xref: /aosp_15_r20/external/coreboot/src/soc/nvidia/tegra210/i2c6.c (revision b9411a12aaaa7e1e6a6fb7c5e057f44ee179a49c)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 
3 #include <device/mmio.h>
4 #include <delay.h>
5 #include <soc/addressmap.h>
6 #include <soc/clk_rst.h>
7 #include <soc/clock.h>
8 #include <soc/nvidia/tegra/i2c.h>
9 #include <soc/padconfig.h>
10 #include <soc/power.h>
11 
12 #define I2C6_PADCTL		0xC001
13 #define DPAUX_HYBRID_PADCTL	0x545C0124
14 #define DPAUX_HYBRID_SPARE	0x545C0134
15 
enable_sor_periph_clocks(void)16 static void enable_sor_periph_clocks(void)
17 {
18 	clock_enable(CLK_L_HOST1X, 0, 0, 0, 0, CLK_X_DPAUX, 0);
19 
20 	/* Give clocks time to stabilize. */
21 	udelay(IO_STABILIZATION_DELAY);
22 }
23 
disable_sor_periph_clocks(void)24 static void disable_sor_periph_clocks(void)
25 {
26 	clock_disable(CLK_L_HOST1X, 0, 0, 0, 0, CLK_X_DPAUX, 0);
27 
28 	/* Give clocks time to stabilize. */
29 	udelay(IO_STABILIZATION_DELAY);
30 }
31 
unreset_sor_periphs(void)32 static void unreset_sor_periphs(void)
33 {
34 	clock_clr_reset(CLK_L_HOST1X, 0, 0, 0, 0, CLK_X_DPAUX, 0);
35 }
36 
soc_configure_i2c6pad(void)37 void soc_configure_i2c6pad(void)
38 {
39 	/*
40 	 * I2C6 on Tegra1xx requires some special init.
41 	 * The SOR block must be unpowergated, and a couple of
42 	 * display-based peripherals must be clocked and taken
43 	 * out of reset so that a DPAUX register can be
44 	 * configured to enable the I2C6 mux routing.
45 	 * Afterwards, we can disable clocks to the display blocks
46 	 * and put Host1X back in reset. DPAUX must remain out of
47 	 * reset and the SOR partition must remained unpowergated.
48 	 */
49 	soc_configure_host1x();
50 
51 	/* enable SOR_SAFE and DPAUX_1 clocks */
52 	clock_enable_y(CLK_Y_DPAUX1 | CLK_Y_SOR_SAFE);
53 
54 	/* Now we can write the I2C6 mux in DPAUX */
55 	write32((void *)DPAUX_HYBRID_PADCTL, I2C6_PADCTL);
56 	/* Finally, power up the pads */
57 	write32((void *)DPAUX_HYBRID_SPARE, 0);
58 
59 	/*
60 	 * Delay before turning off Host1X/DPAUX clocks.
61 	 * This delay is needed to keep the sequence from
62 	 * hanging the system.
63 	 */
64 	udelay(CLOCK_PLL_STABLE_DELAY_US);
65 
66 	/* Stop Host1X/DPAUX clocks and reset Host1X */
67 	disable_sor_periph_clocks();
68 	clock_set_reset_l(CLK_L_HOST1X);
69 }
70 
soc_configure_host1x(void)71 void soc_configure_host1x(void)
72 {
73 	power_ungate_partition(POWER_PARTID_SOR);
74 
75 	/* Host1X needs a valid clock source so DPAUX can be accessed. */
76 	clock_configure_source(host1x, PLLP, 204000);
77 
78 	enable_sor_periph_clocks();
79 	remove_clamps(POWER_PARTID_SOR);
80 	unreset_sor_periphs();
81 }
82