with
@@ -767,7 +780,8 @@ static int mtk_i2c_calculate_speed(struct mtk_i2c *i2c, unsigned int clk_src,
sample_cnt = base_sample_cnt;
step_cnt = base_step_cnt;

- if ((clk_src / (2 * sample_cnt * step_cnt)) > target_speed) {
+ if ((clk_src / (2 * (sample_cnt * step_cnt - clock_div_constraint))) >
+ target_speed) {
/* In this case, hardware can't support such
* low i2c_bus_freq
*/
@@ -854,13 +868,16 @@ static int mtk_i2c_set_speed_adjust_timing(struct mtk_i2c *i2c,
target_speed = i2c->speed_hz;
parent_clk /= i2c->clk_src_div;

- if (i2c->dev_comp->timing_adjust)
- max_clk_div = MAX_CLOCK_DIV;
+ if (i2c->dev_comp->timing_adjust && i2c->dev_comp->ltiming_adjust)
+ max_clk_div = MAX_CLOCK_DIV_5BITS;
+ else if (i2c->dev_comp->timing_adjust)
+ max_clk_div = MAX_CLOCK_DIV_8BITS;
else
max_clk_div = 1;

for (clk_div = 1; clk_div <= max_clk_div; clk_div++) {
clk_src = parent_clk / clk_div;
+ i2c->ac_timing.inter_clk_div = clk_div - 1;

if (target_speed > I2C_MAX_FAST_MODE_PLUS_FREQ) {
/* Set master code speed register */
@@ -907,8 +924,6 @@ static int mtk_i2c_set_speed_adjust_timing(struct mtk_i2c *i2c,
break;
}

- i2c->ac_timing.inter_clk_div = clk_div - 1;
-
return 0;
}

--
1.9.1

2021-08-23 13:09:20

by Kewei Xu

[permalink] [raw]
Subject: [PATCH 4/7] dt-bindings: i2c: add attribute use-default-timing

Add attribute use-default-timing for DT-binding document.

Fixes: be5ce0e97cc7 ("i2c: mediatek: Add i2c ac-timing adjust support")
Signed-off-by: Kewei Xu <[email protected]>
---
Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt | 2 ++
1 file changed, 2 insertions(+)

diff --git a/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt b/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt
index 5ea216a..4dbb697 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt
@@ -34,6 +34,8 @@ Optional properties:
Only mt6589 and mt8135 support this feature.
- mediatek,use-push-pull: IO config use push-pull mode.
- vbus-supply: phandle to the regulator that provides power to SCL/SDA.
+ - mediatek,use-default-timing: use default timing calculation, no timing
+ adjustment.

Example:

--
1.9.1