From: Suneel Garapati <sgarapati@xxxxxxxxxxx> Handle changes to clock divisor logic for OcteonTX2 SoC family using subsystem ID and using default reference clock source as 100MHz. Signed-off-by: Suneel Garapati <sgarapati@xxxxxxxxxxx> Signed-off-by: Piyush Malgujar <pmalgujar@xxxxxxxxxxx> Acked-by: Andi Shyti <andi.shyti@xxxxxxxxxx> --- MAINTAINERS | 1 + drivers/i2c/busses/i2c-octeon-core.c | 29 ++++++++++++++++++++---- drivers/i2c/busses/i2c-octeon-core.h | 17 ++++++++++++++ drivers/i2c/busses/i2c-thunderx-pcidrv.c | 7 ++++++ 4 files changed, 50 insertions(+), 4 deletions(-) diff --git a/MAINTAINERS b/MAINTAINERS index 960512bec42885c0f1632a7c90851c3d32fbf20e..92b0a55c36e41cf54c7cbf52576d5424b591aa31 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -4725,6 +4725,7 @@ F: drivers/net/wireless/ath/carl9170/ CAVIUM I2C DRIVER M: Robert Richter <rric@xxxxxxxxxx> +M: Suneel Garapati <sgarapati@xxxxxxxxxxx> S: Odd Fixes W: http://www.marvell.com F: drivers/i2c/busses/i2c-octeon* diff --git a/drivers/i2c/busses/i2c-octeon-core.c b/drivers/i2c/busses/i2c-octeon-core.c index 845eda70b8cab52a0453c9f4cb545010fba4305d..1d8e1f4ad859dc44c08629637530842a0ed50bc4 100644 --- a/drivers/i2c/busses/i2c-octeon-core.c +++ b/drivers/i2c/busses/i2c-octeon-core.c @@ -17,6 +17,7 @@ #include <linux/interrupt.h> #include <linux/kernel.h> #include <linux/module.h> +#include <linux/pci.h> #include "i2c-octeon-core.h" @@ -658,31 +659,51 @@ int octeon_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) void octeon_i2c_set_clock(struct octeon_i2c *i2c) { int tclk, thp_base, inc, thp_idx, mdiv_idx, ndiv_idx, foscl, diff; - int thp = 0x18, mdiv = 2, ndiv = 0, delta_hz = 1000000; + int mdiv_min = 2; + /* starting value on search for lowest diff */ + const int huge_delta = INITIAL_DELTA_HZ; + /* + * Find divisors to produce target frequency, start with large delta + * to cover wider range of divisors, note thp = TCLK half period. + */ + unsigned int 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; + } for (ndiv_idx = 0; ndiv_idx < 8 && delta_hz != 0; ndiv_idx++) { /* * An mdiv value of less than 2 seems to not work well * with ds1337 RTCs, so we constrain it to larger values. */ - for (mdiv_idx = 15; mdiv_idx >= 2 && delta_hz != 0; mdiv_idx--) { + for (mdiv_idx = 15; mdiv_idx >= mdiv_min && delta_hz != 0; mdiv_idx--) { /* * For given ndiv and mdiv values check the * two closest thp values. */ tclk = i2c->twsi_freq * (mdiv_idx + 1) * 10; tclk *= (1 << ndiv_idx); - thp_base = (i2c->sys_freq / (tclk * 2)) - 1; + if (octeon_i2c_is_otx2(to_pci_dev(i2c->dev))) + thp_base = (i2c->sys_freq / tclk) - 2; + else + thp_base = (i2c->sys_freq / (tclk * 2)) - 1; for (inc = 0; inc <= 1; inc++) { thp_idx = thp_base + inc; if (thp_idx < 5 || thp_idx > 0xff) continue; - foscl = i2c->sys_freq / (2 * (thp_idx + 1)); + if (octeon_i2c_is_otx2(to_pci_dev(i2c->dev))) + foscl = i2c->sys_freq / (thp_idx + 2); + else + foscl = i2c->sys_freq / + (2 * (thp_idx + 1)); foscl = foscl / (1 << ndiv_idx); foscl = foscl / (mdiv_idx + 1) / 10; diff = abs(foscl - i2c->twsi_freq); + /* Use it if smaller diff from target */ if (diff < delta_hz) { delta_hz = diff; thp = thp_idx; diff --git a/drivers/i2c/busses/i2c-octeon-core.h b/drivers/i2c/busses/i2c-octeon-core.h index 9bb9f64fdda0392364638ecbaafe3fab5612baf6..694c24cecb7b144c1021549d1661b040c21bb998 100644 --- a/drivers/i2c/busses/i2c-octeon-core.h +++ b/drivers/i2c/busses/i2c-octeon-core.h @@ -7,6 +7,7 @@ #include <linux/i2c-smbus.h> #include <linux/io.h> #include <linux/kernel.h> +#include <linux/pci.h> /* Controller command patterns */ #define SW_TWSI_V BIT_ULL(63) /* Valid bit */ @@ -98,6 +99,8 @@ struct octeon_i2c_reg_offset { #define TWSI_INT(x) (x->roff.twsi_int) #define SW_TWSI_EXT(x) (x->roff.sw_twsi_ext) +#define INITIAL_DELTA_HZ 1000000 + struct octeon_i2c { wait_queue_head_t queue; struct i2c_adapter adap; @@ -211,6 +214,20 @@ 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 PCI_SUBSYS_DEVID_9XXX 0xB +/** + * octeon_i2c_is_otx2 - check for chip ID + * @pdev: PCI dev structure + * + * Returns TRUE if OcteonTX2, FALSE otherwise. + */ +static inline bool octeon_i2c_is_otx2(struct pci_dev *pdev) +{ + u32 chip_id = (pdev->subsystem_device >> 12) & 0xF; + + return (chip_id == PCI_SUBSYS_DEVID_9XXX); +} + /* Prototypes */ irqreturn_t octeon_i2c_isr(int irq, void *dev_id); int octeon_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num); diff --git a/drivers/i2c/busses/i2c-thunderx-pcidrv.c b/drivers/i2c/busses/i2c-thunderx-pcidrv.c index a77cd86fe75ed7401bc041b27c651b9fedf67285..75569774003857dc984e8540ef8f4d1bb084cfb0 100644 --- a/drivers/i2c/busses/i2c-thunderx-pcidrv.c +++ b/drivers/i2c/busses/i2c-thunderx-pcidrv.c @@ -28,6 +28,7 @@ #define PCI_DEVICE_ID_THUNDER_TWSI 0xa012 #define SYS_FREQ_DEFAULT 700000000 +#define OTX2_REF_FREQ_DEFAULT 100000000 #define TWSI_INT_ENA_W1C 0x1028 #define TWSI_INT_ENA_W1S 0x1030 @@ -205,6 +206,12 @@ static int thunder_i2c_probe_pci(struct pci_dev *pdev, if (ret) goto error; + /* + * For OcteonTX2 chips, set reference frequency to 100MHz + * as refclk_src in TWSI_MODE register defaults to 100MHz. + */ + if (octeon_i2c_is_otx2(pdev)) + i2c->sys_freq = OTX2_REF_FREQ_DEFAULT; octeon_i2c_set_clock(i2c); i2c->adap = thunderx_i2c_ops; -- 2.42.0
