[PATCH v6 2/4] i2c: thunderx: Support for High speed mode
From: Piyush Malgujar
Date: Tue Apr 02 2024 - 09:41:07 EST
From: Suneel Garapati <sgarapati@xxxxxxxxxxx>
To support bus operations for high speed bus frequencies greater than
400KHZ following control bits need to be setup accordingly
- hs_mode (bit 0) field in Mode register to switch controller
between low-speed and high-speed frequency operating mode.
- Setup clock divisors for desired TWSI bus frequency using
FOSCL output frequency divisor (D):
0 - sets the divisor to 10 for low speed mode
1 - sets the divisor to 15 for high speed mode.
The TWSI bus output frequency, in master mode is based on:
TCLK = 100MHz / (THP + 2)
FOSCL = FSAMP / (M+1)×D = TCLK / (2 ^ N × (M + 1) × 15)
FSAMP = TCLK / 2 ^ N
where,
N is <2:0> and M is <6:3> of TWSI Clock Control Register
D is 10 for low speed or 15 for HS_MODE
With high speed mode support, HLC mode usage is limited to
low speed frequency (<=400KHz) bus transfers in hardware.
Signed-off-by: Suneel Garapati <sgarapati@xxxxxxxxxxx>
Signed-off-by: Piyush Malgujar <pmalgujar@xxxxxxxxxxx>
---
drivers/i2c/busses/i2c-octeon-core.c | 100 ++++++++++++++---------
drivers/i2c/busses/i2c-octeon-core.h | 32 +++++---
drivers/i2c/busses/i2c-thunderx-pcidrv.c | 3 +-
3 files changed, 82 insertions(+), 53 deletions(-)
diff --git a/drivers/i2c/busses/i2c-octeon-core.c b/drivers/i2c/busses/i2c-octeon-core.c
index 75efb375d8e49479267e214772d4df48352be358..76a5ec100d3039b840ba28ae7a817da447923d4f 100644
--- a/drivers/i2c/busses/i2c-octeon-core.c
+++ b/drivers/i2c/busses/i2c-octeon-core.c
@@ -85,7 +85,7 @@ static int octeon_i2c_wait(struct octeon_i2c *i2c)
static bool octeon_i2c_hlc_test_valid(struct octeon_i2c *i2c)
{
- return (__raw_readq(i2c->twsi_base + SW_TWSI(i2c)) & SW_TWSI_V) == 0;
+ return (__raw_readq(i2c->twsi_base + OCTEON_REG_SW_TWSI(i2c)) & SW_TWSI_V) == 0;
}
static void octeon_i2c_hlc_int_clear(struct octeon_i2c *i2c)
@@ -185,10 +185,10 @@ static int octeon_i2c_check_status(struct octeon_i2c *i2c, int final_read)
/*
* This is ugly... in HLC mode the status is not in the status register
- * but in the lower 8 bits of SW_TWSI.
+ * but in the lower 8 bits of OCTEON_REG_SW_TWSI.
*/
if (i2c->hlc_enabled)
- stat = __raw_readq(i2c->twsi_base + SW_TWSI(i2c));
+ stat = __raw_readq(i2c->twsi_base + OCTEON_REG_SW_TWSI(i2c));
else
stat = octeon_i2c_stat_read(i2c);
@@ -424,12 +424,12 @@ static int octeon_i2c_hlc_read(struct octeon_i2c *i2c, struct i2c_msg *msgs)
else
cmd |= SW_TWSI_OP_7;
- octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI(i2c));
+ octeon_i2c_writeq_flush(cmd, i2c->twsi_base + OCTEON_REG_SW_TWSI(i2c));
ret = octeon_i2c_hlc_wait(i2c);
if (ret)
goto err;
- cmd = __raw_readq(i2c->twsi_base + SW_TWSI(i2c));
+ cmd = __raw_readq(i2c->twsi_base + OCTEON_REG_SW_TWSI(i2c));
if ((cmd & SW_TWSI_R) == 0)
return octeon_i2c_check_status(i2c, false);
@@ -437,7 +437,7 @@ static int octeon_i2c_hlc_read(struct octeon_i2c *i2c, struct i2c_msg *msgs)
msgs[0].buf[j] = (cmd >> (8 * i)) & 0xff;
if (msgs[0].len > 4) {
- cmd = __raw_readq(i2c->twsi_base + SW_TWSI_EXT(i2c));
+ cmd = __raw_readq(i2c->twsi_base + OCTEON_REG_SW_TWSI_EXT(i2c));
for (i = 0; i < msgs[0].len - 4 && i < 4; i++, j--)
msgs[0].buf[j] = (cmd >> (8 * i)) & 0xff;
}
@@ -474,15 +474,15 @@ static int octeon_i2c_hlc_write(struct octeon_i2c *i2c, struct i2c_msg *msgs)
for (i = 0; i < msgs[0].len - 4 && i < 4; i++, j--)
ext |= (u64)msgs[0].buf[j] << (8 * i);
- octeon_i2c_writeq_flush(ext, i2c->twsi_base + SW_TWSI_EXT(i2c));
+ octeon_i2c_writeq_flush(ext, i2c->twsi_base + OCTEON_REG_SW_TWSI_EXT(i2c));
}
- octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI(i2c));
+ octeon_i2c_writeq_flush(cmd, i2c->twsi_base + OCTEON_REG_SW_TWSI(i2c));
ret = octeon_i2c_hlc_wait(i2c);
if (ret)
goto err;
- cmd = __raw_readq(i2c->twsi_base + SW_TWSI(i2c));
+ cmd = __raw_readq(i2c->twsi_base + OCTEON_REG_SW_TWSI(i2c));
if ((cmd & SW_TWSI_R) == 0)
return octeon_i2c_check_status(i2c, false);
@@ -515,19 +515,19 @@ static int octeon_i2c_hlc_comp_read(struct octeon_i2c *i2c, struct i2c_msg *msgs
cmd |= SW_TWSI_EIA;
ext = (u64)msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
cmd |= (u64)msgs[0].buf[1] << SW_TWSI_IA_SHIFT;
- octeon_i2c_writeq_flush(ext, i2c->twsi_base + SW_TWSI_EXT(i2c));
+ octeon_i2c_writeq_flush(ext, i2c->twsi_base + OCTEON_REG_SW_TWSI_EXT(i2c));
} else {
cmd |= (u64)msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
}
octeon_i2c_hlc_int_clear(i2c);
- octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI(i2c));
+ octeon_i2c_writeq_flush(cmd, i2c->twsi_base + OCTEON_REG_SW_TWSI(i2c));
ret = octeon_i2c_hlc_wait(i2c);
if (ret)
goto err;
- cmd = __raw_readq(i2c->twsi_base + SW_TWSI(i2c));
+ cmd = __raw_readq(i2c->twsi_base + OCTEON_REG_SW_TWSI(i2c));
if ((cmd & SW_TWSI_R) == 0)
return octeon_i2c_check_status(i2c, false);
@@ -535,7 +535,7 @@ static int octeon_i2c_hlc_comp_read(struct octeon_i2c *i2c, struct i2c_msg *msgs
msgs[1].buf[j] = (cmd >> (8 * i)) & 0xff;
if (msgs[1].len > 4) {
- cmd = __raw_readq(i2c->twsi_base + SW_TWSI_EXT(i2c));
+ cmd = __raw_readq(i2c->twsi_base + OCTEON_REG_SW_TWSI_EXT(i2c));
for (i = 0; i < msgs[1].len - 4 && i < 4; i++, j--)
msgs[1].buf[j] = (cmd >> (8 * i)) & 0xff;
}
@@ -582,16 +582,16 @@ static int octeon_i2c_hlc_comp_write(struct octeon_i2c *i2c, struct i2c_msg *msg
set_ext = true;
}
if (set_ext)
- octeon_i2c_writeq_flush(ext, i2c->twsi_base + SW_TWSI_EXT(i2c));
+ octeon_i2c_writeq_flush(ext, i2c->twsi_base + OCTEON_REG_SW_TWSI_EXT(i2c));
octeon_i2c_hlc_int_clear(i2c);
- octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI(i2c));
+ octeon_i2c_writeq_flush(cmd, i2c->twsi_base + OCTEON_REG_SW_TWSI(i2c));
ret = octeon_i2c_hlc_wait(i2c);
if (ret)
goto err;
- cmd = __raw_readq(i2c->twsi_base + SW_TWSI(i2c));
+ cmd = __raw_readq(i2c->twsi_base + OCTEON_REG_SW_TWSI(i2c));
if ((cmd & SW_TWSI_R) == 0)
return octeon_i2c_check_status(i2c, false);
@@ -612,25 +612,27 @@ int octeon_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
struct octeon_i2c *i2c = i2c_get_adapdata(adap);
int i, ret = 0;
- if (num == 1) {
- if (msgs[0].len > 0 && msgs[0].len <= 8) {
- if (msgs[0].flags & I2C_M_RD)
- ret = octeon_i2c_hlc_read(i2c, msgs);
- else
- ret = octeon_i2c_hlc_write(i2c, msgs);
- goto out;
- }
- } else if (num == 2) {
- if ((msgs[0].flags & I2C_M_RD) == 0 &&
- (msgs[1].flags & I2C_M_RECV_LEN) == 0 &&
- msgs[0].len > 0 && msgs[0].len <= 2 &&
- msgs[1].len > 0 && msgs[1].len <= 8 &&
- msgs[0].addr == msgs[1].addr) {
- if (msgs[1].flags & I2C_M_RD)
- ret = octeon_i2c_hlc_comp_read(i2c, msgs);
- else
- ret = octeon_i2c_hlc_comp_write(i2c, msgs);
- goto out;
+ if (IS_LS_FREQ(i2c->twsi_freq)) {
+ if (num == 1) {
+ if (msgs[0].len > 0 && msgs[0].len <= 8) {
+ if (msgs[0].flags & I2C_M_RD)
+ ret = octeon_i2c_hlc_read(i2c, msgs);
+ else
+ ret = octeon_i2c_hlc_write(i2c, msgs);
+ goto out;
+ }
+ } else if (num == 2) {
+ if ((msgs[0].flags & I2C_M_RD) == 0 &&
+ (msgs[1].flags & I2C_M_RECV_LEN) == 0 &&
+ msgs[0].len > 0 && msgs[0].len <= 2 &&
+ msgs[1].len > 0 && msgs[1].len <= 8 &&
+ msgs[0].addr == msgs[1].addr) {
+ if (msgs[1].flags & I2C_M_RD)
+ ret = octeon_i2c_hlc_comp_read(i2c, msgs);
+ else
+ ret = octeon_i2c_hlc_comp_write(i2c, msgs);
+ goto out;
+ }
}
}
@@ -664,12 +666,12 @@ void octeon_i2c_set_clock(struct octeon_i2c *i2c)
{
int tclk, thp_base, inc, thp_idx, mdiv_idx, ndiv_idx, foscl, diff;
bool is_plat_otx2;
- unsigned int mdiv_min = 2;
/*
* Find divisors to produce target frequency, start with large delta
- * to cover wider range of divisors, note thp = TCLK half period.
+ * to cover wider range of divisors, note thp = TCLK half period and
+ * ds is OSCL output frequency divisor.
*/
- unsigned int thp = TWSI_MASTER_CLK_REG_DEF_VAL, mdiv = 2, ndiv = 0;
+ unsigned int thp, mdiv_min, mdiv = 2, ndiv = 0, ds = 10;
unsigned int delta_hz = INITIAL_DELTA_HZ;
is_plat_otx2 = octeon_i2c_is_otx2(to_pci_dev(i2c->dev));
@@ -677,6 +679,11 @@ void octeon_i2c_set_clock(struct octeon_i2c *i2c)
if (is_plat_otx2) {
thp = TWSI_MASTER_CLK_REG_OTX2_VAL;
mdiv_min = 0;
+ if (!IS_LS_FREQ(i2c->twsi_freq))
+ ds = 15;
+ } else {
+ thp = TWSI_MASTER_CLK_REG_DEF_VAL;
+ mdiv_min = 2;
}
for (ndiv_idx = 0; ndiv_idx < 8 && delta_hz != 0; ndiv_idx++) {
@@ -689,7 +696,7 @@ void octeon_i2c_set_clock(struct octeon_i2c *i2c)
* For given ndiv and mdiv values check the
* two closest thp values.
*/
- tclk = i2c->twsi_freq * (mdiv_idx + 1) * 10;
+ tclk = i2c->twsi_freq * (mdiv_idx + 1) * ds;
tclk *= (1 << ndiv_idx);
if (is_plat_otx2)
thp_base = (i2c->sys_freq / tclk) - 2;
@@ -707,7 +714,9 @@ void octeon_i2c_set_clock(struct octeon_i2c *i2c)
foscl = i2c->sys_freq /
(2 * (thp_idx + 1));
foscl = foscl / (1 << ndiv_idx);
- foscl = foscl / (mdiv_idx + 1) / 10;
+ foscl = foscl / (mdiv_idx + 1) / ds;
+ if (foscl > i2c->twsi_freq)
+ continue;
diff = abs(foscl - i2c->twsi_freq);
/*
* Diff holds difference between calculated frequency
@@ -725,6 +734,17 @@ void octeon_i2c_set_clock(struct octeon_i2c *i2c)
}
octeon_i2c_reg_write(i2c, SW_TWSI_OP_TWSI_CLK, thp);
octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_CLKCTL, (mdiv << 3) | ndiv);
+ if (is_plat_otx2) {
+ u64 mode;
+
+ mode = __raw_readq(i2c->twsi_base + OCTEON_REG_MODE(i2c));
+ /* Set REFCLK_SRC and HS_MODE in TWSX_MODE register */
+ if (!IS_LS_FREQ(i2c->twsi_freq))
+ mode |= TWSX_MODE_HS_MASK;
+ else
+ mode &= ~TWSX_MODE_HS_MASK;
+ octeon_i2c_writeq_flush(mode, i2c->twsi_base + OCTEON_REG_MODE(i2c));
+ }
}
int octeon_i2c_init_lowlevel(struct octeon_i2c *i2c)
diff --git a/drivers/i2c/busses/i2c-octeon-core.h b/drivers/i2c/busses/i2c-octeon-core.h
index 69bd62940f99eb786877026380cd1d02a4eaadb9..39481e23e36fad098cf72dfd764e368e778f2840 100644
--- a/drivers/i2c/busses/i2c-octeon-core.h
+++ b/drivers/i2c/busses/i2c-octeon-core.h
@@ -94,11 +94,18 @@ struct octeon_i2c_reg_offset {
unsigned int sw_twsi;
unsigned int twsi_int;
unsigned int sw_twsi_ext;
+ unsigned int mode;
};
-#define SW_TWSI(x) (x->roff.sw_twsi)
-#define TWSI_INT(x) (x->roff.twsi_int)
-#define SW_TWSI_EXT(x) (x->roff.sw_twsi_ext)
+#define OCTEON_REG_SW_TWSI(x) ((x)->roff.sw_twsi)
+#define OCTEON_REG_TWSI_INT(x) ((x)->roff.twsi_int)
+#define OCTEON_REG_SW_TWSI_EXT(x) ((x)->roff.sw_twsi_ext)
+#define OCTEON_REG_MODE(x) ((x)->roff.mode)
+
+/* Set REFCLK_SRC and HS_MODE in TWSX_MODE register */
+#define TWSX_MODE_REFCLK_SRC BIT(4)
+#define TWSX_MODE_HS_MODE BIT(0)
+#define TWSX_MODE_HS_MASK (TWSX_MODE_REFCLK_SRC | TWSX_MODE_HS_MODE)
struct octeon_i2c {
wait_queue_head_t queue;
@@ -136,16 +143,16 @@ static inline void octeon_i2c_writeq_flush(u64 val, void __iomem *addr)
* @eop_reg: Register selector
* @data: Value to be written
*
- * The I2C core registers are accessed indirectly via the SW_TWSI CSR.
+ * The I2C core registers are accessed indirectly via the OCTEON_REG_SW_TWSI CSR.
*/
static inline void octeon_i2c_reg_write(struct octeon_i2c *i2c, u64 eop_reg, u8 data)
{
int tries = 1000;
u64 tmp;
- __raw_writeq(SW_TWSI_V | eop_reg | data, i2c->twsi_base + SW_TWSI(i2c));
+ __raw_writeq(SW_TWSI_V | eop_reg | data, i2c->twsi_base + OCTEON_REG_SW_TWSI(i2c));
do {
- tmp = __raw_readq(i2c->twsi_base + SW_TWSI(i2c));
+ tmp = __raw_readq(i2c->twsi_base + OCTEON_REG_SW_TWSI(i2c));
if (--tries < 0)
return;
} while ((tmp & SW_TWSI_V) != 0);
@@ -171,9 +178,9 @@ static inline int octeon_i2c_reg_read(struct octeon_i2c *i2c, u64 eop_reg,
int tries = 1000;
u64 tmp;
- __raw_writeq(SW_TWSI_V | eop_reg | SW_TWSI_R, i2c->twsi_base + SW_TWSI(i2c));
+ __raw_writeq(SW_TWSI_V | eop_reg | SW_TWSI_R, i2c->twsi_base + OCTEON_REG_SW_TWSI(i2c));
do {
- tmp = __raw_readq(i2c->twsi_base + SW_TWSI(i2c));
+ tmp = __raw_readq(i2c->twsi_base + OCTEON_REG_SW_TWSI(i2c));
if (--tries < 0) {
/* signal that the returned data is invalid */
if (error)
@@ -193,26 +200,27 @@ static inline int octeon_i2c_reg_read(struct octeon_i2c *i2c, u64 eop_reg,
octeon_i2c_reg_read(i2c, SW_TWSI_EOP_TWSI_STAT, NULL)
/**
- * octeon_i2c_read_int - read the TWSI_INT register
+ * octeon_i2c_read_int - read the OCTEON_REG_TWSI_INT register
* @i2c: The struct octeon_i2c
*
* Returns the value of the register.
*/
static inline u64 octeon_i2c_read_int(struct octeon_i2c *i2c)
{
- return __raw_readq(i2c->twsi_base + TWSI_INT(i2c));
+ return __raw_readq(i2c->twsi_base + OCTEON_REG_TWSI_INT(i2c));
}
/**
- * octeon_i2c_write_int - write the TWSI_INT register
+ * octeon_i2c_write_int - write the OCTEON_REG_TWSI_INT register
* @i2c: The struct octeon_i2c
* @data: Value to be written
*/
static inline void octeon_i2c_write_int(struct octeon_i2c *i2c, u64 data)
{
- octeon_i2c_writeq_flush(data, i2c->twsi_base + TWSI_INT(i2c));
+ octeon_i2c_writeq_flush(data, i2c->twsi_base + OCTEON_REG_TWSI_INT(i2c));
}
+#define IS_LS_FREQ(twsi_freq) ((twsi_freq) <= 400000)
#define PCI_SUBSYS_DEVID_9XXX 0xB
#define PCI_SUBSYS_MASK GENMASK(15, 12)
/**
diff --git a/drivers/i2c/busses/i2c-thunderx-pcidrv.c b/drivers/i2c/busses/i2c-thunderx-pcidrv.c
index 75569774003857dc984e8540ef8f4d1bb084cfb0..31f11b77ab663626967c86086a03213876bf4a07 100644
--- a/drivers/i2c/busses/i2c-thunderx-pcidrv.c
+++ b/drivers/i2c/busses/i2c-thunderx-pcidrv.c
@@ -166,6 +166,7 @@ static int thunder_i2c_probe_pci(struct pci_dev *pdev,
i2c->roff.sw_twsi = 0x1000;
i2c->roff.twsi_int = 0x1010;
i2c->roff.sw_twsi_ext = 0x1018;
+ i2c->roff.mode = 0x1038;
i2c->dev = dev;
pci_set_drvdata(pdev, i2c);
@@ -210,7 +211,7 @@ static int thunder_i2c_probe_pci(struct pci_dev *pdev,
* For OcteonTX2 chips, set reference frequency to 100MHz
* as refclk_src in TWSI_MODE register defaults to 100MHz.
*/
- if (octeon_i2c_is_otx2(pdev))
+ if (octeon_i2c_is_otx2(pdev) && IS_LS_FREQ(i2c->twsi_freq))
i2c->sys_freq = OTX2_REF_FREQ_DEFAULT;
octeon_i2c_set_clock(i2c);
--
2.43.0