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authorAngelos Mouzakitis <a.mouzakitis@virtualopensystems.com>2023-10-10 14:33:42 +0000
committerAngelos Mouzakitis <a.mouzakitis@virtualopensystems.com>2023-10-10 14:33:42 +0000
commitaf1a266670d040d2f4083ff309d732d648afba2a (patch)
tree2fc46203448ddcc6f81546d379abfaeb323575e9 /roms/u-boot/arch/x86/cpu/apollolake/uart.c
parente02cda008591317b1625707ff8e115a4841aa889 (diff)
Add submodule dependency filesHEADmaster
Change-Id: Iaf8d18082d3991dec7c0ebbea540f092188eb4ec
Diffstat (limited to 'roms/u-boot/arch/x86/cpu/apollolake/uart.c')
-rw-r--r--roms/u-boot/arch/x86/cpu/apollolake/uart.c142
1 files changed, 142 insertions, 0 deletions
diff --git a/roms/u-boot/arch/x86/cpu/apollolake/uart.c b/roms/u-boot/arch/x86/cpu/apollolake/uart.c
new file mode 100644
index 000000000..876fa592b
--- /dev/null
+++ b/roms/u-boot/arch/x86/cpu/apollolake/uart.c
@@ -0,0 +1,142 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Special driver to handle of-platdata
+ *
+ * Copyright 2019 Google LLC
+ *
+ * Some code from coreboot lpss.c
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <dt-structs.h>
+#include <malloc.h>
+#include <ns16550.h>
+#include <spl.h>
+#include <asm/io.h>
+#include <asm/pci.h>
+#include <asm/lpss.h>
+#include <dm/device-internal.h>
+#include <asm/arch/uart.h>
+
+/* Low-power Subsystem (LPSS) clock register */
+enum {
+ LPSS_CLOCK_CTL_REG = 0x200,
+ LPSS_CNT_CLOCK_EN = 1,
+ LPSS_CNT_CLK_UPDATE = 1U << 31,
+ LPSS_CLOCK_DIV_N_SHIFT = 16,
+ LPSS_CLOCK_DIV_N_MASK = 0x7fff << LPSS_CLOCK_DIV_N_SHIFT,
+ LPSS_CLOCK_DIV_M_SHIFT = 1,
+ LPSS_CLOCK_DIV_M_MASK = 0x7fff << LPSS_CLOCK_DIV_M_SHIFT,
+
+ /* These set the UART input clock speed */
+ LPSS_UART_CLK_M_VAL = 0x25a,
+ LPSS_UART_CLK_N_VAL = 0x7fff,
+};
+
+static void lpss_clk_update(void *regs, u32 clk_m_val, u32 clk_n_val)
+{
+ u32 clk_sel;
+
+ clk_sel = clk_n_val << LPSS_CLOCK_DIV_N_SHIFT |
+ clk_m_val << LPSS_CLOCK_DIV_M_SHIFT;
+ clk_sel |= LPSS_CNT_CLK_UPDATE | LPSS_CNT_CLOCK_EN;
+
+ writel(clk_sel, regs + LPSS_CLOCK_CTL_REG);
+}
+
+static void uart_lpss_init(void *regs)
+{
+ /* Take UART out of reset */
+ lpss_reset_release(regs);
+
+ /* Set M and N divisor inputs and enable clock */
+ lpss_clk_update(regs, LPSS_UART_CLK_M_VAL, LPSS_UART_CLK_N_VAL);
+}
+
+void apl_uart_init(pci_dev_t bdf, ulong base)
+{
+ /* Set UART base address */
+ pci_x86_write_config(bdf, PCI_BASE_ADDRESS_0, base, PCI_SIZE_32);
+
+ /* Enable memory access and bus master */
+ pci_x86_write_config(bdf, PCI_COMMAND, PCI_COMMAND_MEMORY |
+ PCI_COMMAND_MASTER, PCI_SIZE_32);
+
+ uart_lpss_init((void *)base);
+}
+
+/*
+ * This driver uses its own compatible string but almost everything else from
+ * the standard ns16550 driver. This allows us to provide an of-platdata
+ * implementation, since the platdata produced by of-platdata does not match
+ * struct apl_ns16550_plat.
+ *
+ * When running with of-platdata (generally TPL), the platdata is converted to
+ * something that ns16550 expects. When running withoutof-platdata (SPL, U-Boot
+ * proper), we use ns16550's of_to_plat routine.
+ */
+
+static int apl_ns16550_probe(struct udevice *dev)
+{
+ struct apl_ns16550_plat *plat = dev_get_plat(dev);
+
+ if (!CONFIG_IS_ENABLED(PCI))
+ apl_uart_init(plat->ns16550.bdf, plat->ns16550.base);
+
+ return ns16550_serial_probe(dev);
+}
+
+static int apl_ns16550_of_to_plat(struct udevice *dev)
+{
+#if CONFIG_IS_ENABLED(OF_PLATDATA)
+ struct dtd_intel_apl_ns16550 *dtplat;
+ struct apl_ns16550_plat *plat = dev_get_plat(dev);
+ struct ns16550_plat ns;
+
+ /*
+ * The device's plat uses struct apl_ns16550_plat which starts with the
+ * dtd struct, but the ns16550 driver expects it to be struct ns16550.
+ * Set up what that driver expects. Note that this means that the values
+ * cannot be read in this driver when using of-platdata.
+ *
+ * TODO(sjg@chromium.org): Consider having a separate plat pointer for
+ * of-platdata so that it is not necessary to overwrite this.
+ */
+ dtplat = &plat->dtplat;
+ ns.base = dtplat->early_regs[0];
+ ns.reg_width = 1;
+ ns.reg_shift = dtplat->reg_shift;
+ ns.reg_offset = 0;
+ ns.clock = dtplat->clock_frequency;
+ ns.fcr = UART_FCR_DEFVAL;
+ ns.bdf = pci_ofplat_get_devfn(dtplat->reg[0]);
+ memcpy(plat, &ns, sizeof(ns));
+#else
+ int ret;
+
+ ret = ns16550_serial_of_to_plat(dev);
+ if (ret)
+ return ret;
+#endif /* OF_PLATDATA */
+
+ return 0;
+}
+
+#if !CONFIG_IS_ENABLED(OF_PLATDATA)
+static const struct udevice_id apl_ns16550_serial_ids[] = {
+ { .compatible = "intel,apl-ns16550" },
+ { },
+};
+#endif
+
+U_BOOT_DRIVER(intel_apl_ns16550) = {
+ .name = "intel_apl_ns16550",
+ .id = UCLASS_SERIAL,
+ .of_match = of_match_ptr(apl_ns16550_serial_ids),
+ .plat_auto = sizeof(struct apl_ns16550_plat),
+ .priv_auto = sizeof(struct ns16550),
+ .ops = &ns16550_serial_ops,
+ .of_to_plat = apl_ns16550_of_to_plat,
+ .probe = apl_ns16550_probe,
+};