i2c: synquacer: SNI Synquacer I2C controller

Add driver for class of I2C controllers found on
Socionext Synquacer platform.

Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
This commit is contained in:
Jassi Brar 2021-06-04 18:44:48 +09:00 committed by Tom Rini
parent 971a344285
commit 4483fbab81
3 changed files with 346 additions and 0 deletions

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@ -455,6 +455,13 @@ config SYS_I2C_STM32F7
_ Optional clock stretching
_ Software reset
config SYS_I2C_SYNQUACER
bool "Socionext SynQuacer I2C controller"
depends on ARCH_SYNQUACER && DM_I2C
help
Support for Socionext Synquacer I2C controller. This I2C controller
will be used for RTC and LS-connector on DeveloperBox.
config SYS_I2C_TEGRA
bool "NVIDIA Tegra internal I2C controller"
depends on ARCH_TEGRA

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@ -43,6 +43,7 @@ obj-$(CONFIG_SYS_I2C_SANDBOX) += sandbox_i2c.o i2c-emul-uclass.o
obj-$(CONFIG_SYS_I2C_SH) += sh_i2c.o
obj-$(CONFIG_SYS_I2C_SOFT) += soft_i2c.o
obj-$(CONFIG_SYS_I2C_STM32F7) += stm32f7_i2c.o
obj-$(CONFIG_SYS_I2C_SYNQUACER) += synquacer_i2c.o
obj-$(CONFIG_SYS_I2C_TEGRA) += tegra_i2c.o
obj-$(CONFIG_SYS_I2C_UNIPHIER) += i2c-uniphier.o
obj-$(CONFIG_SYS_I2C_UNIPHIER_F) += i2c-uniphier-f.o

338
drivers/i2c/synquacer_i2c.c Normal file
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@ -0,0 +1,338 @@
// SPDX-License-Identifier: GPL-2.0+
/*
*/
#include <dm/device_compat.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/io.h>
#include <linux/sizes.h>
#include <linux/types.h>
#include <dm.h>
#include <fdtdec.h>
#include <i2c.h>
#include <clk.h>
#define REG_BSR 0x0
#define REG_BCR 0x4
#define REG_CCR 0x8
#define REG_ADR 0xc
#define REG_DAR 0x10
#define REG_CSR 0x14
#define REG_FSR 0x18
#define REG_BC2R 0x1c
/* I2C register bit definitions */
#define BSR_FBT BIT(0) // First Byte Transfer
#define BSR_GCA BIT(1) // General Call Address
#define BSR_AAS BIT(2) // Address as Slave
#define BSR_TRX BIT(3) // Transfer/Receive
#define BSR_LRB BIT(4) // Last Received Bit
#define BSR_AL BIT(5) // Arbitration Lost
#define BSR_RSC BIT(6) // Repeated Start Cond.
#define BSR_BB BIT(7) // Bus Busy
#define BCR_INT BIT(0) // Interrupt
#define BCR_INTE BIT(1) // Interrupt Enable
#define BCR_GCAA BIT(2) // Gen. Call Access Ack.
#define BCR_ACK BIT(3) // Acknowledge
#define BCR_MSS BIT(4) // Master Slave Select
#define BCR_SCC BIT(5) // Start Condition Cont.
#define BCR_BEIE BIT(6) // Bus Error Int Enable
#define BCR_BER BIT(7) // Bus Error
#define CCR_CS_MASK (0x1f) // CCR Clock Period Sel.
#define CCR_EN BIT(5) // Enable
#define CCR_FM BIT(6) // Speed Mode Select
#define CSR_CS_MASK (0x3f) // CSR Clock Period Sel.
#define BC2R_SCLL BIT(0) // SCL Low Drive
#define BC2R_SDAL BIT(1) // SDA Low Drive
#define BC2R_SCLS BIT(4) // SCL Status
#define BC2R_SDAS BIT(5) // SDA Status
/* PCLK frequency */
#define BUS_CLK_FR(rate) (((rate) / 20000000) + 1)
#define I2C_CLK_DEF 62500000
/* STANDARD MODE frequency */
#define CLK_MASTER_STD(rate) \
DIV_ROUND_UP(DIV_ROUND_UP((rate), I2C_SPEED_STANDARD_RATE) - 2, 2)
/* FAST MODE frequency */
#define CLK_MASTER_FAST(rate) \
DIV_ROUND_UP((DIV_ROUND_UP((rate), I2C_SPEED_FAST_RATE) - 2) * 2, 3)
/* (clkrate <= 18000000) */
/* calculate the value of CS bits in CCR register on standard mode */
#define CCR_CS_STD_MAX_18M(rate) \
((CLK_MASTER_STD(rate) - 65) \
& CCR_CS_MASK)
/* calculate the value of CS bits in CSR register on standard mode */
#define CSR_CS_STD_MAX_18M(rate) 0x00
/* calculate the value of CS bits in CCR register on fast mode */
#define CCR_CS_FAST_MAX_18M(rate) \
((CLK_MASTER_FAST(rate) - 1) \
& CCR_CS_MASK)
/* calculate the value of CS bits in CSR register on fast mode */
#define CSR_CS_FAST_MAX_18M(rate) 0x00
/* (clkrate > 18000000) */
/* calculate the value of CS bits in CCR register on standard mode */
#define CCR_CS_STD_MIN_18M(rate) \
((CLK_MASTER_STD(rate) - 1) \
& CCR_CS_MASK)
/* calculate the value of CS bits in CSR register on standard mode */
#define CSR_CS_STD_MIN_18M(rate) \
(((CLK_MASTER_STD(rate) - 1) >> 5) \
& CSR_CS_MASK)
/* calculate the value of CS bits in CCR register on fast mode */
#define CCR_CS_FAST_MIN_18M(rate) \
((CLK_MASTER_FAST(rate) - 1) \
& CCR_CS_MASK)
/* calculate the value of CS bits in CSR register on fast mode */
#define CSR_CS_FAST_MIN_18M(rate) \
(((CLK_MASTER_FAST(rate) - 1) >> 5) \
& CSR_CS_MASK)
/* min I2C clock frequency 14M */
#define MIN_CLK_RATE (14 * 1000000)
/* max I2C clock frequency 200M */
#define MAX_CLK_RATE (200 * 1000000)
/* I2C clock frequency 18M */
#define CLK_RATE_18M (18 * 1000000)
#define SPEED_FM 400 // Fast Mode
#define SPEED_SM 100 // Standard Mode
DECLARE_GLOBAL_DATA_PTR;
struct synquacer_i2c {
void __iomem *base;
unsigned long pclkrate;
unsigned long speed_khz;
};
static int wait_irq(struct udevice *dev)
{
struct synquacer_i2c *i2c = dev_get_priv(dev);
int timeout = 500000;
do {
if (readb(i2c->base + REG_BCR) & BCR_INT)
return 0;
} while (timeout--);
pr_err("%s: timeout\n", __func__);
return -1;
}
static int synquacer_i2c_xfer_start(struct synquacer_i2c *i2c,
int addr, int read)
{
u8 bsr, bcr;
writeb((addr << 1) | (read ? 1 : 0), i2c->base + REG_DAR);
bsr = readb(i2c->base + REG_BSR);
bcr = readb(i2c->base + REG_BCR);
if ((bsr & BSR_BB) && !(bcr & BCR_MSS))
return -EBUSY;
if (bsr & BSR_BB) {
writeb(bcr | BCR_SCC, i2c->base + REG_BCR);
} else {
if (bcr & BCR_MSS)
return -EAGAIN;
/* Start Condition + Enable Interrupts */
writeb(bcr | BCR_MSS | BCR_INTE | BCR_BEIE, i2c->base + REG_BCR);
}
udelay(100);
return 0;
}
static int synquacer_i2c_xfer(struct udevice *bus,
struct i2c_msg *msg, int nmsgs)
{
struct synquacer_i2c *i2c = dev_get_priv(bus);
u8 bsr, bcr;
int idx;
for (; nmsgs > 0; nmsgs--, msg++) {
synquacer_i2c_xfer_start(i2c, msg->addr, msg->flags & I2C_M_RD);
if (wait_irq(bus))
return -EREMOTEIO;
bsr = readb(i2c->base + REG_BSR);
if (bsr & BSR_LRB) {
debug("%s: No ack received\n", __func__);
return -EREMOTEIO;
}
idx = 0;
do {
bsr = readb(i2c->base + REG_BSR);
bcr = readb(i2c->base + REG_BCR);
if (bcr & BCR_BER) {
debug("%s: Bus error detected\n", __func__);
return -EREMOTEIO;
}
if ((bsr & BSR_AL) || !(bcr & BCR_MSS)) {
debug("%s: Arbitration lost\n", __func__);
return -EREMOTEIO;
}
if (msg->flags & I2C_M_RD) {
bcr = BCR_MSS | BCR_INTE | BCR_BEIE;
if (idx < msg->len - 1)
bcr |= BCR_ACK;
writeb(bcr, i2c->base + REG_BCR);
if (wait_irq(bus))
return -EREMOTEIO;
bsr = readb(i2c->base + REG_BSR);
if (!(bsr & BSR_FBT))
msg->buf[idx++] = readb(i2c->base + REG_DAR);
} else {
writeb(msg->buf[idx++], i2c->base + REG_DAR);
bcr = BCR_MSS | BCR_INTE | BCR_BEIE;
writeb(bcr, i2c->base + REG_BCR);
if (wait_irq(bus))
return -EREMOTEIO;
bsr = readb(i2c->base + REG_BSR);
if (bsr & BSR_LRB) {
debug("%s: no ack\n", __func__);
return -EREMOTEIO;
}
}
} while (idx < msg->len);
}
/* Force bus state to idle, terminating any ongoing transfer */
writeb(0, i2c->base + REG_BCR);
udelay(100);
return 0;
}
static void synquacer_i2c_hw_reset(struct synquacer_i2c *i2c)
{
/* Disable clock */
writeb(0, i2c->base + REG_CCR);
writeb(0, i2c->base + REG_CSR);
/* Set own Address */
writeb(0, i2c->base + REG_ADR);
/* Set PCLK frequency */
writeb(BUS_CLK_FR(i2c->pclkrate), i2c->base + REG_FSR);
/* clear IRQ (INT=0, BER=0), Interrupt Disable */
writeb(0, i2c->base + REG_BCR);
writeb(0, i2c->base + REG_BC2R);
}
static int synquacer_i2c_get_bus_speed(struct udevice *bus)
{
struct synquacer_i2c *i2c = dev_get_priv(bus);
return i2c->speed_khz * 1000;
}
static int synquacer_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
{
struct synquacer_i2c *i2c = dev_get_priv(bus);
u32 rt = i2c->pclkrate;
u8 ccr_cs, csr_cs;
/* Set PCLK frequency */
writeb(BUS_CLK_FR(i2c->pclkrate), i2c->base + REG_FSR);
if (speed >= SPEED_FM * 1000) {
i2c->speed_khz = SPEED_FM;
if (i2c->pclkrate <= CLK_RATE_18M) {
ccr_cs = CCR_CS_FAST_MAX_18M(rt);
csr_cs = CSR_CS_FAST_MAX_18M(rt);
} else {
ccr_cs = CCR_CS_FAST_MIN_18M(rt);
csr_cs = CSR_CS_FAST_MIN_18M(rt);
}
/* Set Clock and enable, Set fast mode */
writeb(ccr_cs | CCR_FM | CCR_EN, i2c->base + REG_CCR);
writeb(csr_cs, i2c->base + REG_CSR);
} else {
i2c->speed_khz = SPEED_SM;
if (i2c->pclkrate <= CLK_RATE_18M) {
ccr_cs = CCR_CS_STD_MAX_18M(rt);
csr_cs = CSR_CS_STD_MAX_18M(rt);
} else {
ccr_cs = CCR_CS_STD_MIN_18M(rt);
csr_cs = CSR_CS_STD_MIN_18M(rt);
}
/* Set Clock and enable, Set standard mode */
writeb(ccr_cs | CCR_EN, i2c->base + REG_CCR);
writeb(csr_cs, i2c->base + REG_CSR);
}
return 0;
}
static int synquacer_i2c_of_to_plat(struct udevice *bus)
{
struct synquacer_i2c *priv = dev_get_priv(bus);
struct clk ck;
int ret;
ret = clk_get_by_index(bus, 0, &ck);
if (ret < 0) {
priv->pclkrate = I2C_CLK_DEF;
} else {
clk_enable(&ck);
priv->pclkrate = clk_get_rate(&ck);
}
return 0;
}
static int synquacer_i2c_probe(struct udevice *bus)
{
struct synquacer_i2c *i2c = dev_get_priv(bus);
i2c->base = dev_read_addr_ptr(bus);
synquacer_i2c_hw_reset(i2c);
synquacer_i2c_set_bus_speed(bus, 400000); /* set default speed */
return 0;
}
static const struct dm_i2c_ops synquacer_i2c_ops = {
.xfer = synquacer_i2c_xfer,
.set_bus_speed = synquacer_i2c_set_bus_speed,
.get_bus_speed = synquacer_i2c_get_bus_speed,
};
static const struct udevice_id synquacer_i2c_ids[] = {
{
.compatible = "socionext,synquacer-i2c",
},
{ }
};
U_BOOT_DRIVER(sni_synquacer_i2c) = {
.name = "sni_synquacer_i2c",
.id = UCLASS_I2C,
.of_match = synquacer_i2c_ids,
.of_to_plat = synquacer_i2c_of_to_plat,
.probe = synquacer_i2c_probe,
.priv_auto = sizeof(struct synquacer_i2c),
.ops = &synquacer_i2c_ops,
};