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| author | Carlos Song <carlos.song@nxp.com> | 2024-07-19 10:02:33 +0200 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2024-09-17 16:48:40 +0200 |
| commit | 96267f358c14e88e07f1d96ed6f1827da59e9ecc (patch) | |
| tree | fb75c23edc74b0f99eb1e556fb2d931d7c6b4ead /drivers/i3c | |
| parent | i3c: master: svc: use slow speed for first broadcast address (diff) | |
| download | linux-96267f358c14e88e07f1d96ed6f1827da59e9ecc.tar.xz linux-96267f358c14e88e07f1d96ed6f1827da59e9ecc.zip | |
i3c: master: svc: adjust SDR according to i3c spec
According to I3C Specification(Version 1.1) 5.1.2.4 "Use of Clock
Speed to Prevent Legacy I2C Devices From Seeing I3C traffic", when
slow i2c devices(FM/FM+ rate i2c frequency without 50ns filter)
works on i3c bus, i3c SDR should work at FM/FM+ rate.
Adjust timing for difference mode.
Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Carlos Song <carlos.song@nxp.com>
Signed-off-by: Frank Li <frank.li@nxp.com>
Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20240719080233.842771-1-carlos.song@nxp.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Diffstat (limited to 'drivers/i3c')
| -rw-r--r-- | drivers/i3c/master/svc-i3c-master.c | 31 |
1 files changed, 22 insertions, 9 deletions
diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c index 8ad0421e7a2e..423db3dca257 100644 --- a/drivers/i3c/master/svc-i3c-master.c +++ b/drivers/i3c/master/svc-i3c-master.c @@ -127,6 +127,8 @@ /* This parameter depends on the implementation and may be tuned */ #define SVC_I3C_FIFO_SIZE 16 +#define SVC_I3C_PPBAUD_MAX 15 +#define SVC_I3C_QUICK_I2C_CLK 4170000 #define SVC_I3C_EVENT_IBI BIT(0) #define SVC_I3C_EVENT_HOTJOIN BIT(1) @@ -585,6 +587,7 @@ static int svc_i3c_master_bus_init(struct i3c_master_controller *m) struct i3c_bus *bus = i3c_master_get_bus(m); struct i3c_device_info info = {}; unsigned long fclk_rate, fclk_period_ns; + unsigned long i2c_period_ns, i2c_scl_rate, i3c_scl_rate; unsigned int high_period_ns, od_low_period_ns; u32 ppbaud, pplow, odhpp, odbaud, odstop, i2cbaud, reg; int ret; @@ -605,12 +608,15 @@ static int svc_i3c_master_bus_init(struct i3c_master_controller *m) } fclk_period_ns = DIV_ROUND_UP(1000000000, fclk_rate); + i2c_period_ns = DIV_ROUND_UP(1000000000, bus->scl_rate.i2c); + i2c_scl_rate = bus->scl_rate.i2c; + i3c_scl_rate = bus->scl_rate.i3c; /* * Using I3C Push-Pull mode, target is 12.5MHz/80ns period. * Simplest configuration is using a 50% duty-cycle of 40ns. */ - ppbaud = DIV_ROUND_UP(40, fclk_period_ns) - 1; + ppbaud = DIV_ROUND_UP(fclk_rate / 2, i3c_scl_rate) - 1; pplow = 0; /* @@ -620,7 +626,7 @@ static int svc_i3c_master_bus_init(struct i3c_master_controller *m) */ odhpp = 1; high_period_ns = (ppbaud + 1) * fclk_period_ns; - odbaud = DIV_ROUND_UP(240 - high_period_ns, high_period_ns) - 1; + odbaud = DIV_ROUND_UP(fclk_rate, SVC_I3C_QUICK_I2C_CLK * (1 + ppbaud)) - 2; od_low_period_ns = (odbaud + 1) * high_period_ns; switch (bus->mode) { @@ -629,20 +635,27 @@ static int svc_i3c_master_bus_init(struct i3c_master_controller *m) odstop = 0; break; case I3C_BUS_MODE_MIXED_FAST: - case I3C_BUS_MODE_MIXED_LIMITED: /* * Using I2C Fm+ mode, target is 1MHz/1000ns, the difference * between the high and low period does not really matter. */ - i2cbaud = DIV_ROUND_UP(1000, od_low_period_ns) - 2; + i2cbaud = DIV_ROUND_UP(i2c_period_ns, od_low_period_ns) - 2; odstop = 1; break; + case I3C_BUS_MODE_MIXED_LIMITED: case I3C_BUS_MODE_MIXED_SLOW: - /* - * Using I2C Fm mode, target is 0.4MHz/2500ns, with the same - * constraints as the FM+ mode. - */ - i2cbaud = DIV_ROUND_UP(2500, od_low_period_ns) - 2; + /* I3C PP + I3C OP + I2C OP both use i2c clk rate */ + if (ppbaud > SVC_I3C_PPBAUD_MAX) { + ppbaud = SVC_I3C_PPBAUD_MAX; + pplow = DIV_ROUND_UP(fclk_rate, i3c_scl_rate) - (2 + 2 * ppbaud); + } + + high_period_ns = (ppbaud + 1) * fclk_period_ns; + odhpp = 0; + odbaud = DIV_ROUND_UP(fclk_rate, i2c_scl_rate * (2 + 2 * ppbaud)) - 1; + + od_low_period_ns = (odbaud + 1) * high_period_ns; + i2cbaud = DIV_ROUND_UP(i2c_period_ns, od_low_period_ns) - 2; odstop = 1; break; default: |