From: Kewei Xu <kewei.xu@mediatek.com>
To: <wsa@the-dreams.de>
Cc: <matthias.bgg@gmail.com>, <robh+dt@kernel.org>,
<linux-i2c@vger.kernel.org>, <devicetree@vger.kernel.org>,
<linux-arm-kernel@lists.infradead.org>,
<linux-kernel@vger.kernel.org>,
<linux-mediatek@lists.infradead.org>,
<srv_heupstream@mediatek.com>, <leilk.liu@mediatek.com>,
<qii.wang@mediatek.com>, <liguo.zhang@mediatek.com>,
<caiyu.chen@mediatek.com>, <ot_daolong.zhu@mediatek.com>,
<yuhan.wei@mediatek.com>, <kewei.xu@mediatek.com>
Subject: [RESEND PATCH v5 6/7] i2c: mediatek: Isolate speed setting via dts for special devices
Date: Tue, 24 Aug 2021 11:30:27 +0800 [thread overview]
Message-ID: <1629775828-19993-7-git-send-email-kewei.xu@mediatek.com> (raw)
In-Reply-To: <1629775828-19993-1-git-send-email-kewei.xu@mediatek.com>
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 <kewei.xu@mediatek.com>
---
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
next prev parent reply other threads:[~2021-08-24 3:30 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-24 3:30 [RESEND PATCH v5 0/7] Introducing an attribute to select the time setting Kewei Xu
2021-08-24 3:30 ` [RESEND PATCH v5 1/7] i2c: mediatek: fixing the incorrect register offset Kewei Xu
2021-08-24 3:30 ` [RESEND PATCH v5 2/7] i2c: mediatek: Reset the handshake signal between i2c and dma Kewei Xu
2021-08-24 3:30 ` [RESEND PATCH v5 3/7] i2c: mediatek: Dump i2c/dma register when a timeout occurs Kewei Xu
2021-08-24 3:30 ` [RESEND PATCH v5 4/7] dt-bindings: i2c: add attribute use-default-timing Kewei Xu
2021-08-24 16:52 ` Rob Herring
2021-08-24 3:30 ` [RESEND PATCH v5 5/7] i2c: mediatek: Add OFFSET_EXT_CONF setting back Kewei Xu
2021-08-24 3:30 ` Kewei Xu [this message]
2021-08-24 3:30 ` [RESEND PATCH v5 7/7] i2c: mediatek: modify bus speed calculation formula Kewei Xu
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