board: sl28: add board specific nvm command
The board supports 16 configuration bits which can be manipulated with
this command. See the board's README for a detailed explanation on each
bit.
Signed-off-by: Michael Walle <michael@walle.cc>
Tested-by: Heiko Thiery <heiko.thiery@gmail.com>
Reviewed-by: Priyanka Jain <priyanka.jain@nxp.com>
diff --git a/board/kontron/sl28/cmds.c b/board/kontron/sl28/cmds.c
new file mode 100644
index 0000000..046d3b4
--- /dev/null
+++ b/board/kontron/sl28/cmds.c
@@ -0,0 +1,178 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * sl28 extension commands
+ *
+ * Copyright (c) 2020 Kontron Europe GmbH
+ */
+
+#include <common.h>
+#include <command.h>
+#include <i2c.h>
+#include <linux/delay.h>
+
+#define CPLD_I2C_ADDR 0x4a
+#define REG_UFM_CTRL 0x02
+#define UFM_CTRL_DCLK BIT(1)
+#define UFM_CTRL_DIN BIT(2)
+#define UFM_CTRL_PROGRAM BIT(3)
+#define UFM_CTRL_ERASE BIT(4)
+#define UFM_CTRL_DSHIFT BIT(5)
+#define UFM_CTRL_DOUT BIT(6)
+#define UFM_CTRL_BUSY BIT(7)
+
+static int ufm_shift_data(struct udevice *dev, u16 data_in, u16 *data_out)
+{
+ int i;
+ int ret;
+ u16 data = 0;
+
+ /* latch data */
+ ret = dm_i2c_reg_write(dev, REG_UFM_CTRL, 0);
+ if (ret < 0)
+ return ret;
+ ret = dm_i2c_reg_write(dev, REG_UFM_CTRL, UFM_CTRL_DCLK);
+ if (ret < 0)
+ return ret;
+
+ /* assert drshift */
+ ret = dm_i2c_reg_write(dev, REG_UFM_CTRL,
+ UFM_CTRL_DSHIFT | UFM_CTRL_DCLK);
+ if (ret < 0)
+ return ret;
+
+ /* clock 16 data bits, reverse order */
+ for (i = 15; i >= 0; i--) {
+ u8 din = (data_in & (1 << i)) ? UFM_CTRL_DIN : 0;
+
+ ret = dm_i2c_reg_write(dev, REG_UFM_CTRL, UFM_CTRL_DSHIFT
+ | din);
+ if (ret < 0)
+ return ret;
+ if (data_out) {
+ ret = dm_i2c_reg_read(dev, REG_UFM_CTRL);
+ if (ret < 0)
+ return ret;
+ if (ret & UFM_CTRL_DOUT)
+ data |= (1 << i);
+ }
+ ret = dm_i2c_reg_write(dev, REG_UFM_CTRL,
+ UFM_CTRL_DSHIFT | UFM_CTRL_DCLK | din);
+ if (ret < 0)
+ return ret;
+ }
+
+ /* deassert drshift */
+ ret = dm_i2c_reg_write(dev, REG_UFM_CTRL, UFM_CTRL_DCLK);
+ if (ret < 0)
+ return ret;
+
+ if (data_out)
+ *data_out = data;
+
+ return ret;
+}
+
+static int ufm_erase(struct udevice *dev)
+{
+ int ret;
+
+ /* erase, tEPMX is 500ms */
+ ret = dm_i2c_reg_write(dev, REG_UFM_CTRL,
+ UFM_CTRL_DCLK | UFM_CTRL_ERASE);
+ if (ret < 0)
+ return ret;
+ ret = dm_i2c_reg_write(dev, REG_UFM_CTRL, UFM_CTRL_DCLK);
+ if (ret < 0)
+ return ret;
+ mdelay(500);
+
+ return 0;
+}
+
+static int ufm_program(struct udevice *dev)
+{
+ int ret;
+
+ /* program, tPPMX is 100us */
+ ret = dm_i2c_reg_write(dev, REG_UFM_CTRL,
+ UFM_CTRL_DCLK | UFM_CTRL_PROGRAM);
+ if (ret < 0)
+ return ret;
+ ret = dm_i2c_reg_write(dev, REG_UFM_CTRL, UFM_CTRL_DCLK);
+ if (ret < 0)
+ return ret;
+ udelay(100);
+
+ return 0;
+}
+
+static int ufm_write(struct udevice *dev, u16 data)
+{
+ int ret;
+
+ ret = ufm_shift_data(dev, data, NULL);
+ if (ret < 0)
+ return ret;
+
+ ret = ufm_erase(dev);
+ if (ret < 0)
+ return ret;
+
+ return ufm_program(dev);
+}
+
+static int ufm_read(struct udevice *dev, u16 *data)
+{
+ return ufm_shift_data(dev, 0, data);
+}
+
+static int do_sl28_nvm(struct cmd_tbl *cmdtp, int flag, int argc,
+ char *const argv[])
+{
+ struct udevice *dev;
+ u16 nvm;
+ int ret;
+ char *endp;
+
+ if (i2c_get_chip_for_busnum(0, CPLD_I2C_ADDR, 1, &dev))
+ return CMD_RET_FAILURE;
+
+ if (argc > 1) {
+ nvm = simple_strtoul(argv[1], &endp, 16);
+ if (*endp != '\0') {
+ printf("ERROR: argument is not a valid number\n");
+ ret = -EINVAL;
+ goto out;
+ }
+
+ /*
+ * We swap all bits, because the a zero bit in hardware means the
+ * feature is enabled. But this is hard for the user.
+ */
+ nvm ^= 0xffff;
+
+ ret = ufm_write(dev, nvm);
+ if (ret)
+ goto out;
+ printf("New settings will be activated after the next power cycle!\n");
+ } else {
+ ret = ufm_read(dev, &nvm);
+ if (ret)
+ goto out;
+ nvm ^= 0xffff;
+
+ printf("%04hx\n", nvm);
+ }
+
+ return CMD_RET_SUCCESS;
+
+out:
+ printf("command failed (%d)\n", ret);
+ return CMD_RET_FAILURE;
+}
+
+static char sl28_help_text[] =
+ "nvm [<hex>] - display/set the 16 non-volatile bits\n";
+
+U_BOOT_CMD_WITH_SUBCMDS(sl28, "SMARC-sAL28 specific", sl28_help_text,
+ U_BOOT_SUBCMD_MKENT(nvm, 2, 1, do_sl28_nvm));