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| author | Tom Rini <trini@konsulko.com> | 2025-01-08 14:19:22 -0600 |
|---|---|---|
| committer | Tom Rini <trini@konsulko.com> | 2025-01-08 14:19:22 -0600 |
| commit | 3bfd12008bef1a8353e7ceaca2cb06cf388527ed (patch) | |
| tree | ac25e8db2f18bcba9f48518249fc020a05cb576c /drivers/serial/serial_omap.c | |
| parent | 6d41f0a39d6423c8e57e92ebbe9f8c0333a63f72 (diff) | |
| parent | d6da3dbaef57fc1d319b6b552efa009e2489d7d9 (diff) | |
Merge branch 'next'
Diffstat (limited to 'drivers/serial/serial_omap.c')
| -rw-r--r-- | drivers/serial/serial_omap.c | 56 |
1 files changed, 55 insertions, 1 deletions
diff --git a/drivers/serial/serial_omap.c b/drivers/serial/serial_omap.c index 94672655c28..224d9cbf29d 100644 --- a/drivers/serial/serial_omap.c +++ b/drivers/serial/serial_omap.c @@ -15,6 +15,12 @@ #include <clk.h> #include <linux/err.h> +/* + * These are the definitions for the MDR1 register + */ +#define UART_OMAP_MDR1_16X_MODE 0x00 /* UART 16x mode */ +#define UART_OMAP_MDR1_13X_MODE 0x03 /* UART 13x mode */ + #ifndef CFG_SYS_NS16550_CLK #define CFG_SYS_NS16550_CLK 0 #endif @@ -151,6 +157,54 @@ static const struct udevice_id omap_serial_ids[] = { }; #endif /* OF_REAL */ +static int omap_serial_calc_divisor(struct ns16550 *com_port, int clock, int baudrate) +{ + unsigned int div_13, div_16; + unsigned int abs_d13, abs_d16; + /* + * The below logic sets the MDR1 register based on clock and baudrate. + */ + div_13 = DIV_ROUND_CLOSEST(clock, 13 * baudrate); + div_16 = DIV_ROUND_CLOSEST(clock, 16 * baudrate); + + if (!div_13) + div_13 = 1; + if (!div_16) + div_16 = 1; + + abs_d13 = abs(baudrate - clock / 13 / div_13); + abs_d16 = abs(baudrate - clock / 16 / div_16); + + if (abs_d13 >= abs_d16) + serial_out(UART_OMAP_MDR1_16X_MODE, &com_port->mdr1); + else + serial_out(UART_OMAP_MDR1_13X_MODE, &com_port->mdr1); + + return abs_d13 >= abs_d16 ? div_16 : div_13; +} + +static int omap_serial_setbrg(struct udevice *dev, int baudrate) +{ + struct ns16550 *const com_port = dev_get_priv(dev); + struct ns16550_plat *plat = com_port->plat; + int clock_divisor; + + clock_divisor = omap_serial_calc_divisor(com_port, plat->clock, baudrate); + + ns16550_setbrg(com_port, clock_divisor); + + return 0; +} + +const struct dm_serial_ops omap_serial_ops = { + .putc = ns16550_serial_putc, + .pending = ns16550_serial_pending, + .getc = ns16550_serial_getc, + .setbrg = omap_serial_setbrg, + .setconfig = ns16550_serial_setconfig, + .getinfo = ns16550_serial_getinfo, +}; + #if CONFIG_IS_ENABLED(SERIAL_PRESENT) U_BOOT_DRIVER(omap_serial) = { .name = "omap_serial", @@ -162,7 +216,7 @@ U_BOOT_DRIVER(omap_serial) = { #endif .priv_auto = sizeof(struct ns16550), .probe = ns16550_serial_probe, - .ops = &ns16550_serial_ops, + .ops = &omap_serial_ops, #if !CONFIG_IS_ENABLED(OF_CONTROL) .flags = DM_FLAG_PRE_RELOC, #endif |