diff mbox series

[v3,08/11] i2c: riic: Add support for fast mode plus

Message ID 20240711115207.2843133-9-claudiu.beznea.uj@bp.renesas.com
State Superseded
Headers show
Series i2c: riic: Add support for Renesas RZ/G3S | expand

Commit Message

Claudiu July 11, 2024, 11:52 a.m. UTC 
From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>

Fast mode plus is available on most of the IP variants that RIIC driver
is working with. The exception is (according to HW manuals of the SoCs
where this IP is available) the Renesas RZ/A1H. For this, patch
introduces the struct riic_of_data::fast_mode_plus.

Fast mode plus was tested on RZ/G3S, RZ/G2{L,UL,LC}, RZ/Five by
instantiating the RIIC frequency to 1MHz and issuing i2c reads on the
fast mode plus capable devices (and the i2c clock frequency was checked on
RZ/G3S).

Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
---

Changes in v3:
- enabled FM+ for all riic_rz_a_info based platforms except RZ/A1H
  as requested in review comments; with this, dropped the riic_rz_g2_info
  and RZ/G2 specific compatibles in riic_i2c_dt_ids[];

  Note that it has been tested only on platforms mentioned in commit
  description (as I don't have all the other RZ/A platforms).

Changes in v2:
- dropped code that handles the renesas,riic-no-fast-mode-plus
- updated commit description

 drivers/i2c/busses/i2c-riic.c | 25 ++++++++++++++++++++++---
 1 file changed, 22 insertions(+), 3 deletions(-)

Comments

Wolfram Sang Aug. 8, 2024, 3:25 p.m. UTC | #1 
> +	if (info->fast_mode_plus && t->bus_freq_hz == I2C_MAX_FAST_MODE_PLUS_FREQ)
> +		riic_clear_set_bit(riic, 0, ICFER_FMPE, RIIC_ICFER);

Shouldn't that be something like

	t->bus_freq_hz > I2C_MAX_FAST_MODE_FREQ

? On R-Car, we have to enable the FM+ bit as soon as we exceed plain
FastMode bus speeds.
Claudiu Aug. 9, 2024, 7:24 a.m. UTC | #2 
On 08.08.2024 18:25, Wolfram Sang wrote:
> 
>> +	if (info->fast_mode_plus && t->bus_freq_hz == I2C_MAX_FAST_MODE_PLUS_FREQ)
>> +		riic_clear_set_bit(riic, 0, ICFER_FMPE, RIIC_ICFER);
> 
> Shouldn't that be something like
> 
> 	t->bus_freq_hz > I2C_MAX_FAST_MODE_FREQ

You're right, it should be.

Looking though the HW manual, it specifies this about FPM bit: "Set this
bit to 1 when using the transmission rate within a range up to 1 Mbps".

Thank  you,
Claudiu Beznea

> 
> ? On R-Car, we have to enable the FM+ bit as soon as we exceed plain
> FastMode bus speeds.
>
diff mbox series

Patch

diff --git a/drivers/i2c/busses/i2c-riic.c b/drivers/i2c/busses/i2c-riic.c
index 0019a8e56dbb..ba969ad5f015 100644
--- a/drivers/i2c/busses/i2c-riic.c
+++ b/drivers/i2c/busses/i2c-riic.c
@@ -63,6 +63,8 @@ 
 #define ICMR3_ACKWP	0x10
 #define ICMR3_ACKBT	0x08
 
+#define ICFER_FMPE	0x80
+
 #define ICIER_TIE	0x80
 #define ICIER_TEIE	0x40
 #define ICIER_RIE	0x20
@@ -80,6 +82,7 @@  enum riic_reg_list {
 	RIIC_ICCR2,
 	RIIC_ICMR1,
 	RIIC_ICMR3,
+	RIIC_ICFER,
 	RIIC_ICSER,
 	RIIC_ICIER,
 	RIIC_ICSR2,
@@ -92,6 +95,7 @@  enum riic_reg_list {
 
 struct riic_of_data {
 	const u8 *regs;
+	bool fast_mode_plus;
 };
 
 struct riic_dev {
@@ -311,11 +315,14 @@  static int riic_init_hw(struct riic_dev *riic)
 	int total_ticks, cks, brl, brh;
 	struct i2c_timings *t = &riic->i2c_t;
 	struct device *dev = riic->adapter.dev.parent;
+	const struct riic_of_data *info = riic->info;
 
-	if (t->bus_freq_hz > I2C_MAX_FAST_MODE_FREQ) {
+	if ((!info->fast_mode_plus && t->bus_freq_hz > I2C_MAX_FAST_MODE_FREQ) ||
+	    (info->fast_mode_plus && t->bus_freq_hz > I2C_MAX_FAST_MODE_PLUS_FREQ)) {
 		dev_err(&riic->adapter.dev,
-			"unsupported bus speed (%dHz). %d max\n",
-			t->bus_freq_hz, I2C_MAX_FAST_MODE_FREQ);
+			"unsupported bus speed (%dHz). %d max\n", t->bus_freq_hz,
+			info->fast_mode_plus ? I2C_MAX_FAST_MODE_PLUS_FREQ :
+			I2C_MAX_FAST_MODE_FREQ);
 		return -EINVAL;
 	}
 
@@ -401,6 +408,9 @@  static int riic_init_hw(struct riic_dev *riic)
 	riic_writeb(riic, 0, RIIC_ICSER);
 	riic_writeb(riic, ICMR3_ACKWP | ICMR3_RDRFS, RIIC_ICMR3);
 
+	if (info->fast_mode_plus && t->bus_freq_hz == I2C_MAX_FAST_MODE_PLUS_FREQ)
+		riic_clear_set_bit(riic, 0, ICFER_FMPE, RIIC_ICFER);
+
 	riic_clear_set_bit(riic, ICCR1_IICRST, 0, RIIC_ICCR1);
 
 	pm_runtime_mark_last_busy(dev);
@@ -526,6 +536,7 @@  static const u8 riic_rz_a_regs[RIIC_REG_END] = {
 	[RIIC_ICCR2] = 0x04,
 	[RIIC_ICMR1] = 0x08,
 	[RIIC_ICMR3] = 0x10,
+	[RIIC_ICFER] = 0x14,
 	[RIIC_ICSER] = 0x18,
 	[RIIC_ICIER] = 0x1c,
 	[RIIC_ICSR2] = 0x24,
@@ -537,6 +548,11 @@  static const u8 riic_rz_a_regs[RIIC_REG_END] = {
 
 static const struct riic_of_data riic_rz_a_info = {
 	.regs = riic_rz_a_regs,
+	.fast_mode_plus = true,
+};
+
+static const struct riic_of_data riic_rz_a1h_info = {
+	.regs = riic_rz_a_regs,
 };
 
 static const u8 riic_rz_v2h_regs[RIIC_REG_END] = {
@@ -544,6 +560,7 @@  static const u8 riic_rz_v2h_regs[RIIC_REG_END] = {
 	[RIIC_ICCR2] = 0x01,
 	[RIIC_ICMR1] = 0x02,
 	[RIIC_ICMR3] = 0x04,
+	[RIIC_ICFER] = 0x05,
 	[RIIC_ICSER] = 0x06,
 	[RIIC_ICIER] = 0x07,
 	[RIIC_ICSR2] = 0x09,
@@ -555,6 +572,7 @@  static const u8 riic_rz_v2h_regs[RIIC_REG_END] = {
 
 static const struct riic_of_data riic_rz_v2h_info = {
 	.regs = riic_rz_v2h_regs,
+	.fast_mode_plus = true,
 };
 
 static int riic_i2c_suspend(struct device *dev)
@@ -603,6 +621,7 @@  static const struct dev_pm_ops riic_i2c_pm_ops = {
 
 static const struct of_device_id riic_i2c_dt_ids[] = {
 	{ .compatible = "renesas,riic-rz", .data = &riic_rz_a_info },
+	{ .compatible = "renesas,riic-r7s72100", .data =  &riic_rz_a1h_info, },
 	{ .compatible = "renesas,riic-r9a09g057", .data = &riic_rz_v2h_info },
 	{ /* Sentinel */ },
 };