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

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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: Carlos Song <carlos.song@nxp.com>
Reviewed-by: Frank Li <frank.li@nxp.com>
Link: https://lore.kernel.org/r/20240910051626.4052552-2-carlos.song@nxp.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
This commit is contained in:
Carlos Song 2024-09-10 13:16:26 +08:00 committed by Alexandre Belloni
parent aef79e189b
commit 20ade67bb1
1 changed files with 52 additions and 0 deletions
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52
drivers/i3c/master/svc-i3c-master.c
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@ -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)