* [PATCH v10,0/1] Introducing an attribute to select the time setting
@ 2022-02-17 12:22 Kewei Xu
2022-02-17 12:22 ` [PATCH v10,1/1] i2c: mediatek: modify bus speed calculation formula Kewei Xu
0 siblings, 1 reply; 4+ messages in thread
From: Kewei Xu @ 2022-02-17 12:22 UTC (permalink / raw)
To: wsa
Cc: matthias.bgg, robh+dt, linux-i2c, devicetree, linux-arm-kernel,
linux-kernel, linux-mediatek, srv_heupstream, leilk.liu,
qii.wang, liguo.zhang, caiyu.chen, housong.zhang, yuhan.wei,
kewei.xu, ryan-jh.yu, david-yh.chiu
v10:
Remove the Change-Id tag in v9.
v9:
1. Remove received patch
2. Update ac-timing calculation algorithm to make i2c ac-timing meet
specification and function normal.
v8:
Remove received patch
v7:
Resubmit the patch based on version 5.15-rc1
v6:
1. Add the judgment condition, clear the handshake signal between dma and
i2c when multiple msgs are transmitted.
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 commit 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 (1):
i2c: mediatek: modify bus speed calculation formula
drivers/i2c/busses/i2c-mt65xx.c | 51 +++++++++++++++++++++++++++++++++--------
1 file changed, 41 insertions(+), 10 deletions(-)
--
1.9.1
^ permalink raw reply [flat|nested] 4+ messages in thread* [PATCH v10,1/1] i2c: mediatek: modify bus speed calculation formula 2022-02-17 12:22 [PATCH v10,0/1] Introducing an attribute to select the time setting Kewei Xu @ 2022-02-17 12:22 ` Kewei Xu 2022-02-28 6:31 ` Qii Wang 2022-03-01 15:18 ` Wolfram Sang 0 siblings, 2 replies; 4+ messages in thread From: Kewei Xu @ 2022-02-17 12:22 UTC (permalink / raw) To: wsa Cc: matthias.bgg, robh+dt, linux-i2c, devicetree, linux-arm-kernel, linux-kernel, linux-mediatek, srv_heupstream, leilk.liu, qii.wang, liguo.zhang, caiyu.chen, housong.zhang, yuhan.wei, kewei.xu, ryan-jh.yu, david-yh.chiu 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 <kewei.xu@mediatek.com> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> --- drivers/i2c/busses/i2c-mt65xx.c | 51 +++++++++++++++++++++++++++++++++-------- 1 file changed, 41 insertions(+), 10 deletions(-) diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c index aa4d218..682293e 100644 --- a/drivers/i2c/busses/i2c-mt65xx.c +++ b/drivers/i2c/busses/i2c-mt65xx.c @@ -67,11 +67,12 @@ #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) @@ -604,6 +605,31 @@ static int mtk_i2c_max_step_cnt(unsigned int target_speed) return MAX_STEP_CNT_DIV; } +static int mtk_i2c_get_clk_div_restri(struct mtk_i2c *i2c, + unsigned int sample_cnt) +{ + int clk_div_restri = 0; + + if (i2c->dev_comp->ltiming_adjust == 0) + return 0; + + if (sample_cnt == 1) { + if (i2c->ac_timing.inter_clk_div == 0) + clk_div_restri = 0; + else + clk_div_restri = 1; + } else { + if (i2c->ac_timing.inter_clk_div == 0) + clk_div_restri = -1; + else if (i2c->ac_timing.inter_clk_div == 1) + clk_div_restri = 0; + else + clk_div_restri = 1; + } + + return clk_div_restri; +} + /* * Check and Calculate i2c ac-timing * @@ -732,6 +758,7 @@ 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 clk_div_restri = 0; if (target_speed > I2C_MAX_HIGH_SPEED_MODE_FREQ) target_speed = I2C_MAX_HIGH_SPEED_MODE_FREQ; @@ -749,7 +776,8 @@ static int mtk_i2c_calculate_speed(struct mtk_i2c *i2c, unsigned int clk_src, * optimizing for sample_cnt * step_cnt being minimal */ for (sample_cnt = 1; sample_cnt <= MAX_SAMPLE_CNT_DIV; sample_cnt++) { - step_cnt = DIV_ROUND_UP(opt_div, sample_cnt); + clk_div_restri = mtk_i2c_get_clk_div_restri(i2c, sample_cnt); + step_cnt = DIV_ROUND_UP(opt_div + clk_div_restri, sample_cnt); cnt_mul = step_cnt * sample_cnt; if (step_cnt > max_step_cnt) continue; @@ -763,7 +791,7 @@ static int mtk_i2c_calculate_speed(struct mtk_i2c *i2c, unsigned int clk_src, best_mul = cnt_mul; base_sample_cnt = sample_cnt; base_step_cnt = step_cnt; - if (best_mul == opt_div) + if (best_mul == (opt_div + clk_div_restri)) break; } } @@ -774,7 +802,8 @@ 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 - clk_div_restri))) > + target_speed) { /* In this case, hardware can't support such * low i2c_bus_freq */ @@ -803,13 +832,16 @@ static int mtk_i2c_set_speed(struct mtk_i2c *i2c, unsigned int parent_clk) 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 */ @@ -856,7 +888,6 @@ static int mtk_i2c_set_speed(struct mtk_i2c *i2c, unsigned int parent_clk) break; } - i2c->ac_timing.inter_clk_div = clk_div - 1; return 0; } -- 1.9.1 ^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v10,1/1] i2c: mediatek: modify bus speed calculation formula 2022-02-17 12:22 ` [PATCH v10,1/1] i2c: mediatek: modify bus speed calculation formula Kewei Xu @ 2022-02-28 6:31 ` Qii Wang 2022-03-01 15:18 ` Wolfram Sang 1 sibling, 0 replies; 4+ messages in thread From: Qii Wang @ 2022-02-28 6:31 UTC (permalink / raw) To: Kewei Xu, wsa Cc: matthias.bgg, robh+dt, linux-i2c, devicetree, linux-arm-kernel, linux-kernel, linux-mediatek, srv_heupstream, leilk.liu, liguo.zhang, caiyu.chen, housong.zhang, yuhan.wei, ryan-jh.yu, david-yh.chiu On Thu, 2022-02-17 at 20:22 +0800, Kewei Xu wrote: > 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 <kewei.xu@mediatek.com> > Reviewed-by: AngeloGioacchino Del Regno < > angelogioacchino.delregno@collabora.com> Reviewed-by: Qii Wang <qii.wang@mediatek.com> > --- > drivers/i2c/busses/i2c-mt65xx.c | 51 > +++++++++++++++++++++++++++++++++-------- > 1 file changed, 41 insertions(+), 10 deletions(-) > ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v10,1/1] i2c: mediatek: modify bus speed calculation formula 2022-02-17 12:22 ` [PATCH v10,1/1] i2c: mediatek: modify bus speed calculation formula Kewei Xu 2022-02-28 6:31 ` Qii Wang @ 2022-03-01 15:18 ` Wolfram Sang 1 sibling, 0 replies; 4+ messages in thread From: Wolfram Sang @ 2022-03-01 15:18 UTC (permalink / raw) To: Kewei Xu Cc: matthias.bgg, robh+dt, linux-i2c, devicetree, linux-arm-kernel, linux-kernel, linux-mediatek, srv_heupstream, leilk.liu, qii.wang, liguo.zhang, caiyu.chen, housong.zhang, yuhan.wei, ryan-jh.yu, david-yh.chiu [-- Attachment #1: Type: text/plain, Size: 407 bytes --] On Thu, Feb 17, 2022 at 08:22:43PM +0800, Kewei Xu wrote: > 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 <kewei.xu@mediatek.com> > Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> Applied to for-next, thanks! [-- Attachment #2: signature.asc --] [-- Type: application/pgp-signature, Size: 833 bytes --] ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2022-03-01 15:24 UTC | newest] Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2022-02-17 12:22 [PATCH v10,0/1] Introducing an attribute to select the time setting Kewei Xu 2022-02-17 12:22 ` [PATCH v10,1/1] i2c: mediatek: modify bus speed calculation formula Kewei Xu 2022-02-28 6:31 ` Qii Wang 2022-03-01 15:18 ` Wolfram Sang
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