* [PATCH v2 1/2] i2c: rcar: introduce Gen4 devices
2023-12-14 7:43 [PATCH v2 0/2] i2c: rcar: add support for Gen4 devices Wolfram Sang
@ 2023-12-14 7:43 ` Wolfram Sang
2023-12-14 8:03 ` Geert Uytterhoeven
2023-12-14 20:47 ` Andi Shyti
2023-12-14 7:43 ` [PATCH v2 2/2] i2c: rcar: add FastMode+ support for Gen4 Wolfram Sang
2023-12-19 12:42 ` [PATCH v2 0/2] i2c: rcar: add support for Gen4 devices Wolfram Sang
2 siblings, 2 replies; 9+ messages in thread
From: Wolfram Sang @ 2023-12-14 7:43 UTC (permalink / raw)
To: linux-renesas-soc
Cc: Wolfram Sang, Andi Shyti, Geert Uytterhoeven, Magnus Damm,
linux-i2c, linux-kernel
So far, we treated Gen4 as Gen3. But we are soon adding FM+ as a Gen4
specific feature, so prepare the code for the new devtype.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
Changes since v1:
* rebased to 6.7-rc4
* moved S4 specific handling to patch 2
drivers/i2c/busses/i2c-rcar.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
index 829ac053bbb7..973811a6c27b 100644
--- a/drivers/i2c/busses/i2c-rcar.c
+++ b/drivers/i2c/busses/i2c-rcar.c
@@ -132,6 +132,7 @@ enum rcar_i2c_type {
I2C_RCAR_GEN1,
I2C_RCAR_GEN2,
I2C_RCAR_GEN3,
+ I2C_RCAR_GEN4,
};
struct rcar_i2c_priv {
@@ -431,8 +432,8 @@ static void rcar_i2c_cleanup_dma(struct rcar_i2c_priv *priv, bool terminate)
dma_unmap_single(chan->device->dev, sg_dma_address(&priv->sg),
sg_dma_len(&priv->sg), priv->dma_direction);
- /* Gen3 can only do one RXDMA per transfer and we just completed it */
- if (priv->devtype == I2C_RCAR_GEN3 &&
+ /* Gen3+ can only do one RXDMA per transfer and we just completed it */
+ if (priv->devtype >= I2C_RCAR_GEN3 &&
priv->dma_direction == DMA_FROM_DEVICE)
priv->flags |= ID_P_NO_RXDMA;
@@ -886,8 +887,8 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
if (ret < 0)
goto out;
- /* Gen3 needs a reset before allowing RXDMA once */
- if (priv->devtype == I2C_RCAR_GEN3) {
+ /* Gen3+ needs a reset. That also allows RXDMA once */
+ if (priv->devtype >= I2C_RCAR_GEN3) {
priv->flags &= ~ID_P_NO_RXDMA;
ret = rcar_i2c_do_reset(priv);
if (ret)
@@ -1075,7 +1076,7 @@ static const struct of_device_id rcar_i2c_dt_ids[] = {
{ .compatible = "renesas,rcar-gen1-i2c", .data = (void *)I2C_RCAR_GEN1 },
{ .compatible = "renesas,rcar-gen2-i2c", .data = (void *)I2C_RCAR_GEN2 },
{ .compatible = "renesas,rcar-gen3-i2c", .data = (void *)I2C_RCAR_GEN3 },
- { .compatible = "renesas,rcar-gen4-i2c", .data = (void *)I2C_RCAR_GEN3 },
+ { .compatible = "renesas,rcar-gen4-i2c", .data = (void *)I2C_RCAR_GEN4 },
{},
};
MODULE_DEVICE_TABLE(of, rcar_i2c_dt_ids);
@@ -1151,7 +1152,7 @@ static int rcar_i2c_probe(struct platform_device *pdev)
if (of_property_read_bool(dev->of_node, "smbus"))
priv->flags |= ID_P_HOST_NOTIFY;
- if (priv->devtype == I2C_RCAR_GEN3) {
+ if (priv->devtype >= I2C_RCAR_GEN3) {
priv->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
if (IS_ERR(priv->rstc)) {
ret = PTR_ERR(priv->rstc);
--
2.35.1
^ permalink raw reply related [flat|nested] 9+ messages in thread* [PATCH v2 2/2] i2c: rcar: add FastMode+ support for Gen4
2023-12-14 7:43 [PATCH v2 0/2] i2c: rcar: add support for Gen4 devices Wolfram Sang
2023-12-14 7:43 ` [PATCH v2 1/2] i2c: rcar: introduce " Wolfram Sang
@ 2023-12-14 7:43 ` Wolfram Sang
2023-12-14 8:19 ` Geert Uytterhoeven
2023-12-14 20:54 ` Andi Shyti
2023-12-19 12:42 ` [PATCH v2 0/2] i2c: rcar: add support for Gen4 devices Wolfram Sang
2 siblings, 2 replies; 9+ messages in thread
From: Wolfram Sang @ 2023-12-14 7:43 UTC (permalink / raw)
To: linux-renesas-soc
Cc: Wolfram Sang, Andi Shyti, Geert Uytterhoeven, Magnus Damm,
linux-i2c, linux-kernel
To support FM+, we mainly need to turn the SMD constant into a parameter
and set it accordingly. That also means we can finally fix SMD to our
needs instead of bailing out. A sanity check for SMD then becomes a
sanity check for 'x == 0'. After all that, activating the enable bit for
FM+ is all we need to do. Tested with a Renesas Falcon board using R-Car
V3U.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
Changes since v1:
* rebased to 6.7-rc4
* gained S4 specific handling from patch 1
* keep SCL filters active for FM+ by still writing to CDF
* if default SMD is too large, fix it instead of bailing out
drivers/i2c/busses/i2c-rcar.c | 38 +++++++++++++++++++++++++----------
1 file changed, 27 insertions(+), 11 deletions(-)
diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
index 973811a6c27b..828aa2ea0fe4 100644
--- a/drivers/i2c/busses/i2c-rcar.c
+++ b/drivers/i2c/busses/i2c-rcar.c
@@ -89,6 +89,7 @@
#define TMDMAE BIT(0) /* DMA Master Transmitted Enable */
/* ICCCR2 */
+#define FMPE BIT(7) /* Fast Mode Plus Enable */
#define CDFD BIT(2) /* CDF Disable */
#define HLSE BIT(1) /* HIGH/LOW Separate Control Enable */
#define SME BIT(0) /* SCL Mask Enable */
@@ -122,11 +123,12 @@
#define ID_NACK BIT(4)
#define ID_EPROTO BIT(5)
/* persistent flags */
+#define ID_P_FMPLUS BIT(27)
#define ID_P_NOT_ATOMIC BIT(28)
#define ID_P_HOST_NOTIFY BIT(29)
#define ID_P_NO_RXDMA BIT(30) /* HW forbids RXDMA sometimes */
#define ID_P_PM_BLOCKED BIT(31)
-#define ID_P_MASK GENMASK(31, 28)
+#define ID_P_MASK GENMASK(31, 27)
enum rcar_i2c_type {
I2C_RCAR_GEN1,
@@ -149,6 +151,7 @@ struct rcar_i2c_priv {
u32 icccr;
u16 schd;
u16 scld;
+ u8 smd;
u8 recovery_icmcr; /* protected by adapter lock */
enum rcar_i2c_type devtype;
struct i2c_client *slave;
@@ -240,9 +243,14 @@ static void rcar_i2c_init(struct rcar_i2c_priv *priv)
if (priv->devtype < I2C_RCAR_GEN3) {
rcar_i2c_write(priv, ICCCR, priv->icccr);
} else {
- rcar_i2c_write(priv, ICCCR2, CDFD | HLSE | SME);
+ u32 icccr2 = CDFD | HLSE | SME;
+
+ if (priv->flags & ID_P_FMPLUS)
+ icccr2 |= FMPE;
+
+ rcar_i2c_write(priv, ICCCR2, icccr2);
rcar_i2c_write(priv, ICCCR, priv->icccr);
- rcar_i2c_write(priv, ICMPR, RCAR_DEFAULT_SMD);
+ rcar_i2c_write(priv, ICMPR, priv->smd);
rcar_i2c_write(priv, ICHPR, priv->schd);
rcar_i2c_write(priv, ICLPR, priv->scld);
rcar_i2c_write(priv, ICFBSCR, TCYC17);
@@ -279,6 +287,7 @@ static int rcar_i2c_clock_calculate(struct rcar_i2c_priv *priv)
/* Fall back to previously used values if not supplied */
i2c_parse_fw_timings(dev, &t, false);
+ priv->smd = RCAR_DEFAULT_SMD;
/*
* calculate SCL clock
@@ -304,6 +313,11 @@ static int rcar_i2c_clock_calculate(struct rcar_i2c_priv *priv)
if (cdf >= 1U << cdf_width)
goto err_no_val;
+ if (t.bus_freq_hz > I2C_MAX_FAST_MODE_FREQ && priv->devtype >= I2C_RCAR_GEN4)
+ priv->flags |= ID_P_FMPLUS;
+ else
+ priv->flags &= ~ID_P_FMPLUS;
+
/* On Gen3+, we use cdf only for the filters, not as a SCL divider */
ick = rate / (priv->devtype < I2C_RCAR_GEN3 ? (cdf + 1) : 1);
@@ -345,30 +359,30 @@ static int rcar_i2c_clock_calculate(struct rcar_i2c_priv *priv)
* x as a base value for the SCLD/SCHD ratio:
*
* SCL = clkp / (8 + 2 * SMD + SCLD + SCHD + F[(ticf + tr + intd) * clkp])
- * SCL = clkp / (8 + 2 * RCAR_DEFAULT_SMD + RCAR_SCLD_RATIO * x
+ * SCL = clkp / (8 + 2 * SMD + RCAR_SCLD_RATIO * x
* + RCAR_SCHD_RATIO * x + F[...])
*
* with: sum_ratio = RCAR_SCLD_RATIO + RCAR_SCHD_RATIO
- * and: smd = RCAR_DEFAULT_SMD
*
* SCL = clkp / (8 + 2 * smd + sum_ratio * x + F[...])
* 8 + 2 * smd + sum_ratio * x + F[...] = clkp / SCL
* x = ((clkp / SCL) - 8 - 2 * smd - F[...]) / sum_ratio
*/
x = DIV_ROUND_UP(rate, t.bus_freq_hz ?: 1);
- x = DIV_ROUND_UP(x - 8 - 2 * RCAR_DEFAULT_SMD - round, sum_ratio);
- scl = rate / (8 + 2 * RCAR_DEFAULT_SMD + sum_ratio * x + round);
+ x = DIV_ROUND_UP(x - 8 - 2 * priv->smd - round, sum_ratio);
+ scl = rate / (8 + 2 * priv->smd + sum_ratio * x + round);
- /* Bail out if values don't fit into 16 bit or SMD became too large */
- if (x * RCAR_SCLD_RATIO > 0xffff || RCAR_DEFAULT_SMD > x * RCAR_SCHD_RATIO)
+ if (x == 0 || x * RCAR_SCLD_RATIO > 0xffff)
goto err_no_val;
priv->icccr = cdf;
priv->schd = RCAR_SCHD_RATIO * x;
priv->scld = RCAR_SCLD_RATIO * x;
+ if (priv->smd >= priv->schd)
+ priv->smd = priv->schd - 1;
- dev_dbg(dev, "clk %u/%u(%lu), round %u, CDF: %u SCHD %u SCLD %u\n",
- scl, t.bus_freq_hz, rate, round, cdf, priv->schd, priv->scld);
+ dev_dbg(dev, "clk %u/%u(%lu), round %u, CDF: %u SCHD %u SCLD %u SMD %u\n",
+ scl, t.bus_freq_hz, rate, round, cdf, priv->schd, priv->scld, priv->smd);
}
return 0;
@@ -1073,6 +1087,8 @@ static const struct of_device_id rcar_i2c_dt_ids[] = {
{ .compatible = "renesas,i2c-r8a7794", .data = (void *)I2C_RCAR_GEN2 },
{ .compatible = "renesas,i2c-r8a7795", .data = (void *)I2C_RCAR_GEN3 },
{ .compatible = "renesas,i2c-r8a7796", .data = (void *)I2C_RCAR_GEN3 },
+ /* S4 has no FM+ bit */
+ { .compatible = "renesas,i2c-r8a779f0", .data = (void *)I2C_RCAR_GEN3 },
{ .compatible = "renesas,rcar-gen1-i2c", .data = (void *)I2C_RCAR_GEN1 },
{ .compatible = "renesas,rcar-gen2-i2c", .data = (void *)I2C_RCAR_GEN2 },
{ .compatible = "renesas,rcar-gen3-i2c", .data = (void *)I2C_RCAR_GEN3 },
--
2.35.1
^ permalink raw reply related [flat|nested] 9+ messages in thread