arm: s5p4418: dm_serial: add driver source code

Add dm_serial driver source code for S5P4418 SOC. Extend the "arm,pl011"
driver by init of UART-clock and UART-reset.

Signed-off-by: Stefan Bosch <stefan_b@posteo.net>

diff --git a/MAINTAINERS b/MAINTAINERS
index 3fc4cd0f12d3b8deae5681acb6713c59183bd912..5f9636f4e186d7cce6044565147757c62fce8ca7 100644 (file)
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -436,6 +436,7 @@ F:  drivers/gpio/nx_gpio.c
 F:     drivers/i2c/nx_i2c.c
 F:     drivers/mmc/nexell_dw_mmc_dm.c
 F:     drivers/pinctrl/nexell/
+F:     drivers/serial/serial_s5p4418_pl011.c
 F:     drivers/video/nexell/
 F:     drivers/video/nexell_display.c
 F:     include/configs/s5p4418_nanopi2.h

diff --git a/drivers/serial/serial_s5p4418_pl011.c b/drivers/serial/serial_s5p4418_pl011.c
new file mode 100644 (file)
index 0000000..e4492e6
--- /dev/null
+++ b/drivers/serial/serial_s5p4418_pl011.c
@@ -0,0 +1,94 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2022  Stefan Bosch <stefan_b@posteo.net>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <asm/arch/clk.h>
+#include <asm/arch/reset.h>
+#include <linux/delay.h>
+
+#include <dm/platform_data/serial_pl01x.h>
+#include <serial.h>
+#include "serial_pl01x_internal.h"
+
+int s5p4418_pl011_serial_probe(struct udevice *dev)
+{
+       struct pl01x_serial_plat *plat = dev_get_plat(dev);
+       struct clk *nx_clk;
+       ulong rate_act;
+       char uart_clk_name[10];
+       int uart_num = -1;
+       int rst_id, ret;
+
+       if (!plat->skip_init) {
+               uart_num = dev->seq_;
+               rst_id = RESET_ID_UART0 + uart_num;
+
+               if (uart_num < 0 || rst_id > RESET_ID_UART5) {
+                       /* invalid UART-number */
+                       debug("%s: sequence/uart number %d is invalid!\n", __func__, uart_num);
+                       return -ENODEV;
+               }
+
+               sprintf(uart_clk_name, "nx-uart.%d", uart_num);
+               nx_clk = clk_get(uart_clk_name);
+               if (!nx_clk) {
+                       debug("%s: clk_get('%s') failed!\n", __func__, uart_clk_name);
+                       return -ENODEV;
+               }
+
+               /* wait to make sure all pending characters have been sent */
+               mdelay(100);
+       }
+
+       /*
+        * Note: Unless !plat->skip_init, the UART is disabled here, so printf()
+        * or debug() must not be used until pl01x_serial_setbrg() has been called
+        * (enables the UART). Otherwise u-boot is hanging!
+        */
+       ret = pl01x_serial_probe(dev);
+       if (ret)
+               return ret;
+
+       if (!plat->skip_init) {
+               /* do reset UART */
+               nx_rstcon_setrst(rst_id, RSTCON_ASSERT);
+               udelay(10);
+               nx_rstcon_setrst(rst_id, RSTCON_NEGATE);
+               udelay(10);
+               clk_disable(nx_clk);
+
+               rate_act = clk_set_rate(nx_clk, plat->clock);
+               clk_enable(nx_clk);
+
+               plat->clock = rate_act;
+       }
+
+       return 0;
+}
+
+static const struct dm_serial_ops s5p4418_pl011_serial_ops = {
+       .putc = pl01x_serial_putc,
+       .pending = pl01x_serial_pending,
+       .getc = pl01x_serial_getc,
+       .setbrg = pl01x_serial_setbrg,
+};
+
+static const struct udevice_id s5p4418_pl011_serial_id[] = {
+       {.compatible = "nexell,s5p4418-pl011", .data = TYPE_PL011},
+       {}
+};
+
+U_BOOT_DRIVER(s5p4418_pl011_uart) = {
+       .name   = "s5p4418_pl011",
+       .id     = UCLASS_SERIAL,
+       .of_match = of_match_ptr(s5p4418_pl011_serial_id),
+       .of_to_plat = of_match_ptr(pl01x_serial_of_to_plat),
+       .plat_auto      = sizeof(struct pl01x_serial_plat),
+       .probe = s5p4418_pl011_serial_probe,
+       .ops    = &s5p4418_pl011_serial_ops,
+       .flags  = DM_FLAG_PRE_RELOC,
+       .priv_auto      = sizeof(struct pl01x_priv),
+};