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authorWolfram Sang <wsa+renesas@sang-engineering.com>2023-12-14 10:43:58 +0300
committerWolfram Sang <wsa@kernel.org>2024-01-18 23:10:42 +0300
commitd0520eb3ed54df89eb5961ec3b88634f313123f2 (patch)
tree2140b3acb9130806e616442124e4844f8d803be1 /drivers/i2c
parent2b523c46e81ebd621515ab47117f95de197dfcbf (diff)
downloadlinux-d0520eb3ed54df89eb5961ec3b88634f313123f2.tar.xz
i2c: rcar: add FastMode+ support for Gen4
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> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Andi Shyti <andi.shyti@kernel.org> Signed-off-by: Wolfram Sang <wsa@kernel.org>
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/busses/i2c-rcar.c38
1 files 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 },