diff options
| -rw-r--r-- | drivers/clk/bcm/clk-bcm2835.c | 144 |
1 files changed, 119 insertions, 25 deletions
diff --git a/drivers/clk/bcm/clk-bcm2835.c b/drivers/clk/bcm/clk-bcm2835.c index 2e7423d8f5bb..025853870619 100644 --- a/drivers/clk/bcm/clk-bcm2835.c +++ b/drivers/clk/bcm/clk-bcm2835.c @@ -39,6 +39,7 @@ #include <linux/clk.h> #include <linux/clk/bcm2835.h> #include <linux/debugfs.h> +#include <linux/delay.h> #include <linux/module.h> #include <linux/of.h> #include <linux/platform_device.h> @@ -98,7 +99,8 @@ #define CM_SMIDIV 0x0b4 /* no definition for 0x0b8 and 0x0bc */ #define CM_TCNTCTL 0x0c0 -#define CM_TCNTDIV 0x0c4 +# define CM_TCNT_SRC1_SHIFT 12 +#define CM_TCNTCNT 0x0c4 #define CM_TECCTL 0x0c8 #define CM_TECDIV 0x0cc #define CM_TD0CTL 0x0d0 @@ -338,6 +340,61 @@ static inline u32 cprman_read(struct bcm2835_cprman *cprman, u32 reg) return readl(cprman->regs + reg); } +/* Does a cycle of measuring a clock through the TCNT clock, which may + * source from many other clocks in the system. + */ +static unsigned long bcm2835_measure_tcnt_mux(struct bcm2835_cprman *cprman, + u32 tcnt_mux) +{ + u32 osccount = 19200; /* 1ms */ + u32 count; + ktime_t timeout; + + spin_lock(&cprman->regs_lock); + + cprman_write(cprman, CM_TCNTCTL, CM_KILL); + + cprman_write(cprman, CM_TCNTCTL, + (tcnt_mux & CM_SRC_MASK) | + (tcnt_mux >> CM_SRC_BITS) << CM_TCNT_SRC1_SHIFT); + + cprman_write(cprman, CM_OSCCOUNT, osccount); + + /* do a kind delay at the start */ + mdelay(1); + + /* Finish off whatever is left of OSCCOUNT */ + timeout = ktime_add_ns(ktime_get(), LOCK_TIMEOUT_NS); + while (cprman_read(cprman, CM_OSCCOUNT)) { + if (ktime_after(ktime_get(), timeout)) { + dev_err(cprman->dev, "timeout waiting for OSCCOUNT\n"); + count = 0; + goto out; + } + cpu_relax(); + } + + /* Wait for BUSY to clear. */ + timeout = ktime_add_ns(ktime_get(), LOCK_TIMEOUT_NS); + while (cprman_read(cprman, CM_TCNTCTL) & CM_BUSY) { + if (ktime_after(ktime_get(), timeout)) { + dev_err(cprman->dev, "timeout waiting for !BUSY\n"); + count = 0; + goto out; + } + cpu_relax(); + } + + count = cprman_read(cprman, CM_TCNTCNT); + + cprman_write(cprman, CM_TCNTCTL, 0); + +out: + spin_unlock(&cprman->regs_lock); + + return count * 1000; +} + static int bcm2835_debugfs_regset(struct bcm2835_cprman *cprman, u32 base, struct debugfs_reg32 *regs, size_t nregs, struct dentry *dentry) @@ -473,6 +530,8 @@ struct bcm2835_clock_data { bool is_vpu_clock; bool is_mash_clock; + + u32 tcnt_mux; }; struct bcm2835_gate_data { @@ -1008,6 +1067,17 @@ static int bcm2835_clock_on(struct clk_hw *hw) CM_GATE); spin_unlock(&cprman->regs_lock); + /* Debug code to measure the clock once it's turned on to see + * if it's ticking at the rate we expect. + */ + if (data->tcnt_mux && false) { + dev_info(cprman->dev, + "clk %s: rate %ld, measure %ld\n", + data->name, + clk_hw_get_rate(hw), + bcm2835_measure_tcnt_mux(cprman, data->tcnt_mux)); + } + return 0; } @@ -1765,7 +1835,8 @@ static const struct bcm2835_clk_desc clk_desc_array[] = { .ctl_reg = CM_OTPCTL, .div_reg = CM_OTPDIV, .int_bits = 4, - .frac_bits = 0), + .frac_bits = 0, + .tcnt_mux = 6), /* * Used for a 1Mhz clock for the system clocksource, and also used * bythe watchdog timer and the camera pulse generator. @@ -1799,13 +1870,15 @@ static const struct bcm2835_clk_desc clk_desc_array[] = { .ctl_reg = CM_H264CTL, .div_reg = CM_H264DIV, .int_bits = 4, - .frac_bits = 8), + .frac_bits = 8, + .tcnt_mux = 1), [BCM2835_CLOCK_ISP] = REGISTER_VPU_CLK( .name = "isp", .ctl_reg = CM_ISPCTL, .div_reg = CM_ISPDIV, .int_bits = 4, - .frac_bits = 8), + .frac_bits = 8, + .tcnt_mux = 2), /* * Secondary SDRAM clock. Used for low-voltage modes when the PLL @@ -1816,13 +1889,15 @@ static const struct bcm2835_clk_desc clk_desc_array[] = { .ctl_reg = CM_SDCCTL, .div_reg = CM_SDCDIV, .int_bits = 6, - .frac_bits = 0), + .frac_bits = 0, + .tcnt_mux = 3), [BCM2835_CLOCK_V3D] = REGISTER_VPU_CLK( .name = "v3d", .ctl_reg = CM_V3DCTL, .div_reg = CM_V3DDIV, .int_bits = 4, - .frac_bits = 8), + .frac_bits = 8, + .tcnt_mux = 4), /* * VPU clock. This doesn't have an enable bit, since it drives * the bus for everything else, and is special so it doesn't need @@ -1836,7 +1911,8 @@ static const struct bcm2835_clk_desc clk_desc_array[] = { .int_bits = 12, .frac_bits = 8, .flags = CLK_IS_CRITICAL, - .is_vpu_clock = true), + .is_vpu_clock = true, + .tcnt_mux = 5), /* clocks with per parent mux */ [BCM2835_CLOCK_AVEO] = REGISTER_PER_CLK( @@ -1844,19 +1920,22 @@ static const struct bcm2835_clk_desc clk_desc_array[] = { .ctl_reg = CM_AVEOCTL, .div_reg = CM_AVEODIV, .int_bits = 4, - .frac_bits = 0), + .frac_bits = 0, + .tcnt_mux = 38), [BCM2835_CLOCK_CAM0] = REGISTER_PER_CLK( .name = "cam0", .ctl_reg = CM_CAM0CTL, .div_reg = CM_CAM0DIV, .int_bits = 4, - .frac_bits = 8), + .frac_bits = 8, + .tcnt_mux = 14), [BCM2835_CLOCK_CAM1] = REGISTER_PER_CLK( .name = "cam1", .ctl_reg = CM_CAM1CTL, .div_reg = CM_CAM1DIV, .int_bits = 4, - .frac_bits = 8), + .frac_bits = 8, + .tcnt_mux = 15), [BCM2835_CLOCK_DFT] = REGISTER_PER_CLK( .name = "dft", .ctl_reg = CM_DFTCTL, @@ -1868,7 +1947,8 @@ static const struct bcm2835_clk_desc clk_desc_array[] = { .ctl_reg = CM_DPICTL, .div_reg = CM_DPIDIV, .int_bits = 4, - .frac_bits = 8), + .frac_bits = 8, + .tcnt_mux = 17), /* Arasan EMMC clock */ [BCM2835_CLOCK_EMMC] = REGISTER_PER_CLK( @@ -1876,7 +1956,8 @@ static const struct bcm2835_clk_desc clk_desc_array[] = { .ctl_reg = CM_EMMCCTL, .div_reg = CM_EMMCDIV, .int_bits = 4, - .frac_bits = 8), + .frac_bits = 8, + .tcnt_mux = 39), /* General purpose (GPIO) clocks */ [BCM2835_CLOCK_GP0] = REGISTER_PER_CLK( @@ -1885,7 +1966,8 @@ static const struct bcm2835_clk_desc clk_desc_array[] = { .div_reg = CM_GP0DIV, .int_bits = 12, .frac_bits = 12, - .is_mash_clock = true), + .is_mash_clock = true, + .tcnt_mux = 20), [BCM2835_CLOCK_GP1] = REGISTER_PER_CLK( .name = "gp1", .ctl_reg = CM_GP1CTL, @@ -1893,7 +1975,8 @@ static const struct bcm2835_clk_desc clk_desc_array[] = { .int_bits = 12, .frac_bits = 12, .flags = CLK_IS_CRITICAL, - .is_mash_clock = true), + .is_mash_clock = true, + .tcnt_mux = 21), [BCM2835_CLOCK_GP2] = REGISTER_PER_CLK( .name = "gp2", .ctl_reg = CM_GP2CTL, @@ -1908,40 +1991,46 @@ static const struct bcm2835_clk_desc clk_desc_array[] = { .ctl_reg = CM_HSMCTL, .div_reg = CM_HSMDIV, .int_bits = 4, - .frac_bits = 8), + .frac_bits = 8, + .tcnt_mux = 22), [BCM2835_CLOCK_PCM] = REGISTER_PER_CLK( .name = "pcm", .ctl_reg = CM_PCMCTL, .div_reg = CM_PCMDIV, .int_bits = 12, .frac_bits = 12, - .is_mash_clock = true), + .is_mash_clock = true, + .tcnt_mux = 23), [BCM2835_CLOCK_PWM] = REGISTER_PER_CLK( .name = "pwm", .ctl_reg = CM_PWMCTL, .div_reg = CM_PWMDIV, .int_bits = 12, .frac_bits = 12, - .is_mash_clock = true), + .is_mash_clock = true, + .tcnt_mux = 24), [BCM2835_CLOCK_SLIM] = REGISTER_PER_CLK( .name = "slim", .ctl_reg = CM_SLIMCTL, .div_reg = CM_SLIMDIV, .int_bits = 12, .frac_bits = 12, - .is_mash_clock = true), + .is_mash_clock = true, + .tcnt_mux = 25), [BCM2835_CLOCK_SMI] = REGISTER_PER_CLK( .name = "smi", .ctl_reg = CM_SMICTL, .div_reg = CM_SMIDIV, .int_bits = 4, - .frac_bits = 8), + .frac_bits = 8, + .tcnt_mux = 27), [BCM2835_CLOCK_UART] = REGISTER_PER_CLK( .name = "uart", .ctl_reg = CM_UARTCTL, .div_reg = CM_UARTDIV, .int_bits = 10, - .frac_bits = 12), + .frac_bits = 12, + .tcnt_mux = 28), /* TV encoder clock. Only operating frequency is 108Mhz. */ [BCM2835_CLOCK_VEC] = REGISTER_PER_CLK( @@ -1954,7 +2043,8 @@ static const struct bcm2835_clk_desc clk_desc_array[] = { * Allow rate change propagation only on PLLH_AUX which is * assigned index 7 in the parent array. */ - .set_rate_parent = BIT(7)), + .set_rate_parent = BIT(7), + .tcnt_mux = 29), /* dsi clocks */ [BCM2835_CLOCK_DSI0E] = REGISTER_PER_CLK( @@ -1962,25 +2052,29 @@ static const struct bcm2835_clk_desc clk_desc_array[] = { .ctl_reg = CM_DSI0ECTL, .div_reg = CM_DSI0EDIV, .int_bits = 4, - .frac_bits = 8), + .frac_bits = 8, + .tcnt_mux = 18), [BCM2835_CLOCK_DSI1E] = REGISTER_PER_CLK( .name = "dsi1e", .ctl_reg = CM_DSI1ECTL, .div_reg = CM_DSI1EDIV, .int_bits = 4, - .frac_bits = 8), + .frac_bits = 8, + .tcnt_mux = 19), [BCM2835_CLOCK_DSI0P] = REGISTER_DSI0_CLK( .name = "dsi0p", .ctl_reg = CM_DSI0PCTL, .div_reg = CM_DSI0PDIV, .int_bits = 0, - .frac_bits = 0), + .frac_bits = 0, + .tcnt_mux = 12), [BCM2835_CLOCK_DSI1P] = REGISTER_DSI1_CLK( .name = "dsi1p", .ctl_reg = CM_DSI1PCTL, .div_reg = CM_DSI1PDIV, .int_bits = 0, - .frac_bits = 0), + .frac_bits = 0, + .tcnt_mux = 13), /* the gates */ |