stm32-ipcc.c
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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) STMicroelectronics 2019 - All Rights Reserved
*/
#include <common.h>
#include <clk.h>
#include <dm.h>
#include <mailbox-uclass.h>
#include <malloc.h>
#include <asm/io.h>
#include <dm/device_compat.h>
/*
* IPCC has one set of registers per CPU
* IPCC_PROC_OFFST allows to define cpu registers set base address
* according to the assigned proc_id.
*/
#define IPCC_PROC_OFFST 0x010
#define IPCC_XSCR 0x008
#define IPCC_XTOYSR 0x00c
#define IPCC_HWCFGR 0x3f0
#define IPCFGR_CHAN_MASK GENMASK(7, 0)
#define RX_BIT_CHAN(chan) BIT(chan)
#define TX_BIT_SHIFT 16
#define TX_BIT_CHAN(chan) BIT(TX_BIT_SHIFT + (chan))
#define STM32_MAX_PROCS 2
struct stm32_ipcc {
void __iomem *reg_base;
void __iomem *reg_proc;
u32 proc_id;
u32 n_chans;
};
static int stm32_ipcc_request(struct mbox_chan *chan)
{
struct stm32_ipcc *ipcc = dev_get_priv(chan->dev);
debug("%s(chan=%p)\n", __func__, chan);
if (chan->id >= ipcc->n_chans) {
debug("%s failed to request channel: %ld\n",
__func__, chan->id);
return -EINVAL;
}
return 0;
}
static int stm32_ipcc_free(struct mbox_chan *chan)
{
debug("%s(chan=%p)\n", __func__, chan);
return 0;
}
static int stm32_ipcc_send(struct mbox_chan *chan, const void *data)
{
struct stm32_ipcc *ipcc = dev_get_priv(chan->dev);
debug("%s(chan=%p, data=%p)\n", __func__, chan, data);
if (readl(ipcc->reg_proc + IPCC_XTOYSR) & BIT(chan->id))
return -EBUSY;
/* set channel n occupied */
setbits_le32(ipcc->reg_proc + IPCC_XSCR, TX_BIT_CHAN(chan->id));
return 0;
}
static int stm32_ipcc_recv(struct mbox_chan *chan, void *data)
{
struct stm32_ipcc *ipcc = dev_get_priv(chan->dev);
u32 val;
int proc_offset;
debug("%s(chan=%p, data=%p)\n", __func__, chan, data);
/* read 'channel occupied' status from other proc */
proc_offset = ipcc->proc_id ? -IPCC_PROC_OFFST : IPCC_PROC_OFFST;
val = readl(ipcc->reg_proc + proc_offset + IPCC_XTOYSR);
if (!(val & BIT(chan->id)))
return -ENODATA;
setbits_le32(ipcc->reg_proc + IPCC_XSCR, RX_BIT_CHAN(chan->id));
return 0;
}
static int stm32_ipcc_probe(struct udevice *dev)
{
struct stm32_ipcc *ipcc = dev_get_priv(dev);
fdt_addr_t addr;
const fdt32_t *cell;
struct clk clk;
int len, ret;
debug("%s(dev=%p)\n", __func__, dev);
addr = dev_read_addr(dev);
if (addr == FDT_ADDR_T_NONE)
return -EINVAL;
ipcc->reg_base = (void __iomem *)addr;
/* proc_id */
cell = dev_read_prop(dev, "st,proc_id", &len);
if (len < sizeof(fdt32_t)) {
dev_dbg(dev, "Missing st,proc_id\n");
return -EINVAL;
}
ipcc->proc_id = fdtdec_get_number(cell, 1);
if (ipcc->proc_id >= STM32_MAX_PROCS) {
dev_err(dev, "Invalid proc_id (%d)\n", ipcc->proc_id);
return -EINVAL;
}
ipcc->reg_proc = ipcc->reg_base + ipcc->proc_id * IPCC_PROC_OFFST;
ret = clk_get_by_index(dev, 0, &clk);
if (ret)
return ret;
ret = clk_enable(&clk);
if (ret)
goto clk_free;
/* get channel number */
ipcc->n_chans = readl(ipcc->reg_base + IPCC_HWCFGR);
ipcc->n_chans &= IPCFGR_CHAN_MASK;
return 0;
clk_free:
clk_free(&clk);
return ret;
}
static const struct udevice_id stm32_ipcc_ids[] = {
{ .compatible = "st,stm32mp1-ipcc" },
{ }
};
struct mbox_ops stm32_ipcc_mbox_ops = {
.request = stm32_ipcc_request,
.rfree = stm32_ipcc_free,
.send = stm32_ipcc_send,
.recv = stm32_ipcc_recv,
};
U_BOOT_DRIVER(stm32_ipcc) = {
.name = "stm32_ipcc",
.id = UCLASS_MAILBOX,
.of_match = stm32_ipcc_ids,
.probe = stm32_ipcc_probe,
.priv_auto_alloc_size = sizeof(struct stm32_ipcc),
.ops = &stm32_ipcc_mbox_ops,
};