[PATCH v4 2/4] i2c: thunderx: Add support for High speed mode
From: Piyush Malgujar
Date: Fri Feb 23 2024 - 07:58:16 EST
From: Suneel Garapati <sgarapati@xxxxxxxxxxx>
Support High speed mode clock setup for OcteonTX2 platforms.
hs_mode bit in MODE register controls speed mode setup in controller
and frequency is setup using set_clock function which sets up dividers
for clock control register.
Signed-off-by: Suneel Garapati <sgarapati@xxxxxxxxxxx>
Signed-off-by: Piyush Malgujar <pmalgujar@xxxxxxxxxxx>
---
drivers/i2c/busses/i2c-octeon-core.c | 61 +++++++++++++++---------
drivers/i2c/busses/i2c-octeon-core.h | 6 +++
drivers/i2c/busses/i2c-thunderx-pcidrv.c | 3 +-
3 files changed, 47 insertions(+), 23 deletions(-)
diff --git a/drivers/i2c/busses/i2c-octeon-core.c b/drivers/i2c/busses/i2c-octeon-core.c
index 10330ed3203f9fd99d5c04dbaf29a9bd49ad0f4a..36e7beeab25c63c2341313d6aa3421049ad92990 100644
--- a/drivers/i2c/busses/i2c-octeon-core.c
+++ b/drivers/i2c/busses/i2c-octeon-core.c
@@ -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;
+ }
}
}
@@ -668,7 +670,7 @@ 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.
*/
- unsigned int thp = TWSI_MASTER_CLK_REG_DEF_VAL, mdiv = 2, ndiv = 0;
+ unsigned int ds = 10, thp = TWSI_MASTER_CLK_REG_DEF_VAL, mdiv = 2, ndiv = 0;
unsigned int delta_hz = INITIAL_DELTA_HZ;
bool is_plat_otx2 = octeon_i2c_is_otx2(to_pci_dev(i2c->dev));
@@ -676,6 +678,8 @@ 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;
}
for (ndiv_idx = 0; ndiv_idx < 8 && delta_hz != 0; ndiv_idx++) {
@@ -688,7 +692,7 @@ 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;
@@ -706,7 +710,9 @@ 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
@@ -724,6 +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 (is_plat_otx2) {
+ 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 |= TWSX_MODE_HS_MASK;
+ else
+ mode &= ~TWSX_MODE_HS_MASK;
+ 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..5927d24926ce898efbee111046092960e48ce3ff 100644
--- a/drivers/i2c/busses/i2c-octeon-core.h
+++ b/drivers/i2c/busses/i2c-octeon-core.h
@@ -93,11 +93,16 @@ 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)
+
+/* Set REFCLK_SRC and HS_MODE in TWSX_MODE register */
+#define TWSX_MODE_HS_MASK (BIT(4) | BIT(0))
struct octeon_i2c {
wait_queue_head_t queue;
@@ -212,6 +217,7 @@ 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 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