From: Clark Wang <xiaoning.wang@nxp.com>
To: aisheng.dong@nxp.com, shawnguo@kernel.org, s.hauer@pengutronix.de
Cc: kernel@pengutronix.de, festevam@gmail.com, linux-imx@nxp.com,
sumit.semwal@linaro.org, christian.koenig@amd.com,
linux-i2c@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: [PATCH 09/11] i2c: imx-lpi2c: fix i2c timing issue
Date: Wed, 17 Mar 2021 14:53:57 +0800 [thread overview]
Message-ID: <20210317065359.3109394-10-xiaoning.wang@nxp.com> (raw)
In-Reply-To: <20210317065359.3109394-1-xiaoning.wang@nxp.com>
The clkhi and clklo ratio was not very precise before that can make the
time of START/STOP/HIGH LEVEL out of specification.
Therefore, the calculation of these times has been modified in this patch.
At the same time, the mode rate definition of i2c is corrected.
Reviewed-by: Fugang Duan <fugang.duan@nxp.com>
Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
---
drivers/i2c/busses/i2c-imx-lpi2c.c | 27 ++++++++++++++-------------
1 file changed, 14 insertions(+), 13 deletions(-)
diff --git a/drivers/i2c/busses/i2c-imx-lpi2c.c b/drivers/i2c/busses/i2c-imx-lpi2c.c
index 7216a393095d..5dbe85126f24 100644
--- a/drivers/i2c/busses/i2c-imx-lpi2c.c
+++ b/drivers/i2c/busses/i2c-imx-lpi2c.c
@@ -73,17 +73,17 @@
#define MCFGR1_IGNACK BIT(9)
#define MRDR_RXEMPTY BIT(14)
-#define I2C_CLK_RATIO 2
+#define I2C_CLK_RATIO 24 / 59
#define CHUNK_DATA 256
#define I2C_PM_TIMEOUT 1000 /* ms */
enum lpi2c_imx_mode {
- STANDARD, /* 100+Kbps */
- FAST, /* 400+Kbps */
- FAST_PLUS, /* 1.0+Mbps */
- HS, /* 3.4+Mbps */
- ULTRA_FAST, /* 5.0+Mbps */
+ STANDARD, /* <=100Kbps */
+ FAST, /* <=400Kbps */
+ FAST_PLUS, /* <=1.0Mbps */
+ HS, /* <=3.4Mbps */
+ ULTRA_FAST, /* <=5.0Mbps */
};
enum lpi2c_imx_pincfg {
@@ -156,13 +156,13 @@ static void lpi2c_imx_set_mode(struct lpi2c_imx_struct *lpi2c_imx)
unsigned int bitrate = lpi2c_imx->bitrate;
enum lpi2c_imx_mode mode;
- if (bitrate < I2C_MAX_FAST_MODE_FREQ)
+ if (bitrate <= I2C_MAX_STANDARD_MODE_FREQ)
mode = STANDARD;
- else if (bitrate < I2C_MAX_FAST_MODE_PLUS_FREQ)
+ else if (bitrate <= I2C_MAX_FAST_MODE_FREQ)
mode = FAST;
- else if (bitrate < I2C_MAX_HIGH_SPEED_MODE_FREQ)
+ else if (bitrate <= I2C_MAX_FAST_MODE_PLUS_FREQ)
mode = FAST_PLUS;
- else if (bitrate < I2C_MAX_ULTRA_FAST_MODE_FREQ)
+ else if (bitrate <= I2C_MAX_HIGH_SPEED_MODE_FREQ)
mode = HS;
else
mode = ULTRA_FAST;
@@ -209,7 +209,8 @@ static void lpi2c_imx_stop(struct lpi2c_imx_struct *lpi2c_imx)
} while (1);
}
-/* CLKLO = I2C_CLK_RATIO * CLKHI, SETHOLD = CLKHI, DATAVD = CLKHI/2 */
+/* CLKLO = (1 - I2C_CLK_RATIO) * clk_cycle, SETHOLD = CLKHI, DATAVD = CLKHI/2
+ CLKHI = I2C_CLK_RATIO * clk_cycle */
static int lpi2c_imx_config(struct lpi2c_imx_struct *lpi2c_imx)
{
u8 prescale, filt, sethold, clkhi, clklo, datavd;
@@ -232,8 +233,8 @@ static int lpi2c_imx_config(struct lpi2c_imx_struct *lpi2c_imx)
for (prescale = 0; prescale <= 7; prescale++) {
clk_cycle = clk_rate / ((1 << prescale) * lpi2c_imx->bitrate)
- - 3 - (filt >> 1);
- clkhi = (clk_cycle + I2C_CLK_RATIO) / (I2C_CLK_RATIO + 1);
+ - (2 + filt) / (1 << prescale);
+ clkhi = clk_cycle * I2C_CLK_RATIO;
clklo = clk_cycle - clkhi;
if (clklo < 64)
break;
--
2.25.1
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next prev parent reply other threads:[~2021-03-17 6:58 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-17 6:53 [PATCH 00/11] i2c: imx-lpi2c: New features and bug fixes Clark Wang
2021-03-17 6:53 ` [PATCH 01/11] i2c: imx-lpi2c: directly retrun ISR when detect a NACK Clark Wang
2021-03-19 4:25 ` Aisheng Dong
2021-03-17 6:53 ` [PATCH 02/11] i2c: imx-lpi2c: add runtime pm support Clark Wang
2021-03-19 4:40 ` Aisheng Dong
2021-03-19 5:33 ` Clark Wang
2021-03-19 6:16 ` Clark Wang
2021-03-19 8:00 ` Clark Wang
2021-03-19 10:26 ` Aisheng Dong
2021-03-17 6:53 ` [PATCH 03/11] i2c: imx-lpi2c: add ipg clk for lpi2c driver Clark Wang
2021-03-19 4:46 ` Aisheng Dong
2021-03-19 6:23 ` Clark Wang
2021-03-19 9:18 ` Aisheng Dong
2021-03-17 6:53 ` [PATCH 04/11] i2c: imx-lpi2c: manage irq resource request/release in runtime pm Clark Wang
2021-03-19 4:53 ` Aisheng Dong
2021-03-19 7:03 ` Clark Wang
2021-03-19 10:12 ` Aisheng Dong
2021-03-17 6:53 ` [PATCH 05/11] i2c: imx-lpi2c: add debug message when i2c peripheral clk doesn't work Clark Wang
2021-03-19 4:56 ` Aisheng Dong
2021-03-19 7:07 ` Clark Wang
2021-03-17 6:53 ` [PATCH 06/11] i2c: imx-lpi2c: improve i2c driver probe priority Clark Wang
2021-03-19 5:05 ` Aisheng Dong
2021-03-19 5:38 ` Wolfram Sang
2021-03-19 7:39 ` [EXT] " Clark Wang
2021-03-17 6:53 ` [PATCH 07/11] i2c: imx-lpi2c: increase PM timeout to avoid operate clk frequently Clark Wang
2021-03-19 5:10 ` Aisheng Dong
2021-03-17 6:53 ` [PATCH 08/11] i2c: imx-lpi2c: add bus recovery feature Clark Wang
2021-03-19 5:11 ` Aisheng Dong
2021-03-17 6:53 ` Clark Wang [this message]
2021-03-19 5:15 ` [PATCH 09/11] i2c: imx-lpi2c: fix i2c timing issue Aisheng Dong
2021-03-19 7:21 ` Clark Wang
2021-03-17 6:53 ` [PATCH 10/11] i2c: imx-lpi2c: fix type char overflow issue when calculating the clock cycle Clark Wang
2021-03-19 5:16 ` Aisheng Dong
2021-03-17 6:53 ` [PATCH 11/11] i2c: imx-lpi2c: add edma mode support Clark Wang
2021-03-19 5:28 ` Aisheng Dong
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