Commit 20ade67b authored by Carlos Song's avatar Carlos Song Committed by Alexandre Belloni
Browse files

i3c: master: svc: use slow speed for first broadcast address 



I3C controller should support adjusting open drain timing for the first
broadcast address to make I3C device working as a i2c device can see slow
broadcast address to close its Spike Filter to change working at i3c mode.

Signed-off-by: default avatarCarlos Song <carlos.song@nxp.com>
Reviewed-by: default avatarFrank Li <frank.li@nxp.com>
Link: https://lore.kernel.org/r/20240910051626.4052552-2-carlos.song@nxp.com


Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
parent aef79e18

drivers/i3c/master/svc-i3c-master.c

+52 −0
Original line number Diff line number Diff line
@@ -182,6 +182,7 @@ struct svc_i3c_regs_save { 
 * @ibi.lock: IBI lock

 * @lock: Transfer lock, protect between IBI work thread and callbacks from master

 * @enabled_events: Bit masks for enable events (IBI, HotJoin).

 * @mctrl_config: Configuration value in SVC_I3C_MCTRL for setting speed back.

 */

struct svc_i3c_master {

	struct i3c_master_controller base;
@@ -212,6 +213,7 @@ struct svc_i3c_master { 
	} ibi;

	struct mutex lock;

	int enabled_events;

	u32 mctrl_config;

};



/**
@@ -529,6 +531,54 @@ static irqreturn_t svc_i3c_master_irq_handler(int irq, void *dev_id) 
	return IRQ_HANDLED;

}



static int svc_i3c_master_set_speed(struct i3c_master_controller *m,

				     enum i3c_open_drain_speed speed)

{

	struct svc_i3c_master *master = to_svc_i3c_master(m);

	struct i3c_bus *bus = i3c_master_get_bus(&master->base);

	u32 ppbaud, odbaud, odhpp, mconfig;

	unsigned long fclk_rate;

	int ret;



	ret = pm_runtime_resume_and_get(master->dev);

	if (ret < 0) {

		dev_err(master->dev, "<%s> Cannot get runtime PM.\n", __func__);

		return ret;

	}



	switch (speed) {

	case I3C_OPEN_DRAIN_SLOW_SPEED:

		fclk_rate = clk_get_rate(master->fclk);

		if (!fclk_rate) {

			ret = -EINVAL;

			goto rpm_out;

		}

		/*

		 * Set 50% duty-cycle I2C speed to I3C OPEN-DRAIN mode, so the first

		 * broadcast address is visible to all I2C/I3C devices on the I3C bus.

		 * I3C device working as a I2C device will turn off its 50ns Spike

		 * Filter to change to I3C mode.

		 */

		mconfig = master->mctrl_config;

		ppbaud = FIELD_GET(GENMASK(11, 8), mconfig);

		odhpp = 0;

		odbaud = DIV_ROUND_UP(fclk_rate, bus->scl_rate.i2c * (2 + 2 * ppbaud)) - 1;

		mconfig &= ~GENMASK(24, 16);

		mconfig |= SVC_I3C_MCONFIG_ODBAUD(odbaud) | SVC_I3C_MCONFIG_ODHPP(odhpp);

		writel(mconfig, master->regs + SVC_I3C_MCONFIG);

		break;

	case I3C_OPEN_DRAIN_NORMAL_SPEED:

		writel(master->mctrl_config, master->regs + SVC_I3C_MCONFIG);

		break;

	}



rpm_out:

	pm_runtime_mark_last_busy(master->dev);

	pm_runtime_put_autosuspend(master->dev);



	return ret;

}



static int svc_i3c_master_bus_init(struct i3c_master_controller *m)

{

	struct svc_i3c_master *master = to_svc_i3c_master(m);
@@ -611,6 +661,7 @@ static int svc_i3c_master_bus_init(struct i3c_master_controller *m) 
	      SVC_I3C_MCONFIG_I2CBAUD(i2cbaud);

	writel(reg, master->regs + SVC_I3C_MCONFIG);



	master->mctrl_config = reg;

	/* Master core's registration */

	ret = i3c_master_get_free_addr(m, 0);

	if (ret < 0)
@@ -1645,6 +1696,7 @@ static const struct i3c_master_controller_ops svc_i3c_master_ops = { 
	.disable_ibi = svc_i3c_master_disable_ibi,

	.enable_hotjoin = svc_i3c_master_enable_hotjoin,

	.disable_hotjoin = svc_i3c_master_disable_hotjoin,

	.set_speed = svc_i3c_master_set_speed,

};



static int svc_i3c_master_prepare_clks(struct svc_i3c_master *master)