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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /arch/powerpc/boot/cpm-serial.c
parentInitial commit. (diff)
downloadlinux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz
linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip
Adding upstream version 4.19.249.upstream/4.19.249upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/powerpc/boot/cpm-serial.c')
-rw-r--r--arch/powerpc/boot/cpm-serial.c295
1 files changed, 295 insertions, 0 deletions
diff --git a/arch/powerpc/boot/cpm-serial.c b/arch/powerpc/boot/cpm-serial.c
new file mode 100644
index 000000000..dfb56829c
--- /dev/null
+++ b/arch/powerpc/boot/cpm-serial.c
@@ -0,0 +1,295 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * CPM serial console support.
+ *
+ * Copyright 2007 Freescale Semiconductor, Inc.
+ * Author: Scott Wood <scottwood@freescale.com>
+ *
+ * It is assumed that the firmware (or the platform file) has already set
+ * up the port.
+ */
+
+#include "types.h"
+#include "io.h"
+#include "ops.h"
+#include "page.h"
+
+struct cpm_scc {
+ u32 gsmrl;
+ u32 gsmrh;
+ u16 psmr;
+ u8 res1[2];
+ u16 todr;
+ u16 dsr;
+ u16 scce;
+ u8 res2[2];
+ u16 sccm;
+ u8 res3;
+ u8 sccs;
+ u8 res4[8];
+};
+
+struct cpm_smc {
+ u8 res1[2];
+ u16 smcmr;
+ u8 res2[2];
+ u8 smce;
+ u8 res3[3];
+ u8 smcm;
+ u8 res4[5];
+};
+
+struct cpm_param {
+ u16 rbase;
+ u16 tbase;
+ u8 rfcr;
+ u8 tfcr;
+ u16 mrblr;
+ u32 rstate;
+ u8 res1[4];
+ u16 rbptr;
+ u8 res2[6];
+ u32 tstate;
+ u8 res3[4];
+ u16 tbptr;
+ u8 res4[6];
+ u16 maxidl;
+ u16 idlc;
+ u16 brkln;
+ u16 brkec;
+ u16 brkcr;
+ u16 rmask;
+ u8 res5[4];
+};
+
+struct cpm_bd {
+ u16 sc; /* Status and Control */
+ u16 len; /* Data length in buffer */
+ u8 *addr; /* Buffer address in host memory */
+};
+
+static void *cpcr;
+static struct cpm_param *param;
+static struct cpm_smc *smc;
+static struct cpm_scc *scc;
+static struct cpm_bd *tbdf, *rbdf;
+static u32 cpm_cmd;
+static void *cbd_addr;
+static u32 cbd_offset;
+
+static void (*do_cmd)(int op);
+static void (*enable_port)(void);
+static void (*disable_port)(void);
+
+#define CPM_CMD_STOP_TX 4
+#define CPM_CMD_RESTART_TX 6
+#define CPM_CMD_INIT_RX_TX 0
+
+static void cpm1_cmd(int op)
+{
+ while (in_be16(cpcr) & 1)
+ ;
+
+ out_be16(cpcr, (op << 8) | cpm_cmd | 1);
+
+ while (in_be16(cpcr) & 1)
+ ;
+}
+
+static void cpm2_cmd(int op)
+{
+ while (in_be32(cpcr) & 0x10000)
+ ;
+
+ out_be32(cpcr, op | cpm_cmd | 0x10000);
+
+ while (in_be32(cpcr) & 0x10000)
+ ;
+}
+
+static void smc_disable_port(void)
+{
+ do_cmd(CPM_CMD_STOP_TX);
+ out_be16(&smc->smcmr, in_be16(&smc->smcmr) & ~3);
+}
+
+static void scc_disable_port(void)
+{
+ do_cmd(CPM_CMD_STOP_TX);
+ out_be32(&scc->gsmrl, in_be32(&scc->gsmrl) & ~0x30);
+}
+
+static void smc_enable_port(void)
+{
+ out_be16(&smc->smcmr, in_be16(&smc->smcmr) | 3);
+ do_cmd(CPM_CMD_RESTART_TX);
+}
+
+static void scc_enable_port(void)
+{
+ out_be32(&scc->gsmrl, in_be32(&scc->gsmrl) | 0x30);
+ do_cmd(CPM_CMD_RESTART_TX);
+}
+
+static int cpm_serial_open(void)
+{
+ disable_port();
+
+ out_8(&param->rfcr, 0x10);
+ out_8(&param->tfcr, 0x10);
+ out_be16(&param->mrblr, 1);
+ out_be16(&param->maxidl, 0);
+ out_be16(&param->brkec, 0);
+ out_be16(&param->brkln, 0);
+ out_be16(&param->brkcr, 0);
+
+ rbdf = cbd_addr;
+ rbdf->addr = (u8 *)rbdf - 1;
+ rbdf->sc = 0xa000;
+ rbdf->len = 1;
+
+ tbdf = rbdf + 1;
+ tbdf->addr = (u8 *)rbdf - 2;
+ tbdf->sc = 0x2000;
+ tbdf->len = 1;
+
+ sync();
+ out_be16(&param->rbase, cbd_offset);
+ out_be16(&param->tbase, cbd_offset + sizeof(struct cpm_bd));
+
+ do_cmd(CPM_CMD_INIT_RX_TX);
+
+ enable_port();
+ return 0;
+}
+
+static void cpm_serial_putc(unsigned char c)
+{
+ while (tbdf->sc & 0x8000)
+ barrier();
+
+ sync();
+
+ tbdf->addr[0] = c;
+ eieio();
+ tbdf->sc |= 0x8000;
+}
+
+static unsigned char cpm_serial_tstc(void)
+{
+ barrier();
+ return !(rbdf->sc & 0x8000);
+}
+
+static unsigned char cpm_serial_getc(void)
+{
+ unsigned char c;
+
+ while (!cpm_serial_tstc())
+ ;
+
+ sync();
+ c = rbdf->addr[0];
+ eieio();
+ rbdf->sc |= 0x8000;
+
+ return c;
+}
+
+int cpm_console_init(void *devp, struct serial_console_data *scdp)
+{
+ void *vreg[2];
+ u32 reg[2];
+ int is_smc = 0, is_cpm2 = 0;
+ void *parent, *muram;
+ void *muram_addr;
+ unsigned long muram_offset, muram_size;
+
+ if (dt_is_compatible(devp, "fsl,cpm1-smc-uart")) {
+ is_smc = 1;
+ } else if (dt_is_compatible(devp, "fsl,cpm2-scc-uart")) {
+ is_cpm2 = 1;
+ } else if (dt_is_compatible(devp, "fsl,cpm2-smc-uart")) {
+ is_cpm2 = 1;
+ is_smc = 1;
+ }
+
+ if (is_smc) {
+ enable_port = smc_enable_port;
+ disable_port = smc_disable_port;
+ } else {
+ enable_port = scc_enable_port;
+ disable_port = scc_disable_port;
+ }
+
+ if (is_cpm2)
+ do_cmd = cpm2_cmd;
+ else
+ do_cmd = cpm1_cmd;
+
+ if (getprop(devp, "fsl,cpm-command", &cpm_cmd, 4) < 4)
+ return -1;
+
+ if (dt_get_virtual_reg(devp, vreg, 2) < 2)
+ return -1;
+
+ if (is_smc)
+ smc = vreg[0];
+ else
+ scc = vreg[0];
+
+ param = vreg[1];
+
+ parent = get_parent(devp);
+ if (!parent)
+ return -1;
+
+ if (dt_get_virtual_reg(parent, &cpcr, 1) < 1)
+ return -1;
+
+ muram = finddevice("/soc/cpm/muram/data");
+ if (!muram)
+ return -1;
+
+ /* For bootwrapper-compatible device trees, we assume that the first
+ * entry has at least 128 bytes, and that #address-cells/#data-cells
+ * is one for both parent and child.
+ */
+
+ if (dt_get_virtual_reg(muram, &muram_addr, 1) < 1)
+ return -1;
+
+ if (getprop(muram, "reg", reg, 8) < 8)
+ return -1;
+
+ muram_offset = reg[0];
+ muram_size = reg[1];
+
+ /* Store the buffer descriptors at the end of the first muram chunk.
+ * For SMC ports on CPM2-based platforms, relocate the parameter RAM
+ * just before the buffer descriptors.
+ */
+
+ cbd_offset = muram_offset + muram_size - 2 * sizeof(struct cpm_bd);
+
+ if (is_cpm2 && is_smc) {
+ u16 *smc_base = (u16 *)param;
+ u16 pram_offset;
+
+ pram_offset = cbd_offset - 64;
+ pram_offset = _ALIGN_DOWN(pram_offset, 64);
+
+ disable_port();
+ out_be16(smc_base, pram_offset);
+ param = muram_addr - muram_offset + pram_offset;
+ }
+
+ cbd_addr = muram_addr - muram_offset + cbd_offset;
+
+ scdp->open = cpm_serial_open;
+ scdp->putc = cpm_serial_putc;
+ scdp->getc = cpm_serial_getc;
+ scdp->tstc = cpm_serial_tstc;
+
+ return 0;
+}