[PATCH 2/3] i2c: thunderx: Add support for High speed mode

Piyush Malgujar
2023-03-30T13:43:44Z

From: Suneel Garapati <sgarapati@marvell.com>

Support High speed mode clock setup for OcteonTX2 platforms.

Signed-off-by: Suneel Garapati <sgarapati@marvell.com>
Signed-off-by: Piyush Malgujar <pmalgujar@marvell.com>
---
drivers/i2c/busses/i2c-octeon-core.c | 78 ++++++++++++++++--------
drivers/i2c/busses/i2c-octeon-core.h | 3 +
drivers/i2c/busses/i2c-thunderx-pcidrv.c | 3 +-
3 files changed, 57 insertions(+), 27 deletions(-)

diff --git a/drivers/i2c/busses/i2c-octeon-core.c b/drivers/i2c/busses/i2c-octeon-core.c
index dfd58bbec47b1f0554ae0c100c680b6ba9be61ec..7c49dc8ccbd2ef05fec675d282193b98f2b69835 100644
--- a/drivers/i2c/busses/i2c-octeon-core.c
+++ b/drivers/i2c/busses/i2c-octeon-core.c
@@ -61,10 +61,19 @@ static int octeon_i2c_wait(struct octeon_i2c *i2c)
return octeon_i2c_test_iflg(i2c) ? 0 : -ETIMEDOUT;
}

- i2c->int_enable(i2c);
- time_left = wait_event_timeout(i2c->queue, octeon_i2c_test_iflg(i2c),
- i2c->adap.timeout);
- i2c->int_disable(i2c);
+ if (IS_LS_FREQ(i2c->twsi_freq)) {
+ i2c->int_enable(i2c);
+ time_left = wait_event_timeout(i2c->queue,
+ octeon_i2c_test_iflg(i2c),
+ i2c->adap.timeout);
+ i2c->int_disable(i2c);
+ } else {
+ time_left = 1000; /* 1ms */
+ do {
+ if (time_left--)
+ __udelay(1);
+ } while (!octeon_i2c_test_iflg(i2c) && time_left);
+ }

if (i2c->broken_irq_check && !time_left &&
octeon_i2c_test_iflg(i2c)) {
@@ -608,25 +617,27 @@ 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;
+ }
}
}

@@ -666,11 +677,13 @@ void octeon_i2c_set_clock(struct octeon_i2c *i2c)
* Find divisors to produce target frequency, start with large delta
* to cover wider range of divisors, note thp = TCLK half period.
*/
- int thp = 0x18, mdiv = 2, ndiv = 0, delta_hz = huge_delta;
+ int ds = 10, thp = 0x18, mdiv = 2, ndiv = 0, delta_hz = huge_delta;

if (octeon_i2c_is_otx2(to_pci_dev(i2c->dev))) {
thp = 0x3;
mdiv_min = 0;
+ if (!IS_LS_FREQ(i2c->twsi_freq))
+ ds = 15;
}

for (ndiv_idx = 0; ndiv_idx < 8 && delta_hz != 0; ndiv_idx++) {
@@ -683,7 +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 (octeon_i2c_is_otx2(to_pci_dev(i2c->dev)))
thp_base = (i2c->sys_freq / tclk) - 2;
@@ -701,7 +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);
/* Use it if smaller diff from target */
if (diff < delta_hz) {
@@ -715,6 +730,17 @@ 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 (octeon_i2c_is_otx2(to_pci_dev(i2c->dev))) {
+ u64 mode;
+
+ mode = __raw_readq(i2c->twsi_base + MODE(i2c));
+ /* Set REFCLK_SRC and HS_MODE in TWSX_MODE register */
+ if (!IS_LS_FREQ(i2c->twsi_freq))
+ mode |= BIT(4) | BIT(0);
+ else
+ mode &= ~(BIT(4) | BIT(0));
+ octeon_i2c_writeq_flush(mode, i2c->twsi_base + 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 8a0033c94a8a291fb255b0da03858274035c46f4..89d7d3bb8e30bd5787978d17d5a9b20ab0d41e22 100644
--- a/drivers/i2c/busses/i2c-octeon-core.h
+++ b/drivers/i2c/busses/i2c-octeon-core.h
@@ -93,11 +93,13 @@ 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 MODE(x) (x->roff.mode)

struct octeon_i2c {
wait_queue_head_t queue;
@@ -212,6 +214,7 @@ static inline void octeon_i2c_write_int(struct octeon_i2c *i2c, u64 data)
octeon_i2c_writeq_flush(data, i2c->twsi_base + TWSI_INT(i2c));
}

+#define IS_LS_FREQ(twsi_freq) ((twsi_freq) <= 400000)
#define PCI_SUBSYS_DEVID_9XXX 0xB
/**
* octeon_i2c_is_otx2 - check for chip ID
diff --git a/drivers/i2c/busses/i2c-thunderx-pcidrv.c b/drivers/i2c/busses/i2c-thunderx-pcidrv.c
index eecd27f9f1730e522dcccafc9f12ea891a3b59ef..3dd5a4d798f99e9b5282360cf9d5840042fc8dcc 100644
--- a/drivers/i2c/busses/i2c-thunderx-pcidrv.c
+++ b/drivers/i2c/busses/i2c-thunderx-pcidrv.c
@@ -165,6 +165,7 @@ 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);
@@ -209,7 +210,7 @@ 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 = 100000000;
octeon_i2c_set_clock(i2c);

--
2.17.1