blob: e5c3dcffc1c6cf045eb3695866a47e2c749963e3 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0+
/*
* Qualcomm GENI serial engine UART driver
*
* (C) Copyright 2021 Dzmitry Sankouski <dsankouski@gmail.com>
*
* Based on Linux driver.
*/
#include <asm/io.h>
#include <clk.h>
#include <common.h>
#include <dm.h>
#include <errno.h>
#include <linux/delay.h>
#include <linux/time.h>
#include <misc.h>
#include <serial.h>
#define UART_OVERSAMPLING 32
#define STALE_TIMEOUT 160
/* Registers*/
#define GENI_FORCE_DEFAULT_REG 0x20
#define GENI_SER_M_CLK_CFG 0x48
#define GENI_SER_S_CLK_CFG 0x4C
#define SE_HW_PARAM_0 0xE24
#define SE_GENI_STATUS 0x40
#define SE_GENI_S_CMD0 0x630
#define SE_GENI_S_CMD_CTRL_REG 0x634
#define SE_GENI_S_IRQ_CLEAR 0x648
#define SE_GENI_S_IRQ_STATUS 0x640
#define SE_GENI_S_IRQ_EN 0x644
#define SE_GENI_M_CMD0 0x600
#define SE_GENI_M_CMD_CTRL_REG 0x604
#define SE_GENI_M_IRQ_CLEAR 0x618
#define SE_GENI_M_IRQ_STATUS 0x610
#define SE_GENI_M_IRQ_EN 0x614
#define SE_GENI_TX_FIFOn 0x700
#define SE_GENI_RX_FIFOn 0x780
#define SE_GENI_TX_FIFO_STATUS 0x800
#define SE_GENI_RX_FIFO_STATUS 0x804
#define SE_GENI_TX_WATERMARK_REG 0x80C
#define SE_GENI_TX_PACKING_CFG0 0x260
#define SE_GENI_TX_PACKING_CFG1 0x264
#define SE_GENI_RX_PACKING_CFG0 0x284
#define SE_GENI_RX_PACKING_CFG1 0x288
#define SE_UART_RX_STALE_CNT 0x294
#define SE_UART_TX_TRANS_LEN 0x270
#define SE_UART_TX_STOP_BIT_LEN 0x26c
#define SE_UART_TX_WORD_LEN 0x268
#define SE_UART_RX_WORD_LEN 0x28c
#define SE_UART_TX_TRANS_CFG 0x25c
#define SE_UART_TX_PARITY_CFG 0x2a4
#define SE_UART_RX_TRANS_CFG 0x280
#define SE_UART_RX_PARITY_CFG 0x2a8
#define M_TX_FIFO_WATERMARK_EN (BIT(30))
#define DEF_TX_WM 2
/* GENI_FORCE_DEFAULT_REG fields */
#define FORCE_DEFAULT (BIT(0))
#define S_CMD_ABORT_EN (BIT(5))
#define UART_START_READ 0x1
/* GENI_M_CMD_CTRL_REG */
#define M_GENI_CMD_CANCEL (BIT(2))
#define M_GENI_CMD_ABORT (BIT(1))
#define M_GENI_DISABLE (BIT(0))
#define M_CMD_ABORT_EN (BIT(5))
#define M_CMD_DONE_EN (BIT(0))
#define M_CMD_DONE_DISABLE_MASK (~M_CMD_DONE_EN)
#define S_GENI_CMD_ABORT (BIT(1))
/* GENI_S_CMD0 fields */
#define S_OPCODE_MSK (GENMASK(31, 27))
#define S_PARAMS_MSK (GENMASK(26, 0))
/* GENI_STATUS fields */
#define M_GENI_CMD_ACTIVE (BIT(0))
#define S_GENI_CMD_ACTIVE (BIT(12))
#define M_CMD_DONE_EN (BIT(0))
#define S_CMD_DONE_EN (BIT(0))
#define M_OPCODE_SHIFT 27
#define S_OPCODE_SHIFT 27
#define M_TX_FIFO_WATERMARK_EN (BIT(30))
#define UART_START_TX 0x1
#define UART_CTS_MASK (BIT(1))
#define M_SEC_IRQ_EN (BIT(31))
#define TX_FIFO_WC_MSK (GENMASK(27, 0))
#define RX_FIFO_WC_MSK (GENMASK(24, 0))
#define S_RX_FIFO_WATERMARK_EN (BIT(26))
#define S_RX_FIFO_LAST_EN (BIT(27))
#define M_RX_FIFO_WATERMARK_EN (BIT(26))
#define M_RX_FIFO_LAST_EN (BIT(27))
/* GENI_SER_M_CLK_CFG/GENI_SER_S_CLK_CFG */
#define SER_CLK_EN (BIT(0))
#define CLK_DIV_MSK (GENMASK(15, 4))
#define CLK_DIV_SHFT 4
/* SE_HW_PARAM_0 fields */
#define TX_FIFO_WIDTH_MSK (GENMASK(29, 24))
#define TX_FIFO_WIDTH_SHFT 24
#define TX_FIFO_DEPTH_MSK (GENMASK(21, 16))
#define TX_FIFO_DEPTH_SHFT 16
/* GENI SE QUP Registers */
#define QUP_HW_VER_REG 0x4
#define QUP_SE_VERSION_2_5 0x20050000
/*
* Predefined packing configuration of the serial engine (CFG0, CFG1 regs)
* for uart mode.
*
* Defines following configuration:
* - Bits of data per transfer word 8
* - Number of words per fifo element 4
* - Transfer from MSB to LSB or vice-versa false
*/
#define UART_PACKING_CFG0 0xf
#define UART_PACKING_CFG1 0x0
DECLARE_GLOBAL_DATA_PTR;
struct msm_serial_data {
phys_addr_t base;
u32 baud;
u32 oversampling;
};
unsigned long root_freq[] = {7372800, 14745600, 19200000, 29491200,
32000000, 48000000, 64000000, 80000000,
96000000, 100000000};
/**
* get_clk_cfg() - Get clock rate to apply on clock supplier.
* @clk_freq: Desired clock frequency after build-in divider.
*
* Return: frequency, supported by clock supplier, multiple of clk_freq.
*/
static int get_clk_cfg(unsigned long clk_freq)
{
for (int i = 0; i < ARRAY_SIZE(root_freq); i++) {
if (!(root_freq[i] % clk_freq))
return root_freq[i];
}
return 0;
}
/**
* get_clk_div_rate() - Find clock supplier frequency, and calculate divisor.
* @baud: Baudrate.
* @sampling_rate: Clock ticks per character.
* @clk_div: Pointer to calculated divisor.
*
* This function searches for suitable frequency for clock supplier,
* calculates divisor for internal divider, based on found frequency,
* and stores divisor under clk_div pointer.
*
* Return: frequency, supported by clock supplier, multiple of clk_freq.
*/
static int get_clk_div_rate(u32 baud, u64 sampling_rate, u32 *clk_div)
{
unsigned long ser_clk;
unsigned long desired_clk;
desired_clk = baud * sampling_rate;
ser_clk = get_clk_cfg(desired_clk);
if (!ser_clk) {
pr_err("%s: Can't find matching DFS entry for baud %d\n",
__func__, baud);
return ser_clk;
}
*clk_div = ser_clk / desired_clk;
return ser_clk;
}
static int geni_serial_set_clock_rate(struct udevice *dev, u64 rate)
{
struct clk *clk;
int ret;
clk = devm_clk_get(dev, NULL);
if (IS_ERR(clk))
return PTR_ERR(clk);
ret = clk_set_rate(clk, rate);
return ret;
}
/**
* geni_se_get_tx_fifo_depth() - Get the TX fifo depth of the serial engine
* @base: Pointer to the concerned serial engine.
*
* This function is used to get the depth i.e. number of elements in the
* TX fifo of the serial engine.
*
* Return: TX fifo depth in units of FIFO words.
*/
static inline u32 geni_se_get_tx_fifo_depth(long base)
{
u32 tx_fifo_depth;
tx_fifo_depth = ((readl(base + SE_HW_PARAM_0) & TX_FIFO_DEPTH_MSK) >>
TX_FIFO_DEPTH_SHFT);
return tx_fifo_depth;
}
/**
* geni_se_get_tx_fifo_width() - Get the TX fifo width of the serial engine
* @base: Pointer to the concerned serial engine.
*
* This function is used to get the width i.e. word size per element in the
* TX fifo of the serial engine.
*
* Return: TX fifo width in bits
*/
static inline u32 geni_se_get_tx_fifo_width(long base)
{
u32 tx_fifo_width;
tx_fifo_width = ((readl(base + SE_HW_PARAM_0) & TX_FIFO_WIDTH_MSK) >>
TX_FIFO_WIDTH_SHFT);
return tx_fifo_width;
}
static inline void geni_serial_baud(phys_addr_t base_address, u32 clk_div,
int baud)
{
u32 s_clk_cfg = 0;
s_clk_cfg |= SER_CLK_EN;
s_clk_cfg |= (clk_div << CLK_DIV_SHFT);
writel(s_clk_cfg, base_address + GENI_SER_M_CLK_CFG);
writel(s_clk_cfg, base_address + GENI_SER_S_CLK_CFG);
}
static int msm_serial_setbrg(struct udevice *dev, int baud)
{
struct msm_serial_data *priv = dev_get_priv(dev);
u64 clk_rate;
u32 clk_div;
int ret;
priv->baud = baud;
clk_rate = get_clk_div_rate(baud, priv->oversampling, &clk_div);
ret = geni_serial_set_clock_rate(dev, clk_rate);
if (ret < 0) {
pr_err("%s: Couldn't set clock rate: %d\n", __func__, ret);
return ret;
}
geni_serial_baud(priv->base, clk_div, baud);
return 0;
}
/**
* qcom_geni_serial_poll_bit() - Poll reg bit until desired value or timeout.
* @base: Pointer to the concerned serial engine.
* @offset: Offset to register address.
* @field: AND bitmask for desired bit.
* @set: Desired bit value.
*
* This function is used to get the width i.e. word size per element in the
* TX fifo of the serial engine.
*
* Return: true, when register bit equals desired value, false, when timeout
* reached.
*/
static bool qcom_geni_serial_poll_bit(const struct udevice *dev, int offset,
int field, bool set)
{
u32 reg;
struct msm_serial_data *priv = dev_get_priv(dev);
unsigned int baud;
unsigned int tx_fifo_depth;
unsigned int tx_fifo_width;
unsigned int fifo_bits;
unsigned long timeout_us = 10000;
baud = 115200;
if (priv) {
baud = priv->baud;
if (!baud)
baud = 115200;
tx_fifo_depth = geni_se_get_tx_fifo_depth(priv->base);
tx_fifo_width = geni_se_get_tx_fifo_width(priv->base);
fifo_bits = tx_fifo_depth * tx_fifo_width;
/*
* Total polling iterations based on FIFO worth of bytes to be
* sent at current baud. Add a little fluff to the wait.
*/
timeout_us = ((fifo_bits * USEC_PER_SEC) / baud) + 500;
}
timeout_us = DIV_ROUND_UP(timeout_us, 10) * 10;
while (timeout_us) {
reg = readl(priv->base + offset);
if ((bool)(reg & field) == set)
return true;
udelay(10);
timeout_us -= 10;
}
return false;
}
static void qcom_geni_serial_setup_tx(u64 base, u32 xmit_size)
{
u32 m_cmd;
writel(xmit_size, base + SE_UART_TX_TRANS_LEN);
m_cmd = UART_START_TX << M_OPCODE_SHIFT;
writel(m_cmd, base + SE_GENI_M_CMD0);
}
static inline void qcom_geni_serial_poll_tx_done(const struct udevice *dev)
{
struct msm_serial_data *priv = dev_get_priv(dev);
int done = 0;
u32 irq_clear = M_CMD_DONE_EN;
done = qcom_geni_serial_poll_bit(dev, SE_GENI_M_IRQ_STATUS,
M_CMD_DONE_EN, true);
if (!done) {
writel(M_GENI_CMD_ABORT, priv->base + SE_GENI_M_CMD_CTRL_REG);
irq_clear |= M_CMD_ABORT_EN;
qcom_geni_serial_poll_bit(dev, SE_GENI_M_IRQ_STATUS,
M_CMD_ABORT_EN, true);
}
writel(irq_clear, priv->base + SE_GENI_M_IRQ_CLEAR);
}
static u32 qcom_geni_serial_tx_empty(u64 base)
{
return !readl(base + SE_GENI_TX_FIFO_STATUS);
}
/**
* geni_se_setup_s_cmd() - Setup the secondary sequencer
* @se: Pointer to the concerned serial engine.
* @cmd: Command/Operation to setup in the secondary sequencer.
* @params: Parameter for the sequencer command.
*
* This function is used to configure the secondary sequencer with the
* command and its associated parameters.
*/
static inline void geni_se_setup_s_cmd(u64 base, u32 cmd, u32 params)
{
u32 s_cmd;
s_cmd = readl(base + SE_GENI_S_CMD0);
s_cmd &= ~(S_OPCODE_MSK | S_PARAMS_MSK);
s_cmd |= (cmd << S_OPCODE_SHIFT);
s_cmd |= (params & S_PARAMS_MSK);
writel(s_cmd, base + SE_GENI_S_CMD0);
}
static void qcom_geni_serial_start_tx(u64 base)
{
u32 irq_en;
u32 status;
status = readl(base + SE_GENI_STATUS);
if (status & M_GENI_CMD_ACTIVE)
return;
if (!qcom_geni_serial_tx_empty(base))
return;
irq_en = readl(base + SE_GENI_M_IRQ_EN);
irq_en |= M_TX_FIFO_WATERMARK_EN | M_CMD_DONE_EN;
writel(DEF_TX_WM, base + SE_GENI_TX_WATERMARK_REG);
writel(irq_en, base + SE_GENI_M_IRQ_EN);
}
static void qcom_geni_serial_start_rx(struct udevice *dev)
{
u32 status;
struct msm_serial_data *priv = dev_get_priv(dev);
status = readl(priv->base + SE_GENI_STATUS);
geni_se_setup_s_cmd(priv->base, UART_START_READ, 0);
setbits_le32(priv->base + SE_GENI_S_IRQ_EN, S_RX_FIFO_WATERMARK_EN | S_RX_FIFO_LAST_EN);
setbits_le32(priv->base + SE_GENI_M_IRQ_EN, M_RX_FIFO_WATERMARK_EN | M_RX_FIFO_LAST_EN);
}
static void qcom_geni_serial_abort_rx(struct udevice *dev)
{
struct msm_serial_data *priv = dev_get_priv(dev);
u32 irq_clear = S_CMD_DONE_EN | S_CMD_ABORT_EN;
writel(S_GENI_CMD_ABORT, priv->base + SE_GENI_S_CMD_CTRL_REG);
qcom_geni_serial_poll_bit(dev, SE_GENI_S_CMD_CTRL_REG,
S_GENI_CMD_ABORT, false);
writel(irq_clear, priv->base + SE_GENI_S_IRQ_CLEAR);
writel(FORCE_DEFAULT, priv->base + GENI_FORCE_DEFAULT_REG);
}
static void msm_geni_serial_setup_rx(struct udevice *dev)
{
struct msm_serial_data *priv = dev_get_priv(dev);
qcom_geni_serial_abort_rx(dev);
writel(UART_PACKING_CFG0, priv->base + SE_GENI_RX_PACKING_CFG0);
writel(UART_PACKING_CFG1, priv->base + SE_GENI_RX_PACKING_CFG1);
geni_se_setup_s_cmd(priv->base, UART_START_READ, 0);
setbits_le32(priv->base + SE_GENI_S_IRQ_EN, S_RX_FIFO_WATERMARK_EN | S_RX_FIFO_LAST_EN);
setbits_le32(priv->base + SE_GENI_M_IRQ_EN, M_RX_FIFO_WATERMARK_EN | M_RX_FIFO_LAST_EN);
}
static int msm_serial_putc(struct udevice *dev, const char ch)
{
struct msm_serial_data *priv = dev_get_priv(dev);
writel(DEF_TX_WM, priv->base + SE_GENI_TX_WATERMARK_REG);
qcom_geni_serial_setup_tx(priv->base, 1);
qcom_geni_serial_poll_bit(dev, SE_GENI_M_IRQ_STATUS,
M_TX_FIFO_WATERMARK_EN, true);
writel(ch, priv->base + SE_GENI_TX_FIFOn);
writel(M_TX_FIFO_WATERMARK_EN, priv->base + SE_GENI_M_IRQ_CLEAR);
qcom_geni_serial_poll_tx_done(dev);
return 0;
}
static int msm_serial_getc(struct udevice *dev)
{
struct msm_serial_data *priv = dev_get_priv(dev);
u32 rx_fifo;
u32 m_irq_status;
u32 s_irq_status;
writel(1 << S_OPCODE_SHIFT, priv->base + SE_GENI_S_CMD0);
qcom_geni_serial_poll_bit(dev, SE_GENI_M_IRQ_STATUS, M_SEC_IRQ_EN,
true);
m_irq_status = readl(priv->base + SE_GENI_M_IRQ_STATUS);
s_irq_status = readl(priv->base + SE_GENI_S_IRQ_STATUS);
writel(m_irq_status, priv->base + SE_GENI_M_IRQ_CLEAR);
writel(s_irq_status, priv->base + SE_GENI_S_IRQ_CLEAR);
qcom_geni_serial_poll_bit(dev, SE_GENI_RX_FIFO_STATUS, RX_FIFO_WC_MSK,
true);
if (!readl(priv->base + SE_GENI_RX_FIFO_STATUS))
return 0;
rx_fifo = readl(priv->base + SE_GENI_RX_FIFOn);
return rx_fifo & 0xff;
}
static int msm_serial_pending(struct udevice *dev, bool input)
{
struct msm_serial_data *priv = dev_get_priv(dev);
if (input)
return readl(priv->base + SE_GENI_RX_FIFO_STATUS) &
RX_FIFO_WC_MSK;
else
return readl(priv->base + SE_GENI_TX_FIFO_STATUS) &
TX_FIFO_WC_MSK;
return 0;
}
static const struct dm_serial_ops msm_serial_ops = {
.putc = msm_serial_putc,
.pending = msm_serial_pending,
.getc = msm_serial_getc,
.setbrg = msm_serial_setbrg,
};
static int geni_set_oversampling(struct udevice *dev)
{
struct msm_serial_data *priv = dev_get_priv(dev);
ofnode parent_node = ofnode_get_parent(dev_ofnode(dev));
u32 geni_se_version;
fdt_addr_t addr;
priv->oversampling = UART_OVERSAMPLING;
/*
* It could happen that GENI SE IP is missing in the board's device
* tree or GENI UART node is a direct child of SoC device tree node.
*/
if (!ofnode_device_is_compatible(parent_node, "qcom,geni-se-qup")) {
pr_err("%s: UART node must be a child of geniqup node\n",
__func__);
return -ENODEV;
}
/* Read the HW_VER register relative to the parents address space */
addr = ofnode_get_addr(parent_node);
geni_se_version = readl(addr + QUP_HW_VER_REG);
if (geni_se_version >= QUP_SE_VERSION_2_5)
priv->oversampling /= 2;
return 0;
}
static inline void geni_serial_init(struct udevice *dev)
{
struct msm_serial_data *priv = dev_get_priv(dev);
phys_addr_t base_address = priv->base;
u32 tx_trans_cfg;
u32 tx_parity_cfg = 0; /* Disable Tx Parity */
u32 rx_trans_cfg = 0;
u32 rx_parity_cfg = 0; /* Disable Rx Parity */
u32 stop_bit_len = 0; /* Default stop bit length - 1 bit */
u32 bits_per_char;
/*
* Ignore Flow control.
* n = 8.
*/
tx_trans_cfg = UART_CTS_MASK;
bits_per_char = BITS_PER_BYTE;
/*
* Make an unconditional cancel on the main sequencer to reset
* it else we could end up in data loss scenarios.
*/
qcom_geni_serial_poll_tx_done(dev);
qcom_geni_serial_abort_rx(dev);
writel(UART_PACKING_CFG0, base_address + SE_GENI_TX_PACKING_CFG0);
writel(UART_PACKING_CFG1, base_address + SE_GENI_TX_PACKING_CFG1);
writel(UART_PACKING_CFG0, base_address + SE_GENI_RX_PACKING_CFG0);
writel(UART_PACKING_CFG1, base_address + SE_GENI_RX_PACKING_CFG1);
writel(tx_trans_cfg, base_address + SE_UART_TX_TRANS_CFG);
writel(tx_parity_cfg, base_address + SE_UART_TX_PARITY_CFG);
writel(rx_trans_cfg, base_address + SE_UART_RX_TRANS_CFG);
writel(rx_parity_cfg, base_address + SE_UART_RX_PARITY_CFG);
writel(bits_per_char, base_address + SE_UART_TX_WORD_LEN);
writel(bits_per_char, base_address + SE_UART_RX_WORD_LEN);
writel(stop_bit_len, base_address + SE_UART_TX_STOP_BIT_LEN);
}
static int msm_serial_probe(struct udevice *dev)
{
struct msm_serial_data *priv = dev_get_priv(dev);
int ret;
ret = geni_set_oversampling(dev);
if (ret < 0)
return ret;
/* No need to reinitialize the UART after relocation */
if (gd->flags & GD_FLG_RELOC)
return 0;
geni_serial_init(dev);
msm_geni_serial_setup_rx(dev);
qcom_geni_serial_start_rx(dev);
qcom_geni_serial_start_tx(priv->base);
return 0;
}
static int msm_serial_ofdata_to_platdata(struct udevice *dev)
{
struct msm_serial_data *priv = dev_get_priv(dev);
priv->base = dev_read_addr(dev);
if (priv->base == FDT_ADDR_T_NONE)
return -EINVAL;
return 0;
}
static const struct udevice_id msm_serial_ids[] = {
{ .compatible = "qcom,geni-debug-uart" },
{ }
};
U_BOOT_DRIVER(serial_msm_geni) = {
.name = "serial_msm_geni",
.id = UCLASS_SERIAL,
.of_match = msm_serial_ids,
.of_to_plat = msm_serial_ofdata_to_platdata,
.priv_auto = sizeof(struct msm_serial_data),
.probe = msm_serial_probe,
.ops = &msm_serial_ops,
.flags = DM_FLAG_PRE_RELOC,
};
#ifdef CONFIG_DEBUG_UART_MSM_GENI
static struct msm_serial_data init_serial_data = {
.base = CONFIG_VAL(DEBUG_UART_BASE)
};
/* Serial dumb device, to reuse driver code */
static struct udevice init_dev = {
.priv_ = &init_serial_data,
};
#include <debug_uart.h>
#define CLK_DIV (CONFIG_DEBUG_UART_CLOCK / \
(CONFIG_BAUDRATE * UART_OVERSAMPLING))
#if (CONFIG_DEBUG_UART_CLOCK % (CONFIG_BAUDRATE * UART_OVERSAMPLING) > 0)
#error Clocks cannot be set at early debug. Change CONFIG_BAUDRATE
#endif
static inline void _debug_uart_init(void)
{
phys_addr_t base = CONFIG_VAL(DEBUG_UART_BASE);
geni_serial_init(&init_dev);
geni_serial_baud(base, CLK_DIV, CONFIG_BAUDRATE);
qcom_geni_serial_start_tx(base);
}
static inline void _debug_uart_putc(int ch)
{
phys_addr_t base = CONFIG_VAL(DEBUG_UART_BASE);
writel(DEF_TX_WM, base + SE_GENI_TX_WATERMARK_REG);
qcom_geni_serial_setup_tx(base, 1);
qcom_geni_serial_poll_bit(&init_dev, SE_GENI_M_IRQ_STATUS,
M_TX_FIFO_WATERMARK_EN, true);
writel(ch, base + SE_GENI_TX_FIFOn);
writel(M_TX_FIFO_WATERMARK_EN, base + SE_GENI_M_IRQ_CLEAR);
qcom_geni_serial_poll_tx_done(&init_dev);
}
DEBUG_UART_FUNCS
#endif